27 Jul 2021

Lucara Botswana occupies an enviable top spot in the international diamond mining industry as the producer of large and rare stones, thanks largely to its use of cutting edge technology. 

The mine attributes its recovery of large stones to its use of Mega Diamond Recovery (MDR) XRT circuit that allows for diamond recovery post primary crushing and prior to milling. 

“Sorting is based on carbon transmission, as opposed to fluorescence properties used by conventional x-ray machines, thus more tonnage is sent to the recovery plants which improves chances of more diamonds being recovered,” said General Manager Mr Johane Mchive. 

He said the XRT presented more opportunities to recover diamonds in their natural form without breakage, as well as opportunities to recycle tailings from the machine for further crushing and recovery of fine diamonds. 

Mr Mchive said the diamond sorting method, which was developed in Germany, was first used in Europe in the food industry as well as for waste separation. Currently XRT machines are used for diamond recovery in different countries such as United States of America, Angola, South Africa, Botswana, Lesotho, Europe, Brazil and Russia among others, he said. 

He said it was a very sustainable method due to its strong technical structure, high recovery performance and continual strides in technological development by the original equipment manufacturer. 

All Lucara’s large stones were recovered at its Karowe Mine, located within the mining licence ML 2008/6L, in the Orapa/Letlhakane Kimberlite district of north-central Botswana. 

The mine has three lobes of the broader ore body, being the North, South and Centre Lobes, with the South Lobe reportedly having high quality, high value diamonds. Its latest recovery is that of a 1,174.76-carat diamond. 

The stone, measuring 77x55x33mm, has been described as ‘a clivage gem of variable quality with significant domains of high-quality white gem material’. The stone represents the third +1,000 carat diamond recovered from the South Lobe since 2015. 

Previous recoveries include the record biggest diamond in Botswana’s history, a 1 758 carat stone named Sewelô recovered in April 2019 and a 1 109 carat gem Lesedi La Rona, extracted in November 16, 2015. 

The same lobe has produced Boitumelo, a 62.7 carat fancy pink Type 11 a gem diamond. 

The gem remains the largest fancy pink gem to be recovered in Botswana and one of the world’s largest rough pink diamonds on record. 

Lucara said in a press release soon after the recovery of Boitumelo that the gem was recovered along with a 22.21 carat fancy pink gem of similar quality and additional pink gems of similar colour and purity weighing 11.17 and 5.05 carats. 

The world’s largest gem-quality rough diamond was the Cullinan Diamond weighing 3 106.75 carats discovered at the Premier No2 mine in South Africa in January 1905, followed by Lucara Botswana’s Sewelo. The latest find at 1 174 takes the third spot, followed by Lesedi La Rona at 1 109, and Debswana’s 1 098carat diamond recovered on June 01.  

Although Lucara is 100 per cent privately owned, the government benefits handsomely from its profits. 

“The government gets 10 per cent royalties and sliding scale tax up to 55 per cent. Even though the government does not own the company it in a way recoups its dividends through the mechanism. 

We’ve also played our part in meaningful job creation especially for locals; our localisation stands at 98 per cent. Ends