入料特性对干法磁选净化加重质中煤粉的影响

Influence of feed characteristics on dry magnetic separator used for purifying fine coal from heavy medium

干法磁选净化加重质中煤粉对维持流态化连续分选的床层密度稳定及控制介质损失有着重要影响,而给料物性直接影响影响干法磁净化煤粉的效果。为此本文在实验室着重考察了煤粉粒度、煤粉含量、加重质水分与磁铁矿粉粒度等主要物性因素对干法磁选净化煤粉效果的影响规律,结果表明:(1)当磁铁矿粉中煤粉含量在4%至20%之间变化时,煤粉净化率、磁铁矿粉回收率和磁选效率随煤粉含量增大而逐渐变小;(2)磁铁矿粉回收率随磁铁矿粉中水分逐渐变大而变小,磁选效率和煤粉净化率随磁铁矿粉中水分逐渐变大呈现先变大而后变小的趋势;(3)当磁铁矿粉粒度和煤粉粒度逐渐变大时,煤粉净化率、磁铁矿粉回收率和磁选效率均呈现先变大而后基本不变的趋势。

Purifying the fine coal from magnetite powder by dry magnetic separation has an important influence on the density stability and magnetite powder loss in continuous fluidization separation.However,feed characteristics has a direct effect on dry magnetic separation.Therefore,the influence laws of coal particle size,fine coal content,magnetite powder water content and magnetite powder particle size in dry magnetic separation were examined in the laboratory.The results show that：（1）the recovery yield of magnetite powder,fine coal purifying efficiency and magnetic separation efficiency gradually decrease with the content of fine coal increasing from 4%to 20%;（2）with the increase of magnetite powder moisture,the recovery yield of magnetite powder gradually decreases;（3）the purifying efficiency of fine coal,magnetic separation efficiency firstly increase and then decrease with the increment of magnetite powder moisture.The recovery yield of magnetite powder,the purifying efficiency of fine coal,magnetic separation efficiency rapidly increase and basically stabilize with the increasing size fraction of particle size of fine coal or magnetite powder.