A novel coating technique was developed for controlling Pyrite oxidation. The technique invo1ved leachingpyrite particles with a solution containing low concentrations of phosphate and hydrogen peroxide. Duringthe lea...A novel coating technique was developed for controlling Pyrite oxidation. The technique invo1ved leachingpyrite particles with a solution containing low concentrations of phosphate and hydrogen peroxide. Duringthe leaching process, the iron released from pyrite by hydrogen proxide was precipitated by phosphate as aferric phosphate coating. This coating was shown to be able to effectively prevent Pyrite from oxidation and itcould be established at the expense of only surface portions of Pyrite. The emergence of this technique couldprovide a unique potential route for abating acid mine drainage and reclaiming sulfide-containing degradedmining land.展开更多
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 Fe...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.展开更多
文摘A novel coating technique was developed for controlling Pyrite oxidation. The technique invo1ved leachingpyrite particles with a solution containing low concentrations of phosphate and hydrogen peroxide. Duringthe leaching process, the iron released from pyrite by hydrogen proxide was precipitated by phosphate as aferric phosphate coating. This coating was shown to be able to effectively prevent Pyrite from oxidation and itcould be established at the expense of only surface portions of Pyrite. The emergence of this technique couldprovide a unique potential route for abating acid mine drainage and reclaiming sulfide-containing degradedmining land.
基金Project(2004CB619200) supported by the State Basic Research Development Program of ChinaProject(Z200515002) supported by the Key Project Foundation of the Education Department of Hubei Province, China
文摘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.
