Experimental Research On Precipitator Dust From The Head Of Sintering Machine For Hot Metal Pretreatment

With the rapid development of iron and steel enterprises in the past few years, iron and steel industry has already become a large consumer of energy and also a pollution source. Therefore, the recovery and utilization of energy and resources has been a new developing direction for iron and steel enterprises.The precipitator dust from the head of sintering is common solid iron bearing material in iron and steel enterprises,whose recovery and utilization not only accords with the policy of energy saving and emission reduction, but also creats a new way to reduce production cost in ironmaking Hot metal pretreatment is an important link in ferrous metallurgy.In the consideration of the energy saving and cost reduction in enterprises, high-efficiency operation of hot metal pretreatment is especially of great importance. In this study, S and P in pig iron are pretreated by adding the precipitator dust to quicklime and meanwhile the results are analyzed. After a series of studies, following conclusions are drawn:(1)By analyzing the chemical composition, phases composition, particle size and microstructure of precipitator dust, it contains 22.87% Fe, 19.84% K, 2.81% Ca,4.08%Al, and 1.15% Na.(2)By adding different proportion of precipitator dust to CaO, and measuring the melting temperature of hemisphere point, it can be drawn that when the proportion of precipitator dust is 20%, the lowest melting temperature of 1354?can be obtained.(3)The experiments of dephosphorization and desulphurization in hot metal were conducted by adding different proportion of precipitator dust to CaO the superior proportion of precipitator dust is between 10% and 20%. ?[P] can be reduced from0.067% to 0.042%, and the dephosphorization efficiency increased to 37.31%. ?[S]can be reduced from 0.065% to 0.048%, and the desulphurization efficiency increased to 26.15%.(4)The thermodynamic parameters of dephosphorization and desulphurization in hot metal are calculated,the results indicated that lgLP increases by 13.02% from2.082 to 2.353. lgCPO43- increases by 0.56% from 19.583 to 19.694. lg?P2O5 drops by3.15% from-15.827 to-16.325. lgLS increases by 7.76% from 1.108 to 1.194. And lgCs increases 2.15% from-3.511 to-3.425. lg?s2- drops by 3.35% from-2.439 to-2.525.