Johannesburg's Mine Dumps Bite the Dust
By Lucille Davie
JOHANNESBURG, South Africa, January 27, 2004 (ENS) - The familiar mine dumps south of Johannesburg are disappearing. Some 170 million tons of sand have so far been removed from the dumps, and the plan is to eventually remove them all, and in the process, change the face of south Joburg.
That is, so long as the price of gold remains around R85,000 (US$11,950) a kilogram, or more. If the price falls and stays below R80,000, the cost of processing one kilogram, the operation would have to be reconsidered, says Charles Symons, general manager of Crown Gold Recoveries.
The scattered mine dumps are the remains of mine workings from the birth of Johannesburg in 1886. The dumps are actually crushed rock, and because the gold extraction processes were not very refined in those early days, there are traces of gold still in the dumps. Sophisticated modern processes are able to extract these residues.
There are about 200 dumps in and around the city, some as tall as 50 meters (164 feet), consisting of fine cream colored sand. Crown Gold has the rights to mine 70 of them by 2007.
In total there are 438 million tons of mine dump soil, stretching from Boksburg on the East Rand right through to Krugersdorp, about 30 kilometers (50 miles) southwest of the city. About 40 percent of that has so far been removed.
A dump is considered viable when 0.4 grams of gold can be obtained from every ton. But some dumps yield more: Menell's dump, southeast of the city, has produced 0.65 grams a ton. Some 800,000 tons of sand are treated every month.
The treated sand is being moved to three huge dumps being created alongside the Nasrec Expo Centre that was the location of the Global Peoples Forum at the 2002 World Summit on Sustainable Development.
To keep dust blowing off the sand dumps and polluting the surrounding suburbs, first wheat and then grass is being planted on their surfaces.
Witwatersrand University runs a dust monitoring program, where a series of dust bucket monitors are placed on the top of buildings and factories, towers, and in residential backyards. Once a month these buckets are cleared and their contents analyzed.
Quarterly dust monitoring meetings, which are open to the public, are held. "We like to believe that we have a good relationship with the local communities," says Symons. The communities most affected are those in Diepkloof, Diepmeadow and Meadowlands.
"There is a certain amount of runoff of polluted water from the dumps." But spills seldom get into the water course, says Symons."
Cyanide was used in the early days to remove the gold but Symons says cyanide has a short shelf life and when subjected to sunlight, it breaks down, so now, 100 years later, there are few traces of it.
Still he admits five to six incidents happen every year. "We have a good relationship with the local authorities," Symons says, "and if a pollution incident occurs, we let them know and then we take the necessary action to clean the area. We're open and honest with people."
When the dumps are removed, the two companies that own the land - I Prop, and the Witwatersrand Gold Mine Trust - intend to build on it.
Petro Heydenrych, CEO of I Prop, says they have successfully converted 65 hectares of reclaimed land to mixed use purposes at Crown City, south of Edgardale. Current uses are for industrial, distribution and office space. "The land use will depend on what we find when the dump is removed," says Heydenrych.
And for those who used to take the drive up the dump that was converted into a drive-in, called the Top Star, just beyond the M2 south of the city, you may want to take a last nostalgic trip up the winding road to see a movie. Feasibility studies are being conducted, and it seems likely that the Top Star mine dump will be treated for its gold residue and flattened.
{Published in cooperation with the Johannesburg News Agency.}