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羧甲基纤维素钠(CMC-Na)作为一种制粒粘结剂,在低品位矿石生物堆浸中有着潜在的应用价值。作为前期研究工作,本文主要考查了CMC-Na对细菌氧化活性及其浸矿性能的影响。首先考察了CMC-Na浓度(0~10g·L-1)、细菌接种量(5~30%)、初始p H值(1.2~2.4)、温度(15~45oC)和Fe2+浓度(3~9g·L-1)等因素对细菌氧化活性的影响;通过逐步的驯化培养,使细菌的耐受CMC-Na浓度从4g·L-1达到了10g·L-1。接着,利用实时荧光定量PCR技术对耐受CMC-Na浓度为0~10 g·L-1的菌液进行了细菌种群结构分析,结果表明菌液中均存在Acidithiobacillus sp.,Leptopirillum sp.,Ferroplasma sp.三种细菌,其中Acidithiobacillus sp.均为优势菌种;最后通过正交试验L9(34)考查了CMC-Na浓度(2~10 g·L-1)、细菌接种量(10~30%)、初始p H值(1.2~2.4)、矿浆浓度(2~5%)等因素对低品位矿石生物浸出时浸出率的影响,得出各因素影响的主次顺序为:CMC-Na浓度>细菌接种量>初始p H值>矿浆浓度。
Sodium carboxymethyl cellulose (CMC-Na), as a granulating binder, has potential applications in low-grade ore bio-heap leaching. As a preliminary research work, this paper examines the impact of CMC-Na on bacterial oxidation activity and its leaching performance. Firstly, the effects of CMC-Na concentration (0 ~ 10g · L-1), bacterial inoculum (5 ~ 30%), initial pH value of 1.2 ~ 2.4, temperature of 15 ~ 45oC and Fe2 + · L-1) and other factors on the bacterial oxidation activity; through gradual domestication culture, the bacterial tolerance CMC-Na concentration from 4g · L-1 reached 10g · L-1. Then, the bacterial population structure was analyzed by real-time fluorescence quantitative PCR to the bacterium solution which tolerated the concentration of CMC-Na was 0-10 g · L-1. The results showed that both Acidithiobacillus sp., Leptopirillum sp., Ferroplasma sp. Three kinds of bacteria, Acidithiobacillus sp., were the dominant species. Finally, the concentration of CMC-Na (2 ~ 10 g · L-1) and bacterial inoculum (10-30% ), The initial p H value (1.2 ~ 2.4), the pulp concentration (2 ~ 5%) and other factors on the leaching rate of low-grade ore bio-leaching. Bacterial inoculum> initial p H value> pulp concentration.