【摘要】 采用化学分析和偏光矿相显微镜矿物鉴定方法研究了高砷硫低镍钴硫化矿的生物浸出工艺矿物学:黄铁矿是有益组分镍、钴的主要载体矿物,结晶程度差,结构松散,易被细菌侵蚀,镍、钴容易被浸取,但细菌氧化黄铁矿而将产出较多的酸和浸出较多的铁;矿石中存在一部分颗粒微细并分散在结构致密的脉石中的含镍矿物,这是影响镍细菌浸出速率的主要原因。结合工艺矿物学研究结果,采用现代微生物驯化育种技术,选育了抗毒性强和适合浸出高砷硫低镍钴硫化矿的浸矿菌种RetechⅢ三代驯化菌,并采用亚铁离子氧化速率法、生物显微镜直接计数法及氧化还原电位法测定其浸矿活性,Fe2+氧化为Fe3+速率达到1.4g.(L.h)-1,培养60h细菌浓度由初始时的3.78×105cells.ml-1上升到1.67×108cells.ml-1,菌液氧化还原电位达到600(mV,vs.SCE)。采用摇瓶细菌浸出方法研究了浸出介质pH值、细菌接种量、浸出周期、矿浆浓度、温度等影响生物浸出的关键因素,获得了高砷硫低镍钴硫化矿生物浸出最优工艺参数,镍和钴的浸出率分别达到85.46%和99.23%。更多还原

【Abstract】 Bioleaching process mineralogy of high arsenic(sulfur),low nickel(cobalt)sulfide ore was studied by using chemical analysis and polarization microscope mineral identification method.The results showed that pyrite with low crystallinity,loose structure and easily etched by bacteria,is the main carrier mineral of interested components nickel and cobalt.Nickel and cobalt are easily leached,but more acid was produced and more iron was leached during biooxidation of pyrite.It is the main reason affecting nickel bioleaching rate that a fraction of fine particle nickel-bearing mineral is dispersed within the dense gauge.Based on process mineralogy.It was shown that high toxic-resistant and domesticated bioleaching bacteria Retech Ⅲ suitable for high arsenic(sulfur),low nickel(cobalt)sulfide ore was selected.Ferrous ion oxidation rate method,microscope count method and redox potential method were used to determine bioleaching activity.Ferrous oxidation rate reached 1.4 g·(L·h)-1.Bacteria concentration increased from 3.78×105 cells·ml-1 to 1.67×108 cells·ml-1 after culturing 60 h.The bacteria liquor redox potential came to 600(mV,vs.SCE).Shake flask leaching was planned to study the effects of key bioleaching factors:pH value of the leaching solution,inoculation volume,leaching period,pulp density and temperature.Optimized process parameters in bioleaching of high arsenic(sulfur),low nickel(cobalt)sulfide ore were obtained and recovery of nickel and cobalt reached 72.33% and 98.58%,respectively.更多还原