Optimization Of Converter Process Under Different Scrap Ratio

As production increase of scrap steel,its price gradually decreased in recent years.Therefore,each steel works try to raise scrap ratio of the converter to reduce the cost and enhance the benefit of steelmaking process now.However,heat shortage will be the limiting factor as the increase of scrap ratio in converter.Therefore,optimizing process operation of oxygen supply system and slagging regime under the current converter equipment condition has great significance to realize high scrap ratio in converter.As production increase of scrap steel,its price gradually decreasing in recent years.Therefore,each steel works try to raise scrap ratio of the converter to reduce the cost and enhance the benefit of steelmaking process now.However,heat shortage will be the limiting factor as the increase of scrap ratio in converter.Therefore,optimizing process operation of oxygen supply system and slagging regime under the current converter equipment condition has great significance to realize high scrap ratio in converter.Supporting the 100t BOF of Huai-an steel,process optimization research under different scrap ratio to improve hit rate of end-point in converter was done,and the research content is as follows:First of all,under the condition of regular scrap ratio,the pressure loss measurement,oxygen lance nozzle optimization,water model test and field test were carried out,and the conclusions are as follows:(1)The resistance loss of oxygen pipeline is 0.08-0.10MPa during the using pressure0.8MPa;(2)The water modeling experiment shows that,the impact depth of metal bath increased by 7~8mm,the impact area of metal bath enlarged by 28-65mm~2 and the mixing time of bath shortened by 1.9-9.3s;(3)The industrial test results show that hit rate of BOF end-point temperature improved by 39.87%;the dephosphorization rate improved by 2.58%;the total slagging materials consumption reduced by about 8.5 kg per ton steel and the smelting time shortened by 0.53 minutes.Secondly,under the condition of high scrap ratio,the design,water model test and field test of the secondary oxygen lance nozzle were carried out,and the conclusions are as follows:(1)The design parameters of the secondary oxygen lance nozzle are the four main holes which Mach Number is 1.96 and 8 secondary holes which Mach Number is 1.0;(2)The water modeling experiment shows that,smelting effect is the best when the top blowing flow is 75.57m~3/h;(3)The average end-point temperature was 1625?,the end-point phosphorus content was 0.017%on average,and secondary combustion rate increased by 7.16%;(4)The smelting cycle was shortened by 0.5min,and the oxygen consumption per ton was reduced by 0.7m~3 and the gas recovery per ton was reduced by 3000m~3.Finally,according to the field data,the terminal control model of converter is developed,the results are as follows:(1)The hit rate of end-point temperature±10?was reached 66.7%,and the hit rate of end-point carbon±0.01%was more than 94.3%;(2)The amount of lime consumption per ton in the final control model is 25.75kg,which is significantly improved compared with the previous average of 34.9kg.This model is of great help to reduce the amount of lime.