十二胺盐酸盐在长石石英表面的吸附机理及pH值对吸附的影响

胺类捕收剂的吸附主要是静电作用,矿物表面的水解和药剂的解离都由介质pH值所决定。本文通过ξ-电位测定、吸附量测定、红外光谱分析等手段,研究了十二胺在长石、石英表面的吸附情况及pH值对吸附的影响。研究表明,分子离子二聚物的形成大大提高了药剂在矿物表面的吸附量。在可能的条件下,应使矿浆保持在分子离子二聚物浓度较高的pH范围内,改善捕收剂的捕收能力。对零电点相近的长石和石英来说,采用静电吸附的胺类捕收剂时,浮选没有选择性。

ADSORPTION MECHANISM OF DODECYL AMINE-HYDROCHLORIDE ON FELDSPAR AND QUARTZ AND EFFECT OF pH

The adsorption of amine collector is proceeded mainly by electrostatic effect. The basicity of flotation medium controls the hydrolysis of mineral surface and the dissolution of reagents. The adsorption behaviour of dodecyl amine on feldspar and quartz as well as the effect of pH value has been investigated through Zeta potential and adsorptive capacity measurement, IR spectral analysis. Results indicate that the adsorptive capacity of amine will increase greatly while molecular-ion bipolymer forms in pulp. If possible, pH of flotation pulp should be kept in the range suitable for bipolymer formation. In this case, the collecting ability of the reagent could be improved. The PZC values of quartz and feldspar are quite close, so that the flotation with amine based on electrostatic effect has no selectivity.