The changes of clay mineral association after high-gradient magnetic separation (HGMS) treatment, and the effects of chemical and physical technologies on concentrating Fe oxides for main soils in central and southern...The changes of clay mineral association after high-gradient magnetic separation (HGMS) treatment, and the effects of chemical and physical technologies on concentrating Fe oxides for main soils in central and southern China were investigated by means of X-ray diffraction (XRD) and chemical analysis methods. Results indicated that the concentrating times of Fe oxides by HGMS treatment were the largest for 0.2-2 μmsize fractions in the examined soils. For the soils in which 2: 1 phyllosilicates were dominant, concentrating times of iron oxides by HGMS treatment were larger than by 5 mol L-1 NaOH treatment. Phyllosili-cates were decreased after HGMS treatment; however, the decrease was less than that of kaorolinite. The goet bite / (goethite + hematie) values in Fe oxides of the soils kept virtually constant after HGMSt reatment.展开更多
The removal of phosphate from municipal sewage by high gradient magnetic separation using aluminium sulphate as precipitating agent and Fe3O4 as seeding material was studied. The effects of aluminium sulphate, Fe3O4, ...The removal of phosphate from municipal sewage by high gradient magnetic separation using aluminium sulphate as precipitating agent and Fe3O4 as seeding material was studied. The effects of aluminium sulphate, Fe3O4, magnetic field intensity, pH value and flow-rate of sewage on phosphorus removal rate were investigated. The results show that addition of 200 mg/L Al2（SO4）3·18H2O and 300 mg/L Fe3O4, magnetic field intensity of 200 kA/m, pH value of 4.57.0 and flow-rate of 6.15 cm/s are both efficient and economic technical parameters for removal of phosphate. The pH value has a tremendous effect on the removal of phosphate. In the pH range of （4.5）7.0, more than 95% phosphate can be removed. Theoretical analysis indicates that the solubility of AlPO4 is minimum at pH 4.07.0 and the electrostatic attractive force between AlPO4 and Fe3O4 is maximum at pH 4.5（6.5.）展开更多
文摘The changes of clay mineral association after high-gradient magnetic separation (HGMS) treatment, and the effects of chemical and physical technologies on concentrating Fe oxides for main soils in central and southern China were investigated by means of X-ray diffraction (XRD) and chemical analysis methods. Results indicated that the concentrating times of Fe oxides by HGMS treatment were the largest for 0.2-2 μmsize fractions in the examined soils. For the soils in which 2: 1 phyllosilicates were dominant, concentrating times of iron oxides by HGMS treatment were larger than by 5 mol L-1 NaOH treatment. Phyllosili-cates were decreased after HGMS treatment; however, the decrease was less than that of kaorolinite. The goet bite / (goethite + hematie) values in Fe oxides of the soils kept virtually constant after HGMSt reatment.
文摘The removal of phosphate from municipal sewage by high gradient magnetic separation using aluminium sulphate as precipitating agent and Fe3O4 as seeding material was studied. The effects of aluminium sulphate, Fe3O4, magnetic field intensity, pH value and flow-rate of sewage on phosphorus removal rate were investigated. The results show that addition of 200 mg/L Al2（SO4）3·18H2O and 300 mg/L Fe3O4, magnetic field intensity of 200 kA/m, pH value of 4.57.0 and flow-rate of 6.15 cm/s are both efficient and economic technical parameters for removal of phosphate. The pH value has a tremendous effect on the removal of phosphate. In the pH range of （4.5）7.0, more than 95% phosphate can be removed. Theoretical analysis indicates that the solubility of AlPO4 is minimum at pH 4.07.0 and the electrostatic attractive force between AlPO4 and Fe3O4 is maximum at pH 4.5（6.5.）
