Puffed Curing Prepared By Spfs Process

Preparation of SPFS from pyrite cinder via expanding solidification processing was investigated in this paper. Effects of the evaporation moisture content, the amount of expanding agent, the PFS basicity, the reaction temperature and the drying temperature on the quality of SPFS and solidification time were studied. The optimum conditions were as foliowings: the moisture content rate of evaporation was 30%, the amount coefficient of expanding agent was 1.1, PFS basicity was 13%, the reaction temperature was 60℃and the drying temperature was 60℃. The SPFS obtained under this condition is brittle and the water-solubility is good. The drying time and the nature solidification time is also the shortest, which is 15h and 15d, respectively.The solidification time of PFS decreased after added additives SPFS powders and alum respectively during the solidification processing. When compound additives with SPFS powders and alum were added to reaction processing, the drying time and spontaneous drying time was 1.5-2h and 12h, respectively.The XRD patterns indicated these SPFS were Fe_4.67(SO₄)₆(OH)₂·20H₂O and additives hadn't no effect on the structure of SPFS. The SEM images showed the morphologies of SPFS obtained by expanding solidification processing were plate and the shape of SPFS synthesized with additives became larger significantly. The Ferron time complexing color method was used to determine the form of PFS-FeSO₄. The results indicated that the form of PFS-FeSO₄ was in turn Fe(b)/Fe_total＞Fe(a) /Fe_total＞Fe(c)/Fe_total. When n(Fe³⁺)/n(Fe²⁺) was 1:0, Fe(a)/Fe_total and Fe(c)/Fe_total reached 17.04% and 2.84%, respectively, and Fe(b)/Fe_total reached 80.12%. When n(Fe³⁺)/n(Fe²⁺) was 1:2, both Fe(a)/Fe_total and Fe(c)/Fe_total reached 0% and 0.28%, respectively, and Fe(b)/Fe_total reached 99.72%.Lime and sodium hydroxide by adjusting pH value in aqueous solution were used to treat synthetic acid mine wastewater. The experiments showed the removal rate of Mn increased with pH value. When wastewater pH is adjusted to 10 by lime, the removal rate of Mn was 100%, and which was adjusted to 11 by sodium hydroxide, the removal rate of Mn was 97%. Using PFS to treat synthetic acid mine wastewater, the removal rate of Mn increased with pH vaule. When wastewater pH was adjusted to 13 by Lime or sodium hydroxide, the removal rate was 100%. When PSF and lime were used to synthetic acid mine wastewater, a large numbers of residues with low content of iron oxide was presented, But both PSF and sodium as treating agents were used to synthetic acid mine wastewater, a small amount of residue was obtained and 55.06% iron oxide of that as a secondary resource was recycled after being calcined at 400℃for dehydration.