疏水体系中微细粒锡石的团聚与絮凝

The aggregation and flocculation of ultrafine cassiterite in hydrophobic system

研究了粒径小于 10 μm的微细粒锡石在油酸钠疏水体系中的团聚行为 ,通过沉降试验考察了大分子絮凝剂聚丙烯酰胺对锡石絮凝的影响 .此外 ,通过动电位测定和DLVO理论计算研究了油酸钠对锡石疏水絮凝的影响 .研究结果表明 :油酸钠可以强化锡石的絮凝 ,絮凝物产率提高 ;添加了一定油酸钠的锡石矿浆疏水体系 ,油酸钠使锡石的表面zeta电位变负 ,当pH =7.0时 ,zeta电位降低 10mV ;当颗粒间的作用距离为 (10～ 10 0 )× 10 -10 m时 ,利用扩展的DLVD理论计算得到的微细粒锡石颗粒之间的作用势能恒为负 ;对于表面疏水化的锡石颗粒 ,疏水絮凝可自发进行 ;由于在锡石—油酸钠—水体系中 ,锡石微小絮团已生成 ,加入适量的相对分子质量较大的絮凝剂聚丙烯酰胺后 ,絮团扩大 ,有利于锡石的疏水絮凝 .

The phenomena of adsorption of sodium oleate on surface of -10 μm cassiterite was studied, and the reliability was discussed using zeta potential measurement and extended DLVO theory. The results show that the aggregation of cassiterite can be improved by sodium oleate in the absence or presence of polyacrylonitrilamide and the recovery of aggregate increases about 5%. The zeta potential of cassiterite becomes negative because of adsorption of sodium oleate on its surface, and the potential decreases by an average of 5% at pH 7.0. The main factor to determine whether the mineral particles can flocculate is the hydration hydrophobic interaction between mineral fines. The potential of polar hydration hydrophobic interaction of -10 μm cassiterite is negative. When the distance of interaction between ultrafine cassiterite particles is from 10×10 -10 m to 100×10 -10 m, the aggregation of cassiterite particles is spontaneous.