New off-shore diamond miner

Augetto Graig - LK Mining has applied for Mining Licence ML220 to mine diamonds from the seabed at Hottentots Bay, about 60 km north of Lüderitz.It is waiting for an environmental clearance certificate from the ministry to environment, forestry and tourism after submission of an environmental impact assessment and its environmental management plan. Under the experienced leadership of Carel Neethling, LK Mining intends to operate a purpose-built vessel for mining at a depth range of 10 m to 30 m, in a new niche depth zone, according to a scoping report released in July.LK Mining conducted exploration activities between 2016 to 2019 and delineated a viable diamond resource that could be mined. The mining licence applied for extends from the shore to 2 km offshore, and about 45 m depth, and stretches along the coast over a distance of 6 km. ML220 covers an area of 42.3 km².The area falls within the Namibian Island Marine Protected Area. Of particular significance is Neglectus Islet and the disused jetty at Hottentots Bay. These provide important breeding sites for African penguins, as well as Bank, Cape, Crowned and White-breasted cormorants, and are given special protection under NIMPA. The proposed mining area overlaps with the recommended, but not proclaimed, conservation zone proposed to offer biodiversity protection to Neglectus Islet and the disused Hottentots Bay jetty.Two rock lobster sanctuaries exist in the vicinity of the project area: the Ichaboe lobster sanctuary and the Lüderitz Bay sanctuary. According to the mining hopefuls, the lobster industry does not operate in exactly the same seabed area and the two industries will be able to each remain viable. The mining activities could also cause disturbance and loss of benthic marine fauna, impact on the photosynthetic capability of phytoplankton, the feeding success of pelagic predators as well as egg and larval development.LK Mining plans to buy a supply vessel and to convert it into a remote mining vessel. The mining vessel would use a suitable shallow and mid-water gravel pump system for operating in the 14 m to 40 m water depth range. The mining system would comprise of a suspended steel mining tool fitted with a digging mining head, suction hoses and an on-board mining pump. The opening of the mining tool would be fitted with grizzly cross-bars to allow sized gravel to pass through and prevent blockages in the suction system. Fixed-head remote exploration/mining systems, operating in the shallow and mid-water depth range, can efficiently extract gravel in areas of thicker overburden. Mining would involve the removal of only the unconsolidated surficial sediments.The dredged sediment-slurry would be pumped to the surface and discharged onto a series of screens. The tailings, which typically comprise about 99% of the dredged material, will be discharged below the surface to the sea. The fine material forms turbid plumes that are carried away from the vessel by ambient currents, while the coarse material falls directly to the sea floor below the vessel. During the extraction process the operator generally attempts to deposit the coarse tailings in previously excavated areas to prevent re-mining of already processed material.After screening, plant feed is fed through a crusher to fragment the shell and clay components, mixed with ferrosilicon and pumped under pressure to an on-board Dense Media Separation (DMS) plant. Low density materials, known as float, are separated from the concentrated plant feed and discarded overboard following magnetic recovery of the ferrosilicon. The remaining high-density material is dried and passed through an X-ray sorting process to separate the diamonds from the residual gravels. Non-fluorescent gravel material is discarded overboard with the float material, and the fluorescent fraction containing the diamonds is then hand sorted. Mining would commence over Mining Area 1, which at 228 ha covers 5.4% of the total licence area. The current mine plan is for seven years, and through additional resource development over Target Areas 2, 3 and 4 the mine plan could be extended another 3 years, at least. It is proposed to take a total of 35 point samples over a 100 m sampling grid in each target area. Each sample will disturb an area of ~ 20 m2 , with a total area of 2 100 m2 being disturbed. The point sampling will be followed by a bulk sampling phase during which a total of 12 block samples (50 x 50 m) will be taken over another total area of 30 000 m2 . In total, sampling and resource development will thus be conducted over a total area of 32 100 m2 , which equates to less than 0.07% of the total licence area.Sampling and mining operations would be conducted to depths of between 14 m and 24 m from the fully self-contained mining vessel with its on-board processing plant. The vessel would operate a semi-mobile mining platform, anchored by a static positioning system, commonly on a four-anchor spread. Positioning winches will enable the vessel to be located precisely over the mining block where it would ‘crab’ across the target area removing overburden and ore down to bedrock. The mining vessel would thus have limited manoeuvrability and other vessels should remain at a safe distance.The majority of crew members will be Namibian, but some of the specialists on board might need to be sourced from outside Namibia. The aim is to employ as many Namibians as possible. The crew will consist of 14 people, rotating seven on duty for 12-hour shifts each on 28-day cycles with the other crew. After 28 days, the shift will be changed in Lüderitz. It is anticipated that the vessel will operate for 11 months per year. LK Mining will also have an office in Lüderitz, according to the report.augetto@republikein.com.na

New off-shore diamond miner

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Namibian Sun 2024-11-19

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New off-shore diamond miner

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Namibian Sun 2024-11-19

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