Depth Of Lowering The Sulfur-containing Pyrite Research

Along with the rapid growth of steel and iron output in our country,the quantity of blast-furnace smelting raw material is increasing greatly in demand.Our country is rich in reserves,but have the characteristic of "poor,fine,mixed",the run of mine average grade only 33.00%,and high in harmful impurity,such as S,P,SiO₂,Al₂O₃ and so on.when compared with foreign countries,we lack of competitive ability.so the domestic iron ore dressing plants take raising the iron concentrate grade and reducing S,P,SiO₂,Al₂O₃ and so on as the major event.In the production process of iron and steel,the sulfur is one of the main element which removed and controlled,because it has the various influence to the steel performance.The sulfur not only is easy to cause the steel to have hot shortness phenomenon,moreover has the adverse effect to the steel hot-working performance, mechanics performance,the welding performance,also cause serious pollution to the environment,therfore,it appears that control the content of impurity S of the blast-furnace smelting raw material especially important.Jiang feng iron mine is a rather big iron mine in our country.The run of mine contains iron 29.69 percent,sulfur 3.70 percent.The industry spot applys one stage grinding,once roughing and once cleaning low intensity magnetic separation technology.The iron concentrate contains iron about 60 percent,sulfur about 1.80 percent.The content of sulfur of the iron concentrate exceeds standard for long,far beyond the request of the sulfur content in the iron concentrate quality standard in our country.The research of ore properties indicate that its main iron mineral is magnetite,main sulfide minerals is characterised by polymetallic sulfide as pyrite, pyrrhotite,chalcopyrite and so on.Through test research,we decide to apply two stage grinding,low intensity magnetic separation,floatation tenchnology,namely first stage rough grinding to discard tailings,rough concentrate entering second stage grinding to regrinding and reconcentration,desulfur concentrate by floatation.By a series of condition experiment,first stage grinding discarding tailings,when run of mine grind to under 0.074 mm 30 percent,obtaining rough concentrate with 40.57 percent weight percent,56.34 percent iron content,2.34 percent sulfur content, iron recovery 76.98 percent;Rough concentrate entering second grinding to regrinding and reconcentrate,obtaining iron concentrate with 31.17 weight percent, 65.69 percent iron content,1.44 percent sulfur content,iron recovery 68.69 percent.By two stage grinding,low intensity magnetic separation of run of mine,the sulfur content of iron concentration still high to 1.44%,we find out that sulfur in iron concentrate mainly composed by pyrrhotite,lard a little pyrite and chalcopyrite.It is very hard to reduce the sulfur content of iron concentrate merely by magnetic separation.Through once floatation to reduce sulfur,apply new activator TS and new collector DH,obtaining iron concentrate with 96.10 percent middle weight percent, 66.74 percent iron content,0.087 percent sulfur content,97.64 percent iron recovery.New activator TS and new collector DH was developed in the experiment,the effect of desulfur is extremely obvious to Jiang feng iron mine,simpled the craft, achieve the purpose of deeply desulfur,the sulfur of iron concentrate can be reduced to 0.06%.the grade of iron concentrate raised when deeply desulfur realized.The industrial experiment and industrial production flow is first stage rough grinding to discard tailings,rough concentrate entering second stage grinding to regrinding and reconcentration,desulfur concentrate by Cyclone-static microbubble flotation column,the result of industrial experiment indicate that obtaining iron concentrate with iron content more than 66 percent,sulfur content about 0.1 percent.The grade of iron concentrate more than 65 percent,sulfur content lower 0.15 percent since Jiang feng iron mine was put into production from June,2007,and the index is stable,further achieve the index required by the contract.The flow determined is reasonable,The compatibility of the reagent is strong,realized the purpose of deeply desulfur.