疏水体系中微细粒锡石的团聚与絮凝

来源期刊：中南大学学报(自然科学版)2001年第3期

论文作者：吴伯增 王淀佐 邱冠周 覃文庆

文章页码：239 - 242

关键词：锡石;疏水絮凝; DLVO理论

Key words：cassiterite; polyacrylonitrilamide aggregation flocculation; DLVO theory

摘    要：研究了粒径小于10μm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10 mV;当颗粒间的作用距离为(10~100)×10^-10m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.

Abstract: The phenomena of adsorption of sodiumoleate on surface of -10μmcassiteritewas 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 sodiumoleate in the absence or presence of polyacrylonitrilamide and the recoveryof aggregate increases about 5%. The zeta potential of cassiterite becomes negative because of adsorption of sodiumoleate 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 hydrationhydrophobic interaction of -10μm cassiterite is negative. When the distance of interaction between ultrafine cassiterite particles is from 10×10^-10m to 100×10^-10m, the aggregation of cassiterite particles is spontaneous.