Latent heat of amorphous slags and their utilization as a high temperature PCM

Abstract

In a previous study, a rotary cylinder atomizing (RCLA) method for slag was developed and the slag spouting behavior from a nozzle was investigated. The theoretical approach of the previous study agreed well with the observed result. In this study, the potential of slag particles obtained by RCLA method as a phase changing material (PCM) was investigated. The latent heats and the temperature ranges of heat generation were measured for two kinds of amorphous slags (slag particles and water granulated-slag from blast furnace) using DTA (differential thermal analysis). Mathematical simulation of a countercurrent heat exchanger was performed and the effect of slag latent heat on gas temperature was estimated. The temperature range of the latent heat of amorphous slag was estimated to range from 800 to 950°C. The values of latent heat for slag particles and the water-granulated slag were 294 kJ/kg and 235 kJ/kg, respectively. Simulation results indicated that the latent heat of slag can decrease the temperature of waste gas which might increased the usable kind of waste gas. © 2010 ISIJ.