Analysis: RADHE KRISHNA
SINCE prehistoric times, mining has been an integral part of man’s existence. Hence the term ‘mining’ in its broadest context means encompassing the extraction of all naturally occurring mineral substances (solid, liquid and gas) from the earth for utilisation. Utilisation refers to all essential human needs and desires that have been met by minerals throughout the ages.
In fact, most of the cultural ages of man are associated and identified by minerals or their derivatives. These include the Stone Age (prior to 4000 BC), the Bronze Age (4000 to 1500 BC), the Iron Age (1500 BC to 4000 BC), the Iron Age (1500 B.C. to A.D. 1780), the Steel Age (1780 to 1945), and the Nuclear Age since 1945. Many milestones in human history such as Marco Polo’s journey to China, Vasco Da Gama’s voyages to Africa and India, Columbus’ discovery of the new world were achieved with minerals as the prime incentive.
It is also true that minerals and mining have been associated with the dominance of great civilisation of history.
Development of mining technology
Mining began in the Palaeolithic Era some 450,000 years ago. This was in the early Old Stone Age. There are, of course, no records to substantiate the fact, but flint implements have been found in the bones for early man from the Old Stone Age. He extracted these from the earth and learned to shape them by crude techniques. At that time he was satisfied to recover raw material from surface excavations but by the beginning of the New Stone Age he had progressed to underground mining in systematic openings up to one metre height and 10m in depth. The oldest known underground mine believed to be an iron mine in Swaziland is 40,000 years old. Early deep miners employed crude methods of ground control, ventilation, hoisting, lighting and a method of rock breakage. Egyptians attained a depth of 250 metre in underground mines.
Metallic minerals attracted the attention of prehistoric man and initially were used in their native form, probably obtained by washing river sand to get several minerals including gold. However, man discovered how to break a rock easily by smelting thereby reducing ore to native metal or alloy form.
Among the greatest discoveries of humankind and the first technological breakthrough in mining, the art and science of rock breakages are of fundamental importance. No other technological advancement in mining had an equal impact, until black powder.(low explosive – the Chinese discovery) was first used to blast rocks in the seventeenth century.
At the close of the eighteenth century there was spectacular improvement in mining technology, especially in scientific concepts and mechanisation and these improvements have continued to this date. Currently mining is being done more than four kilometres below the earth surface.
Environmental problems and disasters in mines
Environment – It is impossible to extract minerals from the earth without changing the natural environment in some way, as technology improves the adverse effects of mining on the environment will also continue to be reduced.
Disasters in mines
Disasters in mines are naturally a matter of great concern as they seem to be caused by lack of precision or miscalculation. But statistics show that it is much more often by neglect, ignorance or over specialisation. Also, nature has a habit of taking advantage of those who turn their backs on it. Subsurface conditions can hardly be known or predicted accurately in advance. Therefore, decisions are made and cost estimates are based on the best information that can be obtained.
Future of mining
Mineral deposits are a wasting asset and are irreplaceable. Despite this fact, the long established dependence of man on this mineral heritage will continue indefinitely. Requirements of technological progress will place increasing demands upon the mineral industry to produce more and greater variety of elements.
Progress in technology will make ore out of many rocks which are considered useless today. Methods will change as a way to make mining safer as well as reduce environmental impairments.
The art and science of mining began with the early man and is changing rapidly. It is certain that mining will continue as long as man lives on earth.
The author is a professor at the University of Zambia, School of Mines, Department of Mining Engineering.
Source: Zambia Daily Mail