Abstract

The bioleaching of nickel-containing sulfide minerals from five ophiolitic ore samples was investigated in this study, using a mesophilic, acidophilic consortium that included Acidithiobacillus thiooxidans, Acidithiobacillus ferrooxidans, and Leptospirillum ferrooxidans. The experiments were carried out in the presence and absence of ferrous iron and elemental sulfur as additional energy sources for the bacteria. After 30 days of contact at 5% pulp density, nickel dissolution was in the range of 15–29% in the chemical leaching and 58–83% in the bioleaching. Accessory forsterite (Mg₂SiO₄) in the ophiolitic ore samples increased the acid consumption, attributed to the protonation of Mg-silicate surfaces. The ore samples with low Cr₂O₃/MgO ratios had high acid consumption. Post-leaching examination of solid residues showed the presence of a jarosite and sulfur layers, indicating mineral surface passivation and diffusion limitation.

• Research highlights

• The chemical and bioleaching of five Ni-sulfide samples was investigated

• Ni bioleaching from some samples responded to Fe and sulfur addition

• Leaching of samples with pentlandite yielded the highest Ni recoveries

• Sulfur and a jarosite-type precipitate were formed as secondary phases

• Lizardite was formed as a serpentinization alteration product of Mg-silicates

摘要

在这项研究中，使用包括氧化硫硫杆菌、氧化亚铁硫杆菌和氧化亚铁钩端螺旋体在内的中温、嗜酸联合体研究了从五个蛇绿岩矿石样品中生物浸出含镍硫化物矿物。实验是在存在和不存在亚铁和元素硫作为细菌的额外能源的情况下进行的。在 5% 矿浆密度下接触 30 天后，化学浸出中镍的溶解率为 15-29%，生物浸出中为 58-83%。镁橄榄石（Mg ₂ SiO ₄) 在蛇绿岩矿石样品中增加了酸消耗，这归因于硅酸镁表面的质子化。_{具有低Cr 2} O ₃ /MgO 比的矿石样品具有高酸消耗。固体残留物的浸出后检查表明存在黄钾铁矾和硫层，表明矿物表面钝化和扩散受限。

• 研究亮点

• 研究了五个镍硫化物样品的化学和生物浸出

• 一些样品中的镍生物浸出对铁和硫的添加有反应

• 用镍铬铁矿浸出样品产生最高的镍回收率

• 硫和黄钾铁矾型沉淀物作为第二相形成

• Lizardite 是镁硅酸盐的蛇纹石化蚀变产物