Study Of Factors Influencing Leaching Of Low-grade Phosphate Ore With Acidithiobacillus

With the fast development of national economy, the demand for phosphorus resource is expanding constantly, and the resource reduces constantly, especially there are fewer and fewer rich ores that can be utilized directly, and the price of the phosphorus ore is going up constantly too. Based on the research of our country, it is very difficult, for the traditional mineral processing techniques, to achieve the satisfied effect. It is urgent to seek for new technologies which are economic and practical. Leaching of low-grade phosphate ore with thiobacillus has the important significance of saving resources, reducing costs, protecting environment, and enhancing the rate of resource utilization.Several facets are studied on the leaching of low-grade phosphate ore with Acidithiobacillus thiooxidans and Acidthiobacillus ferrooxidans.Firstly, according to the experiment of leaching the low-grade phosphate ore with dilute sulfuric acid,which showed that dilute sulfuric acid can leach the phosphate ore, comparing the differences between bio-leaching and sulfuric acid leaching .The last, discussing the mechanism of bio-leaching phosphate ores with Acidithiobacillus thiooxidans.Secondly, the article studies the enrichment, separation and purification of Acidithiobacillus thiooxidans, Acidthiobacillus ferrooxidans. Further more, the choice of the different culture medium is dissused. The experiment of leaching ore indicated that the two Thiobacillus all can leach the phosphate ores, and the rate of phosphate leached with the two thiobacillus is higher than the sulfuric acid at the same pH, and the effect of Acidithiobacillus thiooxidans is better than Acidthiobacillus ferrooxidans.It has been indicated that 10% is the best inoculating quantity throught the experiments.Finally, through comparative experiments, the growth characteristics and bio-leaching effect of Acidithiobacillus thiooxidans in the phosphorus-containing Starkey culture medium and the phosphorus-free Starkey culture medium are especially studied , the differences between bio-leaching and sulfuric acid leaching are compared. The results indicated that not only phosphorus-free culture medium can...