DISCUSSION ON DEVELOPMENT OF HEAT RECOVERY TECHNOLOGY FOR HIGH TEMPERATURE MOLTEN SLAG

In China, the annual output of high temperature molten slag is higher than 6×10⁸ t, which has a great value of heat. However, by now, most of heat resource can not be recovered. In this paper, four heat recovery technologies, including dry granulation, chemical method, waste heat utilization of cooling water and production using molten slag as the raw material, were discussed. The key factor for the application of heat recovery technology was the maximum utilization and economic efficiency. To recover heat resource, dry granulation and chemical method were adopted to treat the molten slag with lower content of active materials. Whereas, molten slag containing higher content of active materials needed to be treated without decreasing slag activity. Furthermore, waste heat utilization of cooling water could be adopted according to the actual condition. The difficulties in production using molten slag as the raw material should be overcome, which is beneficial for increasing the quality and decreasing the cost of the product. Finally, the structure variation during the liquid-solid transformation of molten slag should be further researched, contributing to realize the control of the mineral composition of solidified slag.