Influence Of Steel Slag Blending On Properties Of Coke

Since that the production capacity of iron and steel industry expands continuouslyand the blast furnace is becoming larger leads excessive consumption of high-qualitycoking coal, the high-quality coking coal shortage has become an important factoraffecting coke production and its cost. Reducing the temperature of the heat preservationin the process of blast furnace ironmaking, the reaction efficiency can be improved,which leads the coke rate reduces and the amount of CO2release decreases. Addingcatalytic slag in coal blending for coking can improve the coke reactivity, reduce initialreaction temperature, improve reaction efficiency and achieve waste recycling.In this paper, some kinds of typical caking coal—Pengcheng fat coal, Kangzhuang1/3coking coal and Liulin coking coal—are selected. The crucible coke experiment and40kg small coking oven coal mixing experiment have been carried out with different sizeand blending ratios of slag to study the coke properties, such as strength, thermalproperties, ash and sulfur. The effects of steel slag size and addition on the coke qualityhave been discussed to determine the optimum craft parameters of steel slag addition andto provide theory basis for steel slag blending.From crucible coke experimental results, it shows that the coke solution loss rateincreases with the amount of the slag, and the post-reaction strength of coke reaches themaximum. When the additions are consistent, the smaller the slag size is, the higher thecoke reactivity index is. Ash and sulfur of coke increases and sulfur reaches a maximumwhen addition of the slag is increased. The specific surface area analyzer, X-raydiffraction and SEM analysis etc are carried out to study the pore structure of coke, andthe microcrystalline structure. In this paper, the effect rules of slag on coke reactivity andthe rules of distribution and state of slag in coke are obtained. The mechanism of theeffects of steel slag on coking properties has been analyzed theoretically.From the coking coal blending experimental in coking oven of40kg, it is concludedthat when coke quality is met, the blended amount of slag can be increased by1-2%,which can decrease the initial temperature of the coke solution loss reaction by33℃,improve the reaction efficiency in the furnace, reduce the coke ratio and decrease theamount of CO2release. It opens up new ways of utilization of steel slag.