Botswana is the world’s leading producer of gem quality diamonds in the world, producing some 26.4 Mct in 2001.
Diamond production in Botswana is dominated by Debswana, a joint venture company owned by De Beers Investments (50%) and the Government of Botswana (50%). Debswana has 3 operational mines, Lethlhakane (produced 960 000ct in 2000), Orapa (produced 12.2 Mct in 2000) and Jwaneng (produced 11.5 Mct in 2000). 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. Jwaneng has been earmarked for the installation of the new “aquarius” technology – a new method of sorting rough diamonds without any human intervention. This is to be implemented in early 2000.
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. Orapa has completed an expansion to its open pit, hoping to double production to 12 Mct/year. Through this process, 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. Orapa increased production 1999, mainly as a result of an increase of grade experienced at the mine (from an average of 75 cpht in 1998 to 95 ctpht in 1999) as well as improved treatment and recovery efficiencies. On the other hand, Jwaneng experienced a decrease in average grade (125.8 ctpht in 1999 from 136.9 ctpht in 1998).
Debswana and the Botswana Government are developing the new Damtshaa mine (previously known as the BK 9 pipe) that is located between Orapa and Lethlakane. Although Damtshaa is a low grade, marginal kimberlite, its proximity to Orapa has made the project feasible. The $23 million project will produce an initial 200 000ct/year, beginning late 2002.
Smaller mining operations exist near Martins Drift, close to the border with South Africa. Tswapong Mining Company, a joint venture between De Beers Prospecting Services (85%) and the Government of Botswana (15%) operate Martin’s Drift. The operation has a limited life around four years – with production coming from five smaller pipes. Tswapong produced 25 000ct from its trial mining activities in 1999.
All diamonds are sorted and valued by Botswana Diamond Valuing Company, which is a subsidiary of the Debswana Diamond Company.
Diamonds account for 60% of all prospecting licenses issued in Botswana, although the government is trying to diversify the focus of minerals exploration in the country.
De Beers and Falconbridge are investigating the feasibility of the Gope cluster in the Central Kalahari Game Reserve. Although this project has potential for a large low-grade operation, development is subject to environmental issues, yet to be resolved. The economic GO25 pipe is blanketed by an extensive cover of Kalahari sand and underlying basalt. Some 78 Mt of sand and 90 Mt of basalt would need to be stripped prior to exposing GO25 for open pit mining. $80 million has already been spent on the feasibility study. Although the feasibility study has been completed, plans for development are being assessed in light of current economic conditions. In the light of De Beers’ impressive 1999 results and long term commitment to Botswana, it appears that the Gope mine might well become a reality in the near future. A Mining Licence has apparantly been applied for by the joint venture.
Aros Resources has an option to earn 80% of the Molopo property (located in southwestern Botswana) from the Southern Africa Minerals Corporation. As many as 90 kimberlites have been discovered on the Molopo property, of which the M1 pipe is considered to be one of the largest pipes in the world.
MIT Ventures and Auridiam are testing the BK16 kimberlite on their Tendaka prospect, situated near De Beers’ Orapa Mine. A bulk 2300t sample was taken to follow up on previous samples that had returned microdiamonds. However, resulting grades from the sampling were low and did not warrant any further bulk sampling. Mit are now continuing to evaluate the area for additional kimberlites. The BK16 pipe was discovered under 24m of Kalahari overburden.
African diamond miner, Trivalence Mining Corporation have completed an aerial geophysical survey over the Kokong prospect and have also signed an agreement with RioTinto over the exploration of the Kokong Property (Trivalence currently have a joint venture with Rio Tinto over the Aredor development in Guinea). The Kokong area is host to at least 34 kimberlite pipes, of which 14 are known to be diamondiferous. Based on these results, Trivalence have identified more than 100 potential kimberlite targets that are to be tested. Previously, De Beers and Falconbridge had carried out an extensive drilling programme over this area.
Diamond exploration continues in Botswana with numerous local and foreign companies carrying out various phases of exploration. Due to the extensive Kalahari sand cover (and Karoo basalts underneath), sophisticated and innovative sampling and geophysical techniques are required to locate undiscovered kimberlites. In general most of Botswana is prospective for kimberlite discovery, and based on discoveries and mining operations to date, the potential for the discovery of diamondiferous kimberlites is high.
Firestone Diamonds Plc has continued work over its Mopipi prospect, where the joint venture has completed high density ground sampling. Results have identified areas of high indicator mineral counts suggestive of a proximal kimberlite source.
De Beers Investments
De Beers’ subsidiary Debswana, has a 50% interest with the Botswana Government in three opencast mining operations: Orapa, Jwaneng and Lethlakane.
Debswana Diamond Company (Pty) Limited
Debswana has a 50% interest in the three largest diamond mines in Botswana: Orapa, Jwaneng and Lethlakane.
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