| Natural sulfur was very scarce in our country, and the exploitation value was low, by the price contril of the imported sulfur, pyrite was still used for the production of sulfuric acid in most of the domestic sulfuric acid plant, so the existence of sulfate slag was long-standing. Iron was riched in the pyrite cinder, the Fe content was about 30%~60%, and the pyrite cinder would be one of the important twice iron resources. If the pyrite cinder was producted into the iron ore powder, and was as iron making raw materials, which would relieve the shortage situation of domestic iron ore. To the pyrite cinder from Wengfu group, the process mineralogy would be studied firstly in this paper, then the sulfur reduction and iron enriching was conducted respectively, the optimizing of leaching process was done finally, the main results was as follows:(1) Exploration experiment. Leaching tests were carried out using aqua regia and hydrofluoric acid as dissolvant, roasting test was done using self-made WJ reagent as additives. The results showed that, the effect of the aqua regia on the enriching iron was obscure. under the optimum conditions, the iron content of the pyrite cinder reached 55%, and the sulfur content was 0.74%. There was a big distance between the pyrite cinder treated and ironmaking raw material requireed. HF had a special effect on silica in pyrite cinder, the iron could be enriched to about 57%, but there are not any effect on the sulfur removal, in addition, the experimental condition was harsh, therefore, the further study was not done. From the results of XRD test, the effect of WJ reagent on sulfur reduction was obvious, sulfur content could be reduced to 0.23%, the enriching Fe and reducing S would be done in depth based on the results above.(2) Research on the reducing sulfur. the effect of WJ regent on reducing sulfur was studied considering roasting temperature, roasting time and WJ additive amount. Under the optimal conditions, when the roasting temperature was 500℃, the roasting time was 0.5h, WJ additive amount was 1g(10% in weight), the sulfur content in pyrite cinder sulfur was 0.3%, and this met the requirements of ironmaking raw materia.(3) Research on the effect of roasting process on enriching iron.The test considering the melting temperature, time and NaOH reagent volume, from the single factor test results, orthogonal test was designed and done. The optimal conditions was that,,the roasting time was 650℃, the roasting time was 0.5h, and the additive amount of sodium hydroxide is 1g(10% in weight). Under this condition, the iron content could reach 60.21%, the results was in agreement with the theoretical calculation of the regression equation. WJ and sodium hydroxide did not interplay for the enriching iron and reducing sulfur in the roasting process, and the content of iron, and sulphur in slag could meet the requirements of ironmaking raw material.(4) Research on the effect of leaching process on enriching iron. The effect of leaching process on enriching iron was done considering the four factors, acid leaching temperature, time, pH and the ratio of liquid to solid. Under the optimum process conditions, acid leaching temperature was 20℃, the reaction time was 10 min, the pH was 1.5, and the ratio of liquid to solid was 6, the iron content in pyrite cinder was 60.4%, and the sulfur content was 0.227%, which would meet the requirements of the ironmaking raw material. |
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