二元组合捕收剂浮选分离一水硬铝石与高岭石的机理研究

Study on the Mechanism of Flotation Separation of Diaspore from Kaolinite by the Binary Mixed Collector

以油酸钠为主要捕收剂,与苯甲羟肟酸组合使用,复配出二元组合捕收剂,再通过单矿物浮选试验考察二元组合捕收剂对一水硬铝石和高岭石两种铝硅矿物的捕收性能。通过表面张力测定和激光粒度测试,系统研究了二元组合捕收剂的浮选作用机理,旨在为我国铝土矿浮选脱硅捕收剂的开发提供理论指导。结果发现,二元组合捕收剂NaOL/BHA对一水硬铝石和高岭石伴生的铝硅酸盐矿物的浮选效果明显超过单一油酸钠捕收剂,研究的二元组合捕收剂中油酸钠与苯甲羟肟酸的最佳摩尔配比为9∶1。二元组合捕收剂溶液的表面张力随着BHA浓度的增加而下降,在较低浓度下表面张力明显下降到拐点达到稳定值,该现象表明组合捕收剂活性高,捕收性能强,拐点处对应的两种药剂摩尔配比与单矿物浮选实验得出的最佳组合摩尔比一致。二元组合捕收剂可以明显促进一水硬铝石颗粒表观粒度增大,使其形成疏水性聚团,致使浮选回收率增大,而对高岭石表观粒度几乎没有影响。

In this paper,sodium oleate is used as the main collector and combined with benzohydroxamic acid,and then the binary mixed collector is prepared.The flotation performance for diaspore and kaolinite by the binary mixed collector is tested through the single minerals flotation tests.The flotation mechanism of binary mixed collector is systematically studied through surface tension measurements and laser particle size tests,in order to provide the theoretical guidance for the development of desiliconization collector in bauxite flotation.The results showed that the NaOL/BHA was more selective in the flotation separation of diaspore from kaolinite,than the single sodium oleate collector.The surface tension of the binary mixed collector solution decreases with the increase of BHA concentration,and the inflexion can reach a stable value at a lower concentration,which indicates that the mixed collector has great activity and strong collecting ability,and the concentration ratio of the compound at the inflexion is consistent with the optimum combination molar ratio obtained by the single mineral flotation tests.The binary mixed collector can obviously promote the increase of the apparent grain size of diaspore and form hydrophobic aggregates,which leads to the increase of the diaspore flotation recovery,but has little effect on the apparent grain size of kaolinite.