Kyoei Steel and Kajima creates circularity for toxic metal waste

Steelmaker Kyoei Steel Ltd. and construction giant Kajima Corporation have announced a partnership to create a circular economy for metal waste contaminated with hazardous materials. This partnership will detoxify and recycle steel scrap containing lead paint and asbestos from demolished buildings, turning it into new construction materials.

Many structures built from the 1960s onwards used lead-based paints for rust prevention and asbestos for its heat-resistant and insulating properties. As these buildings reach the end of their life, their demolition generates waste that poses significant health and environmental risks. Current regulations have restricted or banned the use of these substances due to their confirmed adverse effects.

Under the new system, Kajima Corporation will send contaminated metal waste from its demolition sites to Kyoei Steel. Kyoei Steel will use its electric arc furnaces, which reach temperatures of several thousand degrees Celsius, to melt the scrap. This high-temperature process neutralises the hazardous substances while recycling the steel into new products, which the company brands as “Ethical Steel.” Kajima will then use this recycled steel in its new construction projects, establishing a closed-loop resource cycle.

This collaboration provides a solution to the challenges of managing such waste. Previously, contaminated metal had to be landfilled or have the hazardous materials stripped on-site, a process that exposed workers to health risks and increased their workload. The new method eliminates the need for on-site stripping, improving worker safety and productivity while preventing hazardous materials from entering landfills.

Kyoei Steel is currently the only electric furnace steelmaker in Japan with the necessary permits to process waste contaminated with both lead and asbestos. This unique capability is central to the partnership’s success. Kyoei Steel intends to secure permits for its other facilities beyond its current Yamaguchi plant, and both firms will work to strengthen their collection and transport infrastructure to support this expansion.