金精矿生物氧化过程中砷的氧化行为初探

Preliminary discussion on the arsenic oxidization behavior in gold concentrate biologic oxidization process

用金精矿和砷精矿配出含砷量分别为2.46%、8.23%、14.00%的3个试样,分别进行生物氧化试验。试验结果表明,氧化液中三价砷含量与试样的砷含量有关。含砷较低的试样氧化时,氧化液中三价砷含量很低,溶液中砷大部分为五价砷;试样含砷越高,氧化液中三价砷含量越高,五价砷含量越低;氧化液中三价砷含量越高,则二价铁含量越高,Eh越低。由试验结果分析,生物氧化过程中毒砂中砷主要被Fe3+氧化,是间接作用机理的生物氧化过程。

3 samples with different arsenic content of 2.46 %, 8.23 % and 14.00 % are prepared by mixing gold concentrate and arsenic concentrate. The samples are processed by biologie oxidization. The experiments reveal that the content of trivalent arsenic in oxidization solution relates to the content of arsenic in samples. When samples with low arsenic content are oxidized, the content of trivalent arsenic in solution is low and that of quinquevalent arse- nie is high. The eontent of trivalent arsenie in solution increases with the eontent of arsenic in samples. While the Fe^2＋ content increases with the content of trivalent arsenic in solution and the Eh value decreases with the index. The experiments show that in the biologic oxidization process, arsenic in arsenopyrite is mainly oxidized by Fe^3＋ , which is the indirect effect mechanism of biologic oxidization.