Sumitomo Metal Mining to Recover Zinc from Slag

Sumitomo Metal Mining will recover zinc from slag from smelting process. The firm sets an electric furnace at Harima plant in Hyogo to reduce slug with 9% of zinc. The firm starts the operation in fiscal 2007 ending March 2008 to recover annual 3,000 tonnes of zinc. The investment value is unknown. The firm also expands the recycling raw materials output from steel making dust at Shisaka plant in Ehime. The firm tries to expand the material sources including long term purchase contract from new developing mine to keep stabile supply of zinc ingot.

The smelting furnace to reduce and volatilize zing materials produces around 60,000 tonnes of slag per year. The firm sells the slag with 9% of zinc for cement and aggregate material. However, the firm decided to utilize the zinc from slag to improve the material source variation when zinc ore supply is very tight.

The firm will set the electric furnace to recover zinc from slag from March 2007 when the firm plans 2-month outage for every 3-year maintenance. The firm repairs around the smelting furnace and sets the new furnace. The firm tries to recover annual 3,000 tonnes of zinc from slag though the produced slag contains total 5,000-6,000 tonnes of zinc.

Zinc oxide ore, which Shisaka plant recovers from steel making dust, represents a third of total raw materials for zinc at Harima plant. The firm will increase the dust treatment by 25-30% at Shisaka and increase the recycling raw material rate at Harima when zinc ore supply gets tighter.