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.