Diamond Mining is the major element of the Botswana mining industry and diamonds account for 80% of the country’s export earnings ($1.74 billion in 1994). Diamond mining is dominated by Debswana Diamond Company Ltd, owned by De Beers Centenary AG and the Botswana government. Debswana is the country’s biggest employer with 6000 employees. The Three Botswana diamond mines – Orapa, Letlhakane and Jwaneng – between them produced 15,54 million carats of diamonds in the year to December 1994, which is considerably more than the output from the other southern African operations. In August 1996, the CSO signed a further five year sales contract with Botswana.
Discovered in 1967, the Orapa deposit came into production in 1971 and has yielded 118m carats of diamond. The Orapa pipe, about 250km west of Francistown in northern Botswana, is the world’s second largest kimberlite pipe being mined in terms of area, covering 117 ha. The pit bottom is now 110 metres below the surface. Current proven reserves extend to 260 metres below surface and an exploration drilling programme is underway to define the shape of the pipe down to 500 metres – 600 metres. At a depth of 210 metres the pipe splits into two lobes, each measuring about 20 ha. Orapa production increased to 6.74 million carats in 1997 from 5.64m in 1996. To date the mine has shifted a total of 170 Mt of material, of which just 2.4 Mt has been waste. By 2000, Orapa will be mining 60 Mt/year, of which 20 Mt will be ore and 40 Mt waste. Once mining operations in the open pit reach their maximum economic depth, Orapa will become an underground mining operation working through twin vertical shafts to get at the bottom sections of the kimberlite pipe. The underground mine would have a life of around 25 years.
Debswana Diamond Company Ltd was first registered in 1969 after discovery of diamonds at Orapa. The Letlhakane mine near Orapa was founded in 1973, as was the much larger Jwaneng mine in the south of the country but, while Letlhakane came into production by 1977, Jwaneng did not start mining operations until 1982. Jwaneng is by far the richest and the largest of the three mines and one of the largest diamond mines in the world, and during 1994 produced 9.1 million carats at grade of 137 carats per hundred metric tons of ore. Debswana became a 50/50 partnership in 1975 after the Botswana government’s shareholding was raised from 15% to 50%. Appointment of directors to the board, is split equally between De Beers Centenary and the Botswana government. Debswana is the largest private sector employer in Botswana, currently employing over 6000 workers of whom 90% are Botswana citizens.
The Orapa, Letlhakane and Jwaneng mines are operated by the Debswana Diamond Company. These three mines currently have a total annual production of more than 20 million carats. It is hoped to double the capacity of the Orapa mine by the year 2000, which would raise total production by more than 25 million carats per year. All diamonds are sorted and valued by Botswana Diamond Valuing Company, which is a subsidiary of the Debswana Diamond Company.
Debswana’s mining lease at Orapa has been renewed for a further period to June 2017. Debswana will spend $288 million to double the treatment capacity of Orapa mine. This will raise Debswana’s total production by 6 million carats to 23 million in 2000 from the year 2000. The 117 ha Orapa craterfacies kimberlite is on of the lowest-cost major diamond producers in the world. The mine’s labour requirements will rise by less than 10% while its overhead costs should increase by only 20%. The mine life will be reduced from 60 years to 30 years.
Ashton Mining has an option to earn 50% interest on the Ngami diamond exploration project. This recently expanded 26 000 square kilometre project will require an investment of USD 5.15 over the next three years.
There are potential new mines at Martin’s Drift and Gope and a short term mining lease has been awarded by the Botswana Government to a new subsidiary of De Beers Prospecting Botswana, Tswapong Mining, in which the Government holds 15 per cent, to exploit five small kimberlites at Martins Drift in eastern Botswana on the Botswana-South African border about 400 kilometres east of Gaberone. The contract gives the right to exploit the deposit for a period of four years.
The Botswana Diamondfields company is focusing on three license blocks, covering some 9 400 square km of highly prospective precious stones prospecting licenses. These are the Deception Pan Block; the Mopipi Block; and the Tswapong Block.
Ashton Mining of Australia has agreed to finance the first $U.S.5.5 million of exploration costs at Reunion Mining’s Tsodilo diamond project in north-west Botswana in return for a 50% stake in the 22,000 square kilometres concession.
The Debswana subsidiary, Teemane Manufacturing Company, in Serowe, is involved in cutting and polishing diamonds. The local subsidiary of American company, Lazare Kaplan, is also active in diamond cutting and polishing.