Kareevlei processing plant
JOHANNESBURG (miningweekly.com) – Aim-listed BlueRock Diamonds on Wednesday announced that it expected to start processing weathered kimberlite material from its Kareevlei tenement, in the Northern Cape, this month.
The company said it had excavated about 70 000 t of the tenement’s calcrete overburden to a depth of between 8 m and 10 m from the north-west side of the Kareevlei K1 and K2 pipes, with weathered kimberlite having been encountered at lower levels albeit diluted with calcretised kimberlite as was expected.
Drilling and blasting of the floor of the openpit from about 8 m to 20 m from surface had now been completed, BlueRock stated.
The company added that initial processing was completed on about 750 t of the diluted kimberlite mixture. The material was processed using a dense media-separation (DMS) plant and was sorted.
BlueRock said the first diamonds from the project had been recovered through this process, although the volume processed was too small to be statistically significant.
Meanwhile, following the refurbishment and commissioning of the DMS processing plant, which started in December last year, further work was required to improve the crushing circuits to increase the front-end plant capacity.
This work was completed in January and since then the plant had been able to operate for a sustained period above the expected 25 t/h rate.
“Accordingly, it remains the board’s expectation that the operational capacity of 12 000 t/min is achievable using the existing plant during the trial mining phase, [while] the final recovery plant has also been recommissioned successfully,” BlueRock said.