高碱脉石低品位铜镍复合矿的诱变细菌浸出

Bioleaching of Low Grade of Cu-Ni Complex Ore Containing High Level of Basic Gangue by UV-mutated Thiobacillus Ferrooxidans

金川低品位铜镍复合矿为高碱脉石的氧化—硫化混和矿 ,矿区无土著浸矿细菌。采用经诱变改良的外源混合T .f浸矿菌和控制矿浆 pH(<4 ) ,有效地浸出了该复合矿中的镍和铜 ;控制矿浆pH在细菌生长最适的范围内 ,钙、镁实际耗酸分别只占其总含量的 2 2 %～32 % ;铜、镍在不同浸出阶段表现为相反的浸出行为 ,酸浸时铜优先被浸出 ,菌浸时镍优先被浸出 ;渣样分析表明硫化镍、硫化铜的浸出机制为间接作用。物相分析表明这些浸出行为与浸出对象的赋存状态有关。

The low grade of Cu Ni complex ore from Jinchuan (Gansu Provence, China) is one of oxidized and sulfidized ore with high level of basic gangue. There is no bioleaching bacteria in the surrounding of ore. The Ni and Cu were leached effectively by the UV mutated ameliorated Tiobacillus ferrooxidans under pH<4. Only 22% of Calcium oxide and 32% of Magnesium oxide in the ores consumed acid during the adjustment of pH in the ore sludge in which the bacteria had higher activity. The copper was first leached in the acid adjustment period, but nickel was first leached during bacterial leaching period. It was assured that the bioleaching of Cu and Ni sulfides followed the indirect leaching mechanism, and were related to their states in the ore according to the both elemental and structural analyses of bioleached residues.