(中南大学 矿物工程系， 长沙 410083)
摘 要: 开发合成了一种新型廉价螯合捕收剂COBA，研究了它对一水硬铝石和高岭石的捕收活性、结构-性能关系及作用机理。结果表明：COBA对一水硬铝石的捕收能力强，而对高岭石的捕收能力弱，具有比水杨羟肟酸更好的选择性。其性能差异主要是由极性基结构差异即电负性、拓扑连接指数、断面尺寸和疏水性所引起的。COBA对一水硬铝石的捕收机理为：其分子中的3个O原子通过化学成键与矿物表面Al原子形成了两环螯合物。
关键字: COBA； 捕收剂； 一水硬铝石； 高岭石; 结构-性能关系
carboxyl hydroxidoxime in bauxite flotation
（Department of Mineral Engineering, Central South University,
Changsha 410083, P.R.China）
Abstract:Carboxyl hydroxidoxime (COBA), a new cheap chelating collector, was synthesized and characterized. Its collecting effect on oxide minerals such as diaspore and kaolinite, structure—activity relationship were studied, and collecting mechanism was also investigated. Carboxyl anhydride, hydroxylamine and sodium hydroxide were mixed in mixture solvent of methanol and water, stirred at 40～45 ℃ for 6～8 h, and separated by distillation, acidification and recrystallation to obtain COBA in 86.2% yield with purity of 97.8%. The flotation tests show that the collecting ability of COBA is strong for diaspore than for kaolinite, and it possesses higher selectivity of collecting on comparison with o-hydroxyl benzohydroxidoxime (HOBA) as a collector. The reason of which is that COBA has higher group electronegativity, larger topological connectivity index, larger polar group diameter and stronger hydrophobility comparing to HOBA. Furthermore, some evidence indicates that double ring chelating compound is formed by chemical adsorption between the three oxygen atoms in COBA and the aluminium atom on the surface of diaspore. Thus, COBA may become a new type of selective collector for obverse flotation to remove Al-Si minerals from bauxite.
Key words: carboxy benzohydroxidoxime; collector; diaspore; kaolinite; structure and activity relationship
