A homogeneous, naturally occurring substance which has a definite chemical composition is called a mineral. They can be identified by their physical properties and chemical components. Minerals exist in different types based on their formation. Almost everything we use, from a tiny particle to a huge building or a big ship all, is made up of minerals. Minerals are one of the most valuable resources of the earth. All the stages of human development or progress have been named after them. For example, stone age, copper age, bronze age and Iron Age.
T hey are exhaustible or non renewable. Besides, they are distributed very unevenly. T hey are generally found in the form of ores. T he ore contains several impurities. Minerals are separated from the ores involving a number of distinct processes.
Mode of Occurrence of Minerals
Minerals are generally found in ‘Ores’. It is actually an accumulation of any mineral mixed with other elements. Minerals generally occur in many forms. They are
1. Veins and lodes
A country’s economic development is depending on the minerals. There are several types of minerals, but according to their characteristics and commercial use they are classified as shown in above chart. Minerals generally occur in the cracks, crevices, faults and joints of the igneous and metamorphic rocks. Minerals in smaller occurrence are called a ‘Vein’ and a larger occurrence is called a ‘lode, for example, Copper and Gold are found in lodes and veins.
2. Beds or Layers
Minerals that are formed as a result of deposition, accumulation and concentration generally occur in horizontal layers. E.g. Coal, Potash, etc.
Residual mass of weathered particles
When the decomposed rocks are washed away by water, the soluble particles are removed, leaving a mass containing ores. Such occurrences are called residual mass. E.g. Bauxite
3. Alluvial deposits
T h ese are the deposits found in the sands of valley fl oor and at the foot hills. These deposits consist of the minerals such as Gold, Silver and Platinum.
Th e world distribution of minerals
T h e minerals which contain metal in them are called as metallic minerals. Iron – Ore It is the basic mineral and the backbone of industrial development of the world. Iron Ore is the most widely distributed element of the earth’s crust and it rarely occurs in a free state. It is found as the composition of many rocks and minerals. Iron-ore makes up 4.6% of the earth crusts. Iron is found in the form of Iron – ore. Th ey are classifi ed into 4 categories.
(i) Magnetite: It is red in colour and has 72% of pure Iron
(ii) Hematite: It is black in colour and has 70% of pure Iron
(iii) Limonite: Its colour varies from dark brown to yellow and has 50% of pure iron.
(iv) Siderite: It is brown in colour and contains only 30% of pure iron is present.
T he iron content of these ores is highly variable. If the iron content is less than 30% in an ore, it is considered to be uneconomical. Iron is mixed with fixed proportions of Manganese, Nickel, Chromium or Vanadium to make different varieties of steel.
Distribution of Iron ore
Iron – ore is unevenly distributed in the world. Good quality Iron ore is found in Australia, Brazil, Russia, China, USA, Ukraine, Canada, etc. Russia has the largest reserves of iron ore in the world. Australia is the largest producer of Iron ore in the world. Other leading producers are China, Brazil, India and Russia. The Majority of Iron ore is (84%) produced by 5 countries alone.
It is a kind of Ferro-alloy used to manufacture the special quality steel. A little manganese added to iron, removes gases and acts as a ‘Cleanser’ in the manufacturing process. Nearly 6 Kg of manganese is used for making one ton of steel. Manganese is used for special quality steel making; it makes steel anti – corrosive, hard and clean. It helps to increase toughness, strength and durability to resist oxidation in blast furnaces. It is used to produce alloys with Copper, Bronze, and Nickel. It is used for producing heavy machinery, tools, bleaching powder, insecticides and paints.
Distribution and production of Manganese ore South
Africa, Australia, China, Gabon, Kazakhstan, Brazil, India, Ghana, Ukraine and Mexico are the major countries possessing manganese ore. South Africa is the largest producer of manganese ore in the world, followed by Australia. The other leading manganese producers are China, Gabon and Brazil. India is the 8th largest producer of manganese in the world though it possesses the largest reserves of manganese in the world.
It is a non – ferrous, soft brown metal. It is a good conductor, with high luster, density and melting point. Copper occurs in three forms as native metal in its pure state, as oxides and as sulphide. T he chief ore of copper is copper pyrite. It yields nearly 76% of the world production of copper. Copper is extracted by the process of crushing, concentration, roasting, smelting and refining. It was discovered in the earliest stage of civilization. Copper is one of the first metals known and used by man. It is found in the igneous and metamorphic rocks. Copper is very soft, but by mixing with tin, bronze can be obtained and mixing with zinc, brass can be obtained which is harder and tougher than pure copper. Copper is used in the
* Electrical Engineering Metallurgical Industries
* Making of alloys and making tubes, pipes, pumps, radiators and boilers.
* T hey are also used in the production of a wide range of ornamental materials.
Production and distribution of Copper
Copper deposits are found in almost every country. The main producers are Chile, Peru, China, USA and Congo. Chile is the largest producer of Copper in the world. It produces 27.20% of the world Copper, followed by Peru, which produces 11.53%. India holds 35th rank and it produces only 0.15% of the world’s production.
Others Bauxite is an important ore which is the main source of Aluminum. It is an impure raw material. It generally occurs as an ingredient of chemical compounds in highly complex minerals such as Cryolite, Corundum and Kaolin. Bauxite occurs quite near the surface and is generally mined by open cast method. It has a wide range of applications which include construction of buildings, utensils and airplane parts.
Production and world
distribution of Bauxite T he main Bauxite producers are Australia, China, Brazil, Guinea and India. The World’s greatest Bauxite producers and exporters are the countries located in the tropical and sub tropical region. Australia is the largest producer of bauxite in the world. India is the 5th largest producer of bauxite in the world.
Gold is a precious metal which occurs in alluvial or placer deposits or as reefs or lodes in the underground. Gold is used extensively for jewellery and also in dentistry, glass and porcelain dyes, in medicines and other industries. The purity of gold is expressed in terms of carat. China, Australia, Russia, USA and Canada are the leading producers of gold in the world. I
Platinum is a rare metal. It is costlier than gold. It has a very high melting point. It is a heavy, malleable, ductile, highly inactive, silverish, white transaction metal. It is one of the densest metal almost twice as dense as lead. Platinum is found with other rare metals such as osmium, Palladium, Iridium and rhodium. Platinum is also used in industrial applications. South Africa is the largest producer of platinum in the world. The other leading producers are Russia, Zimbabwe, Canada and USA
Non- metallic minerals
T he minerals which do not contain metal in them are called as non metallic minerals.
Mica is a Latin word micare means to shine, to flash or to glitter. Mica has a crystalline and layered structure and can be split into very thin sheets. It does not react to water, acids, oil or solvents. It is lightweight, flexible and strong. It can resist extremely high temperatures or sudden changes in temperature and is able to withstand high voltages and insulate with low power loss. It can absorb or reflect light, which enables a decorative effect and protects against ultra-violet (UV) light.
Major Uses of Mica
Mica has several applications. There are several main sectors where the use of mica is identified. They are the paint and coatings sector, Cosmetics and personal care companies, Plastics and printing ink manufactures, the electronics sector, the automotive sector, the construction industry and the oil industry.