混匀矿堆料与取料过程物性特征变化研究

Research on the change of physical properties of blended ore during stacking and reclaiming

从优化混匀矿粒度偏析的角度出发,对堆存量为20万t的混匀矿料堆堆取料过程中的物料动安息角、粒度组成、料堆长大过程等物性特征变化进行研究。结果表明:随着堆存高度的增加,两侧动安息角整体呈下降趋势,从前期的37.1°逐渐下降至末期的32.3°,同时在下降过程中表现出有规律的上下波动状态;混匀矿堆料过程中,料堆下部混匀矿的平均粒径均明显高于上部,随着料堆高度的增加,上层取样点混匀矿平均粒径呈下降趋势,下层取样点平均粒径变化无明显规律;料堆两端部分的混匀矿与中间主体部分存在较大偏析,因此在实际取料时需对端部的偏析料进行处理,如返回预配料仓;根据断面分区测试结果,无论是在水平方向还是在垂直方向,混匀矿各粒级颗粒的占比均具有非常高的一致性,偏差保持在5%以内。

From the perspective of optimizing the particle size segregation of blended ore,the material dynamic repose angle,particle size composition,stock heap growth and other physical characteristics in the process of ore stock heap stacking and reclaiming of blended ore with a scale of 200 000 tons are studied.The results show that with the increment of heap accumulation,both sides of the dynamic repose angles decline from 37.1° to 32.3° gradually.At the same time,both sides of the dynamic repose angles show regular fluctuating state in the process of falling.During the stacking process of the blended ore,the average particle size of the blended ore at the lower part of the ore stack is significantly higher than that at the upper part.The average particle size of the blended ore at the upper part decreases with the increase of the accumulation,while the average particle size at the lower part shows no regular variation.There is a large segregation between the blended ore at the head of the stack and the main body.Therefore,the segregation stock at the end should be treated as actually stacking,such as returning to the pre-proportioning bin.According to the test results of the section division,the percentage content of each grade of the blended ore has a very high consistency,both in the horizontal and vertical direction,and the deviation is kept within 5%.