棒介质层数对高梯度磁选指标的影响

EFFECT OF MAGNETIC ELEMENT LAYERS IN ROD MATRIX ON PERFORMANCE OF HIGH GRADIENT MAGNETIC SEPARATLON

棒介质作为高梯度磁选的一种分选介质,广泛应用于氧化铁矿、钛铁矿、黑钨矿等弱磁性金属矿的选矿和高岭土、石英、长石等非金属矿的除铁提纯。棒介质作为分选过程的载体,其结构构造(如排列、丝径、丝距、层数等)对棒介质堆内部的磁场特性和磁性矿粒动力学具有决定性影响,从而显著地影响高梯度磁选的效能。运用"单元介质"分析法,进行棒介质脉动高梯度磁选微细粒赤铁矿试验,分别研究2 mm和3 mm棒介质的介质丝层数对高梯度磁选指标的影响。试验结果表明,对每种层数的棒介质,随着磁感应强度上升,介质丝对磁性矿物的捕获能力增强,精矿产率和铁回收率增大,而精矿和尾矿品位下降,分选效率规律不明显;随棒介质层数的增加,高梯度磁选指标则明显提高。

High gradient magnetic separation is widely applied for the concentration of fine weakly magnetic metallic ores such as oxidized iron ore,ilmenite,wolframite,etc.,and for the purification of non-magnetic ores such as kaolin,quartz and feldspar.Rod matrix,as carrier for magnetic particles in high gradient magnetic separation,its configuration such as arrangement of rod elements,space between rod elements,distance between layers of rod elements and the number of layers in the matrix has a dominant control on the distribution of magnetic field and on the dynamic of magnetic particles in the matrix,thereby producing a significant effect on the separation performance.Pulsating high gradient magnetic separation of ultrafine hematite was investigated to study the effect of layers of rod elements on the performance through Slice-Matrix Analysis （SMA） method.The results indicate that for a given number of layers of matirx element,with the increase in magnetic induction,the capture capability of the matrix for magnetic particles enhances,the concentrate mass and the iron recovery increase,and the concentrate grade decreases,without obvious change in separation efficiency.However,the separation performance is significantly improved with increase in the number of layers.