MATALLIC MENIRALS ROLL NO: 07 Metallic Minerals On an auspicious day, sometime around a million years ago, a member of the Homo habilis species stood erect and walked steadily on his two feet and his two hands became totally free. A new species – Homo erectus—began its journey on a new evolutionary track. This great change took around four million years after his ancestors – the hominids — broke free from the lineage of apes and chimpanzees.
But , perhaps for the next seven to eight hundred thousand years, the descendants of that first Homo erectus kept wondering about what to do with the two free hands apart from holding bones and logs of wood. That was till someone picked up a stone and threw it to some animal – probably because he was scared and was trying to defend himself, or because he was hungry and wanted to get some flesh to eat. But unconsciously, he began the gainful use of a mineral, and unconsciously again, began the evolution of a new species –Homo sapiens, the modern man.
Evolving down the generations, man learnt to be choosy in picking up the stones; he realized that all stones are not good for his needs; he tried and erred, and through innumerable trials and errors spanning over tens and hundreds of thousands of years, finally he zeroed in on a sharp-edged hard mineral that we have named flint. With the sharp edges of flint, he could tear animals for hide and flesh; and much later, he could make knives and axes and spear heads. Flint became the backbone of economy.
He began digging the earth, taking out new treasures and burning them. Thus was produced, some 6000 years ago, a new mineral, and from that a new material to which, much later, we have given the name copper metal. And that day began the Copper Age. In fact, this was the beginning of both mining and metallurgy. Not satisfied with copper any longer than a few hundred years, he began experiments with other metallic ores like tin, zinc and lead, and with a stroke of metallurgical genius, produced bronze.
In the next two thousand years, by now, he knew about gold and silver also — not so much for industrial usage, but more for ornaments and amulets. Then came that wonder metal called iron. Man entered not only the Iron Age, but also what is known as the New World. Iron continues to be the backbone of economy even today, supported not just by copper, tin zinc, lead, gold and silver, but by a host of other metals. Although flint has survived the ages and still lives today — in name at least — in some cigarette lighters, we no longer use it for getting energy.
Coal, petroleum, natural gas and uranium are the sources of energy now. But compared to the thousands of years of history of copper, lead, zinc tin, gold, silver and iron, the oldest amongst these energy minerals i. e. , coal, has come to our life in a big way, only within the past 400 years or so. And we must not forget that for mining and using these energy minerals — and, in fact, all the minerals that we use today – we need machines, we need metals, we need metallic minerals – in America, in Europe, in China, in India.
Even if we do not mine the metals, they still enter from soil into plants and through plants into the cells, tissues and organs of human bodies, to help the humans live healthily. Such is the importance of metals and metallic minerals in industry, in economy and in human life. From any mineral we do not get a metal. The minerals, from which we get metals, are called ores. Amongst the ores, there are many which are used only for extraction of metals, and there is no other use of them. There are also a few ores which have multiple uses.
Of course the most important use is to extract their metal contents, but they can also be used straightaway for making industrial products. As a matter of convention, these are called metallic minerals in economic and statistical circles, to distinguish them from energy minerals and industrial minerals, which are not at all used for extraction of any metal. Examples of such metallic minerals are bauxite, hematite, chromite etc. The importance of these metallic minerals in Indian economy can be gauged from the fact that during the financial year ending March 2006, the total value of production of such minerals was 89. 3 billion rupees i. e. , about 12% of the total value of production of all minerals which was 751. 22 billion rupees and this despite the fact that the value of the metals has not been accounted for in these statistics. But again, the value of metals cannot just be measured in terms of rupees; we should also think what would have happened without the metals. There would not have been any industry, there would not have been any agriculture, and there would not have been any civilization. What are the uses of some Metallic Minerals?
Metals such as nickel, copper and zinc are fundamentally important to modern society since they are used for an endless variety of purposes. A few examples are listed below: * Copper: Copper Pipe, Electrical Wires, Canadian Penny * Nickel: Stainless Steel, Cars And Trucks Frames, Batteries * Titanium: Artificial Joints And Surgical Instruments, Airplane Structures * Iron: Bridges, Car And Truck Frames, Axes, Tools, Steel Girders * Platinum: Petrochemical Industry To Make Gas And Purify Oil, Catalytic Converters On Cars And Trucks To Reduce Emissions * Zinc: Galvanized Nails And Cars Lead: Wet Cell Batteries * Gold: Jewellery, Electrical Wiring Why is a particular metal or a metallic mineral used to perform a particular function or to make a particular product? That is because every metal possesses a unique combination of physical and chemical properties, and in this respect no two metals or two minerals are exactly the same. So a particular use of a metal or a mineral can be best understood if the use is linked to the particular set of physical and chemical criteria.
Now, gone are the days when all the rich near-surface deposits of metallic minerals were there asking to be dug out and processed for extraction of their metal contents. Those deposits are all finished during the last thousands of years. Today, we are left with only the poor grade minerals from deep-seated deposits for our needs of metals. Can we use any grade of a mineral for recovering its metal value? The answer is yes and no. The answer is yes, because firstly, man is not the producer of the mineral.
The mineral was produced by nature hundreds of millions of years ago and stored in safe custody within rocks of the earth; what man does is only draw some quantity from nature’s store house; and so, he has to accept whatever grade nature has created and whatever, out of the nature’s treasure house, his forefathers have left for him. Secondly, recovery of metals from its minerals depend not on the grades alone, but on an interplay of four factors namely grade of the mineral, grades of other input materials for its processing, technology and prices of the final products based on the metal.
Out of these, the price is determined by the market forces of demand-supply on which the producer has no control. But the other three factors are in the domain of the producer; he may mine a high grade mineral at a high cost, and use low grades of other input materials and employ low level technology to recover only a part of its rich metal value, or he may choose to mine an easily available low-grade mineral at low cost, and use high grades of other input materials and employ high level technology to recover almost the whole of whatever metal values are contained in the mineral.
The answer is no, because at a given point of time there is a particular technology developed, and only one particular set of input materials with fixed qualities are available for processing a mineral. So, only one particular grade of the mineral can be processed with that technology and with those input materials, and only that particular grade has to be used at that point of time. The story does not, however, end with processing a mineral, recovering its metal values and using those metals for producing various consumer products.
Nature has not given us minerals containing all metals, and nothing else. In exceptional cases, some pure gold nuggets were found, but they have all been taken away by our forefathers. As it stands today, though there are some metallic minerals like hematite with more than 65% of metal value, there are others that contain less than one percent. What happen to the huge quantities of material that are left out after the metal values are recovered?
Such material may, in some cases, be even up to 99% or more of what is mined. Those are generally referred to as waste materials. Then there are wastages at the stage of manufacturing the consumer products out of the metals and the consumers themselves waste a lot of those products during and after their use. In fact, wastes generate at every stage of economic activity, but it has been the experience that yesterday’s waste is today’s asset and today’s waste will be tomorrow’s asset.
This happens because the developments in technology are not only about recovering the metals, they are also about utilization of the so called wastes. After all, technology is for minimizing the costs at every level starting from mining of the mineral down to the final consumption, so that at every stage the cost is less than the market price. There is another dimension of the usage of metals and minerals – substitution. Though there are some metals which are indispensable in certain uses, there are also some which can be replaced by some other material in a use.
This happens if the cost advantages of using a metal vis-a-vis its performance are lost and a cheaper and/or better material becomes available. A metal can be substituted either by another metal (e. g. , copper by aluminium in electrical transmission wire) or by a non-metallic substance (e. g. , aluminium by plastics in construction material). Distribution of Metallic Minerals World Mineral Map (Metallic) Indian mineral map (metallic)