Investigation On Double-Layer Of Sintering Process By Enriched Oxygen

With the state attaching importance to environmental protection,getting the high level of sintered ore,improving the efficiency of sintering production,reducing energy consumption and getting lower capital costs have become maj or problems dealt with steel companies.During half a century of development,the sintering production equipment is complete,large-scale and automation.The quality of sinter and sintering production efficiency getting higher and higher.Some iron and steel company decided to develop a double-layer sintering process with the premise of not change the equipment and the quality of the sinter to improve the productivity,but the double-layer sintering limited by air flow has the problem which the sinter strength is poor due to the oxygen content is insufficient.Therefore,investigation on double-layer sintering process by enriched oxygen has been carried out,in the present work is research which doing single sintering,double-layer sintering without oxygen supplementation and double-layer sintering by enriched oxygen with the conditions of the sintering process of this iron and steel company and controlling the air volume during sintering.The aims is to provide a theoretical guidance and implementation plan for the application of double-layer sintering process.In the present work,the following conclusions are drawn:(1)Single(650 mm)sintering:Single-layer sintering process parameters which include air volume is 85 m3/h,sintering time is 47 min and O2 concentration in exhaust gas during sintering process is 15.42%are determined.Under this condition,the sintering index production efficiency(sinter pot utilization coefficient)is 0.90 t/m2·h-1 and drum strength is 66.71%.(2)Double-layer(650+300 mm)sintering without oxygen supplementation:The O2 concentration in exhaust gas before the second ignition is 15.42%which belongs to the normal range.The O2 concentration in exhaust gas after the second ignition is 12.48%which is hypoxia.Under this condition,the sintering index production efficiency(sinter pot utilization coefficient)is 1.11 t/m2·h-1 which is 23%higher than the single layer sintering and tumble strength is 55.27%which compared with the single layer sintering obviously deceased.(3)Double-layer(650+300 mm)sintering by enriched oxygen:In the material layer the oxygen burning during sintering increases and the sintering conditions become better.Under this condition,the sintering index production efficiency(sinter pot utilization coefficient)is 1.20-1.40 t/m2·h-1 which is 40-50%higher than the single layer sintering and 21%higher than double-layer sintering without oxygen supplementation.Drum strength is 62-63%with the conditions of oxygen supplement concentration is 3.5-5.5%and oxygen supplement time is 20 min which is close to the single-layer sintering index and 6-7%higher than double-layer sintering without oxygen supplementation.In summary,through the study of this subject,reasonable oxygen supplementation way are carried out for double-layer sintering.Under the premise of ensuring the quality required of the sinter,the production efficiency of the sinter is significantly improved,thereby meeting the steel company's requirements for sinter output.