Recent Developments in Commercial Scale Dry Slag Granulation and Energy Recovery

Abstract

Molten slag from pyrometallurgical furnaces is tapped at high temperature and carries a large amount of high-grade heat. Traditional slag handling methods of slow air cooling and water granulation do not allow for recovery of energy from slag. As such, there have recently been numerous studies into slag granulation and energy recovery technologies to enable the use of slag as a waste heat resource, with dry slag granulation and subsequent heat recovery being intensely studied. However, most of these technologies have never been brought to a commercial scale due to numerous challenges including scalability, cost, low energy recovery efficiencies, and difficulties in energy utilization.

Ecomaister-Hatch has recently developed and brought to commercial scale a reliable and simple dry slag granulation that allows for simultaneous energy recovery from slag. The current article introduces this technology and compares different proposed energy recovery concepts and the level of development that they have achieved.