Analysis: KRISNA RADHE
TRADITIONALLY, environment was seen in terms of the one or two key issues such as water or air pollution, or impact on local land use.
But now every phase of mining involves some degree of ground disturbance. Beyond the confines of the mine, mining wastes if not properly treated can affect public health in nearby communities. Mining waste may include cynide compounds, heavy metals, readionuclides and asbestos, many kinds of hazardous gases and fumes. The common incidents of contamination which could ultimately affect public, aquatic ecosystems including fishing ground, agriculture etc. As environmental issues continue to evolve, all aspect of mine must revived and all practices maybe no longer acceptable. Other problems of underground mining e.g. coal dust and fire damp (methane gas) explosion, inundation (water flooding), fire etc. needs to be controlled as well.
The impact of mineral extraction on the environment is profound and in many cases has been both negative and irreversible.
However, mainly in the last 2 – 3 decades it has become clear that we have passed this point and that the effect is greatly increased and massive. The widespread industrial development has created an environment crisis in many parts of the world.
Since the past two centuries or so, the devastation of landscape in mining areas and the massive volume of smoke and fumes are produced due to mineral processing. It was realised that if man was to achieve the level of prosperity it is extremely important that attitude of people must change.
RECENT YEARS DEVELOPMENT
1. Environmental impacts currently considered at least in four levels that includes (a) physical and biological impact
(b) Socio and Cultural impact
(c) Economic impact and
(d) Country’s revenue.
These are of great concern on which serious thoughts being given.
2. Strict adherence to already existing Acts and Regulations for pollution control.
3. Application of remote sensing is in very much in use enabling the planning of remedial measure. In addition, the potential of remote sensing for the assessment of man – made and natural hazards receiving evermore attention.
4. There are some special mining methods developed that can accommodate simultaneously mining and deposition of tailings (dangerous particles of heavy metal sulphides e.g. cyanides, arsenic, phosphorus compounds.)
5. Recycling of scrap metal in improving the environmental impact. This thinking is very promising and it is going to be used in near future on major scale.
6. Improved mineral processing technique has achieved “zero discharge” of pollutants to the environment.
7. Use of tailings to provide good raw materials for making many useful goods e.g. glass wool, building blocks and for underground support system etc
8. Use of modular plants for mineral concentration. Mobile pilot plants have been in use.
9. Presently, before mining begins topographical survey, hydrology and climatetology are undertaken to deal with proper discharge of pollutants.
10. The application of well recognised microbial process in the metal extraction is being applied which cleans up even the mercury polluted water and terrestrial and aquatic ground water.
11. Landscaping, re vegetation (planting of fruit trees, cashew nuts, cocoa nut etc) and turning them into wildlife parks on the damaged area which are visible eye sores all over the world are being used.
12. Care of large volume of pulp (a mixture of finally divided reactive solids and liquor containing many dissolved toxic and poisonous substances are being discharged in isolated rivers.
Above all, nature itself has the capacity to repair effectively the damage caused on this planet which must be researched to make full use of it.
We should not be too worried in this aspect and must remember man is remarkably ingenious animal; it is only a matter of time until an acceptable way of coping with the problem is arrived at. In the meantime we must keep fighting with the problem. Considering all the above measures, it may not be of great concern at this level.
“STUDYING THE PAST, UNDERSTANDING THE PRESENT AND PLANNING THE FUTURE” should be the motto.
The author is a professor in the University of Zambia, School of Mines.