氢氧化物表面沉淀在石英浮选中的作用

THE INVESTIGATION OF ROLE OF SURFACE PRECIPITATION OF META HYDROXIDE IN FLOTATION OF QUARTZ

采用ζ-电位测定、吸附量测定、浮选实验及溶液化学计算,研究了金属离子在石英表面的吸附行为及其对石英表面ζ-电位和浮选行为的影响。结果表明,表面金属氢氧化物沉淀是金属离子在石英表面吸附的活性组分。表面沉淀生成后,石英表面ζ-电位变正,变正的pH值CR2对应于表面沉淀生成的pH值(pH_s),随着pH值的增加,ζ-电位再次变负的pH值CR3对应于氢氧化物固体的PZC_e。用阴离子捕收剂浮选时,CR2≤pH≤CR3是金属离子起活化作用的有效pH范围。用阳离子捕收剂浮选时,则是起抑制作用的有效范围。

In this paper,the adsorption of metallic ion at quartz and its effects on the surface zeta potential and flotation behavior of quartz have been investigated through flotation tests,measurement of zeta potential and adsorption and solution chemistry calculation.It has been shown that surface hydroxide precipitation is the active species of adsorption of metallic ion at quartz surface.The negative zeta potential of quartz surface is changed into positive with the formation of surface precipitation.The pH value(CR 2)of charge reversal is correspondent to pH value(pH(?))of surface precipitation of metal hydroxide.The zeta potential is again changed into negative with the going up of pH value which is usually attributed to the PZC of metal hydroxide.The pH region of pH_(?)<pH<PZC_e or CR2<pH<CR3,is the effective range of metallic ion activating the anionic collector flotation of quartz,which is also the range of metallic ion depressing the cationic collector flotation of quartz.