摘要
Leaching soluble phosphorus from rock phosphate containing pyrites by Acidithiobacillus ferrooxidans (A.f.) is feasible, and the reaction mechanism is as follows. Pyrites are oxidized by A.f. to produce H_2SO_4 and FeSO_4; the rock phosphate is decomposed by H_2SO_4, forming soluble phosphorus compounds; and Fe2+ from FeSO_4 is oxidized to Fe^3+, providing energy for the growth of A. f.. In this process, as H_2SO_4 is produced in the reaction, an acidic condition in the culture medium is formed, which benefits the growth of A. f. and aids both continuous oxidation of pyrites and leaching of soluble phosphorus from rock phosphate. The fraction of phosphorous leached can reach the largest in the presence of 1.0 g/L Fe^3+, 200 mg/L Mg^2+ and 400 mg/L NH_4^+. The optimal technological parameters on the fraction of phosphorous leached are as follows: the volume fraction of inocula of A. f., the mass ratio of pyrites to rock phosphate and the pH value are in ranges of 5%-25%, 3:1-5:1 and 1.8-2.2, respectively.
Leaching soluble phosphorus from rock phosphate containing pyrites by Acidithiobacillusferrooxidans （A. f.） is feasible, and the reaction mechanism is as follows. Pyrites are oxidized by A. f. to produce H2SO4 and FeSO4; the rock phosphate is decomposed by H2SO4, forming soluble phosphorus compounds; and Fe^2＋ from FeSO4 is oxidized to Fe%3＋, providing energy for the growth ofA. f.. In this process, as H2SO4 is produced in the reaction, an acidic condition in the culture medium is formed, which benefits the growth ofA. f. and aids both continuous oxidation of pyrites and leaching of soluble phosphorus from rock phosphate. The fraction of phosphorous leached can reach the largest in the presence of 1.0 g/L Fe^3＋, 200 mg/L Mg^2＋ and 400 mg/L NH^4＋. The optimal technological parameters on the fraction of phosphorous leached are as follows： the volume fraction of inocula ofA. f., the mass ratio of pyrites to rock phosphate and the pH value are in ranges of 5%-25%, 3：1- 5：1 and 1.8- 2.2, respectively.
基金
Project(2004CB619200) supported by the State Basic Research Development Program of China
Project(Z200515002) supported by the Key Project Foundation of the Education Department of Hubei Province, China
