Double-layer pre-sintering process with stand-support
In order to match the blast furnace and sintering capacity of Anshan Steel,increase the sintering produc-tion and solve the problem that the thickness of sinter layer cannot exceed 900 mm with high-proportion concentrate,Anshan iron and steel group developed a double-layer pre-sintering process,however,the sintering yield decreased and the sintering with grade of[5,10)mm increased in the industrial production process.Therefore,the basic re-search on the 1 000 mm double-layer pre-sintering process with stand-support was carried out in the laboratory.The results show that during the double-layer sintering,after the second ignition,the content of CO2 and CO are in-creased,the volume content of O2 is dropped sharply to about 8％,and the bottom mixture layer burns in a low-oxy-gen atmosphere for a certain period of time.The change of air permeability index during double-layer sintering can be divided into three processes.After adding the stand-support,the average index increases 10.37％and 12.61％of the first stage and the second stage,respectively,and the average index of the lowest point in the third stage increa-ses 28.95％.After adding the stand-support,the time that at the lowest content of oxygen is advanced,and the content of oxygen is increased.Also,the sinter drum strength is decreased,but the yield of sinter is increased.The utilization coefficient can reach 2.12 t/(m2·h),and the quasi-fine ratio of[5,10)mm is reduced significantly.The stand-support of 350 mm can be obtained better technical index compared with the stand-support of 400 mm.Results in laboratory prove that,the stand-support sintering of double-layer process can solve the key problems in actual ap-plication and can release its production capacity further.
double-layer pre-sinteringstand-support sinteringair permeabilityoxygen contentultra-deep bed sintering
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