MODULE 1

IMPORTANT NATURAL RESOURCES; METALLIC

MINERALS AND THEIR ORES, NON- METALLIC

MINERALS AND AGRO BASED MATERIALS.

MODULE OBJECTIVES

This module is aimed at:

(i) introducing students to the important natural resources and

(ii) fostering understanding of the metallic minerals and their ores, non-metallic minerals and

agro based materials.

LEARNING OUTCOMES

At the end of the module, students should be able to recognize important natural minerals,

describe metallic minerals and their ores, non-metallic minerals and agro based materials and

should be able to identify these natural minerals in their day-to-day living.

MODULE 1: UNIT 1

IMPORTANT NATURAL RESOURCES; METALLIC MINERALS AND ORES

AND NON-METALLIC MINERALS

NATURAL RESOURCES

These are materials or substances occurring in nature (i.e they exist without the actions of

mankind) which can be exploited for economic gain. These natural resources include, air,

water, soil, minerals, along with the climate and solar energy, which form the non-living

or ‘abiotic’ part of nature. The ‘biotic’ or living part of nature consists of plants and

animals, including microbes. Thus, forests, grasslands, deserts, mountains, rivers, lakes

and the marine environment all form habitats for plants and animals to live in. Thus, the

natural resources earth on includes sunlight, atmosphere, land, rocks, vegetation, water

(ocean, lakes, streams, seas, and rivers), fossil fuel, animals (fish, wild life, and

domesticated animals), minerals and air.

These natural resources dictate the survival of humans and other life forms on earth

because they provide for the basis of life on earth. It is from the natural resources that

humans obtain and produce the components and materials found within our

environments, the food eaten and water drank.

A natural resource may exist as a separate entity such as fresh water, air, and as well as a

living organism such as a fish, or it may exist in an alternate form that must be processed

to obtain the resource such as metal ores, rare earth metals, petroleum, and most forms of

energy.

Classification of natural resources

The three methods of classifying natural resources are listed below

i. source or origin,

ii. stage of development, and by

iii. the renewability.

For the classification by origin, natural resources may be divided into biotic and abiotic.

The can be classified into organic and inorganic. Those relating to substances whose

origin have to do with living and non-living systems:

• Biotic — Biotic resources are obtained from materials in the biosphere (the

biosphere is the global ecological system integrating all living beings and their

relationships, including their interaction with the elements of the lithosphere, geosphere,

hydrosphere and atmosphere) such as forests and animals, and the materials that can be

obtained from them including substances from decayed organic matter (fossil fuels) such

as coal and petroleum. Thus biotic resources are generally from organic materials.

• Abiotic – Abiotic resources are those that come from non-living or say non-

organic materials. Examples of abiotic resources include land, fresh water, air, rare earth

metals and heavy metals including ores, such as, gold, iron, copper, silver, etc.

Classification by stage of development, natural resources may be classified into

potential, actual, reserve or stock resources as they are those resources that are already

being used or that will be used later either due to the availability or lack of technology.

• Potential resources — Potential resources are those that may be used in the

future—for example, petroleum in sedimentary rocks that, until drilled out and put to use

remains a potential resource.

• Actual resources — these are resources that have been surveyed, their quantity

and quality are already known. These resources are already being used and they depend

on available technology and cost

• Reserve resources — these are natural resources that are ‘reserved’ as the name

implies. They can be developed profitably in the future.

• Stock resources — those that have been surveyed, but cannot be used due to lack

of technology—for example, hydrogen. These resources can only be used upon arrival of

the required technology. As technology improves their use in future is possible.

Classification based on renewability: Many natural resources can be categorized as

either renewable or non-renewable:

• Renewable resources — Renewable resources can be replenished naturally. Some

of these resources, like sunlight, air, wind, water, etc. are continuously available and their

quantities are not noticeably affected by human consumption because they are

replenished over time, though many renewable resources do not have such a rapid

recovery rate, these resources are susceptible to depletion by over-use. Resources from a

human use perspective are classified as renewable so long as the rate of

replenishment/recovery exceeds that of the rate of consumption. Examples include

vegetation, water, and air.

As much as these resources are renewable, it may take tens to hundreds of years to

replace them. The renewable raw materials that come from living things namely animals

and trees are termed as organic renewable resources while those that come from non-

living things such as sun, water and wind are termed as inorganic renewable resources. In

summary we can say that renewable natural resources are linked to natural cycles.

Example is water cycle were water is a natural resource.

• Non-renewable resources – Non-renewable resources either form slowly or do not

form naturally in the environment i.e they cannot simply be substituted or recovered once

they have been utilized or destroyed. Minerals are the most common resource included in

this category. By the human perspective, resources are non-renewable when their rate of

consumption exceeds the rate of replenishment/recovery; a good example of this are

fossil fuels, which are in this category because their rate of formation is extremely slow

(potentially millions of years), meaning they are considered non-renewable. Some

resources actually naturally deplete in amount without human interference, the most

notable of these being radio-active elements such as uranium, which naturally decay into

heavy metals. Some non-renewable resources such as metallic minerals can be re-used by

recycling them, but others such as coal and petroleum cannot be recycled. Once they are

completely used they take millions of years to replenish. Examples of such natural

resources include fossil fuels and minerals. Minerals are categorized as non-renewable

because, even though they take shape naturally through the rock cycle, their formation

periods take thousands of years.

The non-renewable materials that come from living things such as fossil fuels are known

as organic non-renewable resources while those that come from non-living things such as

rocks and soil are referred to as inorganic non-renewable resources.

Natural resources can also be classified broadly into

i. forest resources

ii. water resources

iii. food resources

iv. energy resources

v. land resources

vi. mineral resources

Mineral Resources

Mineral can be defined as natural material featuring strictly determined internal structure,

chemical composition, as well as chemical and physical properties, which was formed as

a result of geological or cosmic processes. In terms of chemistry, mineral is a collection

of molecules of the same chemical compound or, less frequently, mixture of compounds.

Thus, the term minerals does not cover synthetic substances produced in laboratories and

by industry. Sometimes the difference between mineral and chemical compound is

elusive, especially when the substance is formed due to human activities and the forces of

nature. Water is not a mineral while ice formed during geological processes is a mineral.

Mineral resources are divided into metallic (rocks containing gold, copper, aluminium,

iron, etc.) and non-metallic mineral resources, (building stone, gravel, sand, gypsum,

phosphate, salt, etc )

Minerals at present are called physical and chemical homogeneous crystal bodies formed

as a result of physical and chemical processes. Each mineral represents a solid phase and

dimensionally ultimate crystal body and hence minerals are characterized by a crystal

structure. Minerals of the same composition with different structures are identified with

different names e.g marble and calcite, rutile and anatase.

IDENTIFICATION OF MINERALS

The physical properties of minerals include colour and appearance, hardness, crystal

symmetry, special optical properties.

Minerals exhibit a variety of colours, for example the green colour of malachite is a

characteristic colour for copper ore. In some minerals, external shape and form is the

characteristic for identification, for example, quartz and calcite can be identified by their

form and external shape while the fibrous nature of asbestos is a characteristic of that

mineral. The relative hardness of a mineral is assessed against an arbitrary scale, the

Mohs scale of hardness. A harder mineral will leave a stretch mark on a softer one. The

hardness of various minerals are given below :

Mineral Hardness

Talc 1

Gypsum 2

Calcite 3

Fluorspar 4

Apatite 5

Feldspar 6

Quartz 7

Topaz 8

Corundum 9

Diamond 10

The specific gravity of a mineral maybe used to identify it. E.g both galena (PbS) and

barite (BaSO4) feel very heavy in the hand. The magnetic nature of minerals such as

magnetite (Fe3O4) and the natural radioactivity of minerals such as pitchblende

(2UO3.UO2) are further aids to their identification. Amongst other characteristics are

lustre such as metallic, earthy, dull, greasy, etc. cleavages which are the plain of

weakness common in calcite and feldspar.

Classification of Minerals.

Since every mineral has a definite chemical composition and crystal structure. In

mineralogical studies, based on the combination of the chemical composition and crystal

structure, minerals are grouped into the following groups named below:

There are different classifications of minerals. The way they are classified depends on the

aim of the classification. Usually minerals are classified according to their chemical

composition:

I. Native elements, alloys and intermetallic compounds

II. Carbides, nitrides, phosphides and silicides

III. Sulfides and related minerals

IV. Halides

V. Oxides and hydroxides

VI. Salts of oxy-acids (nitrates, iodates, carbonates, selenates, tellurates, borates,

sulfates, chromates, molybdates, tungstates, phosphates, arsenates, antimonates,

vanadates, uranates, geramanates, silicates and aluminosilicates)

VII. Ammonium minerals

VIII. Organic compounds and their derivatives.

Halides, nitrates, borates, phosphates, and sulphates mainly occur in evaporate

deposits along with carbonates, which occur as major rock-forming minerals. Other

groups are dominated by oxides and constitute important ore-forming minerals.

Microscopic studies: in this technique, the minerals are studied under optical

microscopes. Example is ‘polarized light microscopes’ because optical properties are

studied under polarized light.

The microscopic examination involves study of the following important properties for

the identification of minerals

1. Colour: minerals have particular colours

2. Pleochromism: minerals show a change in colour under polarized light when they

are rotated.

3. Form: the characteristic shapes of a mineral. Some are fibrous, needle-shaped,

prismatic etc.

4. Isotropism or anisotropism: minerals are called isotropic when they become

totally dark under crossed nicols. Minerals are called anisotropic when they show

brilliant interference colours in crossed nicols.

5. Extinction angle: the extinction angle is measured under a microscope, between

crystallographic directions of a mineral to its optical direction.

6. Refractive index: this is determined using various standard refractive index

liquids.

Instrumental methods: some of the instrumental methods of identification are

described below in brief:

1. X-ray diffraction: is a ‘finger print’ technique that identifies mineral phases, and

their unit cell dimension in Å units. The minerals are identified on the basis of ‘d’

values (interatomic planar distances) in Å units.

2. Thermal analysis: this technique depends on either the material decomposes on

absorption of heat or recrystallizes on losing the heat. The amount of absorption

of heat is called endothermic values whereas the loss of heat is measured in terms

of exothermic value. These values are compared with the standard inert material.

The values are recorded in the form of curve called differential thermal analysis

(DTA) curve. When the loss of weight of a mineral on heating is recorded

gravimetrically, the curve is called differential thermogravimetric curve (DTG).

This is used particularly for clays, carbonates, oxides etc.

3. Scanning electron microscope with microanalysis facility: The scanning electron

microscope (SEM) gives electron images of minerals at high magnification ( x

100,000) facilitating the study of fine features of minerals. If the microscope is is

provided with microanalysis facility with energy-dispersive X-ray (EDX) or

wavelength dispersive X-ray (WDX) the mineral analysis is possible. The mineral

analysis helps in formulating the composition of a mineral under examination.

Other techniques used are infrared spectroscopy, laser beam spectroscopy and

emission spectroscopy.

The complete identification can be determined using its chemical analysis which

helps in derivation of its empirical formula. The empirical formula of a mineral is

derived from the weight per cent of the elements or molecules divided by their

respective atomic or molecular weight and from its simplest ratio. Example

The chemical analysis of a particular mineral gives the following results:

Sb- 24.34%; S- 19.76%; Pb- 42.88%; and Cu- 13.06%

Thus

Mineral ratio

Sb- 1

S- 3

Pb- 1

Cu- 1

The empirical formula of the mineral is CuSbPbS3

UNIT 2

METALLIC MINERALS AND THEIR ORES

Metals and their discovery

Metals are opaque, shinny, smooth solids that can conduct electricity and be bent,

drawn into wire, or hammered into thin sheets- they look and behave quite differently

from wood, plastics, or rock. This is because; unlike the other substances the atoms that

make up metals are held together by metallic bonds meaning that the outer electrons flow

from atom to atom fairly easily. Despite the mobility of electrons, metals are solids, so

their atoms lie fixed in a regular lattice defining a crystal structure. Not all metals behave

the same way, some are noted for their strengths, others their hardness, some for their

‘malleability’ (how easily they can be bent or moulded) the behaviour of metals depends

on the strength of the bonds between the atoms and on its crystalline structure.

Discovery of metals

Metals such as gold, silver and copper can occur in rocks as native metals. Native

metals consist only of metal atoms and thus look and behave like metal. Hunters

collected nuggets of native metals from stream beds and pounded them together with

stone hammers to make arrow heads, scrappers etc. and because native metals are rare

and durable, people began to use them as money. If we have to rely solely on native

metals as our source of metal, we would have access to only a tiny fraction of our current

metal supply. Most of the metals we use today originated as ions bonded to non-metallic

elements in a great variety of minerals that do not look like metals in themselves. They

were discovered to decompose at high temperatures (smelting) yielding a metal and a

non-metallic residue called slog.

Of the principal metals we use today- copper, iron and aluminium – copper began

to be used first, because copper smelting forms sulphide minerals easily. The use of

copper dates back to as early as 4000 B.C.E., although pure copper has limited value

because it is too soft to retain a sharp edge. Around 2800 B.C.E., Sumerian men

discovered that copper could be mixed with tin to produce bronze an alloy. Whose

strength exceeds that of either metal alone.

Iron fell from space to earth in form of meteorites; it proves superior to copper or

bronze for many purposes, because of its strength, hardness and abundance. Iron

generally appears in the form of iron-oxide minerals (such as hematite, Fe2O3), and the

liberation of iron metal from oxide minerals requires a chemical reaction, not just simple

heating.

More recently steel was discovered, an alloy of iron and carbon, and stainless

steel an alloy of iron, carbon and chrome that resists corrosion.

Aluminium is abundant in rocks of the crust and in many ways is preferable to

iron because of its light weight compared to iron. These days, in addition to aluminium,

iron, tin and copper we use a cast array of different metals. Some are known as precious

metals (gold, silver and platinum) and others as base metals (copper, tin, lead and zinc)

because of the difference in their price.

Ores

An ore is metalliferous mineral or an aggregate of metalliferous minerals mixed

with gangue from which the metallic values can be extracted economically. Various

rocks contain one or more minerals, either metallic or non-metallic. Any rock which can

be processed economically for recovery of one or more metals can be categorized as ore.

The gangue from which the metal is extracted is mostly silica. The process of recovery

the mineral(s) of interest is purely a physical process called ore dressing or beneficiation

of ore which leaves the physical and chemical properties of the individual ores

unchanged. Ores are generally marketed worldwide as ore concentrate.

The most common process of beneficiation of ore is the froth flotation.

A typical ore dressing process of copper ore in an ore processing plant is

described below.

The average feed concentration of copper in the mined ore is 1.2%

1. Primary crushing: ore from mine in the form of big rocks of stones up to size

1200mm is subjected to one crusher and crushed to 150mm size. The coarse

ore is reclaimed by three apron feeder located in a tunnel and discharged on a

belt conveyor provided with a tramp iron magnet and metal detector.

2. Secondary and tertiary crushing: the coarse ore passes through a double beck

vibrating screen. The -40mm fraction is taken to a urge bin located above the

tertiary crusher, while the coarse size fractions are crushed in a secondary

crusher then taken to a surge bin also. The ore is then drawn by belt feeders

and fed to three single deck screens (12mm opening). The screen oversize is

fed to three tertiary con crushers. The undersize is sent to the fine ore bin. The

tertiary crusher product is also taken to the surge bin stick.

3. Grinding: the 12mm crushed ore is charged into feed conveyors feeding the

ore to ball mill for final wet grinding, ball mills operate in close circuit with

hydrocyclones for classification. The cyclone overflow containing about 30%

solids and 60%-200 fraction gravitates to sump and is pumped to flotation

section through a distributor. The cyclone underflow containing about 70%

solids gravitates back to the mills for regrinding.

4. Flotation:the cyclone overflow is distributed through a distributor to rougher

and scavenger flotation cells. Methyl isobutyl carbinol is used as frother and

sodium isopropyl xanthate as collector.

5. Thickening and filtration: the final concentration slurry from the flotation cell

is pumped into a thickener. The thickener overflow is pumped to disc filters

for filtration. The filter concentrate cakes containing moisture are piled up in

roofed yard and after natural drying are dispatched for transportation.

Some common ores and minerals and their characteristics

S/No Name of

metal

Chemical

composition

Important

minerals

Theoretical

percentage

metal

Specific

gravity

Colour

1. Aluminium Gibbsite Al(OH)3 Al2O3- 65.4 2.4 White

Boehmite

Diaspore

AlO(OH)

AlO(OH)

Al2O3- 85.0

Al2O3- 85.0

3.0

3.3

White grey

White grey

2. Copper Chalcopyrite

Bornite

Chalcocite

Cuprite

Malachite

CuFeS2

CuFeS4

Cu2S

CuO

CuCO2.Cu(OH)2

Cu- 34.6

Cu-63.6

Cu-79.8

Cu- 88.8

Cu- 57.5

4.1

5.1

5.7

6.0

4.0

Brass yellow

Reddish

Black grey

Red

Green

3. Iron Hematite

Magnetite

Goethite

Fe2O3

FeO. Fe2O3

FeO(OH)

Fe- 70.0

Fe- 72.0

Fe- 63.0

5.0

5.2

4.2

Black

Reddish yellow

Yellow

4. Tin Cassiterite SnO2 Sn- 78.6 7.0 Brownish-

black

5. Zinc Sphalerite

Smithsonite

ZnS

ZnCO3

Zn- 67

ZnO- 64.8

4.0

4.4

Yellow brown

White

6. Silver Native

Argentite

Cerargyrite

Ag

Ag2S

AgCl

Ag -90

Ag- 87.1

Ag- 75.3

10.0

7.3

5.5

Silver white

Blackish grey

7. Lead Galena

Cerussite

Anglesite

PbS

PbCO3

PbSO4

Pb- 86.6

Pb- 77.5

Pb- 68.3

7.5

6.5

6.1

Yellow

White grey

Yellow

8. Magnesium Magnesite

Dolomite

MgCO3

CaMg(CO3)2

Aluminium ores

The most important ore of aluminium is bauxite. It is non-crystalline earthy-white to reddish

mineral, massive or in grains, having composition Al2O3.2H2O containing theoretically 74%

alumina (Al2O3). Other forms of bauxite are gibbsite Al2O3.3H2O and diaspora Al2O3.H2O.

Generally, the bauxite ore is a mixture of bauxite, diaspora and gibbsite.

Aluminium is extracted/ produced mainly from the bauxite ore. The ore is used for making

aluminium oxide abrasives, for refractories, white cement and for decolourizing and filtering.

Bauxite is graded on the basis of alumina (Al2O3) content. High grade bauxite contains a

minimum of 55% alumina and a maximum of 8% silica. Bauxite has a high melting point of

1820ºC and can be used directly as a refractory.

Filter bauxite or activated bauxite is bauxite that has been crushed, screened and calcined and is

usually 20-60 and 30-60 mesh grades. It is preferred to fuller’s earth for oil refinery filtering

because it can be revivified independently by calcining. Calcined bauxite for thee abrasive

industry is burned bauxite and contains 78-84% alumina.

Calcium and Magnesium Minerals

The minerals of calcium and Magnesium such as limestone, dolomite calcite are classified as

calcareous rock. They occur in combined state such as carbonate, sulphate, and often associated

with other elements such as aluminium, silicon, iron, boron, sodium, potassium titanium etc.

Some of the minerals of commercial importance are:

Limestone CaCO3

Calcite CaCO3

Gypsum CaSO4.2H2O

Dolomite CaCO3.MgCO3

Aragonite CaCO3

Marble CaCO3

Magnesite MgCO3

The chemical structure of limestone and marble is same but differs in crystalanity and grain size.

The marble has more compact crystal structure and hence harder and can be polished. The grains

of various colours in marble are due to inclusion of other coloured minerals. The mineral when

associated with sulphite is termed gypsum. The Iceland spar or calc spar is the name for perfectly

crystallized, water- clear, flawless calcite crystals of optical grade used for manufacture of Nicol

prisms for polarizing microscopes, colorimeters, photometers and polarizers. The common black

calcite contains manganese dioxide.

Copper Ores

Copper is the earliest metal recognised and used by man. It occurs in free state as well as in

combined state as sulphides, oxides and carbonates. It occurs less commonly as antimonides,

arsenates, phosphates, silicates and sulphates. Some commonly known ores are given below:

Sulphides:

Bornite Cu5FeS4

Chalcopyrite CuFeS2

Tetrahedrite Cu12Sb4S13

Chalcocite Cu2S

Covellite CuS

Oxides:

Cuprite Cu2O

Tenorite CuO

Carbonates:

Malachite CuCO3.Cu(OH)2

Azurite CuCO3.Cu(OH)2

Sulphates:

Antlerite Cu3(SO4)(OH)4

Bronchantite CuSO4.3Cu(OH)2

Chlorides:

Atacamite Cu2Cl(OH)3

Silicates

Chrysocolla CuSiO3.2H2O

Complex Ores

Bournonite PbCuSbS3

Enargite 3Cu2S.As2S3

Famatinite Cu3(As,Sb)S4

Olivenite Cu2(AsO4)(OH)

Of the sulphide ores, bornite, chalcopyrite and enargrite are considered to be the “primary”

minerals which are formed by igneous processes deep in the earth’s crust. Minerals such as

covellite and chalcocite are considered to be formed as “secondary” deposits of copper leached

from the sulphides close to the surface and precipitated near the water level. The oxide minerals

are formed through the oxidation of the sulphides.

Iron Ores

Iron is widely abundant and constitutes about 4% of the earth’s crust iron is found in nature as

oxide, carbonate, sulphides, silicates etc. Iron is found associated with numerous minerals of

different elements such as in chrome, manganese, copper, arsenic ores etc. the commercially

important ores of iron are given below:

Oxides

Haematite Fe2O3

Limonite FeO(OH).nH2O

Magnetite Fe3O4

Carbonates

Siderite FeCO3

Sulphides

FeS2 (white pyrite)

Pyrite FeS2

Pyrrhotite FeS (Magnetic pyrite)

Tin Ores

Cassiterite SnO2, is the only tin ore of commercial importance. Over 80% of the world’s tin ore

occurs in low grade alluvial or eluvial placer deposits. In these deposits, the concentration of tin

can be as low as 0.015%. The other sulphide minerals of tin are stannite Cu2S.FeS.SnS2; tealite,

PbSnS2; cylinderite, PbSn4FeSb2S14; and canfieldite, Ag8SnS6. These are found associated with

cassiterite and granitic rock. Tin is often found associated with tungsten minerals.

UNIT THREE

NON METALLIC MINERAL RESOURCES

Nonmetallic minerals are a special group of chemical elements from which no new product can

be generated if they are melted. Nonmetallic minerals are, for example, sand, gravel, limestone,

clay, and marble. Such materials lack metallic characteristics like good electric and thermic

conductivity, luster, rigor, and malleability; they are, however, essential for many industries.

The nonmetallic minerals industry is best known for the production of cement, ceramics, glass,

and lime products. Thus, the range of application is quite broad, from construction materials to

sanitary ware to tableware and decorative products. The transformation of nonmetallic minerals

into these products is often an energy-intensive process, which can include several steps, such as

heating, grinding, mixing, cutting, shaping and honing.

From the ground we get the stone used to make roadbeds and buildings, the chemicals for

fertilizers, the gypsum in drywall, the salt filling salt shakers, and the sand used to make glass-

the list is endless. Thus a few geographical materials are explained below:

Dimension Stone – these are intact slabs and blocks of rock (granite or marble) used for

architectural purposes carefully cut out from the walls of quarries. Note that “mines” supplies ore

while “quarry” supplies stone. To cut stone slabs, quarry operators split rock blocks from

bedrock by hammering a series of wedges into the rock, or to cut it off bedrock using a wireline

saw, thermal lance or a water jet.

Crushed Stone and Concrete – crushed stones forms the substrate of highways and railroads and

serves as the raw material for manufacturing cement, concrete and asphalt. In crushed stone

quarries operators use high explosives to break up bedrock into rubble that they then transport by

truck to a jaw crusher, which reduces the rubble into usable-size fractions.

Common nonmetallic minerals

Limestone- sedimentary rock made of calcite; used for gravel or cement

Crushed stone – any variety of coherent rock (limestone, quartzite, granite, gneiss)

Siltstone- beds of sedimentary rock, used to make flagstone

Granite- coarse igneous rock, used for dimension stone

Marble – coarse igneous rock, used for dimension stone

Slat- metamorphosed shale; used for wallboard

Gypsum- a sulfate salt precipitated from saltwater; used for wallboard

Phosphate- for the mineral apatite; used for fertilizer

Pumice- frothy volcanic rock; used to decorate gardens and paths

Clay- very fine mica-like mineral in sediment; used to make brocks or pottery

Sand- from sandstone, beaches, or riverbeds; quartz sand is used for the construction and for

glass making

Salt- from tee mineral halite, formed by evaporating saltwater; used for food, melting ice on

roads

Sulfur- occurs either as native sulfur, typically above salt domes or in sulfide minerals; used for

fertilizer and chemicals.

The content of non-metallic is rich and varieties in species, it can generally be classified as:

(1) Metallurgical auxiliary material, such as magnesite, refractory clay, silica, dolomite, fluorite,

etc;

(2) Special non-metallic minerals, such as diamond, crystal, Iceland spar, mica, tourmaline, etc;

(3) Chemical non-metallic minerals, such as phosphorus, sulfur, trona, Glauber's salt, ceresin;

(4) Building materials, such as basalt, granite, marble, gypsum;

(5) Ceramic, glass materials, such as kaolin, plastic clay, quartz sand, feldspar;

(6) Other materials, such as vermiculite, pumice, diatomaceous earth, asbestos, graphite, talc and

the like. Non-metallic mineral is mined easily and largely. Some mineral’s beneficiation

technology is relatively complex, required to protect native crystals, such as diamond, mica and

asbestos.