| With the diminishing reduction of non-renewable resources such as coal and oil,and the increasing supervision of the state on energy conservation and emission reduction of large enterprises,steel companies have entered a low-profit period.The energy consumption of the sintering process in the iron and steel smelting process accounts for about 50% of the total energy consumption of ironmaking,therefore,reducing the energy consumption in the sintering production process is an important means to reduce costs and improve the competitiveness of enterprises.At present,iron and steel enterprises have researched and developed advanced sintering technologies such as high alkalinity sinter,small ball sintering,low temperature sintering and low silicon sintering to reduce energy consumption and improve sinter quality.However,there is still much room for research in changing the structure of sintered raw materials.As a by-product of steelmaking,steel slag can be used as sintering flux to realize comprehensive utilization of metallurgical resources and reduce pollution.As a new type of cheap solid fuel,semi-coke can replace coke powder as sintering fuel to reduce production cost and save fossil energy.Therefore,the addition of a suitable proportion of steel slag and semi-coke for the sintering process is of great significance to enterprises in energy conservation and emission reduction.In this paper,the effect of sintering fuel ratio,sintering ore alkalinity,sintering negative pressure and steel slag ratio on the strength of sintered ore drum is studied when steel slag is used as sintering flux to produce sintered ore and the response surface method is used to design the "four factors and three levels" test to obtain the bestsintering conditions,and the sintering process of adding steel slag sintered ore isoptimized.Replacing some coke as a sintering fuel with semi-coke under optimal sintering conditions,the best substitution ratio of semi-coke is obtained by analyzing the metallurgical properties of sintered ore,conclusion as below:(1)Through the analysis of variance and response surface analysis,the influence of four factors on the strength of the sinter drum is sinter alkalinity?steel slag ratio?sintering negative pressure?sintering fuel ratio.The effect of sintering fuel ratio is not significant;the ratio of sintering fuel and sintering negative pressure and sintering negative pressure and steel slag ratio have significant interaction effects on the strength of sinter drum.(2)The best sintering process is simulation analysised by Design Expert software when the drum strength is 71% is: sintering fuel ratio 5.8%,sinter alkalinity 1.85,sintering negative pressure 8.9Kpa,steel slag ratio 7.5%.The strength of the sintered ore drum obtained after the sintering experiment was verified under the optimal sintering conditions was 71.3%,and prove that the simulation results are highly reliable.(3)The vertical sintering speed of the sintering cup experiment is affected by the substitution ratio of semi-coke and the moisture of the mixture,the experiment proves that when the substitution ratio of semi-coke is 35%,the moisture content of the mixture is 9.0%,which has the least influence on the sintering speed;Sintering drum index and FeO content are negatively correlated with semi-coke substitution ratio;The addition of semi-coke increases the softening temperature of the sinter,shortens the softening interval,and helps to improve the softening performance of the sinter;With the increase of the substitution ratio of semi-coke,the reduction of sinter and the reduction of pulverization rate of sinter increased firstly and then decreased.The sinter metallurgical performance is the best when the substitution ratio of semi-coke is 35%.(4)Through simulation analysis and experimental research,the best ratio of steel slag as sintering flux is 7.5% and the best alternative ratio of semi-coke for sintering fuel is 35%.Under this condition,the strength of the sintered ore drum reaches the ISO3271-2015 standard and the metallurgical performance is good. |
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