粗粒辉钼矿水力浮选预抛尾试验研究

Study on Pre-discarding Tailings Test for Coarse Molybdenite by Hydrofloat

传统泡沫浮选粒度上限低,仅为150μm左右,常规全粒级磨矿—浮选工艺能耗高、分选效率低。针对此问题,开发了粗颗粒水力浮选预抛尾技术,大幅提高分选粒度上限至1.0 mm,有助于降低后续磨浮成本,提高分选效率。以河南栾川地区的辉钼矿(-1.0 mm)为研究对象,重点考察表观水速、表观气速、床层高度、进料高度、进料速度等工艺参数对粗粒辉钼矿分选效率的影响。结果表明:表观水速、表观气速及床层高度对水力浮选影响较大,而进料速度、进料高度对水力浮选影响相对较小。最适宜水力浮选条件下尾矿Mo品位低至0.006%,低于选厂浮选尾矿品位,抛尾率高达41.78%,表明粗粒辉钼矿水力浮选预抛尾效果良好。通过分析各条件下水力浮选精、尾矿粒度分布,发现精矿平均粒径小于尾矿平均粒径,分级现象明显,结合表面暴露率结果分析,表明粗粒钼矿水力浮选指标为粒度分级与界面分选共同作用结果。

The upper limit of traditional froth flotation particle size is low about 150 μm,and the conventional full-grain grinding and flotation process has high energy consumption and low sorting efficiency. In the view of this problem,the technology of pre-discarding tailings by the hydrofloat of coarse particles was developed. It not only greatly improves the upper limit of sorting particle size to 1. 0 mm,but also reduces the subsequent grinding and flotation cost and improves the sorting efficiency.Taking molybdenite(-1. 0 mm) of a molybdenum mining company in Henan as a case,the effects of key parameters such as superficial water velocity,superficial gas velocity,bed-level height,feed height and feed speed on the sorting efficiency of coarse molybdenum were studied. It showed that superficial water velocity,superficial gas velocity and bed-level height had a great influence on the hydrofloat,while feed speed and feed height showed relatively less impact. The tailings grade of molybdenite was as low as 0. 006%,which was lower than the tailings grade of the concentrator at optimal conditions. The rejecting rate was 41. 78%. It showed the fluidized bed flotation separator to pre-discard tails vastly performed. Through analyzing the particle size distribution of concentrate and tailings by the hydrofloat,it was found the average particle size of concentrate was smaller than tailings. Combined with the analysis of surface exposure results,it was shown that the separation of coarse-grained molybdenum was resulted from both the size classification and interface separation.