8.1 Mining and mineral processing  (Page 3/7)

1. Refer to the table below showing SA's gold production in tons between 1980 and 2004.

   Year	Production (t)
   1980	675
   1985	660
   1990	600
   1995	525
   2000	425
   2004	340

   Draw a line graph to illustrate these statistics.
2. What percentage did South Africa's gold production contribute towards global production in:
   1. 1980
   2. 2004
3. Outline two reasons for this drop in gold production.
4. Briefly explain how the increased cost of resources such as water contributes towards declining profitability in gold mines.
5. Suggest a reason why the cost of steel might affect gold production.
6. Suggest what impact a decrease in gold production is likely to have on...
   1. South Africa's economy
   2. mine employees
7. Find out what the current price of gold is. Discuss why you think gold is so expensive.

Environmental impacts of gold mining

However, despite the incredible value of gold and its usefulness in a variety of applications, all mining has an environmental cost. The following are just a few of the environmental impacts of gold mining:

• Resource consumption Gold mining needs large amounts of electricity and water.
• Poisoned water Acid from gold processing can leach into nearby water systems such as rivers, causing damage to animals and plants, as well as humans that may rely on that water for drinking. The disposal of other toxic waste (e.g. cyanide) can also have a devastating effect on biodiversity.
• Solid waste This applies particularly to open pit mines, where large amounts of soil and rock must be displaced in order to access the gold reserves. Processing the gold ore also leaves solid waste behind.
• Air pollution Dust from open pit mines, as well as harmful gases such as sulfur dioxide and nitrogen dioxide which are released from the furnaces, contribute to air pollution.
• Threaten natural areas Mining activities often encroach on protected areas and threaten biodiversity in their operation areas.

Discussion : mine rehabilitation

There is a growing emphasis on the need to rehabilitate old mine sites that are no longer in use. If it is too difficult to restore the site to what it was before, then a new type of land use might be decided for that area. Any mine rehabilitation programme should aim to achieve the following:

• ensure that the site is safe and stable
• remove pollutants that are contaminating the site
• restore the biodiversity that was there before mining started
• restore waterways to what they were before mining

There are different ways to achieve these goals. Plants for example, can be used to remove metals from polluted soils and water, and can also help to stabilise the soil so that other vegetation can grow. Land contouring can help to restore drainage in the area.

Discussion:

In groups of 3-4, discuss the following questions:

1. What are the main benefits of mine rehabilitation?
2. What are some of the difficulties that may be experienced in trying to rehabilitate a mine site?
3. Suggest some creative ideas that could be used to encourage mining companies to rehabilitate old sites.
4. One rehabilitation project that has received a lot of publicity is the rehabilitation of dunes that were mined for titanium by Richards Bay Minerals (RBM). As a group, carry out your own research to try to find out more about this project.
   • What actions did RBM take to rehabilitate the dunes?
   • Was the project successful?
   • What were some of the challenges faced?