Preparation of solid polyferric sulfate from pyrite cinders and its structure feature
(College of Metallurgical Science and Engineering, Central South University, Changsha 410083, China)
Abstract: Acid leaching solution was obtained after mixing pyrite cinders with H2SO4, then heating the mixture of pyrite cinders and H2SO4 at 200-300℃, leaching the heated mixture with water and filtrating. Polyferric sulfate (PFS) solution was produced by adding suitable amounts of FeSO4·7H2O and NaClO3 into acid leaching solution. By concentrating and drying PFS solution, solid PFS with alkali degree of 6.40%-22.4% was prepared. Fe4.67(SO4)6(OH)2·20H2O in the solid PFS was discovered by XRD analysis. FT-IR spectroscopy shows that the absorption peaks at 3400cm-1 and 1635cm-1 arise from OH and absorption peaks at 998cm-1 and 669cm-1 come from Fe—OH in the solid PFS.
Key words: pyrite cinders; NaClO3 oxidation; solid polyferric sulfate; structure feature