嗜热酸性菌脱硫试验条件优化及机理分析

Test conditions optimization and mechanism analysis of desulfurization by acidic thermophiles

为降低金属硫化矿自燃的危害性,利用细菌脱硫技术降低硫化矿表面的含硫量。从腾冲热海酸性温泉分离出一株新型嗜热酸性菌,对其脱硫试验条件进行优化。以脱硫率为响应值,通过Plackett-Burman设计法筛选出影响脱硫率的主要因素。在进行最陡爬坡试验获得试验中心点后,使用响应曲面分析法建立连续变量曲面模型。研究结果表明:影响脱硫率的3个主要因素为温度、单质硫质量浓度和硫酸铵质量浓度,其中温度对于脱硫率的贡献率最大。优化浸出条件:温度为80℃,单质硫最佳质量浓度为0.84 g/L,硫酸铵最佳质量浓度为3.81 g/L。优化试验条件下的脱硫率为56.87%,与预测值接近,回归效果好。

To reduce the danger of spontaneous combustion of metal sulfide ore, the sulfur content of sulfide minerals surface was reduced by bacteria desulfurization technology. Bacterial desulfurization experiments were carried out by using a novel strain of thermophile which was isolated from Rehai acidic hot spring in Tengchong in southwestern China. With desulfurization rate used as response, the main factors were studied by Plackett-Burman design method. After obtaining the experiment center by the steepest ascent experiment, a continuous variable surface model was built with the response surface methodology. The results show that the main factors are the concentration of sulfuric acid, concentration of surfactant and temperature of surfactant, the concentration of surfactant is the biggest contributor to the desulfurization rate. By solving quadratic polynomial equation, the optimization leaching conditions is as follows： the temperature being 80 ℃, the concentration of sulfur being 0.84 g/L, the concentration of （NH4）2SO4 being 3.81 mol/L. The desulfiu＇ization rate is 56.87% in the optimization experimental conditions, which is close to the predicted value, showing that regression result is good.