微生物脱砷预处理难冶含砷金矿提金的研究

用化能自养的氧化铁硫杆菌和氧化硫硫杆菌，对河北半壁山含砷金精矿进行了公斤级的预处理氧化脱砷实验．在细菌预处理反应器中的连续和批式脱砷实验表明，目前选育的菌种是有效的．严格控制工艺条件，可以在4天左右便脱砷率高于80％．后续氰化提金实验证实，金的总回收率可达90％以上．用微生物脱砷预处理难冶含砷金矿有金浸出率高、便于固定浸出的砷、免除对环境污染的优点，是有很好应用前景的处理难冶含砷金矿的技术路线．

EXPERIMENTS ON BACTERIAL DEARSENICATION OF REFRACTORY ARSENICAL GOLD CONCENTRATE AND GOLD LEACHING BY CYANIDATION

The paper presents the kilogram scale tests on bacterial pretreatment of re-fractory arsenical gold concentrate from Banbishan, Hebei Province, China. Both continuous treatment in a series of propeller loop reactors and batchwise operation in a single gas-lift loop reactor can dearsenicate effectively the refractory gold conceotrate- The batchwise bioprocess-ing was carried out in a 10 L gas-lift loop reactor with 1 kg load using a mixture of Thiobacillus ferrooxidans and Thiobacillus thiooxidans. The level of dearsenication may reach above 80% in 5 days of bioleaching. Subsequent cyanidation of the treated residue demonstrates that the overall recovery of gold may be over 90% when the bioprocessing and cyhadation is weli controlled. Arsenic leached into the liquor can be easily fixed chendcally to make the bacterial dearsenication an environment-benigh process.