Lucara Diamond has mined a 2,492-carat diamond in Botswana. The gemstone is the second-largest ever discovered by humans and the largest in existence
Canadian mining company Lucara Diamond has discovered a 2,492-carat (498.4 g) diamond at one of its mines in Botswana, the BBC reports. The diamond is the second-largest ever discovered by humans and the largest in existence.
The diamond has not yet been given a name. The gemstone was found at the Karowe mine, 500 km north of Botswana’s capital, Gaborone. It was discovered using X-ray separation technology called XRT.
The XRT separator features an innovative X-ray transmission method for detecting diamonds (XRT in Western terminology), based on the property of materials in the difference in absorption of X-ray radiation.
Diamond, consisting of the light element carbon with an atomic number of 6, absorbs less X-rays than accompanying minerals containing heavier elements. X-rays that pass through a mineral grain are measured using special detectors. The atomic number of the element that the mineral contains is determined by the intensity of the radiation that passes through the mineral grain. Since diamond consists of the light element carbon, the intensity of the radiation that passes through it will be higher than the intensity of the radiation that passes through the grain of the accompanying mineral, with the same grain thickness.
X-rays penetrate the sorted material, are weakened in it and reach the X-ray camera with a system of sensors. The data transmitted by these sensors is analyzed in a high-speed X-ray processing module. Upon receipt of data on the presence of diamonds, they are quickly extracted from the flow using compressed air (pneumatic cutoff).
The results of the XRT separator operation show stable 100% extraction of all types of diamonds, with no failures in their registration and without interruptions in operation.
As noted by world experts, XRT technology allows for more accurate identification of diamonds and continued processing of materials with minimal capital expenditures. The XRT separation project is characterized by high economic efficiency and short payback periods.
Currently, the XRT separation technology is used with high efficiency in the diamond mining mines of Lucapa Diamond Corp (Karove, Lulo, Mothae mines) and De Beers (Jwaneng mine) in southern Africa, as well as in the mines of Lucapa Diamond Company Ltd and Merlin Diamonds Limited in Australia.
The use of XRT separation is most effective in the enrichment of a large class of material, including the extraction of weakly luminescent and non-luminescent type II diamonds, which have a higher value.