Slag Atomising Technology: Unlocking Real Value

Author(s): S. Mostaghel, L.So, M. Cramer, S. Faucher, S.K. Lee, and S.-Y. Oh
The Fourteenth International Ferroalloys Congress, May 31–June 4, 2015, Kiev, Ukraine

Abstract

For most ferroalloy producers, slag has limited or no value after the smelting process is completed. In many cases, slag management represents an increasingly expensive handling and storage challenge. Slag has untapped potential as a source of energy, revenue (from high-value slagsales) and un-recovered alloy droplets. Few, if any, of these traits have been valorized with the current technologies. Present ferroalloy markets are characterised by small margins and increasing regulations and costs. In order to compete in the current market, producers are forced to improve overall productivity in their current operations. Slag valorization plays an important role in generating additional revenue and in increasing operation efficiencies, while improving safety and reducing environmental impacts with limited capital commitment.

Ecomaister-Hatch Slag Atomization Technology (SAT) represents a commercially proven application of air blasting of ferroalloy slags at industrial scale. The technology is extremely robust, easy to install, and cost-effective. By air atomising slag into fine, solidified, and cool particles, the operator is able to avoid the safety risks associated with liquid slag handling and water granulation. This slag treatment method reduces dust creation and water consumption, and also allows for energy recovery from the molten material. Through innovative process designs, slag is now intrinsically valuable as a raw material for a number of other applications e.g. sand blasting, ballast, or roof shingles. The elimination of multiple cooling and treatment steps of a traditional slag handling results in higher throughputs, lower transport and crushing costs, a smaller footprint, and shorter slag cycle. These factors in combination provide short term revenue and long term sustainability.

The current paper will examine the design and benefits of the Ecomaister-Hatch Slag Atomization Technology when applied to, for example, ferrochrome production slags. A business case is also examined utilizing a 200,000 tonne per year ferrochrome operation including a metal recovery plant as an example.