Innovative Solutions for Recycling of Byproducts*

Abstract

Government regulations around the world concerning environmental care are becoming more stringent, also including regulations and restrictions of depositing and use of dust, sludge and slag generated in the iron and steelmaking process. With this scenario, by-products such as iron containing dust, sludge, oxide fines, mill scales and slag, become a valuable resource and recycling may be a profitable activity within a plant. Up to ten percent in mass of the total steel output of dust, sludge and mill scale by-product materials and more than 40% of slag by product are generated within an integrated steel plant with an iron content ranging from 50% to 65% for fines and up to 25% for BOF-slag. Slags are being widely recycled and used in the cement industry, as is the case for BF slag, and in the construction industry in the case of BOF slags and EAF slags. However, value of BOF unmodified slag is typically low and environmental regulations limit the usage of the unmodified BOF slag. This paper describes innovative solutions for recycling of fines using cold briquetting technology and the modification and granulation of slag from steelmaking that increase the value of the by-product and yield a marketable product.

Potential of Alternative Organic Binders in Briquetting and Enhancing Residue Recycling in the Steel Industry

“…The aim is to find new markets and applications for steel by-products and waste materials, such as slag, dust, and sludge. The average quantities of generated dust, fines, sludge, and scales in integrated steel plants are in the range of 60-150 kg per ton of steel, which corresponds to approximately 3-7.5% of the total iron [2]. These fines cannot be directly charged back into the BF or steelmaking unit without conducting proper sorting, mixing, and agglomeration processes.…”