Experimental Study On Desulfurization Technology Of Dulong High-sulfur Iron Concentrate

In China,high-grade iron ore reasours are rare,and domestic iron ore are always accompanied with high level impurities.Some iron dressing plants and metal dressing plants produce iron concentrate with exceed standard sulphur content,and those iron concentrate is unsalable,which increased corporate burden and caused waste of the resources.With the acceleration of China’s modern industrial and national defense construction,new manufacturing in China need high quality steel so that steel market will remain growth in the coming years.Therefore,it’s necessary to take full advantage of high-sulfur iron concentrate efficiently and cleanly,which can change the iron ore supply situation.It’s also help to reduce the dependence of import high-grade iron concentrates overseas and bring profit to domestic steel enterprise in some degree.This paper took high-sulfur iron concentrate of Yunnan Dulong as the study object,we used X-Ray fluorescence analysis,chemical analysis,partical size analysis,phase analysis,X-ray diffraction analysis and optical microscopy analysis to inverstigate chemical composition and mineral assemblage of high-sulfur iron concentrate.The result indicated that the main elements in the ore are Fe,Mg,Si,C,S,Al,etc.,the useful element in the ore is Fe,the grade of Fe is 60.81%,and the noxious element in the ore is S,the grade of S is 2.88%.There are 14 kinds of minerals in the ore,of which,metallic mineral mainly includes magnetite,pyrrhotite,pyrite,arsenopyrite,copper pyrites,blende;and transparent mineral mainly includes mica,calcite,quartz,chlorite,fluorite,diopside,tremolite,zircon.Process mineralogical research indicated the sulfide in the ore is pyrrhotite.Undissociated pyrrhotite forms a series of fine and tightly packed particles with magnetite,which need superfine grinding to dissociation.Meanwhile,dissociated pyrrhotite have micro-fine particle forms,these particles are difficult to separate with magnetite from low intensity magnetic separation because of magnetic flocculation.Both of the two reasons above lead to a higher sulphur content of iron concentrate.So reducing the content of pyrrhotite in the ore is the key to improve the grade of iron concentrate.On the basis of the ore properties,we took flotation and magnetic separation to remove pyrrhotite and recycle magnetite,Grinding fineness is set at 74μm accounted for 90%,vitriol(2000g/t)and copper sulfate(100g/t)as activators,pH=5.4,Sodium nbutylxanthate(175g/t)and Ammonium dibutyl dithiophosphate(125g/t)as collectors,foaming agent terpenic oil was identified as 90g/t;under the magnetic field intensity of 75 mT,a closed-circuit test procedure of one stage roughing-one stage concentrationone stage scavenging,and flotation tailings get into low intensity magnetic separation.Finally,we got a C6 grade iron concentrate with Fe grade was 68.72%,S grade was 0.35%,and Fe recovery is 83.38%.The research methods and related test procedures of the thesis can provide technical support for the comprehensive recovery and utilization of high-sulfur iron ore resources.