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Monday, July 14, 2025

New Process Enables Recycling of Waste Sludges from Steel and Aluminum Manufacturing

 

    Sun Metalon, a Japanese company with U.S. offices now based in Chicago, utilizes an oven-sized chamber to transform metal waste sludge into purified metal pucks that can be recycled back into steel, aluminum, or other metals. Steel and aluminum waste sludges are toxic and costly to landfill. This new process will lower those costs by recycling that waste stream. Most steel and aluminum are already made from recycled metal rather than raw ore. This new process will increase that amount. Sun Metalon notes that up to 20% of metal is lost during manufacturing, and recovering that metal to be reused in original or other processes can add significant value. Any industry that uses these metals, such as automotive and heavy equipment manufacturing, can benefit from the process. The process is referred to as a “non-binder-based sinter technology.” Die casting, metal casting, and machining operations can benefit from the process. Sun Metalon’s equipment is modular and compact, which makes it easy to integrate into existing manufacturing plants.








     According to 3DPrint.com, the process utilizes:

“…an electromagnetic field to concentrate energy, coupled with a unique “booster material” that accelerates recycling and refining processes while enhancing energy efficiency.”

     Canary Media wrote about the process and talked with Sun Metalon’s CEO:

Sun Metalon CEO and co-founder Kazuhiko Nishioka said he got the idea for the technology while working at Nippon Steel and studying for a PhD at Northwestern University near Chicago with Nippon’s support. In 2021, he and two colleagues at Nippon founded the company as they did DIY experiments to clean up tiny scraps too contaminated with oil or other substances to be recycled.”

They received two patents on the heating technology in 2024. Sun Metalon’s units are modular “ovens” that can be placed on a factory or foundry floor; the metal waste fed into them is basically cleaned with intense heat and turned into “pucks” or “coins” that can be recycled in metal-making processes.”

We apply our heating, evaporate fluids, condense [impurities] back to liquid, and collect it,” explained Nishioka, noting the process involves reaching the boiling point of oil. The whole thing is powered by electricity, making it carbon-free if renewable energy is available.

Sometimes scrap has a negative value, especially for sludges — no one can recycle it, so they have to pay for disposal,” he said. “We can bring it up to best or second best” in the value chain of recycled metal feedstock. “Then the profit can be shared among customers.”








     The process has several decarbonization advantages: less waste to transport as it can be reused onsite, more efficient use of available resources, fewer new resources to bring in, environmental impact reduction, and supply chain efficiency improvement.

     The dry briquettes are shown below for the different metals. Copper and nickel alloys can also result from the process.














     Toyota and the construction equipment manufacturer Komatsu have the equipment installed, tested it in their facilities, and are working with Sun Metalon to scale up the technology. Komatsu produces about 150 tons of waste sludge from polishing, ​“a difficult-to-handle mixture of fine metal particles, oil, and water.”

     Canary Media also reported:

The Recycled Materials Association, a trade group that represents metal recycling, noted that over 70% of steel and 80% of aluminum in the U.S. is made from recycled material.”

Compared to the processsing and transportation needed for mining, drilling, harvesting, or other methods of extracting natural resources for manufacturing, the use of recycled materials typically produces fewer greenhouse gas emissions,” Rachel Bookman, a spokesperson for the organization, said by email.

     Canary also presented the CEO’s vision for the technology:

“Nishioka said the technology could be useful for “automotive and aerospace, construction machinery, any product using metal,” adding that he plans to pitch to steel mills and foundries in the Midwest and South.”

“Any process melting metal can benefit,” he continued, “either companies that are melting metal or companies purchasing from those companies.”

“Nishioka imagines that with more innovation, the modular technology could be used not only to prepare metal for recycling but to actually create metal products.

“He’s also hopeful that new industrial processes could spur manufacturing in developing nations, an idea inspired by his time volunteering in Kenya as an undergraduate student.

“My original vision was to bring compact steelmaking processes into a couple different boxes,” he said. “We can bring those boxes wherever we want. It could be in Africa, or on Mars.”

     The technology transforms low‑value swarf into pristine, high‑value metal. Transforming stainless steel polishing sludge is one application. Another is transforming metal chips and lathe turnings. Another is transforming swarf, which is small chips and flakes from roll mills and grinding operations that contain water or oil-based lubricants. This waste cannot be returned directly back into melting furnaces. The new process can change that, resulting in a product of dry briquettes of known alloy composition. According to the mid-2023 announcement of a joint venture with Toyota:

The company is developing a breakthrough metal additive manufacturing technology based on a new principle that enables ultra-high efficient heating resulting in up to 500 times faster speed and cost reductions of 90%. The company core technology also enables high efficient metal recycling applications.”

     Once this technology is fully tested, it may become standard in metals manufacturing, resulting in significant cost and emissions reductions and lower environmental impacts. It is another valuable link in the chain of the circular metals economy. The remaining challenges to this technology include high initial costs and further commercial validation.

 

  


References:

 

Researchers invent new oven-sized device that transforms toxic sludge into valuable material: 'The profit can be shared'. Christine Dulion. The Cool Down. July 7, 2025. Researchers invent new oven-sized device that transforms toxic sludge into valuable material: 'The profit can be shared'

This startup turns steel and aluminum waste into usable metals. Kari Lydersen. Canary Media. June 9, 2025. This startup turns steel and aluminum waste into… | Canary Media

The future of metal recycling. Sun Metalon. Turn your metal waste into revenue – Sun Metalon

Sun Metalon Secures $21M to Accelerate Circular Economy in Metal Manufacturing. Sangmin "Simon" Lee. 3DPrint.com. October 3, 2024. Sun Metalon Secures $21M to Accelerate Circular Economy in Metal Manufacturing - 3DPrint.com | The Voice of 3D Printing / Additive Manufacturing

Sun Metalon Inc. and Toyota Motor Corporation Jointly Develop New Innovative Aluminum Recycling Process. Sun Metalon. May 30, 2023. Turn your metal waste into revenue – Sun Metalon

 

 

 

 

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