In a recent statement ASX-listed Kimberley Diamonds Ltd (KDL), which owns the Lerala diamond mine in Botswana, says it has become aware of some incorrect media articles in Botswana which have reported the closure of the mine. KDL operates Lerala through its Botswana subsidiary, Lerala Diamond Mines Limited (Lerala).
Mining of fresh kimberlite ore from the K3 pit earlier this year. In-pit mining at Lerala has now been temporarily suspended (photo: Kimberley Diamonds).
“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. 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,” says KDL.
“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. The plant remains in production and produces diamonds every day. 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.”
KDL adds that this is a cost saving measure and is not anticipated to impact on expected production levels.
The recommissioned diamond processing plant at the Lerala mine has been operating since Q4 2016. As announced on 1 September 2016, 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, have 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, KDL says several positive milestones have been achieved to date. These have included: the upgrade of the vibrating grizzly feeder to improve material flow from the headfeed bin; the recommissioning of the CDX X-ray recovery machine; and the upgrade of the coarse cyclone feed pump which processes DMS feed in the range +6 mm to 20 mm, which – says KDL – has had a marked impact on the efficiency and reliability of the DMS module.
“As reported previously, successful implementation of the ongoing performance improvement plan is dependent on certain assumptions, most importantly the raising of further funds for capital expenditure, spare parts and working capital,” notes KDL.