STUDY OF THE PROPERTIES AND MORPHOLOGICAL STRUCTURE …

www.wjpps.com │ Vol 10, Issue 11, 2021. │ ISO 9001:2015 Certified Journal │

1813

Fatthee et al. World Journal of Pharmacy and Pharmaceutical Sciences

STUDY OF THE PROPERTIES AND MORPHOLOGICAL

STRUCTURE OF NATURAL ZEOLITE PREPARED FROM LOCAL

CLAY RAW

Firas Emad Fatthee*1

and Omar Musa Ramadhan2

1,2

Department of Chemistry, College of Education for Pure Science, University of Mosul,

Mosul, Iraq.

ABSTRACT

This study included the use of local clay raw, which is found in large

quantities in the Al-Qasr area of Nineveh Governorate, Iraq. The study

showed that it contains many important clay minerals its rich in clay

minerals, which are Montmorillonite (10%), chlorite (4%), Kaolinite

(9%), muscovite (20%) and illite (19%) which represent more than two

thirds of the clay raw, in addition to containing small quantities with

different percentages of non-clay minerals. Chemical treatments have

also proven their ability to remove impurities from clay raw, which

reduces its effectiveness, in addition to its ability to open pores and

channels, and this has been proven in BET and SEM analyzes. Natural

zeolite prepared from clay raw, many measurements were made (TG, DTA, XRD, XRF,

BET, SEM) which proved that natural zeolite was obtained with good qualities, as it can be

used as an ion exchanger or in the various catalytic processes.

KEYWORDS: Local clay raw, Chemical treatment, Natural zeolite, Surface area, SEM.

1. INTRODUCTION

Clay minerals may be rocky, sedimentary deposits, or the result of weathering of primary

silicate minerals, Clay minerals of sedimentary origin, which mainly include the clay mineral

Kaolinite, of varying particle size and usually of low crystalline structure, on the other hand

bentonite is a rock formed by hydrothermal changes, developed and available to volcanic

materials in an aquatic environment (shallow seas, brackish lakes), Most of the sediments are

WORLD JOURNAL OF PHARMACY AND PHARMACEUTICAL SCIENCES

SJIF Impact Factor 7.632

Volume 10, Issue 11, 1813-1826 Research Article ISSN 2278 – 4357

*Corresponding Author

Firas Emad Fatthee

Department of Chemistry,

College of Education for

Pure Science, University of

Mosul, Mosul, Iraq.

Article Received on

20 Sept. 2021,

Revised on 10 October 2021,

Accepted on 30 Oct. 2021,

DOI: 10.20959/wjpps202111-20551


1814


rich in montmorillonite, and because of their diversity and composition, the catalytic activity

of natural clay materials varies according to their structural properties (Benny K.G. T. 2019).

The term „„clay” applies to the materials having a particle size of less than 2 µm, and also to

the family of minerals having similar chemical compositions and common crystal structural

characteristics (Velde, B., (1995). Clay has a variety of physical characteristics such as

plasticity, shrinkage under fire and under air-drying, fineness of grain, colour after firing,

hardness, cohesion, and capacity of the surface to take decoration (Odoma, A.N., & etal

(2013). Clays are hydrous aluminosilicates which composed of mixtures of finegrained clay

minerals, crystals of other minerals, and metal oxides (Mockovciakova, A., and Orolinova,

Z., (2009). On the basis of such qualities, clays are variously divided into classes or groups

such as smectites (montmorillonite, saponite), mica (illite), kaolinite, vermiculite, serpentine,

pyrophyllite (talc) and sepiolite etc (Shichi, T. and Takagi, K. (2000).

Clays and clay minerals have small particle size and complex porous structure with high

specific surface area, which allows strong physical, chemical interactions with dissolved

species. These interactions are due to the electrostatic repulsion, crystallinity, and adsorption

or specific cation exchange reactions. The highly porous surface area that possesses attractive

force suggests that the bonding power will also be high (Grim, R.E., (1962).

Zeolites are crystalline aluminosilicates with physical and chemical properties, including the

loss and absorption of water and other molecules. In addition, they act as molecular sieves

and replace their constituent cations without any change in their structural composition. The

unique and distinct physical and chemical properties of zeolites make them extremely useful

in many diverse applications. Including agricultural engineering, environment, manufacturing

and industrial processes (Hardi, GW, & etal 2020)

Zeolite is a hydrated quaternary alumina silica porous crystalline mineral with a three-

dimensional skeleton, Composed of [SiO4]-4

and [AlO4]-5

tetrahedrons (Stanislav, T., & etal,

2014) These two types are bonded to each other by oxygen atoms in this way which form an

open three-dimensional framework containing channels and cavities filled with metal ions

(usually alkaline or alkaline earth metals) and freely moving water molecules (Cheetam, D.

2014)


1815


Swedish mineralogist named Axel Fredrik Cronstedt in 1756 was the first to discover zeolite

and gave it this name. The word zeolite is composed of two Greek words “zeo” = boil &

“lithos” = stone meaning boiling stone through heating minerals, as the water is removed

when heated (Gottardi, G and Galli, E. 1985)

The general chemical formula for natural zeolite is

zeolites have attracted a great deal of interest among researchers and scientists due to their

flexibility and adaptability, after their discovery in 1756 by Axel Fredrik Cronstedt.

Especially widely used in industry. Zeolites have been used in the separation of straight-chain

hydrocarbons from branched-chain hydrocarbons, chemical sensors in industrial process

control, environmental and indoor air quality monitoring, effluent and automatic exhaust

control, medical monitoring, air separation and heavy metal removal.

Zeolite was first used as an adsorbent in 1777 by Fontana and Shell, due to its sorption

properties as it was applied in a variety of processes used to solve environmental problems.

Later, zeolites were used as good absorbent materials for particles such as H2O, NH3, H2S,

NO, NO2, SO2, and CO2 (Moshoeshoe, M., & et al 2017).

They are used as substitutes for phosphates in laundry detergents, as absorbents for

purification and separation of materials, and as catalysts. Total global consumption of zeolite

is estimated at 5 x 106 tons/year, including about 1.8 x 10

6 tons of synthetic zeolite and 2.9 x

106 tons of natural zeolite (2008) and that the main application areas of zeolites are as

adsorbents, catalysts and ion exchange materials (Hagen, J. 2015)

2. Experimental Part

2.1 Choosing of raw clay

The clay used in our study was obtained from the village of Al-Qasr located in Al-

Hamdaniya district of Nineveh Governorate, 100 gm of clay raw is placed in a manual mortar

for the purpose of preparing the clay raw and in order to prevent or reduce the effect of

crystalline structures on the heat resulting from the grinding process, add 10 cm3 of ethanol to

the clay raw during the grinding process and after each grinding process, the ore is sifted

using a sieve (300 mesh) periodically so that the ground ore is not subjected to further

grinding and then dried in an electric oven for (6-8) hours at a temperature of 130 ° C and

then kept for a purpose Study by Thermogravimetric analysis (TG) differential thermal


1816


analysis (DTA) X-ray diffraction(XRD) and X-ray fluorescence (XRF) (Pansu, M. and

Gautheyrou, J. (2006), Ghazal, R. Y. (2001)

2.2 Chemical treatment of clay raw to get a natural zeolite

The carbonate is initially removed from the clay raw by treating it with hydrochloric acid

(10%) with heating for three hours (Carver, RE, (1976). And then, the iron is removed by

treating the clay raw with a solution of (0.15M H2C2O4) In the presence of (0.5M H2SO4) and

heating to a temperature of 100°C and stirring the mixture using a magnetic stirrer for 90

minutes (Carver, RE, (1976), (Toro, L., and Veglio, F., (1994), as for the amorphous silica is

removed by treating crude clay with a solution (0.5 M NaOH) with heating for five hours and

then filtered, washed well with distilled water and then dried using an electric oven at a

temperature (130°C) and dried, and after these treatments we get Nature Zeolite (NZ) and

kept it in sealed bottles for the purpose of measurements on them by Thermogravimetric

analysis (TG) differential thermal analysis (DTA), X-ray diffraction(XRD) X-ray

fluorescence (XRF), BET Technique and scanning electron microscopic (SEM) .

3. RESULTS AND DISCUSSION

For the purpose of identifying the components of clay raw from clay minerals and non-clay

minerals, it was studied by X-ray diffraction (Figure 1), as it was found by analyzing the

diffraction patterns of clay ore that it consists of Montmorillonite, Chlorite, Kaolinite,

Calcite, Hematite, Quartz and Gypsum, in addition to muscovite and Illite that were

diagnosed. In the clay raw in this study by (X,Pert High Score Plus) the values of [°2Th.] and

atomic distances d-spacing [Å] measured in can be observed as shown in Table (1).

Table (1): Shows the values of atomic distances d-spacing [Å] and angles [° 2Th.] of the

local clay raw.

No. [°2Th.] d-spacing [Å] Intensity No. [°2Th.] d-spacing [Å] Intensity

1 5.105039 17.31076 13.90369 15 39.65368 2.27295 219.7622

2 6.0607 14.58315 87.94697 16 42.70146 2.11752 28.99203

3 8.905255 9.9303 47.41321 17 43.40119 2.08499 118.9994

4 12.38128 7.1491 19.64136 18 47.77308 1.90389 127.6286

5 19.96729 4.44685 158.9125 19 48.74387 1.86822 159.9247

6 21.08227 4.21412 101.0263 20 50.31783 1.81341 39.8764

7 23.29723 3.81824 85.07286 21 56.81545 1.62049 18.36637

8 24.52859 3.62928 48.51737 22 57.59005 1.60052 60.14033

9 26.87501 3.3175 521.9465 23 60.27626 1.53547 43.67696

10 27.97613 3.18938 62.66291 24 61.82385 1.5007 51.89584

11 29.6653 3.01151 904.6009 25 64.83923 1.438 45.35107

12 35.19212 2.5502 98.09603 26 65.87627 1.41786 33.42675

13 36.1873 2.48232 153.8002 27 68.45914 1.37053 32.00934

14 37.44958 2.4015 41.20396 28 73.02008 1.29577 27.77394


1817


Figure (1) shows the X-ray diffraction of local clay raw.

After studying the X-ray diffraction patterns of clay minerals and non-clay minerals their

percentages were calculated as shown in the table (2).

Table (2): Show the Percentage Ratio of clay minerals and non-clay minerals of raw

clay.

Clay and Non

Clay Minerals Percentage Ratio %

Montmorillonite 10%

Chlorite 4%

Muscovite 20%

Kaolinite 9%

Gypsum 12%

Ittite 19%

Quartz 6%

Calcite 13%

Hematite 7%

It appears from the table (2) that the local clay raw is rich in clay minerals, which are

Montmorillonite (10%), chlorite (4%), Kaolinite (9%), Muscovite (20%) and Illite (19%)

which represent more than two thirds of the clay raw in addition to containing small

quantities with different percentages of non-clay minerals.

Table (3) shows the percentages of local clay raw components in the form of oxides obtained

from XRF analysis in comparison with different natural clay minerals (Talaat, H.A., & etal

(2011) (Nayak, P.S. and Singh, B.K., (2007) (Njoku, V.O., & et al (2011) (Bosco, S.M.D., &

et al (2006) (Villegas, R.A.S., & et al (2005).


1818


Table (3): Shows XRF analysis in comparison with different natural clay minerals.

Natural clays Metal Oxide (weight %)

SiO2 Al2O3 Fe2O3 CaO Na2O K2O MgO MnO TiO2

Local clay raw 44.012 9.494 6.754 13.551 0.675 1.495 7.244 0.055 0.491

Egyptian clay 50.65 30.31 4.61 0.27 0.16 --- 0.20 --- 1.65

Indian clay 48.12 43.54 2.48 0.83 --- --- 0.50 --- 0.40

Nigerian clay 48.62 34.82 2.88 0.10 0.06 0.94 0.23 --- 0.01

Tunisia clay 52.50 18.20 3.00 2.81 1.78 1.50 2.45 --- ---

China clay 46.22 38.40 0.68 0.86 --- --- 0.37 --- ---

Brazilian clay 59.57 22.28 11.31 0.72 0.01 2.83 2.83 ---- 1.03

In order to know the thermal stability of the raw, the heating ranges, the amount of adsorbed

water and the water contained within the channels, as well as when the calcination process

occurs, as we can identify what the clay raw contains of water particles and its types, in

addition to the possibility of identifying the minerals calcite and dolomite, which consist

mainly of carbonates and bicarbonates, As clay ores begin to lose crystallization water

molecules at a temperature of (120-110)˚C and at a temperature of (250)˚C, these raw

materials lose all water molecules within the structural channels, but when the temperature is

raised to (360-350)˚C These ores lose the hydroxyl groups present within their structures in

the form of water molecules, as all two hydroxyl groups (-OH) turn into a water molecule

(H2O) and leave one oxygen atom bound within the crystal structure of these raw materials,

and the calcination process for carbonates begins at a temperature of (450)˚C as it loses

carbon dioxide (CO2) and works to convert the elements associated with it into an oxide

form, and this process continues to a temperature of (700)˚C approximately (Brobely, GP,

2007), and Figure (2) shows TG and TG analysis DTA for clay raw.

Figure (2) shows TG and DTA of clay raw.

Natural zeolite is multi-mineral and contains many impurities, which are mostly quartz,

feldspar and hematite, and the presence of these impurities makes it impossible to use it in

industrial processes, so most types of natural zeolite are useless (Akolekar, D., & et al 1997).


1819


Clay crude was taken and grinded well, then some chemical treatments were carried out for

the purpose of removing ineffective components that reduce the catalytic activity and thus be

useless. At first, the moisture content was measured, which amounted to 4%, and then the

clay raw was treated with hydrochloric acid for the purpose of removing carbonates. Because

its presence has a negative effect on the catalyst preparation process, as the carbonate

removed amounted to 18.125%. After that, the clay raw was treated with (0.15M H2C2O4)

and (0.5M H2SO4) for the purpose of removing iron, as the percentage of iron removed was

11%, and then the clay raw was treated with a solution of (0.5 M) sodium hydroxide for the

purpose of removing amorphous silica. It reached 15.9% and after removing all the

ineffective components of carbonate, iron and amorphous silica, the natural zeolite was

obtained.

From the application of TG natural zeolites, it gives us a clear idea of the amount of adsorbed

water present on the surface or inside the pores or channels. The adsorbent water and

hydroxyl groups (-OH) gradually and successively within a range of temperatures ranging

between (100-400°C), and this loss applies to most types of zeolites, as it is clear from Figure

(3) that the natural zeolite when heated from (100-130 ˚C) loses (1.8-3.2%) of its weight and

the reason for this is the loss of water of crystallization and when the temperature is raised to

(230-260˚C) loses (5.1-5.3%) of its weight due to the loss of water molecules within the

internal channels of the catalyst, and when heating continues to (300-360 ˚C), we notice that

the loss (5.8-6%) of its weight is due to the loss of the remnants of water molecules present

within the pores and channels, in addition to the loss of hydroxyl groups located Within the

structure of the catalyst in the form of water molecules, the process of heat raising and weight

loss continues to a temperature of 700 °C (Brobely, GP, 2007). The measurements showed

that the processes of losses at different temperatures are endothermic.

Figure (3) shows TG and DTA of natural zeolite.


1820


In order to identify the contents of natural zeolite from clay minerals and non-clay minerals,

it was studied by X-ray diffraction. Figure (4) It was found by analyzing the diffraction

patterns of the clay raw that it consists of Montmorillonite and kaolin in addition to

Muscovite and Illite with percentages of more than (70%) and low percentages of each of

Hematite, Quartz and Gypsum. The values of [°2Th.] and atomic distances d-spacing [Å]

measured of the diffraction patterns of each of the minerals diagnosed in the natural zeolites

prepared in this study can be observed by (X,Pert High Score Plus) program and the

percentages ratio of each mineral in Table (4) and Table (5) respectively.

Figure (4) shows the X-ray diffraction of natural zeolite.

Table (4): Shows the values of atomic distances d-spacing [Å] and angles [° 2Th.] of the

Natural zeolite.

Intensity d-spacing [Å] [°2Th.]

43.000940 9.95767 8.880729

15.266430 7.01536 12.618270

179.646900 4.42438 20.069730

188.108900 4.19677 21.170450

929.762100 3.30897 26.945590

100.710700 3.20084 27.874010

105.366400 3.00670 29.713870

112.882800 2.57753 34.807070

100.737600 2.43850 36.860690

71.708950 2.11823 42.686330

27.628740 1.97595 45.928870

130.894100 1.81028 50.410870

31.226250 1.66354 55.217680

95.589400 1.53746 60.189930

67.180880 1.49956 61.875780

63.257340 1.36981 68.499970


1821


Table (5): Show the Percentage Ratio of clay minerals and non-clay minerals for

Natural zeolite.

Clay and Non

Clay Minerals Percentage Ratio %

Montmorillonite 14%

Muscovite 26%

Kaolinite 13%

Gypsum 9%

Ittite 20%

Quartz 12%

Hematite 8%

In order to identify the percentages of the components of the prepared natural zeolite and the

rest of the prepared catalysts, which are in the form of oxides, by measuring fluorescent X-

rays, as we note from the Table (6) shows that the proportions of the elements included in the

composition of natural zeolite, which are in the form of oxides, consist of silica SiO2 with a

percentage of (49.174%) and alumina with a percentage of (9.75%) with the presence of

different percentages of sodium oxide Na2O, potassium oxide K2O, calcium oxide CaO and

oxide Magnesium MgO, which is present in the structural interface of zeolite in the form of

exchangeable ions (Ma+2

, Ca+2

, Na+1

, K+1

) With the presence of some impurities that cannot

be removed under the conditions of the study (Ugal, J.R., & et al., (2010).

Table (6): Shows XRF analysis of Natural zeolite.

Sample Metal Oxide (weight %)

SiO2 Al2O3 Fe2O3 CaO Na2O K2O MgO MnO TiO2

Natural zeolite 49.174 9.752 7.281 0.961 0.479 1.774 5.224 0.029 0.78

The BET method is one of the traditional methods that has a clear advantage in facilitating

analyzes, calculating the surface area, and evaluating the size of pores and channels (Naito,

M., & etal 2018). This technique relies on the use of nitrogen gas N2, as it is possible to use

other gases such as CO2, Ar and water However, nitrogen has a boiling point of (77˚K, -

195.79˚C), (Toth, J., (2001). The results showed that the natural zeolite possess a large pore

size and a good surface area Table (7) Figure (5) which enables its to carry out the catalytic

action through The adsorption of the reactants on the outside surface or inside the pores and

channels, and the required reaction occurs, followed by the desorption of the resulting

material molecules, which gives them good selectivity towards the catalytic reactions.


1822


Table (7): Shows the results of the BET analysis of the prepared natural zeolite sample.

Analysis Data Measurements

88.2760 m²/g BET Surface Area

553.8514 m²/g Langmuir Surface Area

0.1868 cm³/g Pore Volume

6.556405 nm Pore Size

-B-

-A-

-D-

-C-

Figure (5) (A) surface area by BET method, (B) surface area by Langmuir method, (C)

represents the pore volume in the case of adsorption and (D) represents the pore volume

in the case of desorption of the prepared natural zeolite.

The scanning electron microscope technique is one of the types of electron microscopes that

produces an image of the sample by scanning it with a focused beam of electrons that interact

with the atoms in the sample, which results in different signals containing information about

the topography and composition of the sample (McMullan, D., (1998) in addition to the

spectroscopic analysis in which the elemental composition of the model appears, the analysis

may be carried out. Figure (6) represents the spectroscopic analysis of the elemental

components of natural zeolite.

The natural zeolite prepared by this technique was measured, as the measurement showed

that it consists of grains of different irregular shapes, and some of these grains have formed

aggregated with each other grains of larger size. Zeolite has good specifications and

properties, and the size of these grains ranges between (32.17 nm to 87.78 nm), and this gives

us an indication of the good specifications of this zeolite Figure (7).


1823


Figure (6) Spectral analysis showing the elemental composition of natural zeolite.

-B-

-A-

-D-

-C-

Figure (7) SEM image of natural zeolite (A = 1µm B = 2µm C = 500 nm D = 200 nm)

4. CONCLUSION

This study shows that the local clay ore has many important characteristics, including its

availability in large quantities, in addition to containing many clay minerals, The chemical

treatments conducted on the local clay raw led to the removal of impurities and opening

channels and pores The XRF analysis shows presence of different percentages of sodium


1824


oxide Na2O, potassium oxide K2O, calcium oxide CaO and oxide Magnesium MgO, which is

present in the structural interface of zeolite in the form of exchangeable ions (Ma+2

, Ca+2

,

Na+1

, K+1

) The BET analysis results showed that the natural zeolite possess a large pore size

and a good surface area and SEM analysis showed crystalline nature.

REFERENCE

1. Akolekar, D., Chaffee, A. and Howe, R.F., (1997), “The Transformation of Kaolin to

Low Silica X Zeolite”, Zeolites, 19(3): 359-365.

2. Benny, K.G. T. (2019) “Clay Mineral Catalysis of Organic Reactions” © 2019 by Taylor

& Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group, an Informa

business. p.p.1.

3. Bosco, S.M.D., Jimenez, R.S., Vignado, C., Fontana, J., Geraldo, B., Figueiredo, F.C.A.,

Mandelli, D., Carvalho, W.A., (2006) “Removal of Mn(II) and Cd(II) from wastewaters

by natural and modified clays” Adsorption, 2006; 12: 133–146.

4. Brobely, G.P., (2007),"Thermal analysis of zeolite", Journal of Molecular Sieves, 5:

67-10.

5. Carver, R.E., (1976), "Procedures in Sedimentary Petrology", Elsevier Scientific

Publishing Co., New York, USA, p.56-58.

6. Cheetam, D. (2014) “Solid State Compound” (Oxford University Press, Oxford, 2014),

pp. 234-237.

7. Ghazal, R.Y., (2001), "Kara Tabbah Bentonite Study of Chemical Composition and Its

Applications in Oil Refining", M.Sc. Thesis, University of Mosul.

8. Gottardi, G. and Galli, E. (1985) “Natural Zeolites”, 1st editio. Munich: Springer-Verlag

Berlin Heidelberg.

9. Grim, R.E., (1962) “Applied Clay Mineralogy”, McGraw Hill Press, 1962.

10. Hagen J. (2015). “Industrial Chemistry” © 2015 Wiley-VCH Verlag GmbH & Co.

KGaA, Boschstr. 12, 69469 Weinheim, Germany p.p. 36 37,301, 310 311, 313 314.

11. Hardi, G.W., Maras, A.J.M., Riva, Y.R., and Rahman, S.F., (2020), “A Review of Natural

Zeolites and Their Applications: Environmental and Industrial Perspectives”,

International Journal of Applied Engineering Research ISSN 0973-4562, 2020; 15(7):

730-734 © Research India Publications. http://www.ripublication.com.

12. McMullan, D., (1998), “Scanning Electron Microscopy 1928–1965”, SCANNING, 1995;

17: 175–185.

http://www.ripublication.com/


1825


13. Mockovciakova, A. Orolinova, Z. (2009), “Adsorption properties of modified bentonite

clay”, Chem. Technol, 2009; 1: 47–50.

14. Moshoeshoe, M. Nadiye-Tabbiruka, M. S. and Obuseng, V., (2017) “A Review of the

Chemistry, Structure, Properties and Applications of Zeolites,” American Journal of

Materials Science, 2017; 5: 196–221. doi: 10.5923/j.materials.20170705.12.

15. Naito, M., Yokoyama, T., Hosokawa, K. and Nogi, K., (2018), “Nanoparticle Technology

Handbook”, 3rd Ed., Elsevier, 5: 23-25.

16. Nayak, P.S., Singh, B.K., (2007) “Instrumental characterization of clay by XRF, XRD

and FTIR”, Bulletin of Materials Science, 2007; 30: 235–238.

17. Njoku, V.O., Oguzie, E.E., Obi, C, Bello, O.S., Ayuk, A.A., (2011) “Adsorption of

copper(II) and lead(II) from aqueous solutions onto a Nigerian natural clay”, Aust. J.

Basic Appl. Sci., 2011; 5: 346–353.

18. Odoma, A.N. Obaje, N.G. Omada, J.I. Idakwo, S.O. Erbacher, J., (2013),

“PALEOCLIMATE reconstruction during Mamu formation (cretaceous) based on clay

mineral distributions” J. Appl. Geol. Geophys, 2013; 1: 40–46.

19. Pansu, M. & Gautheyrou, J., (2006), "Handbook of Soil Analysis", Springer-Verlag, p.15-

18, 226-233.

20. Shichi, T. Takagi, K. (2000) “Clay minerals as photochemical reaction fields”, Journal of

Photochemistry and Photobiology C: Photochemistry Reviews, 2000; 1: 113–130.

21. Stanislav, T., Jozef, V., Peter, A., Emilia, H. and Ondrej, H., (2014) “Influence of natural

zeolite on nitrogen dynamics in soil” Turkish Journal of Agriculture and Forestry, 2014;

38: 739-744.

22. Talaat, H.A., El-Defrawy, N.M., Abulnour, A.G., Hani, H.A., Tawfik, A., (2011)

“Evaluation of heavy metals removal using some Egyptian Clays”, in: 2nd Int. Conf. Env.

Sci. Tech. IPCBEE, 6, IACSIT Press, Singapore, 2011.

23. Toro, L., and Veglio, F., (1994), “Process development of kaolin pressure bleaching using

carbohydrates in acid media”, Int. J. Miner. Process, 41: 239-255.

24. Toth, J., (2001), “Adsorption; Theory, Modeling and Analysis”, Marcel Dekker, Inc., 68-

73, 80-81.

25. Ugal, J.R, Hassan, K.H., and Inam, H., A., (2010) “Preparation of type 4A zeolite from

Iraqi kaolin: Characterisation and properties measurements” Journal of the Association of

Arab Universities for Basic and Applied Sciences, 9: 2–5.

26. Velde, B., (1995) “Composition and Mineralogy of Clay Minerals, Origin and

Mineralogy of Clays” Springer-Verlag Press, 1995; 8–42.


1826


27. Villegas, R.A.S., Santo Jr., E.J.L., de-Mattos, M.C.S., De-Aguiar, M.R.M.P., Guarino,

A.W.S., (2005) “Characterization of natural Brazilian clays and their utilization as

catalysts in the coiodination of alkenes with water and alcohols”, J. Braz. Chem. Soc.,

2005; 16: 565–570. https://doi.org/10.1590/S0103-50532005000400012 .

https://doi.org/10.1590/S0103-50532005000400012

Documents

STUDY OF THE PROPERTIES AND MORPHOLOGICAL STRUCTURE …