Microorganisms Of Low-grade Nickel Sulfide Ore Processing

With the sustainable and stable development of the state economy, the basic and supportable industries, such as information, transportation, energy and raw material industries that consume much nickel relatively, will get much developed. This will promote the increase of the demand for nickel. However, since the nickel resources are exploited excessively, it produces a lot of low-grade ores, surface ores, waste and poor ores. If they are treated by traditional methods, the economic profit will be low and even in vain. Since the biological leaching technology has the advantages on utilization of resources fully with low cost and low investment, and without pollution, microbial oxidation technology used to leach this kind of resource is put forward, which is meaningful to treat the low-grade nickel resources in China.Firstly, process mineralogy characteristics and mineral components of the copper and nickel sulfide ores were studied, then the feasibility of biological leaching were conducted, on the above bases biological leaching experiments on the low-grade Ni-Cu sulfide were carried out through two groups in columns and tubes.The ore samples used in the experiments contain Ni 0.38%, Cu 0.30%, moisture 3.5% and clay 2.3%, among which the main nickel-bearing mineral is pentlandite, which is disseminated at the size of 0.1051-0.0092mm, accounting for 84.68%; the main copper-bearing mineral is chalcopyrite disseminated at the size of 0.2973-0.0185mm, accounting for 74.68%. The particle size used in the experiment is coarser relatively.The bacterium used in the experiment is mainly ferrobacillus sulfooxidans through microscopical observation. Bacterium is enriched and cultivated in the culture medium containing FeSO4 (the ratio of 9K to Leathen is 1:1), and then the bacteria species are purified and separated from solid agar. After that the purified bacteria is domesticated and cultivated to suit the leaching environment, and to endure the leaching nickel ions. The bacteria leaching in static state lasts 150 days at the room temperature, and the nickel leaching rate in column andtube is 33.67-47.43%, 36.87% respectively, and the copper leaching rate in column is 24.22%.Due to no special conditions needed, in the experiments and the ore sample processed in simple and coarser with low cost, therefore, this kind of bacteria has a better economic benefit on leaching this kind of low-grade nickel ore. Therefore the biological method to treat low-grade copper and nickel sulfide ore is effective and practical.