Uses of Metals and Metallic Minerals Publisher: New Age | Pages: 332 | 2007 | ISBN 8122420401 | PDF | 1.5 MB
However, in today’s fast developing situation, there is always a multiple choice available for technologies and grades of input materials. So, technology and input materials can be chosen to suit any grade of a metallic mineral that is available in nature. The only constraints are the market price and the cost of recovering the metal values. The cost has always to be less than the market price, the vagaries of which limit the range of flexibility regarding the specifications of grade. But, even if these specifications are not flexible enough at some point of time, the principles underlying the specifications remain valid all the time. And those principles, rather than the specifications, have been emphasized in this book.
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.
The second consideration in favour of maximization of the utilization of the wastes is related to the environmental problems. Some of the wastes remain on the ground, some go to the rivers and the ground water, some go into the air. The pace at which mining and processing of metals are going on at present, is far faster than it was a few decades ago. Wastes are also being generated at a very fast pace. If nothing is utilized properly, then the amount of damage these wastes will cause to the land, water and air in a few decades hence, is unimaginable.
The third consideration is about concerns for conservation of mineral resources. Conservation as such is not a new concept. Emperor Ashoka thought about it about 2300 years ago. But he thought about conserving the forests, birds and animals. In the 3 century BC, the edicts that he got inscribed on the rocks and iron pillars can be translated thus: “ Twenty six years after my coronation, I declare that parrots, mynas, the aruna, ruddy geese, the nandimukha, cranes, bats, queen ants, terrapins, boneless fish, rhinoceros and all quadrupeds which are not edible are not to be killed; forests must not be burned”. Conservation of mineral resources have become a concern only after the World War-II in 1945, when it was realized by the US Government, followed gradually by other governments, with alarm that higher grade parts of many minerals had all been mined out to meet the needs of the war and the economy, and there is urgent need to conserve what still remained. Conservation does not mean keeping the mineral deposits idle without mining. It means judicious mining, it means avoidance of wasteful practices of use, it means total utilization of the material mined without wastage. In other words, conservation means using not only the useful metal values of a mineral, but also the wastes generated during mining of the mineral to the maximum possible extent. Conservation and ignoring the waste materials generated during mining, processing or using of minerals and metals do not go together.
The second consideration in favour of maximization of the utilization of the wastes is related to the environmental problems. Some of the wastes remain on the ground, some go to the rivers and the ground water, some go into the air. The pace at which mining and processing of metals are going on at present, is far faster than it was a few decades ago. Wastes are also being generated at a very fast pace. If nothing is utilized properly, then the amount of damage these wastes will cause to the land, water and air in a few decades hence, is unimaginable.
The third consideration is about concerns for conservation of mineral resources. Conservation as such is not a new concept. Emperor Ashoka thought about it about 2300 years ago. But he thought about conserving the forests, birds and animals. In the 3 century BC, the edicts that he got inscribed on the rocks and iron pillars can be translated thus: “ Twenty six years after my coronation, I declare that parrots, mynas, the aruna, ruddy geese, the nandimukha, cranes, bats, queen ants, terrapins, boneless fish, rhinoceros and all quadrupeds which are not edible are not to be killed; forests must not be burned”. Conservation of mineral resources have become a concern only after the World War-II in 1945, when it was realized by the US Government, followed gradually by other governments, with alarm that higher grade parts of many minerals had all been mined out to meet the needs of the war and the economy, and there is urgent need to conserve what still remained. Conservation does not mean keeping the mineral deposits idle without mining. It means judicious mining, it means avoidance of wasteful practices of use, it means total utilization of the material mined without wastage. In other words, conservation means using not only the useful metal values of a mineral, but also the wastes generated during mining of the mineral to the maximum possible extent. Conservation and ignoring the waste materials generated during mining, processing or using of minerals and metals do not go together.
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