Study On The Technology And Mechanism Of Desulfuration Of Iron Concen Trate

Iron ore is the main raw material for steel production, the quality of the iron ore directly impacts on the quality of the steel. Sulfur is a harmful impuritie in steel, high content of sulfur would result in bad thermal processing performance of the steel, and the steel industry has strict requirements on the sulfur content of iron ore. Therefore the desulfurization o of iron ore can not only improve the quality of iron ore concentrate and steel, but also increased the iron ore competitiveness,and reduce the amount of iron ore imports. Based on the mineralogy researcch of magnetic iron ore from Jiangxi Yifeng Wanguo, the study on the technology and mechanism on desulfurization of it has investigated.The mineralogy study showed that the TFe grade of concentrate is62%, and the sulfur content in the iron ore cencentrate is high, which mainly presents in pyrrhotite, partly exists pyrite.Experimental study has found that after grinding, the ore monomer dissociation degree improved and fresh surface appeared. Compared with that without grinding, the desulfurization flotation was affected. The flotation-magnetic separation process is much better than the magnetic-flotation separation process. Under the optimum conditions, the concentrate grade of iron concentrate from high sulfur iron ore is65.54%TFe and0.47%TS, and the recovery grade of iron is93.22%. The concentrate grade of iron concentrate from intermediate sulfur iron ore is64.57%TFe and0.43%TS, the recovery grade of iron is94.40%.Mechanistic studies suggest that oxidation of pyrrhotite greatly impacts on the flotation of pyrrhotite. For fresh pyrrhotite, in the acidic conditions, the oxidation time of the pneumatic rises, and the pyrrhotite recovery rate increases, while in alkaline conditions, the oxidation time of the pneumatic rises, and pyrrhotite recovery rate first increases and then decreases, which may be caused by the generate of S0on the surface of pyrrhotite. At different pH values, the dissolved quantity of sulfur and iron is different, and the changes of the mineral surfaces are not the same. For the lower the pH values, the greater amount of iron of pyrrhotite is dissolved. However in alkaline conditions, Fe (OH)3layer hydrophilic film is easy to generate on the surface of pyrrhotite s. Adding activator is conducive to enhance the floatability ofpyrrhotite.