The Orapa diamond mine is the world's largest diamond mine by area. The mine is located in Orapa, a town in the Central District of Botswana about 240 kilometers (150 mi) west of the city of Francistown. Orapa ("resting place for lions") is owned by Debswana, a partnership between the De Beers company and the government of Botswana. It is the oldest of four mines operated by the company, having begun operations in July 1971.
Orapa is an open pit style of mine and is the largest diamond mine in the world by area. The mine is located on two kimberlite pipes that converge near the surface, covering 1.18 square kilometres at ground level.
Orapa operates seven days per week, and produces 20 million tons per year of ore and an additional 40 million tons per year of waste rock.
Currently, the Orapa mine annually produces approximately 11 million carats (2200 kg) of diamonds. The recoverable ore grade at the mine is about 0.87 carats (174 mg) per ton.
The mine was expanded in 1999, doubling its previous capacity. The processing plant at Orapa processes the ore produced at Orapa as well as two of Debswana's three other mines, the Letlhakane and Damtshaa diamond mines.
According to en.wikipedia