In-Suit Industrial Tests of the Highly Efficient Recovery of Waste Heat and Reutilization of the Hot Steel Slag

Abstract

Waste heat recovery from hot steel slag in in-suit production lines has always been a worldwide challenge. In this paper, in-suit industrial-scale tests of the highly efficient recovery of waste heat from the hot steel slag by the air-blast method were performed in a steel mill. The effects of airflow and steel slag thickness on cooling air temperature changes and waste heat recovery were systematically studied. The application performance of the steel slag after heat recovery was also examined. The results showed that the effective heat recovered from 1 kg steel slag by air reached ∼1000 MJ, and the heat recovery rate was as high as 74.4% when the thickness of the hot steel slag in the slag tank was 400 mm (approximately 3.96 t) and the blast volume was 14 687 Nm3/h. The 28 day activity index of the steel slag was similar to that of the original steel slag. Most importantly, this process can be fully integrated into the existing advanced steel slag processing technology in China. Therefore, this method may be a technological innovation on an industrial scale on the waste heat recovery and building materials reutilization for the hot steel slag.