Study on ore dressing technology for a complex low-grade Cu-Sn-W ore of South China

"Besides valuable metals of Cu, Sn, WO3, Zn, there are S, Ag, CaF2, In and so on in a complex ore deposit in south China (which belongs to Hu Nan Shizhuyuan Non-ferrous Metal Limited Liability). Although it proved reserve amounts to 3.5×107 ton, its crystal character limits its utilization in large-scale. It features complex relationships between valuable minerals, finest crystallized particle size, low-graded valuable metals (Cu 0.30%, Zn 0.5-0.7%, Sn 0.2%, W<0.1%). If only tungsten minerals are considered, it means WO3 grade is too low (the cut-off grade of WO3 is 0.1% in China). Only Cu and Sn minerals are recovered from 2006 and Cu recovery is less than 70%, Sn 15-20%. Other valuable metals of W, Zn, S and CaF2 were lost in the tailings. To make good use of the ore, the technology of fully recovering Cu, Sn, W, Zn, CaF2 and rare metals are in urgent need. After systematic researches, the flow sheet of "bulk flotation of Cu-Zn minerals at first, then Cu-Zn separation, then recovering sulphide by flotation, then recovering iron minerals by magnetic separation, then bulk flotation of Sn-W minerals after desliming" is developed. Furthermore, specific Sn-W collectors of BK411 and BK412 are applied into the processes and better indexes are obtained. The industrial indexes are listed as followings: the content of Cu, Zn, Sn, WO3 of ROM ore is 0.31%, 0.65%, 0.13%, 0.03%; Cu and Zn recovery are 82.23% and 37.79% respectively; 63.76% of Sn and 34.34% of WO3 go into the Sn-W bulk concentrates. Economic benefits are remarkable."