Contribution to a Circular Economy (effective use of resources)

Recycling of Low-Grade Nickel Oxide Ores

Low-grade nickel oxide ore for THPAL

Smelting and refining of low-nickel-content oxide ores found near the earth’s surface involves numerous technical challenges that made it difficult to achieve on a commercial basis. However, such low-grade oxide ores are said to account for about 70% of the world’s nickel oxide mineral resources, which lead to worldwide demand for development of technology to enable its processing. Drawing on our advanced equipment engineering and operation technologies, in April 2005 our Group led the world in achieving large-scale commercial production via the hydrometallurgical processing technology known as HPAL at Coral Bay Nickel Corporation (CBNC)¹ in the Philippines.
In 2013, Taganito HPAL Nickel Corporation (THPAL)² began operation as our second HPAL plant. The nickel intermediate smelted and refined at the two HPAL plants is used in Japan as electrolytic nickel and as secondary battery cathode material for electric vehicles. We also recover and recycle cobalt contained in the intermediate and scandium and chromite contained in the ore.

• 1.Coral Bay Nickel Corporation (CBNC): Shareholders: Sumitomo Metal Mining Co., Ltd. (84.375%); Nickel Asia Corporation (15.625%). Head Office: Rio Tuba, Bataraza, Palawan Province, Philippines
• 2.Taganito HPAL Nickel Corporation (THPAL): Shareholders: Sumitomo Metal Mining Co., Ltd. (75%); Mitsui & Co., Ltd. (15%); Nickel Asia Corporation (10%). Head Office: Taganito, Surigao del Norte Province, Philippines

■ Supply Chains for Realizing a Stable Supply of Nickel

Battery Recycling

As automobiles undergo what is expected to be a rapid and long-term shift to electric drive and battery capacity becomes increasingly higher, demand is growing for the copper, nickel, cobalt, and lithium used in lithium-ion secondary batteries (LIBs) for electric vehicles, leading to calls for effective resource recycling.
Since 2017, we have been working to recover and reuse the copper and nickel contained in LIBs through a process that combines the Toyo Smelter & Refinery’s copper smelting and refining processes and the Niihama Nickel Refinery’s nickel smelting and refining processes. The recovered nickel, in particular, is processed into a secondary battery cathode material at the Isoura Plant, realizing Japan’s first “battery to battery” horizontal recycling using materials recovered from used LIBs.
In addition to this, we have been promoting LIB recycling research and development and demonstrated in 2021 that cobalt, for which resource depletion is a concern, can also be recovered, purified to a high level, and reused as a raw material for LIB cathode materials. Moreover, through joint development with Kanto Denka Kogyo Co., Ltd., we established technology that recycles lithium from slag containing lithium into high-purity compounds in 2022, successfully developing a new process for horizontal recycling of copper, nickel, cobalt, and lithium.
In evaluations of battery performance by battery user Primearth EV Energy Co., Ltd., it was demonstrated on the product level that the performance of batteries using LIB cathode materials manufactured through this process is equal to that of batteries manufactured from conventional raw materials, primarily derived from natural resources.
We are currently studying the commercialization of battery recycling with the aim of establishing a system for processing 10,000 tons per year during the term of the 2024 3-Year Business Plan (FY2025–2027). In parallel with this, we are also working to develop technology for reducing CO2 emissions from the perspective of carbon neutrality. If this new process makes it possible to reuse valuable metals as resources on a commercial basis, it can be expected to make a further contribution to resource recycling to combat global resource depletion.
Looking ahead, we will continue to actively work on “battery to battery” horizontal recycling and will contribute to the formation of a sustainable circular economy and the strengthening of resource recycling to combat global resource depletion.

■ Recycling Flow

Other Recycling Initiatives

Percentage of Recycled Input Raw Materials Used

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 FY2022, our percentage of recycled input raw materials used was approximately 236 kt, accounting for 2.21% (2.38% in FY2021) of input raw materials, a slight drop from the previous fiscal year. Production volume of electrolytic copper from recycled raw materials was approximately 93 kt, accounting for 20.9% (23.1% in FY2021) of production volume, a slight drop from the previous fiscal year.

■ Percentage of Recycled Input Raw Materials Used

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

Slag as a Recycled 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 (70% 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 at Hyuga Smelting Co., Ltd., which manufactures ferronickel used as a raw material for stainless steel, is mainly used at steel blast furnaces. With a magnesia content of about 30%, ferronickel slag is used as a source of magnesia for blast furnace flux.

Precious Metal Recovery: Flow Diagram

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.