嗜酸氧化亚铁硫杆菌对煤炭脱硫影响的研究

Biodesulfurization of coal by Acidithiobacillus ferrooxidans

嗜酸氧化亚铁硫杆菌(Acidithiobacillus ferrooxidans)广泛应用于湿法冶金和煤炭脱硫。不同的实验条件对煤炭脱硫效率的影响很大。以QXS菌株为实验对象,分别考查了处理时间、初始pH、煤样粒度、煤浆质量分数等因素对煤炭脱硫效率的影响,结果表明:处理时间达到10d后,全硫脱除率达到65%且不再继续增加;初始pH的影响符合钟罩形曲线,最佳pH条件为2.0左右;伴随煤样粒度和煤浆质量分数的增加,脱硫的效果均呈现减弱趋势。此外,对具有不同Fe2+氧化能力的菌株的脱硫能力进行了对比分析,结果表明它们的脱硫效率与Fe2+氧化能力呈正相关。采用QXS菌株,煤浆质量分数为20%,煤样粒度为200目(<0.074mm),初始pH为2.0,温度30℃,摇床转速为175r/min,接种量为1010～1011·g-1时,10d后煤炭的全硫脱除效率可达65.1%。

Acidithiobacillusferrooxidans have been widely used on hydrometallurgy and coal desulfurization. Different experiment conditions have significant influences on the efficiency of coal desulferization. In order to determine the optimized experiment condition, Some important parameters, such as leaching times, initial pH, coal particle size, coal slurry concentration and so on, were studied on an A.fstrain named QXS. The results showed that 65% sulfur of the coal could be removed after 10 days, and then maintained at this level. The effect of initial pH followed the curve of phosphoriser well, and the optimized initial pH could be 2.0 approximately. However, the rates of coal desulferization would be decreased followed by the increase of coal slurry concentration and coal particle size. Furthermore, four different strains of Acidithiobacillusferrooxidans, which were named CMS, YTW, QXS, CSU respectively, were studied. The results showed that different iron oxidation ability could lead to different efficiencies of coal desulfu- rization It was concluded that, when QXS strain was studied, the optimized experiment conditions were coal slurry concentration： 20%, coal particle size： 〈0.074 mm, intial pH： 1.8, temperature; 30 ℃, rotation speed of roking bed： 175 rmin^-1, inoculum size： 10^10- 10^11cell·g^-1. After 10 days the desulferization rate of total sulfur achieved maximum level 65.1%, and the corresponding desulferization rate of pyrite reached 95.6%.