介质棒排布对细粒高梯度磁选指标的影响
Effect of ferromagnetic rods arrangement in high-gradient magnetic separator on the processing performance of weakly magnetic particles
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摘要: 本文对鞍山式贫赤铁矿石进行高梯度磁选试验,研究在介质棒间隙与直径相同的组合排布下介质棒直径对分选指标的影响。试验结果表明:当给矿粒度-0.074mm≤85%时,相对于小直径(2mm)介质排布下的分选指标,大直径(4mm)介质排布下的精矿品位和回收率均提高;当给矿粒度-0.074mm>85%后,高梯度磁选尾矿中存在金属量流失,这在大直径的介质排布下更为明显。高梯度磁场中弱磁性矿物颗粒的受力分析表明,对于-0.15+0.010mm的颗粒,重力和粘滞阻力的合力为捕收磁力的10-2数量级,但随着介质棒直径的增加,介质棒对细颗粒的捕收磁力减小,非磁性颗粒的机械夹杂减弱,分选指标得到提高。对-0.01mm的颗粒,重力和粘滞阻力的合力接近磁捕收力,介质棒的捕集效果变差。Abstract: Anshan style hematite ores was separated by a high-gradient magnetic separator,and the effect of rods arrangement,in which the rod gap and the rod diameter were same,on separation performance was investigated.The results showed that compared with separation performance using small rods arrangement(e.g.,2mm),concentrates grade and recovery improved using large rods arrangement(e.g., 4mm)at the feed fineness of-0.074mm<85%.The loss of metal content happened in tailings at the feed fineness of-0.074mm<85%,particularly using large rods.The forces of single mineral particles in the high-gradient magnetic field out of a single rod were investigated,and the magnetic force was two orders of magnitude higher than resultant of gravity and viscous resistance for-0.15+0.010mm size fraction particles.As rod diameter increased,magnetic capturing force on fine particles decreased and mechanical entraining of non-magnetic particles weakened.As a result,the separation performance improved.Resultant of gravity and viscous resistance are approximately equal to magnetic force for-0.010size fraction particles,and capture with rods on fine particles weakened.
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