DRY BLAST FURNACE SLAG GRANULATION WITH WASTE HEAT RECOVERY

摘要

Each year, approx. 400 million tons of blast furnace slag is produced worldwide with a tapping temperature of around 1,500°C. Currently, the slag is granulated in wet granulation plants using large volumes of water and to date it has not been possible to utilize the remnant heat energy of the molten slag, with approx. 1.8 GJ of energy per ton.However, in an R&D project currently underway by a consortium of companies led by Primetals Technologies and comprising voestalpine Stahl (Austria), FEhS Building Materials Institute (Germany) and the University of Leoben (Austria), a new dry atomising technology is being investigated to use air to cool molten slag and recover the lost heat energy.Phase 1 of the project has been completed where a technical plant was set up in 2012. The research results have shown the process suitability as an industrial application and the decision was taken to escalate the project to a semi-industrial scale prototype plant.The Phase 2 development of this plant is now underway and is scheduled for installation at the site of voestalpine Stahl in Linz in mid-2017. This paper will show the development path taken to date and the planned route to our goal in 2017 of being the first to industrialise the 'game changing' process.