中温及嗜热菌对不同成因黄铜矿浸出行为的影响

以斑岩型黄铜矿和矽卡岩型黄铜矿为研究对象,考察了嗜酸氧化亚铁微螺菌(L f)和嗜热硫氧化硫化杆菌(S t)对不同成因黄铜矿浸出行为的影响。结果表明,在2种不同细菌浸出体系中矽卡岩型黄铜矿均表现出比斑岩型黄铜矿浸出率高;S t浸出2种不同成因黄铜矿的效率均比L f的好。通过对不同浸矿时间黄铜矿浸出渣的XRD检测并结合黄铜矿浸出过程反应步骤的分析表明,2种细菌浸出不同成因黄铜矿的机制相同,细菌的代谢途径及反应温度是影响同类成因黄铜矿浸出率和代谢产物差异的主要原因。S t作用下浸出后期黄铜矿表面有黄钾铁矾生成,而L f浸出体系黄铜矿表面主要是S的不断积累。同种浸矿菌种浸出不同成因黄铜矿时,矽卡岩型黄铜矿在浸出第15 d有S生成,斑岩型黄铜矿在S t浸出体系S生成的时间更晚,在L f浸出体系S的生成量则更少,推测矿物性质是引起其差异的主要原因。

Effects of Medium-temperature Bacteria and Thermophilic Bacteria on Leaching Behaviors of Chalcopyrite from Different Geo-Genetic Deposits

Bioleaching behaviors of porphyry-type and skarn-type chalcopyrite in the presence of Leptospirillum ferrooxidans (L f) and Sulfobacillus thermosulfidoxidans (S t) were investigated. Results showed that the leaching rate of skarn-type chalcopyrite was higher than that of porphyry-type chalcopyrite in the presence of either L f or S t. Moreover, S t  brought  in better leaching effect than L f for both two types of chalcopyrite. Based on the XRD study for leach residue of pyrite after different leaching time and an analysis of reaction steps for pyrite leaching process, it is found that the mechanism for leaching different types of pyrite with two bacteria is the same. The metabolic pathway and reaction temperature of the bacteria contributed to the difference in leaching rates and metabolites when dealing with the same type of chalcopyrite. Specifically, jarosite was generated on the surface of chalcopyrites at the later stage of leaching process with S t as the bioleaching bacteria, as compared, sulfur was continuously accumulated on the surface of pyrite when using L f as the bioleaching bacteria. Besides, after the bioleaching with same kind of bacteria, it is found that sulfur was generated on skarn-type chalcopyrite on the 15th day of leaching. However, the generation of sulfur need more leaching days when porphyry-type chalcopyrite was bioleached with S t, and less sulfur was generated if bioleached with L f. It is concluded that the mineral properties are the main cause for such difference.