(中南大學(xué) 礦物工程系， 長(zhǎng)沙 410083)
摘 要: 開(kāi)發(fā)合成了一種新型廉價(jià)螯合捕收劑COBA，研究了它對(duì)一水硬鋁石和高嶺石的捕收活性、結(jié)構(gòu)-性能關(guān)系及作用機(jī)理。結(jié)果表明：COBA對(duì)一水硬鋁石的捕收能力強(qiáng)，而對(duì)高嶺石的捕收能力弱，具有比水楊羥肟酸更好的選擇性。其性能差異主要是由極性基結(jié)構(gòu)差異即電負(fù)性、拓?fù)溥B接指數(shù)、斷面尺寸和疏水性所引起的。COBA對(duì)一水硬鋁石的捕收機(jī)理為：其分子中的3個(gè)O原子通過(guò)化學(xué)成鍵與礦物表面Al原子形成了兩環(huán)螯合物。
關(guān)鍵字: COBA； 捕收劑； 一水硬鋁石； 高嶺石; 結(jié)構(gòu)-性能關(guān)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
