Other Recycling Initiatives

Procurement and Use of Recycled Input Raw Materials

The SMM Group procures copper scrap and precious metal scrap from the market, recovers zinc from electric arc furnace dust, and recovers valuable and precious metals from used printed circuit boards and other sources. In FY2023, our percentage of recycled input raw materials used was approximately 202 kt, accounting for 1.68% (2.21% in FY2022) of input raw materials, a slight drop from the previous fiscal year. Production volume of electrolytic copper from recycled raw materials was approximately 76 kt, accounting for 20.2% (20.9% in FY2022) of production volume, a slight drop from the previous fiscal year.

■ Percentage of Recycled Input Raw Materials Used¹

• 1Percentage of recycled input raw materials used: Total raw materials used ÷ recycled materials x 100

Effective Use of Slag as a Recycled Copper Raw Material

Copper slag is a by-product produced during smelting at the Toyo Smelter & Refinery, which manufactures electrolytic copper. The main use for copper slag (80% of the total volume) is cement production for Japan and overseas. With an iron content of about 40%, copper slag is widely used as a source of iron for cement.
The ferronickel slag produced as a by-product at Hyuga Smelting Co., Ltd., which manufactures ferronickel used as a raw material for stainless steel, is mainly used for harbor and civil engineering construction.

Zinc Recovery from Steelmaking Flue Dust

Shisaka Smelting Co., Ltd., a Group company, is using steelmaking flue dust produced by electric arc steelmaking furnaces as the main raw material for recovering zinc (crude zinc oxide). The steelmaking flue dust is reduced and roasted with coke and other materials, and then dust with volatilized zinc undergoes hydrometallurgical refining and is heat dried to remove impurities and recover the zinc.

Precious Metal Recovery

Discarded household appliances and discarded electronic parts collected nationwide, and E-scrap containing high concentrations of gold, silver, copper, palladium, and other valuable metals generated in the manufacturing of these appliances and parts, provide SMM with raw materials for the recovery and recycling of precious metals (gold, silver, platinum, etc.).
After sorting the collected raw materials into parts that contain precious metals and those that do not, the SMM Group company Ohkuchi Electronics Co., Ltd. uses the pyrometallurgical or hydrometallurgical process, depending on the composition and other aspects of the parts, to condense the materials before transporting them to the Toyo Smelter & Refinery.
The Toyo Smelter & Refinery smelts and refines those condensed raw materials along with other copper and precious metal raw materials, and then recycles them into high-grade precious metals.

■ Precious Metal Recovery Flow Diagram