Recycling of refractory bricks used in basic steelmaking: A review

Refractories are indispensable for all high temperatures processes, such as the production of metals, cement, glass and ceramics. It is estimated that up to 28 million tons of spent refractories are generated every year. Despite these significant amounts, recycling of spent refractories has received little attention due to the abundance of low cost virgin raw materials and low disposal costs of the, largely inert, materials. In the last two decades, recycling of spent refractories has started to receive more attention due to environmental considerations and increasing costs for landfilling. However, recycling in applications such as road bed foundations or slag conditioners does not capture the full intrinsic value of the materials. Higher value recycling as refractory raw materials is much more limited, and estimated at only 7% of refractory raw material demand. Recently, rising prices and supply issues for high quality virgin raw materials have created a strong incentive for closed-loop refractory recycling. This review gives an overview of the history of refractory recycling and the main refractory recycling applications, with a particular focus on recycling in new refractories. Current spent refractory processing in view of raw material recycling is discussed, and an outlook is given to future trends and developments.