草酸诱导大水沟碲矿溶解机制

Mechanism of Oxalic Acid Induced Dissolution of Dashuigou Tellurium Deposit

随着社会的发展对碲需求量日益增加,低品位大水沟碲矿的开发利用受到了日益关注。利用草酸在常压下对大水沟碲矿进行溶解研究。结果表明,在草酸浓度0.25 mol L、液固比15∶1、反应时间15 d的条件下,草酸对Fe、Mg、Ca、Al和Si的溶解量分别为662、187、610、686、64 mg L,而Te富集到滤渣中。各矿相溶解的先后顺序为:白云石>磁黄铁矿>碲铋矿。结合计算模拟草酸与白云石、磁黄铁矿和碲铋矿之间的结合方式和电子转移机制,表明草酸通过其氢原子的酸解作用和氧原子的络合作用吸附于矿物表面,并且其电子从草酸向白云石表面转移,而磁黄铁矿和碲铋矿则相反。

With the development of society,the demand for tellurium is increasing,and the exploitation and utilization of low-grade Dashuigou tellurite deposit has attracted more and more attention.Oxalic acid was used to dissolve Dashuigou tellurium deposit under atmospheric pressure.The results show that the dissolution amounts of Fe,Mg,Ca,Al and Si is 662,187,610,686 and 64 mg L,respectively under the conditions of oxalic acid concentration of 0.25 mol L,liquid-solid ratio of 15∶1 and reaction time of 15 d.Te is enriched in filter slag.The sequence of dissolution of mineral phases is dolomite,pyrrhotite and tetradymite.The binding mode and electron transfer mechanism between oxalic acid and dolomite,pyrrhotite and tetradymite were calculated and simulated.The results show that oxalic acid is adsorbed on the surface of mineral through the acid hydrolysis of hydrogen atom and the complexation of oxygen atom,and the electron transfer from oxalic acid to the surface of dolomite,while the opposite is true for pyrrhotite and tetradymite.