Mining
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The Husab mine has five potential mineralised zones on the property, of which we are currently exploiting two zones – Zone 1 and Zone 2. Both are mined through two open pit operations very close to each other.
In this area there are six different formations: the Kalahari forms the overburden, below the Kalahari is the Khan and then Chuos, followed by the Rossing, Karibib and the intrusive layers, which occurs a lot deeper. The ore is concentrated around the Rossing formation. The ore doesn’t seem to occur in any of the formations below the Rossing formation. Our two open pits have now reached depths of close to 90m & 140m, respectively.
Both sites are open pit operations. We use a conventional truck and shovel method to mine the ore body, with hydraulic and electric shovels. The mining fleet consists of: six shovels that include three CAT 6060’s Face Shovels and three CAT 7495 Electric Shovels. In total we have 26 trucks of which 23 are Komatsu 960 E’s, and three are NTE 330’s which are Chinese manufactured trucks. There are twelve drill rigs in the pit, and here we also have a combination of diesel and electric rigs – there are three CAT MD6640 electric drill rigs and four CAT MD6290 diesel driven drill rigs. In addition, we operate one CAT MD 6650 and four Atlas Copco Rock L8’s. The Rock L8’s are mostly for smaller diameter holes for pre-strip drilling. Our hole diameter vary between 127mm for the smaller pre-split holes to 331mm for waste drilling and the ore drilling diameters is 251mm. Extra axillary equipment (mostly Komatsu) include a total of six dozers (three Komatsu 475’s and three Komatsu 375’s), four wheel loaders, also Komatsu (WD600’s) plus three Komatsu 825 graders and four PC850’s for clean-up work and digging trenches. We also have additional support equipment to move the electric cables and infrastructure. The entire fleet is designed to move between 100 million and 120 million tonnes per year. Our production profile currently for this year is to move 100 million tonnes with a compliment of just under 490 people. Given the size of the equipment and the distances covered, our fleet is installed with a Modular Fleet management system which manages, monitors and controls and ensures efficiencies of our fleet.
We are currently targeting 10 million tonnes per year of ore in the short term, ramping up to 15 million tons of ore over the next three years. On average the life of mine feed to the processing plant is 15 million tons per annum (currently it is 10 million per year). The feed grade ranges between 500 and 600 part per million (ppm) over the life of mine.