Improving Overall Concentrator Performance with Stirred Milling

Energy consumption and mineral recovery are among the most important factors affecting the mineral processing economy. There are a number of emerging new technologies which have proven to be more energy efficient for comminution, such as High Pressure Grinding Rolls (HPGR) and stirred milling technology.

The possible merging of the more efficient milling technology with the efficient flotation processing options unlocks opportunities for the design and application of grinding circuits with lower energy usage for low to middle tonnage processing plants. In this paper, a new type of grinding circuit which incorporates a stirred milling grinding stage in conjunction with flash flotation cells is proposed. Preliminary work indicates that higher metal recovery could be obtained from the cyclone underflow stream in the stirred milling stage compared to a standard “flash flotation” application. This increase, plus the reduction in energy consumption associated with efficient milling using Vertimill® technology, has the potential to justify the higher capital investment associated with the new circuit.