金属离子对煤泥浮选细泥罩盖的影响研究

Influence of metal ions on fine slime cover in coal flotation

为了研究不同金属离子对煤泥浮选中细泥罩盖的影响,利用浮选试验和Zeta电位分析等手段考察了不同金属离子对浮选的作用,研究结果表明:钠、钙、镁、铝离子都会不同程度地影响细泥存在下的浮选指标,低浓度的钙、镁、铝离子便可以使细泥罩盖更易发生,而且金属阳离子的价数越高影响越显著。提高捕收剂用量可以减少细泥罩盖对浮选精煤产率的影响,但是会增大浮选精煤灰分。钠离子对细泥罩盖的影响最微弱,但是高浓度的钠离子浓度会通过影响气泡大小及矿浆黏度的方式影响浮选指标,具体表现为钠离子浓度越高气泡越小,矿浆黏度越大。金属阳离子可以通过压缩矿物颗粒表面双电层的方式改变矿物Zeta电位,矿物Zeta电位负值随着金属阳离子浓度的增大而降低,高浓度的铝离子还会使矿物颗粒Zeta电位由负值变为正值。

In order to study the influence of different metal ions on the cover of fine slimes in flotation,the effects of calcium,aluminum and sodium ions on flotation are analyzed through flotation test and Zeta potential analysis.The research results show that sodium,calcium and aluminum ions will affect the indicators of flotation test in the presence of fine slimes to varying degrees,low concentration of calcium and aluminum ions facilitates the cover of fine slimes,the higher the valence number of metal cations,the more significant the effect.The influence of fine clime cover on the yield of flotation cleaned coal is weakened by adding more collector,but the ash content of clean coal rises as well.The influence of sodium ion on the fine slime cover is the weakest,while high concentration of sodium ion influence the flotation index by affecting the bubble size and pulp viscosity.Specifically,the higher the sodium ion concentration,the smaller the bubble,and the greater the pulp viscosity.Metal cations can change the Zeta potential of minerals by compressing the double electric layer on the surface of mineral particles.The negative value of the Zeta potential of minerals decreases with the increase of the concentration of metal cations.High concentration of aluminum ions can also change the Zeta potential of mineral particles from negative to positive.