Botswana – Installation and training was performed by personnel from Bourevestnik’s offices in Germiston, South Africa, with the sorter being commissioned during the second week of 2018.01.19
Historic tailing material, which was first processed through the company’s dense media separation (DMS) plant, was used for the sample material.
During the setup, calibration and instruction period, the POLUS-M recovered its first diamond. The diamond was recovered in the plus 1 and minus 3 mm fraction.
“BK16 is known to be diamondiferous so diamond recovery is expected but the significance of this recovery from tailings and waste that have been sitting for almost 20 years clearly indicates what we have said before is that the rotary plant which was employed in the previous evaluation was inefficient in the recovery of diamonds and reported grades were most likely understated,” says Tsodilo Resources president and COO Dr. Mike de Wit.
Polus-M at a glance
The POLUS-M sorter is designed to treat dry diamond concentrate with grain size – 8 + 6, – 6 + 3 and – 3 + 1 mm in the field in order to carry out geological exploration of diamond deposits.
The POLUS-M sorter will treat the -8mm fraction at the company’s facilities while the plus 8 mm material is currently planned to be hand sorted at the Diamond Technology Park in Gaborone, Botswana although the company is exploring avenues to obtain the use of a larger BV machine to treat this fraction.
The sorter operation concept is based on the use of diamonds’ property of luminescence under X-ray impact and on the difference of those properties with diamonds and associate luminescent minerals.
The mode under reference term “luminescence and absorption: when the X-ray tube and photo detectors are located on both sides of the material flow is implemented. The effect of difference in X-ray absorption by diamonds and associate luminescent minerals is used.
DMS plant update
The refurbishing of the company’s DMS treatment plant is ongoing with adjustments being made to the DMS section with special attention been given to the cyclone and prep-screens. The tailings material continues to be used for this final calibration and once the plant is fully optimise the processing will switch over to the LDD samples.
“It is exciting to see everything coming together and although we still have a bit to go to fine tune the recovery process it is good to know that we are recovering diamonds and now we just need to get everything going at 100% efficiency,” says De Wit.
Moreover, the company has also resumed its evaluation activities on the BK16 kimberlite project in Botswana following the traditional extended holiday break in southern Africa.
Feature image credit: Tsodilo Resources