EFFECT OF WASTE PLASTER OF PARIS ON PHYSICAL AND MECHANICAL

PROPERTIES OF CERAMIC POTTERY BODY

ABDULLAH BIN MAT NAWI

UNIVERSITI TUN HUSSEIN ONN MALAYSIA

EFFECT OF WASTE PLASTER OF PARIS ON PHYSICAL AND MECHANICAL

PROPERTIES OF CERAMIC POTTERY BODY

ABDULLAH BIN MAT NAWI

A thesis submitted in partial fulfilment of the requirement for the award of the

Degree of Master of Mechanical Engineering

Faculty of Mechanical and Manufacturing Engineering

Universiti Tun Hussein Onn Malaysia

MAY 2016

iii

“Special dedicated to my beloved parents and wife who always gave me support and

encouragement”

iv

ACKNOWLEDGEMENTS

In the name of ALLAH, Most Gracious, Most Merciful

I would like to thank Almighthy Allah for giving me life and blessing to gain

knowledge to produce this thesis. I wish to express my sincere gratitude to my

supervisor, Dr. Nur Azam bin Badarulzaman, who built my knowledge base and

experience through his encouragement, support, guidance, comments, suggestions

and resources througout this work. I would also like to thank Universiti Tun Hussien

Onn Malaysia (UTHM) Batu Pahat for giving me the opportunity and facilities to

complete such an exciting research project, and supporting me toward my research

and other intellectual activities. I wish to express my appreciation to the Faculty of

Mechanical and Manufacturing Engineering staffs, who assisted me patiently with

management of raw materials and experimental apparatus loans.

I sincerely acknowledge the sacrifices made by my parents for their

encouragement and help in all aspects of pursuing higher education and research. I

also would like to exspress my appreciation to my beloved wife, Noor Naimah binti

Mohamed Nor, for her guidance and support toward my research writing. Special

thanks to my colleagues Siti Rudiah Karim, Ainorhayat Hamidon, and Siti Salwa

Khamis. Their help is very much appreciated. I wish to thank my relatives and

friends for their moral supports and prayers. It would have been very hard for me to

complete this study without cooperation and support from all.

v

ABSTRACT

Over the years, millions tonnes of waste plaster of Paris (POP) were generated and

disposed in landfills or most of the time was dumped directly into the environment

without any treatments, makes it as one of the environmental issues. Therefore, a

new alternative is required to convert the wastes POP into useful materials and

marketable to minimize the environmental impact. In the early stage, this study

focused on the characterization of the raw material used through particle size

analysis, thermal analysis, and identification of its purity. Then, the slip casting

technique and standard American Society for Test and Materials (ASTM) was

respectively used to fabricate and characterize all of the pottery samples. In the

second stage, the ceramic pottery body was fabricated using different composition of

waste POP, started from 0 wt.% until 12 wt.%. The samples obtained were analysed

through viscosity test and its green body was observed. The results showed that the

samples with compositions of 0 to 10 wt.% of waste POP were the only samples that

can be used in this study. The analysis on the effects of particle sizes ranging from 25

to 73 µm and sintering temperatures ranging from 950 to 1050 °C on the physical

and mechanical properties of the fabricated ceramic pottery body, respectively, were

then determined in the third and fourth stage of this study. The physical properties

were reported in terms of shrinkage, porosity, and density values; whereas, the

mechanical properties were reported in terms of the value of modulus of rupture

(MOR). The result showed that a dense and a high strength of ceramic pottery can be

produced by using a finer size of particle of 25 µm and at a high sintering

temperature of 1050 °C, based on the low porosity value, the high density value,

MOR and also the controllable value of shrinkage. Therefore, it can be concluded

that the waste POP can be successfully used as a filler to enhance the properties of

ceramic pottery body.

vi

ABSTRAK

Selama bertahun-tahun, berjuta-juta tan sisa daripada Plaster Paris (POP) dihasilkan

dan dilupuskan di tapak pelupusan atau seringkali dibuang terus di persekitaran tanpa

sebarang rawatan, menjadikan ia sebagai salah satu isu alam sekitar. Oleh itu, satu

alternatif baru diperlukan untuk menukarkan sisa POP kepada bahan yang sesuai

untuk digunakan dan juga bernilai bagi mengurangkan kesan alam sekitar. Pada

peringkat awal, kajian ini tertumpu kepada pencirian bahan mentah yang digunakan

melalui analisa saiz partikel, analisa terma, dan pengenalpastian keasliannya.

Kemudian, teknik slip pemutus dan standard American Society for Test and

Materials (ASTM) masing-masing digunakan untuk membentuk dan mencirikan

semua sampel tembikar. Pada peringkat kedua, tembikar seramik telah dibentuk

menggunakan komposisi sisa POP yang berlainan, bermula dari 0 wt.% Sehingga 12

wt.%. Sampel yang diperolehi dianalisis melalui ujian kelikatan dan pemerhatian

badan hijau. Keputusan menunjukkan bahawa sampel dengan komposisi 0 hingga 10

wt.% sisa POP adalah satu-satunya sampel yang boleh digunakan dalam kajian ini.

Analisis mengenai kesan saiz zarah antara 25 hingga 73 μm dan suhu pembakaran

antara 950 hingga 1050 °C terhadap sifat-sifat fizikal dan mekanikal badan tembikar

seramik yang dibentuk, masing-masing, kemudiannya ditentukan pada peringkat

ketiga dan keempat kajian ini. Ciri-ciri fizikal dilaporkan dari segi nilai-nilai

pengecutan, keliangan, dan ketumpatan, manakala, sifat-sifat mekanikal dilaporkan

melalui nilai modulus patah (MOR). Keputusan menunjukkan tembikar seramik yang

padat dan berkekuatan tinggi boleh dihasilkan menggunakan saiz zarah yang paling

halus iaitu 25 μm dan pada suhu pembakaran yang tinggi iaitu 1050 °C, berdasarkan

nilai keliangan yang rendah dan nilai ketumpatan, MOR dan juga nilai pengecutan

terkawal yang tinggi. Oleh itu, dapat disimpulkan bahawa sisa POP boleh digunakan

sebagai pengisi untuk meningkatkan sifat-sifat badan tembikar seramik.

vii

TABLE OF CONTENTS

TITLE i

DECLARATION ii

DEDICATION iii

ACKNOWLEDGEMENTS iv

ABSTRACT v

ABSTRAK vi

TABLE OF CONTENTS vii

LIST OF TABLES xi

LIST OF FIGURES xii

LIST OF ABBREVIATIONS xvi

LIST OF SYMBOLS xvii

LIST OF APPENDICES xviii

CHAPTER 1 INTRODUCTION 1

1.1 Research Background 1

1.2 Problem Statement 2

1.3 Objective of Study 4

1.4 Scope of Study 4

1.5 Significance of Study 5

1.6 Outline of the Thesis 6

CHAPTER 2 LITERATURE REVIEW 7

2.1 Ceramics 7

2.2 Physical Properties of Ceramics 9

2.2.1 Shrinkage 10

2.2.2 Porosity 11

viii

2.2.3 Density 13

2.3 Mechanical Properties of Ceramics 14

2.4 Microstructure of Ceramics 16

2.5 Clay 18

2.5.1 Properties of Clay Materials 20

2.5.2 Ball clay 21

2.5.3 Kaolin 22

2.6 Flux 23

2.6.1 Feldspar 24

2.7 Filler 26

2.7.1 Silica 27

2.8 The Substitution Filler 28

2.8.1 Plaster of Paris (POP) 29

2.8.1.1 Composition of POP 32

2.8.1.2 Properties of POP 33

2.9 Fabrication of Ceramic Component 34

2.9.1 Ball Milling 34

2.9.2 Seiving 38

2.9.3 Slip Casting 40

2.9.4 Drying on Ceramics 42

2.9.5 Sintering 43

2.9.5.1 The Sintering Process 45

2.10 Affecting Factors 47

2.10.1 Composition of POP 47

2.10.2 Sintering Temperature 48

2.10.3 Particle Size 49

CHAPTER 3 RESEARCH METHODOLOGY 51

3.1 Introduction 51

3.2 Experimental Procedure 51

3.3 Preparation of the Raw Materials 53

3.4 Material Characterization 57

3.4.1 X-Ray Diffraction (XRD) 57

3.4.2 Thermal Gravimetric (TGA) 59

ix

3.4.3 Particle Size Analysis 59

3.5 Fabrication Process 61

3.5.1 Preparation of Ceramic Slip and Bar

Sample

61

3.5.2 Drying Process 64

3.5.3 Sintering 65

3.6 Analysis 66

3.6.1 Physical Properties Analysis 67

3.6.1.1 Linear Shrinkage 68

3.6.1.2 Porosity and Bulk Density 69

3.6.2 Mechanical Properties Analysis 70

3.6.3 Observation of Microstructure 71

CHAPTER 4 RESULTS AND DISCUSSIONS 74

4.1 Introduction 74

4.2 Raw Material Characterization 74

4.2.1 Thermal Gravimetric Analysis (TGA) 75

4.2.2 Particle Size Analysis (PSA) 77

4.2.3 X-Ray Diffraction (XRD) 82

4.2.4 Viscosity Test 89

4.2.5 Optical Micrograph 91

4.2.6 Energy Dispersive Spectroscopy of

Scanning Electron (SEM-EDS) 94

4.3 Effect of Different Particle Size 98

4.3.1 Shrinkage 98

4.3.2 Porosity and Density 101

4.3.3 Modulus of Rupture (MOR) 103

4.4 Effect of Different Temperature 105

4.4.1 Shrinkage 106

4.4.2 Porosity and Density 109

4.4.3 Modulus of Rupture (MOR) 112

4.5 Synergy Effects 113

CHAPTER 5 CONCLUSIONS AND RECOMMENDATIONS 118

x

5.1 General Conclusions 118

5.2 Recommendations for Future Research 119

REFERENCES 120

Appendices A-C 132-143

Vita

xi

LIST OF TABLES

2.1 The general classifications of traditional ceramics 9

2.2 Firing Shrinkage for different types of clay 11

2.3 The porosity of some fired ceramic product 13

2.4 The bulk density of clay bodies with different

sintering temperature

14

2.5 The mechanical properties of pottery body and clay 16

2.6 Properties of clay 20

2.7 Properties of ball clay 21

2.8 Properties of Kaolin 23

2.9 Composition of feldspar in ceramic product 26

2.10 The current studies on gypsum as a filler 30

2.11 Factors affecting milling process 38

2.12 Types of sintering 44

2.13 Stage of sintering process 47

3.1 Specifications of the raw material used 57

3.2 Particle size groups 60

3.3 Composition of ceramics sample 62

4.1 Particle size distribution for waste POP powder 81

4.2 The database of powder diffraction pattern for each

compound based on JCPDS

83

4.3 The area of optical micrograph of each sintered

sample

92

4.4 Percentage of threshold area of the three different

color

94

xii

LIST OF FIGURES

1.1 Quantity of scheduled waste generation in

Malaysia, by category in the year 2012

3

2.1 A comparison between traditional and advanced

ceramics

8

2.2 The bending test that generates a modulus of

rupture

16

2.3 Schematic presentation of a single crystal and

polycrystalline material

17

2.4 Flow diagram of clay process 19

2.5 Composition diagram of feldspars 25

2.6 Interrelationships between forms of silica 28

2.7 The structure of plaster: (a) 50% relative density

and (b) 70% relative density specimens

33

2.8 Macro pore diameter as a function of relative

density of hydrate plaster of Paris

34

2.9 Processing of the ceramic structure 35

2.10 Schematic of ball mill 36

2.11 Grain size for samples sintered for different time

periods

37

2.12 Stack of sieves, ordered from biggest opening to

smallest

40

2.13 Laboratory sieves for particle size distribution 40

2.14 Water and plaster weight ratio 42

2.15 Sintering mechanism and dependence of the

dominant mechanism on the sintering temperature

source

45

xiii

2.16 Neck formation 46

2.17 Coarsening resulting from low coordination

number

47

3.1 Researches activities flowchart 52

3.2 Cleaning step of waste POP 53

3.3 Crushing step of the waste POP 53

3.4 Coarse size of the waste POP 54

3.5 Particle size machine for rock and soil 54

3.6 The planetary mono mill 55

3.7 The ultrasonic cleaner 56

3.8 The stack of sieves 56

3.9 XRD machine 58

3.10 (a) preparation of sample and (b) powder of waste

POP in the sample holder

58

3.11 Thermogravimetric analyzer machine 59

3.12 The schematic diagram of dry mood mimic screen 60

3.13 The weighing digital balance Mettler Toledo 61

3.14 The mixing slurry was stirred using the hotplate

stirrer

62

3.15 The viscosity test of 25 µm of waste POP 63

3.16 The green body sample 64

3.17 The samples placed on a pedestal and put in an

oven

64

3.18 The dried body was sintered in the Protherm

furnace

65

3.19 The sintering profile 66

3.20 Mounted samples (a) before polish and (b) after

polish

67

3.21 Digital caliper 69

3.22 The sample was measure in dry condition by using

density kit

70

3.23 Three point bending test 71

3.24 The sample observation 72

xiv

3.25 Analytical Scanning Electron Microscopy (SEM) 72

3.26 Coating process using auto fine coater 73

4.1 The TGA analysis plot for the ball clay powder 76

4.2 The TGA analysis plot for the waste POP 77

4.3 PSA for powder in type A 78

4.4 PSA for powder in type B 79

4.5 PSA for powder in type C 79

4.6 PSA for powder in type D 79

4.7 PSA for powder in type E 80

4.8 The particle size distribution for different type of

waste POP powder

81

4.9 The XRD analysis for waste POP 84

4.10 The XRD analysis for ball clay 84

4.11 The XRD analysis for Silica 85

4.12 The XRD analysis for Feldspar 85

4.13 The XRD analysis for Kaolin 86

4.14 The XRD pattern for waste POP and the samples

prepared with and without the waste POP

87

4.15 The EDS spectrum for the sample without the

addition of waste POP

88

4.16 The EDS spectrum for the sample with the

addition of 10 wt. % waste POP

88

4.17 The graph of viscosity versus time for different

compositions of waste POP (25 μm)

90

4.18 The green body samples obtained by slip casting

process

91

4.19 The SEM micrograph (2000× magnification) of

the sintered sample

95

4.20 The EDS analysis at point 1 of sintered sample 96

4.21 The EDS analysis at point 2 of sintered sample 97

4.22 The EDS analysis at point 3 of sintered sample 97

4.23 The percentage shrinkage of length at different

particle size

99

xv

4.24 The percentage shrinkage of width at different

particle size

100

4.25 The percentage shrinkage of thickness at different

particle size

100

4.26 The percentage of porosity for each sample at

different particle sizes

102

4.27 The percentage of density for each sample at

different particle sizes

103

4.28 The MOR values for each sample at different

particle size

105

4.29 The percentage shrinkage of length at different

sintering temperatures

107

4.30 The percentage shrinkage of width at different

sintering temperatures

108

4.31 The percentage shrinkage of thickness at different

sintering temperatures

108

4.32 The percentage of porosity for each sample at

different sintering temperatures

110

4.33 The percentage of density for each sample at

different sintering temperatures

111

4.34 The MOR values for each sample at different

sintering temperatures

113

4.35 The synergy effect of relationship between density

and porosity

115

4.36 The synergy effect of relationship between density

and MOR

116

4.37 The synergy effect of relationship between

porosity and MOR

117

xvi

LIST OF ABBREVIATIONS

O - Oxygen

Al - Aluminium

Si - Silicon

K - Potassium

Na - Sodium

Ca - Calcium

S - Sulfur

Na2O - Sodium Oxide

K2O - Potassium Oxide

Li2O - Lithium Oxide

CaO - Calcium Oxide

MgO - Magnesium Oxide

SO3 - Sulfur Oxide

SiO2 - Silicon Oxide

Al2O3 - Aluminium Oxide

POP - Plaster of Paris

XRD - X-Ray Diffraction

TGA - Thermogravimetric Analysis

SEM - Scanning Electron Microscopy

MOR - Modulus of Rupture

PSA - Particle Size Analysis

ASTM - American Society for Testing and Materials

JCPDS - Joint Committee on Powder Diffraction Standards

SEM-EDS - Energy Dispersive Spectroscopy of Scanning Electron

xvii

LIST OF SYMBOLS

L0 - Length of Ceramic Samples Before Sintering

L1 - Length of Ceramic Samples After Sintering

W0 - Width of Ceramic Samples Before Sintering

W1 - Width of Ceramic Samples After Sintering

t0 - Thickness of Ceramic Samples Before Sintering

t1 - Thickness of Ceramic Samples After Sintering

Wd - Mass of Dry Sample in Air

Ws - Mass of Specimen Immersed and Suspended in Liquid

Ww - Mass of Specimen Immersed and Suspended in Air

F - Force (N)

L - Length (cm)

xviii

LIST OF APPENDICES

A JCPDS number 132

A1 The database of powder diffraction pattern for

Calcium Sulfate Hydrate and Bassanite

133

A2 The database of powder diffraction pattern for

Calcium Sulfate and Anhydrite

134

A3 The database of powder diffraction pattern for

Silicon Oxide, Quartz

135

A4 The database of powder diffraction pattern for

Aluminum Hydroxide, Gibbsite

136

A5 The database of powder diffraction pattern for

Aluminum Silicate Hydroxide, Kaolinite

137

A6 The database of powder diffraction pattern for

Potassium Aluminum Silicate, Microcline

138

A7 The database of powder diffraction pattern for

Potassium Aluminum Silicate Hydroxide,

Muscovite-3T

139

A8 The database of powder diffraction pattern for

Sodium Calcium Aluminum Silicate, Anorthite

140

B Calculation for percentage of threshold area 141

C List of publications 143

CHAPTER 1

INTRODUCTION

1.1 Research background

The word ceramics are usually associated with pottery, tiles, plates and mugs, and

also related to brittles and hard materials. Ceramics have been used since the earliest

civilization. The field of ceramic materials has its roots in more traditional aspects of

the subject like clay based ceramics and glasses. However, during the past few

decades, new developments in the use of ceramics in most advanced technological

applications have attracted considerable amount of attention. Ceramics can be

defined as solid compounds that are formed by the application of heat, and

sometimes heat and pressure (Callister and Rethwisch, 2011). These kinds of

materials are used widely for cookware, electrical insulator and even mobile engine

part.

In recent years, it can be witnessed that there is a growth in social concerns

about the problem of waste management and industrial waste generally, or

particularly, waste from the construction industry. This problem becomes prominent

due to the growing quantity of industrial, construction and demolition waste (Juan et

al., 2010). Ceramic waste is one type of waste which resulted from ceramic

industries. One example for ceramic waste is plaster of Paris (POP) mould.

POP is derived from gypsum or sometimes called calcium sulfate dehydrate

(CaSO4.½H2O), a naturally sedimentary rock occurring through the evaporation of

sea water, trapped in lagoons. Most of the water is driven off when gypsum is

2

heated to 128 °C, resulting in a powdery substance commonly known as POP

(Colditz, 2002). The molecules incorporate each other into the crystalline lattice of

calcium sulfate dehydrate when water is added to the dry plaster (Asante-Kyei,

2012). It is worth noting that a great effort is needed in clearing and classifying in

order to produce POP.

However, recycled gypsum from waste mould can be used in a variety of

applications. Currently, gypsum from natural or synthetic sources was applied into

other materials or products such as polypropylene (Jikan, Arshat, and Badarulzaman,

2013), Portland cement (Chandara et al., 2009), natural rubber (Ngamsurat et al.,

2011), and concrete cube (Kanthe, 2013). Besides, there is a recommendation made

based on the basis of laboratory research which has indicated that there may be

effective and environmentally sound methods of disposing waste gypsum (Gypsum

Association, 1992). In the meantime, the gypsum industry itself is also continuing to

explore research options which will verify that similar results and would be observed

under real world conditions (Gypsum Association, 1992). Thus, from a technical

point of view, recycle and reuse are exactly the most convenient and easiest methods

in managing the waste gypsum.

1.2 Problem statement

Issues related to the environmental damage caused by various productive sectors that

actively discharges their waste materials directly into ecosystems without adequate

treatment has recently become prominent among publics and environmentalists,

especially. This problem leads to the search for a great solution to recycle the waste

materials and reduce the waste disposal problem in order to achieve sustainable

development. This is because, sustainable development of various ceramics

industries and protection of the environment is very important as the waste materials

generated from industries would increase every years.

Based on scheduled waste report issued by Department of Environment

(DOE), it can be noted that Malaysia generates a total of 337,770 metric tonnes of

waste gypsum per year in 2012 as compared to 80,000 metric tonnes in 2009 as

shown in Figure 1.1. This shows that gypsum is one of the main categories of waste

3

produced in this country. Waste gypsum itself is not dangerous. However, a

dangerous gas, known as hydrogen sulfide gas can evolve from it when it is mixed

with organic waste and exposed to rain in an anaerobic environment. One of the most

common waste gypsum is slip casting mould, which is a waste material produced

from the hydration of POP in ceramic factory.

Figure 1.1: Quantity of scheduled waste generation in Malaysia, by category in the

year 2012 (Hassan, 2013)

Typically, the POP mould is disposed off in landfills and often dumped

directly into the environment after it is being used around 150 to 230 times. To add

to that effect, most of the ceramic manufacturing and construction sectors produce

lots of waste POP. Consequently, the amount of used POP that has been disposed

without recycling becomes one of the environmental issues. Therefore, in order to

assist the government in addressing the environmental issue, it is crucial to develop

new material which consists of waste POP. In the meantime, another approach needs

to be implemented to convert waste POP into materials that are fit for use and hence

have commercial value to minimize the environmental impact. Thus, it is aimed in

this study to discover new alternative to recycle waste POP and also evaluate the

suitability of the waste POP in the fabrication of ceramic pottery after considering

their potentials as filler in ceramic processing.

4

1.3 Objectives of study

Reducing, reusing and recycling are often cited as methods for preserving limited

landfill space, and can also reduce landfill toxicity in some cases. In the past, gypsum

production and construction waste was considered as acceptable waste material at

landfill sites. Nowadays, some landfill operators and municipalities are no longer

accepting gypsum wastes of any kind, essentially due to shortage of landfill space.

Moreover, most gypsum manufacturing companies many of which, in the past, have

been involved in some forms of limited recycling, are now learning how to increase

the amount of recycling they are doing and are looking for new uses of waste

materials. There are many recent studies on waste gypsum conducted but further

work in this area is still required.

The main objectives of this study are:

i. To fabricate pottery ceramic body with waste POP as a filler in the

composition of 0 to 12 wt%.

ii. To determine the effect of different particle size distributions of the POP to

the pottery ceramic main body in physical and mechanical properties.

iii. To investigate the effects of different sintering temperature on the physical

and mechanical properties of pottery ceramic.

1.4 Scopes of study

This study aims to discover and evaluate the suitability of waste POP in fabrication

of high performance of ceramic pottery body. To achieve the objectives of this study,

these following scopes and limitations are applied:

i. Characterization of waste POP and other raw material used was conducted

via X-ray diffraction (XRD) technique, thermogravimetric analysis (TGA)

and particle size analyzer.

5

ii. Combination of the waste POP with ball clay, kaolinite, potash feldspar and

silica was prepared according to different quantity of composition.

Composition employed was within the range of 0 to 12 wt.%.

iii. The rheological properties of the slurry obtained was characterized through

viscosity test.

iv. Slip casting technique was carried out for fabrication of the sample.

v. Scanning electron microscopy (SEM) and optical microscopy were used to

observe the microstructure of the pottery.

vi. The sintering temperature and particle size were investigated in the range of

950 °C to 1050 °C and 25 µm to 73 µm, respectively.

vii. The properties of the ceramic structure were characterized based on the

following parameters: physical properties (porosity, density and shrinkage)

and mechanical properties (modulus of rupture).

1.5 Significance of study

This study is important because there has been no research conducted pertaining to

the combination of ceramics with waste POP until today, compared to the research

on combination of ceramics with pure POP. Therefore, it is significant to conduct a

study about the combination of ceramics with waste POP in order to know its

mechanical and physical properties. The results of this research hopefully could

assist all the related parties in producing a high quality product using this kind of

ceramics with substantial cost savings. Besides that, an effective method of disposal

also can be obtained through the reuse of the waste POP as well as reducing the

impact of environmental pollution. This is in line with the recommended practices of

green technology which have been suggested to the people all around the world and

Malaysia especially.

Since the study on combination of ceramics with waste POP has yet been

done, the essential characteristics of this kind of ceramics are not known accurately.

Therefore, again, it appears that it is crucial to implement this study in order to

determine the microstructure, the elements and chemical composition as well as the

6

mechanical and physical properties of the resulting ceramics. Finally, it can also

reduce the production costs and harness the waste POP in a much better way.

1.6 Outline of the thesis

There are five chapters in this study. Chapter 1 includes the research background,

problem statement, objective and scope and also significance of the research

proposed. In order to define this study, literature review was carried out and detailed

in Chapter 2. Literature review includes all the information needed for this study.

Meanwhile, Chapter 3 discusses and elaborates the methods undertaken throughout

the research. Chapter 4 covers the results and discussion on thermal analysis and

identification on the purity of material used in this study, the findings and theoretical

explanations regarding the effects of three parameters, that are composition of waste

POP, sintering temperature and particle size on physical and mechanical properties,

and lastly focuses on the observation of morphology using SEM. Finally, conclusions

and recommendations are provided in Chapter 5.

CHAPTER 2

LITERATURE REVIEW

2.1 Ceramics

The term ceramics comes from the Greek word keramos, which means potter’s clay.

Ceramics can be either crystalline or glass like and have few free electrons at room

temperature. This is the reason why ceramics have some of the properties like

electrical, non-conducting and exhibit low thermal conductivity. Generally ceramics

are hard, brittle, stiff and higher in compressive strength than tensile (Horath, 2001).

Other than that, ceramics are usually associated with mixed bonding which is

a combination of covalent, ionic and some metallic. Ceramics also consist of arrays

of interconnected atom that is not discrete molecules (Carter and Norton, 2007).

Traditionally, ceramics are made from three basic components which are

clay, silica and feldspar. For example, product from traditional ceramics includes

high volume items such as bricks and tiles, toilet bowls (whiteware) and pottery. On

the other hand, advanced ceramics are pure compounds or nearly pure compounds of

primarily oxides, carbides or nitrates (Jacobs and Kilduff, 2004). The product from

advanced ceramics is newer material such as laser host materials, piezoelectric

ceramics, optical and so on. Figure 2.1 shows comparison between traditional and

advanced ceramics from different aspects.

8

Traditional ceramics refers to the ceramic products that are produced from

unrefined clay and combinations of refined clay and powdered or granulated

nonplastic minerals. Often, traditional ceramics refers to the ceramics in which the

clay content exceeds 20 percent. For further understanding, the general

classifications of traditional ceramics were summarized in Table 2.1.

TRADITIONAL

Raw minerals

Clay

Silica

ADVANCED

Chemically prepared powder

Precipitation

Spray dry

Freeze dry

Vapor phase

Sol-gel

Slip casting

Injection molding

Sol-gel

Hot pressing

Rapid prototyping

Potter’s wheel

Slip casting

Electric furnace

Hot press

Reaction sinter

Vapor deposition

Plasma spraying

Microwave furnace

Flame kiln

Erosion

Glazing

Erosion

Laser machining

Plasma spraying

Ion implantation

Coating

Light microscopy

X-ray diffraction

Electron microscopy

Scanned probe microscopy

Neutron diffraction

Surface analytical

Visible

examination

Light microscopy

High

temperature

process

Forming

Raw

material

preparation

Finishing

process

Characterization

Figure 2.1: A comparison between traditional and advanced ceramics

(Carter and Norton, 2007)

9

Table 2.1: The general classifications of traditional ceramics

(Midwest Research Institute, 1996)

Classes Description

Pottery A generic term used for ceramics that contain clay but not be used for

structural, technical, or refractory purposes.

Whiteware

Refers to ceramic ware that is white, ivory, or light gray in colour after

firing.

This type of ceramics can be further classified as stoneware, earthenware,

chinaware, porcelain, and technical ceramics.

Earthenware

Known as glazed or unglazed nonvitreous (porous) clay-based ceramic

ware.

Widely used for manufacturing of art ware, ovenware, tableware,

kitchenware and tile.

Stoneware

Defined as vitreous or semivitreous ceramic ware of fine texture.

Primarily made from nonrefractory fire clay or some combination of clays,

fluxes, and silica.

Its properties are similar to stoneware made from fire clay, when fired.

Applied in manufacturing of art ware, chemical ware, cookware, drainpipe,

kitchenware, tableware, and tile.

Chinaware

Defined as vitreous ceramic ware of zero or low absorption after firing that

are used for nontechnical applications.

Widely used in manufacturing of art ware, ovenware, sanitary ware, and

tableware.

Porcelain

Known as glazed or unglazed vitreous ceramic ware which used primarily

for technical purposes.

Its application include art ware, ball mill balls, ball mill liners, chemical

ware, insulators, and tableware.

Technical ceramics

Include vitreous ceramic whiteware.

Used for such products as electrical insulation, or for chemical, mechanical,

structural, or thermal applications.

2.2 Physical properties of ceramics

Physical properties can be defined as property that can be observed without changing

the identity of the substance. It is important to understand physical properties of the

fabricated ceramic bodies because each material has different property profile.

10

Physical properties of ceramics can be defined through several parameters. These

parameters are colour, melting point, viscosity, density, shrinkage, porosity,

electrical and thermal conductivity. However, the most important parameters are

shrinkage, density and porosity because these three factors influence the quality and

appearance of the pottery ceramic body.

2.2.1 Shrinkage

Linear firing is known as one of the frequently used process control parameter in the

development and ceramic manufacturing field (Correia et al., 2005). Generally, high

temperature is required during sintering process for densification of the samples.

This condition leads to the increment of firing shrinkage values. However, the values

of firing shrinkage can decrease as the addition of steel slag (filler) is increased

(Chukwudi, Ademusuru and Okorie, 2012).

In ceramic manufacturing industries, control on firing is one of the important

criteria because excessive shrinkage can cause deforming of articles during firing.

However, it has been found through research that firing shrinkage can be controlled

by the use of various calcium-containing material fly ash, a by-product of thermal

power plant (Das et al., 2005).

There are several methods available for controlling firing shrinkage of a

green sheet where each method has different variables to be adjusted. One of the

methods is adjusting the mixing time in order to adjust the particle size of ceramic

powders. This kind of method is used when a slurry is prepared by mixing ceramic

powders, a binder, a plasticizer, a dispersant, a solvent, and so forth. Meanwhile, in

another method, variables like amount of binder, temperature, retention time,

atmospheric composition, and gas flow amount are adjusted (Takeuchi et al., 1998).

In the manufacturing of ceramic products, it is important to control the degree

of shrinkage firing in order to increase the accuracy of dimension and shape of

finished products and to avoid defects in the shape. This condition is necessary when

a formed body is produced from a raw material like ceramic powder and the firing is

needed in order to obtain a fired body (Takeuchi et al., 2010). Besides, according to

11

Hadi (2008), there are two factors that can increase shrinkage values. The factors are

high plastic limit and the coarser size of fraction used.

Apart from that, a study conducted by Rice (2015) was found that pottery

which fabricated with difference types of clay given different value of firing

shrinkage as shown in Table 2.2.

Table 2.2: Firing Shrinkage for different types of clay

Clay type Fired shrinkage ( %)

Ohio red clay 11.5 – 12.5

Red clay 11.0 – 15.0

Stoneware clay 9.0 – 12.0

Saggar clay 10.0 – 16.0

ball clay 14.0 – 18.0

Fireclay 8.0 – 11.0

Florida kaolin 12.5 – 18.5

Georgia kaolin 8.0 – 12.0

Shrinkage values were measured by taking down the diameter of the sample before

and after the sintering process. The linear shrinkage for length of a ceramics structure

was determined by using the formula as shown in equation 2.1(Hansen, 1997).

(2.1)

Where L0 is the length of the ceramic samples before the sintering process in

centimeters (cm) and L1 is length of the samples after the sintering process also in

centimeters.

2.2.2 Porosity

The strength of aggregates can be improved by using small pore size and

homogenous pore distribution. Thus, the strength of porous aggregates is highly

%100lengthfor shrinkagePercentage0

10

L

LL

12

affected by porosity and pore size distribution (Wen, Nan and Han, 2005).

Meanwhile, decreasing particle size causes homogenized pores and narrowed

distribution size (Yan et al., 2011). Porosity of green compact, decomposition of

magnesite, expansion caused by formation of spinel and sintering are the four main

factors that affect the porosity and pore size distribution of the specimen. Meanwhile,

the porosity of green compact depends on the particle size of distribution of raw

powder and the pressure of compacting process (Wen, Nan and Han, 2005).

Other than that, porosity is known as one of the dominant factors that are

affecting the performance of ceramic materials. Porosity distribution can be

controlled by using starting alumina compound, sintering temperature and hold time,

and also heating rate. Meanwhile, higher shrinkage during the sintering process is

one of the factors that can lead to the porosity reduction due to the closure of pores

(Vasilyeva et al., 2002).

Apart from that, increment of sintering temperature leads to reduction in

porosity. This is due to elimination of pores between aggregate and agglomerates and

also fast grain growth during sintering (Abd Rahman and Yacob, 2008). Beside

sintering or firing temperature, increase in bulk density can also significantly affect

the ceramic pieces by mean reduction of its porosity (Ten et al., 2010).

For the calculation of the porosity and bulk density of the sample, the

Archimedes’s principle was used as shown in equation 2.2 and 2.3, respectively.

Porosity can be determined by three measurements, which are mass of dry sample in

air, (Wd), mass of the specimen that have been immersed and suspended in liquid,

(Ws), and mass of the specimen that have been immersed and suspended in air, (Ww),

which are respectively calculated in grams (g).

%100 Porosity

WW

WW

sw

dw (2.2)

%100 density Bulk

WW

W

sd

d (2.3)

The existing results for porosity for different product are shown in Table 2.3,

where earthenware bodies are known as one of the ceramic product that was

13

fabricated by using ball clay, kaolin, feldspar and silica as its raw material (Ryan,

1987).

Table 2.3: The porosity of some fired ceramic product (Rise, 2015)

Product Porosity (%)

Stoneware 0.5 – 2.0

Hard porcelain bisque 3.0 – 9.0

Chinaware bisque 2.0 – 11.0

Earthenware bodies 20.0 – 25.0

Tiles 3.0 – 18.0

Buiding brick 10 – 35.0

Porous fireclay brick > 60

Saggars 10 – 40

2.2.3 Density

An increase in density can be linked to the rise of sintering temperature and decline

of porosity in ceramic body (Chukwudi et al., 2012). Bulk density is another physical

magnitude that is necessary to be controlled (Amoros et al., 2010) in industrial

practice, especially in ceramic tile industries. This is because bulk density has direct

relationship to the tile ceramic microstructure. Inappropriate bulk density distribution

in a ceramic tile will cause non uniform fired shrinkage. As a consequence, the end

product could experience a condition called lack of dimensional stability.

Irregularities curvatures and differences in size, either inside a tile or between

different tiles (Amoros et al., 2010) are few example of this condition.

Apart from its impact on inner microstructure, bulk density also gives an

effect towards mechanical strength of ceramic. This has been proven through

research done by Amoros et al., (1996) and Amoros et al., (2008), which reported

that there is an increment in mechanical strength as the bulk density is increased.

This is due to the lower porosity and smaller average pore size. As a result, there is

greater interconnectivity between the solid phases in the ceramic.

14

Meanwhile, research done by Ten et al., (2010) reported the increment of

bulk density due to rise of firing temperature owes to the production of a greater

amount of liquid phase and a drop in liquid phase viscosity. Table 2.4 summarize the

value of bulk density for clay bodies at different sintering temperature. It can be seen

that the bulk density of the clay based ceramic samples increases with the increament

of the sintering temperature. This is because as the sintering temperature increase,

the inter-particle voids or pores were progressively filled up and hence reduce the

volume of the ceramic samples. Besides, reduction in porosity also can be one of the

reason for this kind of behavior as its lead to the increament in the amount of matter

in the sample per unit volume.

Lastly, bulk density can also increase during press process. This is because

there was more movement of ceramic powder during the process that could lead to

the higher bulk density. Consequently, the sintered character of the pressed parts also

improved (Meng, Huang and Yang, 2009).

Table 2.4: The bulk density of clay bodies with different sintering temperature

(Aramide, 2015)

Sintering Temperature (°C) Bulk Density(g/cm3 )

800 2.22

900 2.24

1000 2.30

1100 2.34

1200 2.36

2.3 Mechanical properties of ceramics

Mechanical properties of ceramic bodies usually refer to the properties of the

materials, such as strength, toughness or thermal properties. Pottery is expected to

resist several continuous mechanical stresses without experiencing fracture,

structural damage and losing functionality. Pottery wares are commonly exposed to

impact stress subjected to pure compression. The mechanical properties of pottery

ceramics that make more sense to be looked at are their facture strength and

15

toughness. In bending test, a material can be exposed until cracks initiate on the

surface under tension. The fracture behavior of the brittle material is affected when

the initiation of a crack is usually equivalent to the failure due to unstable crack

growth (Muller et al., 2010).

Beside that, toughness becomes as a highly important mechanical properties

of a ceramic product as its measure of the intrinsic fracture energy. It is required for

crack initiation plus the energy that is absorbed by the material during crack

propagation, through micro mechanisms such as friction, crack deflection and crack

arrest.

Moreover, it is also related to the maintenance of structural integrity after

crack initiation. Apart from that, for traditional ceramics, other variables like type of

clay and firing temperature also influence its fracture strength and toughness (Muller

et al., 2010).

The toughness of the ceramics material is directly proportional to the volume

fraction of inclusions. The rigid inclusion provides the ceramics with additional

means of energy dissipation which is through crack deflection and bifurcation

(Muller et al., 2015). The mechanical strength depends on the method used,

dimensions of the sample and the crack initiator that are presence in the middle of the

sample, in the case of three bending is applied (Stubna et al., 2011). These initiators

are basically not identical. It produces the rupture of the samples at different loading

forces and brings relatively high scatter values of mechanical strength (Mencik, 1992

and Bortzmeyer, Langguth and Orange, 1993).

Meanwhile, in terms of fexural strength, its increment is significantly

influenced by the decrease in porosity (Abd. Rahman and Yacob, 2008). Therefore, it

can be said that the flexural strength is inversely proportional to the porosity (Gibson

and Ashby, 1997 and Dhara et al., 2003).

In the flexure test, through a technique called three or four point loading, a

circular or rectangular cross section of bar specimen is bent until fractured. One of

the most important strength parameters is the modulus of rupture (MOR). MOR is a

value calculated from data in a bending test. It can be defined through equation 2.4.

dB

FL2

3 M (2.4)

16

Where F is the applied force or load in newton (N) that breaks a rectangular

specimen of length L in centimeter (cm), and cross section b x h in square meters

(m2), as shown by a three point bend test in Figure 2.2. Sometimes, this MOR values

is referred to as the flexural strength and as the failure mode in bending. Whereas, in

tensile, it is similar in magnitude to the tensile strength (Shackelford, 2009).

Figure 2.2: The bending test that generates a modulus of rupture (Shackelford, 2009)

A study done by Limpaiboon and Nualanong (2011) was found that the

MOR value for pottery body are greater than clay, as shown in Table 2.5.

Theoritically, pottery body consist three combination of materials which are clay,

flux (feldspar) and filler (silica). The presence of flux normally can improve the

strength, toughness and durability of a ceramic body (Ariffin, 2003).

Table 2.5: The mechanical properties of pottery body and clay

Mechanical Properties Pottery body Clay

Dried MOR (kgf/cm

2

) 23.10±1.52 17.97±1.41

Fired MOR (kgf/cm

2

) 60.14±4.65 46.51±2.54

2.4 Microstructure of ceramics

For the last few decades, microstructures of structural ceramics and their composites

have been developed, mainly for applications under static, thermal, corrosive loads

17

and dynamic mechanical. Based on applications in real life, engineering ceramics are

usually categorized into two major classes which are structural ceramics and

functional ceramics, while the development of structural ceramics is mainly driven

by the optimization of mechanical strength, hardness and toughness. In ceramics

community, structural ceramics can be classified as oxide ceramics (Al2O3, ZrO2,

SiO2) and non-oxide ceramics (SiC, TiC, B4C, TiB2, Si3N4) (An,You, and Lim,

2003).

In a perfect single crystal, a regular pattern of atoms that form the crystal

lattice is uninterrupted throughout the piece. In contrast with the real single crystals,

it usually contains small scale, local, and disruption to the pattern-lattice defects.

Polycrystalline materials are constructed from small crystals, while microcrystalline

referred to as grains of micrometer dimension, as shown in Figure 2.3. The grains,

which were fused together by sintering during the production of the component,

produce compacted fine powder, the particles which are likely to be small single

crystals (Riley, 2009).

Figure 2.3: Schematic presentation of a single crystal and polycrystalline material

(Riley, 2009)

Additionally, the material may be built predominantly from one type of single

material (as in a high purity alumina), or may be a mixture of several phases (as in

porcelain). However, practically, all ceramic materials contain more than one phase

(most of the major phases will be crystalline) but varying amounts of amorphous

(non crystalline) material are almost always present (Riley, 2009).

5 µm

Single crystal

grain µm

50 µm

Polycrystalline

material

18

2.5 Clay

Clay is formed by the action of weathering on several kinds of rocks and formed

naturally almost everywhere in the world. The rocks change to clay slowly in both

physical and chemical ways, thus, its takes thousands of years to formed. Clay was

formed wherever the rocks are exposed to the natural forces such as water, wind and

frost. The rocks crush into coarse grain in physical way. Meanwhile, chemically,

elements are added and taken away. Then, after long time, some of the rock changes

to clay. The more the clay is formed, the more geological period of time is taken.

Most of the clay deposits contain more than one kind or several different kinds of

clay minerals (Petersham, 1984).

Clay is the most widely used ceramic raw material. In additional, clay is often

used as mined without any upgrading of quality and its inexpensive ingredient is

found naturally in great abundance. Clay products may be formed when mixed in

proper proportions of ingredients. Mixture between clay and water forms a plastic

mass that is very handy to shape into objects of desired form. The moisture inside

formed piece can be removed by firing at an elevated temperature to improve its

mechanical strength. Most of clay based products fall within two broad

classifications which are the structural clay products (tiles, building bricks and sewer

pipes-application in which structural integrity is important) and the whitewares.

Furthermore, many of these products also contain non-plastic ingredients, which

influence the changes that take place during drying and firing processes and the

characteristics of the finished piece (Callister, 2010).

Clay is a product of the decomposition of granite rock. Around 75 percent of

the earth's crust is made from two major constituents of clay which are alumina and

silica. Granite decomposes into the most common mineral (feldspar), which is

composed of alumina, silica, and alkaline nature (flux) such as sodium, potassium,

lithium and calcium. Chemical water inside clay is 14 percent and unfired clay also

contains physical water, which evaporates during drying.

Moreover, clay has two major classes which are primary clays and secondary

clays. Primary clays are formed at the site of the parent rock at physical location. It

tends to be less plastic than secondary clays and highly pure. Meanwhile, secondary

clays have been transported from multiple sources by water or wind which may

19

cause them to be sorted according to particle sizes, or by glacier activity, which may

result in grinding but has uneven particle sizes. Primary clay is only white, whereas

secondary clay comes in a variety of colours. These clays have generally had other

materials introduced into their basic composition that change their performance

characteristics such as color, plasticity, and so forth but are still pure (Mayco, 2004).

Figure 2.4 shows the flow diagram of clay process.

Figure 2.4: Flow diagram of clay process (Mayco, 2004)

Decomposition of

igneous rock

Primary Class

China clay

Bentonite

Secondary Class

Fireclays and

prepared

Stoneware bodies

Brick shules and

prepared

Red earthenware

bodies

Red marls

Secondary Class

Ball clays

Stoneware clays

Boulder clays

Red marls

Gault clays

Removed deposited and

covered by other rock

Removed relatively

recently and deposited

in hollows

20

2.5.1 Properties of clay materials

Material properties can be evaluated by few criteria like chemical, physical

characteristics and behaviors. Clay has two fundamental properties which are the

ability to be molded and shaped according to the desired product and how it is fired.

Certain clays tend to be plastic or flexible and certain clays can be fired in high

temperatures while others cannot. Other clays properties that can be considered

include color of the clay body, porosity, vitrification (firing characteristics), glaze fit,

shrinkage and maturing temperature as described in Table 2.6.

Table 2.6: Properties of clay (Mayco, 2004)

Properties Description

Plasticity

Refers to the ability of clay to be molded and shaped. There are several

factors that affect clay’s plasticity is mineral particle size, acidity levels,

amount of water, amount of non-plastic additives etc.

Vitrification

The process under which the clay body experiences chemical and physical

changes during firing. The changes that take place during firing take place

in stages. A vitrified body is impervious to water that is very strong and

dense (a vitrified body shrinks and condenses as the air spaces are filled

with glassy material).

Porosity

Porosity refers to a material’s ability to absorb moisture. Porosity can easily

be measured by weighing a mature fired but unglazed piece of clay or clay

body. The percentage increase in weight represents the porosity of the clay.

Earthenware typically has an absorption rate of 5% to 14%, stoneware 2%

to 6%, and porcelain 1% to 3%.

Shrinkage

Shrinkage occurs in all clay bodies as they are dried and fired. Considerable

shrinkage occurs as water evaporates from the wet greenware stage to the

bone-dry greenware stage. The more plastic the clay body, the greater the

drying shrinkage. A typical shrinkage rate for wet greenware is between 4%

and 10%. Shrinkage from the firing of a clay body in a large part depends

on the flux content and size and quantity of refractory materials. Apure

kaolin clay or clay body can shrink as much as 8% during firing, whereas

refractory bodies may have extremely low shrinkage.

21

2.5.2 Ball clay

Ball clay mixed with water becomes high plasticity in fine particle size (0.1 µm - 1

µm), which is stabilized by a substantial content of organic matter (up to 2 wt.%).

The water demand for ball clays is higher than for most china clays because of the

fine particle size. Additionally, fine particle size also gives ball clay body higher

green strength and higher fired strength than other clays. The color of the ball clay

ranges from light brown to nearly black, depending on the quantity of the organic

content in the ball clay. Besides, due to its workability and strength, ball clays have

been used extensively in traditional ceramics and pottery whitewares. Nevertheless,

their use is minimal in hard porcelains and in other applications where color is

important (James and Robert, 2008).

Enamel clay can also be characterized as ball clay, although somewhat it is

lighter in colour. Thus, it may be concluded that fine grained ball clay of exceptional

purity, which contains appreciable quantities of colloidal organic matter, are

desirable glaze clay (Sutton, 2014).

Processed ball clays and kaolin have similar specific surface areas, but the

quartz impurity level can be significantly higher in ball clays (up to 35% on a dry

weight basis), requiring a much finer particle size for kaolinite fraction. Meanwhile,

white body can be produced by heat treatment to remove organic impurities (Carty

and Senapati, 1998).The physical properties of ball clay are as varied as their

mineralogies, and the variations significantly affect the end uses of the ball clay. This

can be seen from Table 2.7 that summarizes the properties of the ball clay.

Table 2.7: Properties of ball clay (James and Robert, 2008)

Properties Description

Moisture content Between 18% and 22%

Particle sizes Between 15% <0.5 μm and 65% <0.5 μm

Carbon content From 0.1% to >3%

Sulfur content From <10 ppm to as much as 7000 ppm

Specific surface area Between 8 m2/g and 40 m

2/g

sulfate content From between 200 ppm and 5,000 ppm, with aging

Colour White, various shades of gray and brown, black, tan and pink

22

2.5.3 Kaolin

The name “Kaolin” is derived from the word Kau-Ling, or high ridge, the name

given to a hill near Jau-chau Fu, China, where kaolin was first mined (Sepulveda et

al., 1983). Kaolin, that commonly called China clay, is a type of clay that consists of

10 to 95% minerals, majorly kaolinite (85–95%) (Safaeikatouli, Jafariahangari and

Baharlouei, 2011).

Kaolin or china clay is a mixture of different minerals. Its main component is

kaolinite. However, it frequently contains quartz, mica, feldspar, illite, and

montmorillonite. Kaolinite is made up of tiny sheets of triclinic crystals with

pseudohexagonal morphology. Some clay was used for the purpose that is similar

with kaolin which is because of the substantial amounts of quartz usually found in

them (Adamis, Fodor and Williams, 2005).

Similar with clay, Kaolin is also the result of hypogenic of weathering

process. So, it is often found in deep deposits which contain a number of accessory

minerals such as quartz as well as uncovered feldspars and mica (Adamis et al.,

2005). Because of its purity, Kaolin has a high fusion point and it has become the

most refactory of all clays. It also does not absorb water and does not expand when it

comes in contact with water. Kaolin is used widely in casting sanitary ware, ceramics

and refactory. Other than that, Kaolinite is a mineral silicate clay, belonging to the

molecular formula that is common for the kaolinite group (kaolinite, nacrite, dickite),

which is Al2Si2O5(OH)4 (Aroke, El-Nafaty and Osha, 2013).

The structure of Kaolinite is a tetrahedral silica sheet alternating with an

octahedral alumina sheet. These sheets are arranged so that the tips of the silica

tetrahedrons and the adjacent layers of the octahedral sheet form a common layer

(Adamis et al., 2005). Some specific physical and chemical properties of Kaolin are

dependent on the environment of deposition, geological origin, geographic source

and the method of processing (Murray and Kogel, 2005). Table 2.8 summarized

some of the properties of Kaolin.

23

Table 2.8: Properties of Kaolin (Friedman, 1997)

Properties Descriptions

Chemical Formula Al2Si2O5(OH)4

Composition Basic aluminum silicate

Tenacity Brittle, sectile

In Group Silicates; Phyllosilicates

Hardness 2 to 2.5

Crystal System Monoclinic

Rock Type Igneous, Sedimentary, Metamorphic

Color

White, gray, yellow, beige. May also be darker colored

brown, orange, or reddish-brown from iron oxide impurities.

Crystal Forms and Aggregates Most often as unshaped compact masses. Crystals are

microcrytalline as tiny grains and plates.

Environment

As a secondary altering mineral, usually from weathering, in

igneous, metamorphic, and sedimentary environments.

Kaolinite is most often found near the oxidized surface

where it has altered from aluminum silicates such as

feldspar.

2.6 Flux

According to dictionary of chemistry, flux can be defined into two. Firstly, as a

substance added to another to assist fusion of the latter. Secondly, as a substance

used to enable two pieces of metals to be joined together without being oxidized.

Furthermore, a flux can also be easily defined as some special substance

which must possess that needed low melting temperature, so as to flow and join other

substance or material that needs joining. This definition was made based on the

extending idea of flow and joining in ceramics manufacture, in which, the concept of

melting, fluidity and joining are applied equally, where ceramics and metallurgical

material are formed at high temperature.

Apart from that, flux can also be used in welding to join two separate pieces

of metals, besides serving as whole additive in melting and refining metallurgical

system. Thus, for this case, flux can be defined as a substance that is added to a body

24

to enable it to fuse more readily. This is because flux that is usually used in ceramic

engineering involves a powder compositional mixture in large surface area. This

leads to the attainment of sintering or surface sweating or partial melting, which

ensures the desirable mass joining and strength is achieved (Iloghalu and Nnuka,

2014).

Feldspars are known as the most important flux for ceramic productions. It

can be categorized into a group of minerals with similar chemical formula

incorporating silica and alumina. It can be classified into potash feldspar or

orthoclase (KAlSi3O8), soda feldspar or albite (NaAlSi3O8) and lime feldspar or

anorthite (CaAl2Si2O8) (Iloghalu and Nnuka, 2014).

Materials rich in alkaline oxides like Natrium Oxide (Na2O), Cilium Oxide

(K2O) and Lithium Oxide (Li2O) are most common example of fluxes. Other than

that, Calcium Oxide (CaO) and Magnesium Oxides (MgO) can also be used as

fluxes, but in combined form (Worrall, 1975).

At high temperatures, fluxes have an active molecular structure and when

combined with the surface, causing the crystalline structures to dissolve until it is

entirely melted away. Therefore, without fluxes present, other constituents in the

ceramic body would not be able to melt although at normal attainable temperatures.

One of the examples of fluxes application is in glass, which uses fluxes as a major

constituent (Spiller, 2012).

2.6.1 Feldspar

Feldspar is the most abundant group of minerals in the earth's crust, forming about

60 percent of terrestrial rocks. Feldspar minerals are essential components in

igneous, metamorphic and sedimentary rocks and thus can be found throughout

different geological environment, to the point that the classification of a number of

rocks is based on feldspar content. The mineralogical composition of most feldspars

can be expressed in terms of the ternary system, Orthoclase (KAlSi3O8), Albite

(NaAlSi3O8) and Anorthite (CaAl2Si2O8) as illustrated in Figure 2.5. Chemically, the

feldspars are silicates of aluminum, containing sodium, potassium, iron, calcium, or

barium or combinations of all of these elements (Ariffin, 2003).

120

REFERENCES

Abshinova, M. A. and Li, Z. W. (2014). Effect of milling time on dynamic

permeability values of reduced carbonyl iron filled composites. Journal of

Magnetism and Magnetic Materials, 369, 147-154.

Abd Rahman, H. and Yacob, D. H. (2008). Effect of double sintering on the

properties of porous ceramic. Brunei International Conference on

Engineering and Technology 3. Bandar Seri Begawan, Brunei Darussalam:

Institute Technology Brunei.

Abd Rahman, H., Rahmat, N. and Shariff, M. (2009). Microwave drying effects on

the properties of alumina-zeolite foam. Green Technology and Engineering,

521- 525.

Adamis, Z., Fodor, J., & Williams, R. B. (2005). Bentonite, Kaolin, and Selected

Clay Minerals. Geneva: World Health Organization.

Alias, R. (2012). The Effects of Sintering Temperature Variations on Microstructure

Changes of LTCC Substrate. Rijake, Croatia: INTECH Open Access

Publisher.

Allen, T. (1993). Particle Size Measurement. 4th

ed. London: Chapman and Hall.

American Society for Testing and Materials (1999). Standard Test Methods for

Flexural Properties of Ceramic Whiteware Materials. West Conshohocken:

ASTM C674.

American Society for Testing and Materials (2006). Standard Test Method for Water

Absorption, Bulk Density, Apparent Porosity, and Apparent Specific Gravity

of Fired Whiteware Products, Ceramic Tiles, and Glass Tiles. West

Conshohocken: ASTM C373.

Amoros, J. L., Feliu, C., Gines, F. and Agramunt, J. V. (1996). Mechanical strength

and microstructure of green ceramic bodies. Qualicer 96. IV World

121

Congress on Ceramic Tile Quality. General Conferences and Communications Pt. 1.

Castellon.10 (13).

Amoros, J. L., Orts, M. J., Garcia-Ten, J., Gozalbo, A. and Sanchez, E. (2007).

Effect of the green porous texture on porcelain tile properties. Journal of the

European Ceramic Society, 27(5), 2295-2301.

Amoros, J. L., Cantavella, V., Jarque, J. C. and Feliu, C. (2008). Green strength

testing of pressed compacts: an analysis of the different methods. Journal of

the European Ceramic Society, 28(4), 701-710.

Amoros, J. L., Boix, J., Llorens, D., Mallol, G., Fuentes, I. and Feliu, C. (2010).

Non-destructive measurement of bulk density distribution in large-sized

ceramic tiles. Journal of the European Ceramic Society, 30(14), 2927-2936.

An, J. W., You, D. H. and Lim, D. S. (2003). Tribological properties of hot-pressed

alumina–CNT composites. Wear, 255(1), 677-681.

Aramide, F. O. (2015). Effects of sintering temperature on the phase developments

and mechanical properties ifon clay. Leonardo Journal of Sciences, 26, 67-

82.

Arem, J. E. (2011).Observations on the Occurrence of Plagioclase Feldspars. New

York: Van Nostrand Reinhold.

Ariffin, K.A. (2003). Feldspathic Minerals. University Science Malaysia: EBS 425/3

Mineral Preindustrial.

Aroke U. O., El-Nafaty U. A. and Osha O. A. (2013). Properties and characterization

of kaolin clay form Alkaleri, North-Eastern Nigeria. International Journal of

Emerging Technology and Advanced Engineering, 3(11), 387-392.

Asante-Kyei, K. (2012). Manufacturing of local plaster of Paris (pop) from salt

residue mined in Sege in the Dangme east district of the greater Accra

region of Ghana. Research Journal of Environmental and Earth Sciences,

4(11), 953-958.

Atwood, J. D. & Zuckerman, J. J. (1999). Inorganic Reactions and Methods:

Formation of Ceramics. Weinheim: Wiley –VCH publisher.

Barbosa da Silva, J., Silva A. G., Neves, G. A., Barbosa de Lima, W. C. P., de Farias

Neto, S. R., and de Lima, A. G. B. (2012). Heat and mass transfer and volume

variations during drying of industrial ceramic bricks: an experimental

investigation. Defect and Diffusion Forum. 326.

122

Biernacki, R., Haratym, R., and Kwapisz, J. (2012). Evaluation of synthetic gypsum

recovered via wet flue-gas desulfurization from electric power plants for use

in foundries. Archives of Foundry Engineering, 12(3), 5-8.

Bortzmeyer, D., Langguth, G. and Orange, G. (1993). Fracture mechanics of green

products. Journal of the European Ceramic Society, 11(1), 9-16.

Callister, W. D. & Rethwisch, D. G. (2007). Materials Science and Engineering: An

Introduction. 7th

. New York: John Wiley and Sons.

Callister Jr, W. D. (2010). Materials Science and Engineering, an Introduction 8th

Edition Solution Manual. New York: John Wiley and Sons.

Callister, W. D. & Rethwisch, D. G. (2011). Materials Science and Engineering: An

Introduction. New York: John Wiley and Sons.

Carter, C. B. & Norton, M. G. (2007). Ceramic Materials: Science and Engineering.

Berlin: Springer Science & Business Media.

Carty, W. M. and Senapati, U. (1998). Porcelain raw materials, processing, phase

evolution, and mechanical behavior. Journal of the American Ceramic

Society, 81(1), 3-20.

Chandara, C., Azizli, K. A. M., Ahmad, Z. A. and Sakai, E. (2009). Use of waste

gypsum to replace natural gypsum as set retarders in Portland cement. Waste

management, 29(5), 1675-1679 .

Choi, H., Lee, W. and Kim, S. (2009). Effect of grinding aids on the kinetics of fine

grinding energy consumed of calcite powders by a stirred ball mill. Advanced

Powder Technology, 20(4), 350-354.

Chukwudi, B. C., Ademusuru, P. O. and Okorie, B. A. (2012). Characterization of

sintered ceramic tiles produced from steel slag. Journal Mineral Materials

Character Engineering, 11, 863-868.

Colditz, J. C. (2002). Plaster of paris: the forgotten hand splinting material. Journal

of Hand Therapy, 15(2), 144-157.

Correia, S. L., Curto, K. A. S., Hotza, D. and Segadaes, A. M. (2005). Using

experiments design to model linear firing shrinkage of triaxial ceramic

bodies. Materials Science Forum, 498, 430-435.

Das, S. K., Dana, K., Singh, N. and Sarkar, R. (2005). Shrinkage and strength

behaviour of quartzitic and kaolinitic clays in wall tile compositions. Applied

Clay Science, 29(2), 137-143.

123

De Jonghe, L. C. & Rahaman, M. N. (2003). Sintering of Ceramics. Handbook of

Advanced Ceramics: Materials, Applications, Processing and Properties. 2nd

.

California: Academic Press.

De Bellis, A. C. (2002). Computer Modeling of Sintering in Ceramics. University of

Pittsburgh: PhD Thesis.

Dhara, S., Pradhan, M., Ghosh, D. and Bhargava, P. (2003). Nature inspired

processing routes for ceramic foams. Journal of American Ceramic Society,

86, 1645-1657.

Dick, J. S. (2014). Rubber Technology: Compounding and Testing for Performance.

Munich: Carl Hanser Verlag.

Dinger, D. R. (2005). Ceramic Processing E-zine: volume 2. Augusta Rd Clemson:

Dinger Ceramic Consulting Service.

Eichler, J., Rodel, J., Eisele, U. and Hoffman, M. (2007). Effect of grain size on

mechanical properties of submicrometer 3Y‐TZP: fracture strength and

hydrothermal degradation. Journal of the American Ceramic Society, 90(9),

2830-2836.

Ergun, Y. (2004). Development and characterization of PMMA based porous

materials used for high pressure casting of sanitaryware ceramics. Key

Engineering Materials, 264-268, 2235-2238.

Escalante-Garcia, J. I., Magallanes-Rivera, R. X., & Gorokhovsky, A. (2009). Waste

gypsum–blast furnace slag cement in mortars with granulated slag and silica

sand as aggregates. Construction and building materials,23(8), 2851-2855.

Ferreira, S. B., Domingues, P. C., Soares, S. M., and Camarini, G. (2015). Recycled

Plaster and Red Ceramic Waste Based Mortars. International Journal of

Engineering and Technology, 7(3), 209.

Friedman H. (1997). The Mineral kaolinite. Retrieved from

http://www.minerals.net/mineral/kaolinite.aspx

Galmarini, S. (2011). Ceramics: Sintering and microstructure. Work practices

Ceramics Process: TP3 Sintering, 1-15.

Ganesapillai, M., Regupathi, I. and Murugesan, T. (2008). Characterization and

process optimization of microwave drying of plaster of paris. Drying

Technology, 26(12), 1484-1496.

German, R. M. (1985). Liquid Phase Sintering. Berlin: Springer Science & Business

Media.

124

Geotechnical Engineering (2006). Chapter 5.0: Geotechnical Inputs for Pavement

Design. Federal Highway Administration: US Department of Transportation

Publication.

Gibson, L. J. & Ashby, M. F. (1997). Cellular Solids: Structure and Properties.

Cambridge: Cambridge university press.

Godinho-Castro, A. P., Testolin, R. C., Janke, L., Corrêa, A. X., and Radetski, C. M.

(2012). Incorporation of gypsum waste in ceramic block production: Proposal

for a minimal battery of tests to evaluate technical and environmental

viability of this recycling process. Waste management, 32(1), 153-157.

Gypsum Association (1992). Treatment and Disposal of Gypsum Board Waste.

Washington, D.C: Construction Dimensions.

Hadi, K. A. A. (2008). The genesis and characteristics of primary kaolinitic clay

occurrence at Bukit Lampas, Simpang Pulai, Ipoh. Bulletin of the Geological

Society of Malaysia, 54, 9-16.

Handle, F. (2007). Extrusion in Ceramics. Berlin: Springer Science & Business

Media.

Hansen, T. (1997). The Physics of Clay Bodies. Retrieved from

http://www.digitalfire.com/4sight/glossary/glossary_clay_shrinkage.html

Hassan, H. (2013). Overview of schedule waste management in Malaysia and the

way forward. Sustainability and Environmental Management Conference and

Exhibition. Malaysia: ENSEARCH.

Hassan, R. (1997). Teknologi Pembuatan Seramik (Bahan Dan Proses). Universiti

Tun Hussien Onn Malaysia: Degree Thesis.

Hewitt, S. A. and Kibble, K. A. (2009). Effects of ball milling time on the synthesis

and consolidation of nanostructured WC–Co composites. International

Journal of Refractory Metals and Hard Materials, 27(6), 937-948.

Horath, L. D. (2001). Fundamentals of Materials Science for Technologists:

Properties, Testing, and Laboratory Exercises. 2nd

ed. United States of

America: Prentice Hall.

Hwang, S. H., Bang, D. S., Yoon, K. H., & Park, Y. B. (2011). Smart Materials and

Structures Based on Carbon Nanotube Composites. Rijake, Croatia: INTECH

Open Access Publisher.

Iloghalu, F. and Nnuka, E. (2014). Evaluation of the fluxing potentials of okene

potassium feldspar for silicate ceramics production. Evaluation, 1(4).

125

Industrial Accident Prevention Association (2008). Silica in the Workplace. Canada:

Centre for Health & Safety Innovation.

Ismail, N. F. (2012). Consolidation of Single and Double Layers Ceramic Structure.

Universiti Tun Hussein Onn Malaysia: Master Thesis.

Jacobs, J. A. & Kilduff, T. F. (2004). Engineering Materials Technology: Structures,

Processing, Properties, and Selection. United States of America: Prentice

hall.

James, F. S. & Doremus, R. (2008). Ceramic and Glass Materials: Structure,

Properties and Processing. Berlin: Springer.

Jikan, S. S., Arshat, I. and Badarulzaman, N. A. (2013). Melt flow and mechanical

properties of polypropylene/recycled plaster of paris. Applied Mechanics and

Materials, 315, 905-908.

Jillavenkatesa, A., Dapkunas, S. J., & Lum, L.S. H. (2001). Particle Size

Characterization.Washington: National Institute of Standards and

Technology (NIST).

Juan, A., Medina, C., Morán, J. M., Guerra, M. I., De Rojas, M. I. S., Frías, M., and

Aguado, P. J. (2010). Re-Use of Ceramic Wastes in Construction. INTECH

Open Access Publisher.

Kamarudin, R. A., and Zakaria, M. S. (2007). The utilization of red gypsum waste

for glazes. Malaysian Journal of Analytical Sciences, 11(1), 57-64

Kanthe, V. N. (2013). Use of waste plaster of paris in concrete. International Journal

of Innovative Research and Development, 2(3), 855-862.

Kasuriya, S. and Atong, D. (2004). Rapid drying of ceramic and efficient food

processing with a continuous microwave belt furnace. National Metal and

Material Technology Center, 27-28.

Kojima, Y., and Yasue, T. (2006). Synthesis of large plate-like gypsum dihydrate

from waste gypsum board. Journal of the European Ceramic Society, 26(4),

777-783.

Konta, J. (1982). Properties of Ceramic Raw Materials Monographs-Handbook of

Ceramics. Freiburg-Alemanha: Verlang Schmid GmbH.

Kumar, A., Agarwala, V. and Singh, D. (2014). Effect of milling on dielectric and

microwave absorption properties of SiC based composites. Ceramics

International, 40(1), 1797-1806.

126

Lai, M. O., Lu, L. and Laing, W. (2004). Formation of magnesium nanocomposite

via mechanical milling. Composite Structures, 66(1), 301-304.

Leiser D. B. and Whittemore O. J. (1970). Compaction behavior of ceramic particles.

American Ceramic Society Bulletin, 49, 714-717.

Limpaiboon, K., & Nualanong, A. (2011). Influence of different additives at various

contents on the properties of pottery clay body. Walailak Journal of Science

and Technology, 7(2), 155-167.

Liu, J., Lin, L., Li, J., Liu, J., Yuan, Y., Ivanov, M. and Guo, J. (2014). Effects of

ball milling time on microstructure evolution and optical transparency of Nd:

YAG ceramics. Ceramics International, 40(7), 9841-9851.

Lum, L. S., Malghan, S. G. and Schiller, S. B. (1996). Standard reference materials

for particle size analysis of ceramic powders by gravity

sedimentation. Powder Technology, 87(3), 233-238.

Lunn, R. (2014). Silica, Crystalline (Respirable Size). Washington D. C: Department

of Health and Human Services.

Lyckfeldt, O. (2007). Slip Casting and Pressure Slip Casting: Forming of Complex

Shapes. Sweden: Swerea IVF.

Martin-Marquez, J., Rincon, J. M. and Romero, M. (2010). Effect of microstructure

on mechanical properties of porcelain stoneware. Journal of the European

Ceramic Society, 30(15), 3063-3069.

Marzuki, N. M. (2012). Preparation of Ceramic Membrane Via Gelcasting

Technique. Universiti Tun Hussein Onn Malaysia: Degree Thesis.

Mayco. (2004). An introductory course on the basics of ceramics. Ceramics, 101.

Mencek, J. (1992). Strength and Fracture of Glass and Ceramics.

Netherland: Elsevier Science Publishers.

Meng, Z. H., Huang, S. Y. and Yang, M. (2009). Effects of processing parameters on

density and electric properties of electric ceramic compacted by low-voltage

electromagnetic compaction. Journal of Materials Processing Technology,

209(2), 672-678.

Mewis, J. (1979). Thixotropy-a general review. Journal of Non-Newtonian Fluid

Mechanics, 6(1), 1-20.

Midwest Research Institute. (1996). Introduction to Mineral Products Industry:

Ceramic Clay Manufacturing. North Carolina: U.S Environmental Protection

Agency.

127

Miles, W. J. (1990). Mining industry responds to crystalline silica regulations.

Mining Engineering, 19, 345-348.

Mobarak, Y., Bassyouni, M. and Almutawa, M. (2013). Materials selection,

synthesis, and dialectical properties of PVC nanocomposites. Advances in

Materials Science and Engineering.

Moreno, R., Salomoni, A., and Stamenkovic, I. (1997). Influence of slip rheology on

pressure casting of alumina. Journal of the European Ceramic Society, 17(2),

327-331.

Muller, N. S., Kilikoglou, V., Day, P. M. and Vekinis, G. (2010). The influence of

temper shape on the mechanical properties of archaeological ceramics.

Journal of the European Ceramic Society, 30(12), 2457-2465.

Muller, N. S., Vekinis, G., Day, P. M. and Kilikoglou, V. (2015). The influence of

microstructure and texture on the mechanical properties of rock tempered

archaeological ceramics. Journal of the European Ceramic Society, 35(2),

831-843.

Murray, H. H. and Kogel, J. E. (2005). Engineered clay products for the paper

industry. Applied Clay Science, 29(3), 199-206.

Neville, A.M. (2002). Properties of Concrete. 4th

ed. New York: Pearson Education

Limited.

Ngamsurat, S., Boonkerd, K., Leela-adisorn, U. and Potiyaraj, P. (2011). Curing

characteristics of natural rubber filled with gypsum. Energy Procedia, 9, 452-

458.

Nor, M. A. A. M., Akil, H. M. and Ahmad, Z. A. (2009). The effect of polymeric

template density and solid loading on the properties of ceramic foam. Science

of Sintering, 41(3), 319-327.

Norliza, I. Murthy, V. and Teng, W. D. (2009). Ceramic membrane fabrication from

industrial waste: effect of particle size distribution on the porosity. Journal of

Applied Sciences, 9, 3136-3140.

Obradovic, V., Brncic, M., and Jezek, D. (2009). Influence of the sieving amplitude

on the particle size distribution of corn flour for direct expanded extrudates

manufacturing. Agriculturae Conspectus Scientificus, 74(3), 249-252.

Orts, M. J., Escardino, A., Amorós, J. L. and Negre, F. (1993). Microstructural

changes during the firing of stoneware floor tiles. Applied Clay Science, 8(2),

193-205.

128

Pan, D. A., Li, L. J., Yang, J., Bu, J. B., Guo, B., Liu, B., and Volinsky, A. A.

(2015). Production of glass–ceramics from heavy metal gypsum and pickling

sludge. International Journal of Environmental Science and

Technology, 12(9), 3047-3052.

Papageorgiou, A., Tzouvalas, G. and Tsimas, S. (2005). Use of inorganic setting

retarders in cement industry. Cement and Concrete Composites, 27(2), 183-

189.

Petersham, M. (ed.) (1984). Understanding Clay Recognition and Processing.

Virginia: Volunteers in Technical Assistance (VITA).

Potgieter, J.H., Potgieter, S.S. and McCrindle, R.I. (2004). A comparison of the

performance of various synthetic gypsums in plant trials during the

manufacturing of OPC clinker. Cement and Concrete Research, 34, 2245–

2250.

Pye, K. and Blott, S. J. (2004). Particle size analysis of sediments, soils and related

particulate materials for forensic purposes using laser granulometry. Forensic

Science International, 144(1), 19-27.

Rajamannan, B., Viruthagiri, G. and Jawahar, K. S. (2013). Effect of grog addition

on the technological properties of ceramic brick. International Journal of

Latest Research in Science and Technology, 2(6), 81-84.

Rice, P. M. (2015). Pottery analysis: a sourcebook. Chicago: University of Chicago

Press.

Richerson, D.W. (1992). Modern Ceramic Engineering. 2nd

Ed. New York: Marcel

Dekker Inc.

Riedel, R., & Chen, I. W. (2008). Ceramics Science and Technology. New York:

John Wiley & Sons.

Riedel, R., Ionescu, E. and Chen, I. W. (2011). Modern trends in advanced ceramics.

Ceramics Science and Technology, 1, 3-38

Riley, F. (2009). Structural Ceramics: Fundamentals and Case Studies. Cambridge:

Cambridge University Press.

Ryan, W. (1999). The Manufacture of Wall and Floor Tiles. Malaysia: Ceramic

Research Company.

Sacks, M.D. and Tseng, T.Y. (1984). Preparation of SiO2 glass from model powder

compacts. Part 2: Sintering. Journal of the American Ceramic Society, 67(8),

532–537.

129

Sae-oui, P., Sirisinha, C. and Thaptong, P. (2009). Utilization of limestone dust

waste as filler in natural rubber. Journal of Material Cycles and Waste

Management, 11(2), 166-171.

Safaeikatouli, M., Jafariahangari, Y. and Baharlouei, A. (2011). An evaluation on the

effects of dietary kaolin and zeolite on broilers blood parameters, T4, TSH and

growth hormones. Pakistan Journal Nutrition, 10, 233-237.

Shackelford, J.F. (2009). Introduction to Materials Science for Engineers. 7th

Ed.

New Jersey: Pearson Education Inc.

Sharma, A. K. and Mahanwar, P. A. (2010). Effect of particle size of fly ash on

recycled poly (ethylene terephthalate)/fly ash composites. International

Journal of Plastics Technology, 14(1), 53-64.

Singh, N. B. and Middendorf, B. (2007). Calcium sulphate hemihydrate hydration

leading to gypsum crystallization. Progress in Crystal Growth and

Characterizdation of Materials, 53(1), 57-77.

Souza, A. E., Teixeira, S. R., Santos, G. T. A. and Longo, E. (2013). Addition of

sedimentary rock to kaolinite clays: influence on sintering process. Ceramica,

59.

Sperazza, M., Moore, J. N. and Hendrix, M. S. (2004). High-resolution particle size

analysis of naturally occurring very fine-grained sediment through laser

diffractometry. Journal of Sedimentary Research, 74(5), 736-743.

Spiller, M. S. (2012). Dental Ceramics. Albany, NY: Academy of Dental Learning

and OSHA Training.

Stubna, I., Trnik, A., Sin, P., Sokolar, R. and Medved, I. (2011). Relationship

between mechanical strength and modulus young in traditional ceramics.

Material and Technology, 45(4), 375-378.

Stubna, I., Trník, A., Podoba, R., Ondruska, J. and Vozar, L. (2014). The influence

of thermal expansion and mass loss on the young’s modulus of ceramics during

firing. International Journal of Thermophysics, 35(9-10), 1879-1887.

Sutton, S. (2014). Materials Handbook: Ceramic Industry. Troy, Michigan: BNP

Media.

Suzuki, H. and Hayashi, K. (1969). The role of particle size and carbon content in

high strength WC-10% Co alloys. Transactions of the Japan Institute of

Metals, 10(5), 360-364.

130

Tangsathitkulchai, C. (2002). Acceleration of particle breakage rates in wet batch

ball milling. Powder Technology, 124(1), 67-75.

Takeuchi, Y., Nanataki, T., Yamamoto, H. and Takeuchi, K. (1998). Method for

Controlling Firing Shrinkage of Ceramic Green Body. U.S. Patent 5,753,160.

Takeuchi, Y., Nanataki, T., Iwata, K., Takeuchi, K., and Kimura, T. (2010). Method

for Controlling Shrinkage of Formed Ceramic Body. U.S. Patent 7,655,180.

Ten, J. G., Orts, M. J., Saburit, A. and Silva, G. (2010). Thermal conductivity of

traditional ceramics. Part I: influence of bulk density and firing temperature.

Ceramics International, 36(6), 1951-1959.

Ulusoy, U., Yekeler, M., Bicer, C. and Gulsoy, Z. (2006). Combination of the

particle size distributions of some industrial minerals measured by Andresen

pipette and sieving techniques. Particle & Particle Systems Characterization,

23(6), 448-456.

US stoneware (1965). Jar, Ball and Pebble Milling Theory and Practice. East

Palestine, Ohio: Operating Division of ER Advanced Ceramics, Inc.

Valley, H. (2011). Industrial Minerals: Feldspar. North America: Industrial Minerals

Association.

Vasilyeva, E. A., Morozova, I. V., Lapshin, A. E. and Konakov, V. G. (2002).

Ceramic materials with controlled porosity. Materials Physics and Mechanics,

5(1), 43-48.

Vauchy, R., Robisson, A. C., Audubert, F. and Hodaj, F. (2014). Ceramic processing

of uranium–plutonium mixed oxide fuels (U1− yPuy) O2 with high plutonium

content. Ceramics International, 40(7), 10991-10999.

Vekinis, G., Ashby, M. F. and Beaumont, P. W. R. (1993). Plaster of paris as a

model material for brittle porous solids. Journal of Materials Science, 28(12),

3221-3227.

Wen, Y., Nan, L. and Bingqiang, H. (2005). High-strength, lightweight spinel

refractories. American Ceramic Society Bulletin, 84(4), 1-3.

Worrall, W.E. (1975). Clays and Ceramic Raw Materials. London :Applied Science

Pub. Ltd.

Yan, W., Li, N., Li, Y., Liu, G., Han, B. and Xu, J. (2011). Effect of particle size on

microstructure and strength of porous spinel ceramics prepared by pore-

forming in situ technique. Bulletin of Materials Science, 34(5), 1109-1112.

131

Yan, W. and Lin, N. (2006) Pore-size distribution and strength of

porous mullite ceramics. American Ceramic Society Bulletin, 85, 9401-9406.

Yang, Y. and Ding, J. (2012). Microwave property of micron and sub-micron Fe 90

Al 10 flakes fabricated via ball milling and jet milling routes. Journal of Alloys

and Compounds, 528, 58-62.

Zhang, Y., Kong, D. and Feng, X. (2012). Fabrication and properties of porous β-

tricalcium phosphate ceramics prepared using a double slip-casting method

using slips with different viscosities. Ceramics International, 38(4), 2991-

2996.

Zhou, J., Shu, Z., Tiantian, L. I., Dongxue, Y. U., Sheng, Z., and Wang, Y. (2015).

Novel fabrication route for non-fired ceramic tiles only using

gypsum.Ceramics International, 41(7), 9193-9198.