The Husab Project is dominated by a series of north-northeast to northeast trending regionalscale antiforms and synforms, which make up the main structural architecture of the entire Central Zone of the Damara. These meta-sedimentary folds or dome-like structures of the DOB are cored by gneissic and metasedimentary rocks of the Abbabis Formation.

The Husab Uranium Project uranium mineralisation is associated with intrusive alaskite rocks and is informally referred to as a Rössing Type uranium occurrence.

At the Husab Uranium Project, mineralised alaskite occur proximal to the contact between the Khan Formation and calc-silicates of the Rössing Formation. The majority of the uraniferous alaskites are located within the Rössing Formation. The host Rössing Formation can vary from 50m to over 200m wide and mineralised intercepts can vary from a few metres to over 100m wide.

The average width of mineralised horizons is approximately 20m. The mineralisation at Zones 1 to 4 is a near-continuous mineralised area extending across approximately 8km strike length and up to 2km across strike. Individual mineralised units can be traced for several hundred metres along strike and down dip. Metallurgical indicates that uraninite is the main uranium mineral. Elevated uranium grades (for example) associated with beta-Uranophane, an oxidation product of uraninite, have been identified in drillhole RDD002.

In addition to primary alaskite hosted uranium mineralisation, the tenement holding hosts occurrences of secondary uranium vanadate (carnotite), similar to that comprising mineralisation at the Langer Heinrich development project. The best examples of secondary uranium mineralisation are found at the Husab Uranium Project, north of the Husab fluorite mine. A single line of drilling completed on this target zone has intersected calcrete hosted uranium mineralisation in a flat lying paleochannel.

The Husab mine has five potential mineralized 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. Two open pits have now reached depths of close to 90m & 140m, respectively.

Both sites are open pit operations. The Company uses 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, Company has 26 tracks 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 Company 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, Company 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. The hole diameter varies 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) includes 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. The Company 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. 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.

The Company 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 parts per million (ppm) over the life of mine.

The ore is dumped by the mining team into a gyratory crusher (4000 tonnes per hour). The crushed material is then fed onto a course stockpile via an overland conveyor onto a covered coarse ore stockpile with a capacity of 190 000 tonnes. It is then reclaimed through reclaim feeders into a Semi-Autogenous Grinding (SAG) mill before transferring into a Ball mill. From the Ball Mill the undersize reports to six screens, which then separates the material into the correct size distribution for the leaching stage. The undersize reports to the leaching circuit, while the oversize is fed back to the ball mill. Up to that point, the aim is to reduce the size of the material which is small enough to liberate all the uranium, between 0.6mm and 0.8mm.

Husab mine has main facilities: the primary crusher, the milling circuit, the leaching unit, the solid water separation (CCD) and the ion and sulphate exchange, and then the final processing and recovery area.

The undersize report to the leaching circuit, while the oversize is fed back to the ball mill. Up to that point, the aim is to reduce the size of the material which is small enough to liberate all the uranium, between 0.6mm and 0.8mm. In the leach area there are 10 leach tanks in which the slurry is mechanically agitated with blades. In the tanks we add acid and other chemicals to the slurry to dissolve the uranium.

The slurry is passed on to the CCD (counter current decantation), which is the sequence in which the material is fed from the leaching tank versus settling, in other words a solid liquid separating process. The solids which now contain very little uranium, settle at the bottom and are then pumped out to the tailings dam. The solution is then pass ........