烷基胺对盐类矿物捕收性能的溶液化学研究

SOLUTION CHEMISTRY STUDY OF ALKYL AMINE COLLECTING SALT-TYPE MINERALS

根据溶液化学计算,确定了不同碳链长度的烷基胺形成沉淀的临界pH值及其与无机阴离子生成胺盐的顺序为WO_4^(2-)>SO_4^(2-)～PO_4^(3-)〉〉F^-～CO_3^(2-)。浮选实验结果表明,阳离子捕收剂浮选盐类矿物的临界pH值上限对应于生成胺沉淀的临界pH值。烷基胺浮选盐类矿物的捕收能力大小顺序为白钨矿>重晶石～磷灰石>萤石～方解石,与胺和相应矿物阴离子生成胺盐的顺序一致。动电位测定表明,烷基胺使带负电的盐类矿物表面ξ-电位变正,使带正电的萤石表面ξ-电位增加。因而,烷基胺浮选盐类矿物的作用机理主要归因于胺与矿物阴离子生成胺盐。无机阴离子对盐类矿物的胺浮选起活化作用。

Based on solution chemistry calculation, the critical precipitation pH valueof alkyl amine as a function of concentration and chain length in solution hasbeen obtained and the order of forming amine salt of alkyl amine with inorganicanions has been determined to be WO_4^(2-)>SO_4^(2-)>PO_4^(3-)>F^-～CO_3^(2-). Flotation testsreveal that the upper limit of pH value of cationic collector flotation of salt-type mineral is corresponding to that of precipitation of amine salt. The orderof collecting ability of alkyl amine for salt-type minerals is scheelite>barite>apatite>fluorite～calcite, which is agreeable with that of forming amine-mineralanion salt. The test results of zeta potential manifest that the negative zeta pote-ntial of scheelite, barite, apatite and calcite is evidently changed into positive andthe positive zeta potential of fluorite surface is also increased in solution of alkylamine. Hence, the role mechanism of alkyl amine flotation of salt-type mineralmay be attributed to the formation of amine salt. The inorganic anion will activatethe amine flotation of salt-type mineral.