Research On The Domestication Of Bacteria From Copper-Containing Wastewater And Bioleaching Of Copper Ores

Copper is a very important strategic metal and is widely used.Less rich ore and less manageable ore are characteristics of copper mineral resources in China,if the traditional copper extraction technology is used to deal with such mineral resources,the economic and social benefits are not ideal.Bio metallurgical technology is a new technology.It has the advantages of low cost,little environmental pollution and simple operation.It has obvious advantages in dealing with such mineral resources compared with traditional technology.Due to the fact that some copper ores are in cold weather area,the conventional bioleaching is not easy to carry out.Therefore,the research of low temperature bioleaching is a problem to be solved at present.The research object of this subject is Dishui copper ore and Wushan copper ore.The culture,acclimatization and copper leaching process of bacteria are studied at low temperature(15?).With screening and optimization of bacteria at low temperature,Thegrowth cycle of bacteria shrinks to 5 days,and the best initial pH value of bacteriagrowth is 1.65.Copper ion tolerance of the bacteria is improved by increasing copper ion concentration step by step,and the bacteria show perfect tolerance under 30g·L-1 Cu2+.In the experiment on bioleaching and chemical leaching of Dishui copper ore at 3%pulp concentration,the leaching rate of copper in bioleaching system is 89.52%,and the leaching rate of copper in the chemical leaching system is 40.99%.The effect of bacterial leaching of Dishui ore is better than the effect of chemical leaching.The bioleaching rate is 89.05%at 5%pulp concentration.The bioleaching rate is 81.80%at 10%pulp concentration.In the experiment on bioleaching and chemical leaching of Wushan Floatation concentrate at 3%pulp concentration,the leaching rate of copper in bioleaching system is 52.47%,and the leaching rate of copper in the chemical leaching system is 33.78%.It is feasible to recover copper from floatation concentrate of Wushan by biologic metallurgy technology.After bacteria is domesticated with pulp concentration of 3%and 5%,its leaching ability has beengreatly enhanced,the bioleaching rate is 66.22%,increased by 13.75%.Biological column leaching of Wushan raw ore shows that,on the 20th day by direct acid leaching,the leaching rate of copper is 9.5%,the bioleaching rate of copper is 81%.The effect of biological column leaching is better by using the acclimated bacteria.Dynamic corrosion shows molybdenite and chalcopyrite are difficult to decomposition in acid solution,but they can be easier to decomposition in bacterial solution.In this experiment,get the activated bacteria:DBD-515,which hasgood resistance to low temperature and high copper ion concentration.The results of the experiment shows that the leaching effect of the bacteria was very significant at low temperature(15?).