Study On Optimization Of Converter Cooling Technology Based On Cost Control

In the situation of low economic benefit of domestic iron and steel enterprises, process technology optimization of iron and steel production is one of the important directions of cost decreasing and benefit increasing. For the converter steelmaking process, raw material costs account for over 70 percent of the total cost, so it is possible to reduce cost by optimizing the charge structure. It is significant to investagate the influence factor and its influencing mechanism of converter raw material cost explicitly for directing converter charge structure design, reducing converter raw material cost and improves the economic efficiency of enterprises.According to the converter raw material conditions of a domestic steel industry, basing on converter material balance and heat balance, aiming at the cost control, one calculation model of cost per ton steel of converter raw material was established, and its calculation software was developed subsequently. Using the software, the variations of converter raw materials cost were investigated. The results show that it is benefit to reduce the converter cost of raw materials by reducing the temperature of hot metal, reducing silicon content of hot metal, increasing proportion of ore, increasing proportion of limestone, reducing steel scrap ratio. Structural optimization of converter coolant can reduce the cost per ton of raw material significantly.According to influence factors and their variations of converter raw material cost, considering the converter cooling effect and blowing process stability, the optimization principle of converter cooling was established. The principle is that reducing scrap ratio firstly, then using ore and limestone to balance converter heat in sequence. And cooling process was designed at different hot metal condition using the raw material cost calculation software.According to the optimized converter cooling process, the industrial experiments were carried out. The results show that the blowing process of converter is stable, the steel temperature blowing endpoint can be controlled accurately, and the chemical compositions of steel and slag of the blowing endpoint were stable. The contents of C, Mn, S, dissolved oxygen of the blowing endpoint steel and the basicity, FeO content of endpoint slag were equal to the controlling level before optimization, and converter dephosphorization effect was improved slightly.Converter smelting data tracking and statistical results showed that the average cost per ton steel of raw converter materials can be reduced 14.9 yuan using the optimized cooling process. Based on this,22.35 million yuan per year can be reduced on the condition of 1.5 million tons of Q235B grade steel per year.