Processing
-
We have five 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 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 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.
We have five 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 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 coverered 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 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 passed on for clarification where impurities are eliminated. From there it is fed to the ion exchange. The chemical reaction that takes place during this stage, results in the uranium that is in solution, being attracted onto resin, and then, through a series of chemical reactions that solution is concentrated. This solution is then passed on to the final product area where it is precipitated into uranium and then packaged as a final product through a fully automated packaging process. Because of the high radiation the packaging is done in a fully enclosed environment where the product is drummed and sealed in containers, which is taken directly, by road, to the Port of Walvis Bay.