Kimberley Diamonds Ltd (KDL) said in-pit mining has been halted at Lerala mine as it looks to process the existing stock piles while at the same time saving costs. There have been media reports that the mine had closed, but the company moved in to clarify that Basil Read, the contracted mining company, has been advised to suspend pit operations at one kimberlite pipe.
“Mining operations at the Lerala Diamond Mine, which are conducted by external contractor, Basil Read, have continued to date at rates exceeding the plant’s current ability to process feed, which has resulted in the development of a large ore stockpile,” KDL said in a market update.
“As a result, Lerala has asked Basil Read to temporarily suspend their pit mining operations in the K3 kimberlite pipe to allow Lerala to process and reduce these stockpiles to reasonable levels,” it added.
Basil Read has now temporarily ceased all in-pit operations until further notice, however their operations to provide feed from stockpiles to the ROM and into the plant, continue.
KDL said the plant remains in production and produces diamonds every day, adding: “At this stage, Lerala expects the suspension of in-pit operations to continue for approximately 3-4 months or until stockpiles are reduced and mining is required to re-commence.”
“This is a cost saving measure while Lerala implements the performance improvement plan, and is not anticipated to impact on our expected production levels.”
The Lerala Diamond Mines Limited has been operating the recommissioned diamond processing plant at the Lerala Diamond Mine, since Quarter 4, 2016. However, Lerala has identified some shortcomings in certain pre-existing elements of the plant, which combined with the highly abrasive character of the internal waste within the kimberlite ore, has significantly impacted the plant’s ability to operate at maximum capacity on a consistent basis.
In response to this, Lerala has developed a performance improvement plant which looks to address the issues at the plant and is in the process of implementing this plan.
Although this improvement plan has only recently commenced, the following positive milestones have been achieved to date: the Vibrating Grizzly Feeder was substantially upgraded to improve material flow from the headfeed bin; the CDX X-ray recovery machine was recommissioned and recovery tailings retreatment commenced while the coarse cyclone feed pump which processes DMS feed in the range +6mm to – 20mm was upgraded from a “6/4” pump to the substantially larger “8/6” pump which has had a marked impact on the efficiency and reliability of the DMS module.
It is planned to similarly upgrade the fines cyclone feed pump, processing the +1 to – 6mm material, in the next few weeks Also the screening solution after the secondary scrubber which screens off and recycles oversized material to the existing tertiary crusher thereby further improving the reliability of the DMS module, was installed and commissioned.