木质素磺酸钠在锂辉石与脉石矿物低碱度浮选分离中的作用

Effect of sodium lignosulfonate in flotation separation of spodumene and gangue minerals with low alkalinity

在自然p H(pH为8~9)条件下,采用油酸/十二烷基三甲基氯化铵(即季铵)阴阳离子混合捕收剂,研究木质素磺酸钠对3种矿物(锂辉石、长石和石英)浮选及分离行为的影响,并借助接触角测试、吸附量测试、红外光谱分析及密度泛函理论(DFT)计算探讨药剂的作用机理。研究结果表明:木质素磺酸钠对3种矿物的抑制作用具有明显的选择性,是低碱度条件下锂辉石与脉石矿物浮选分离的有效抑制剂;木质素磺酸钠在石英、锂辉石和长石表面的吸附量依次减小;油酸/季铵与木质素磺酸钠在锂辉石、长石和石英表面存在竞争吸附,油酸/季铵在锂辉石表面的吸附强于木质素磺酸钠的吸附,在长石与石英表面的吸附则弱于木质素磺酸钠的吸附。因此,木质素磺酸钠作为一种高效的有机抑制剂,在锂辉石及其脉石矿物低碱度浮选中具有重要的作用。

The effects of sodium lignosulfonate on the floatation and separation behavior of spodumene,feldspar and quartz were studied using oleic acid/dodecyl trimethyl ammonium chloride(quaternary ammonium)as a cationic and anion collector at the natural pH of 8-9.The action mechanism of the agent was discussed by means of contact angle test,adsorption capacity test,infrared spectrum analysis and density functional theory(DFT)calculation.The results show that sodium lignosulfonate has obvious selectivity on the inhibition of three minerals,and it is an effective depressant for the flotation separation of spodumene and gangue minerals under low alkalinity conditions.The adsorption capacity of sodium lignosulfonate on the surface of quartz,spodumene and feldspar are reduced sequentially.There is competitive adsorption between oleic acid/quaternary ammonium and lignosulfonate on spodumene,feldspar and quartz.The adsorption of oleic acid/quaternary ammonium on spodumene is stronger than that on lignosulfonate,but weaker than that on feldspar and quartz surface.Therefore,as a highly efficient organic depressant,sodium lignosulfonate plays an important role in the low basicity flotation of spodumene and gangue minerals.