Development of waste heat recovery technology from steel slag

Abstract

The temperature of molten steel slag produced by the steelmaking process is 1500°c~1700°c, and the total amount of energy contained is considerable. Therefore, the efficient recovery and utilization of sensible heat of steel slag has always been the focus of attention of the metallurgical field all over the world. However, at present, the average recovery rate of waste heat resources per ton of steel in China's iron and steel industry is less than 26%, while the sensible heat recovery rate of various molten slag (including steel slag) is only 1.6%. There are huge room and a broad market for improvement.

Biochar and Other Carbonaceous Materials Used in Steelmaking: Possibilities and Synergies for Power Generation by Direct Carbon Fuel Cell

“…Finally, even though steelmaking processes operate at some of the highest temperatures among all industrial processes, only a small portion of the associated waste heat available (e.g., charge melting, slag cooling, flue gases) is exploited at industrial scale [55][56][57][58]. Indeed, as stated by Zhang et al [59], the current waste heat recovery rate of the steel industry is only at 17%, whereas in China the value reaches 26% according to Yue et al [60]. Consequently, several studies and industrial trials have tried to exploit this energy source, focusing mainly (i.e., by means of organic Rankine cycle systems) [61,62].…”