Hyundai Steel and Samsung Electronics have jointly developed a new technology for recycling sewage sludge (sediment) from semiconductor manufacturing to use it as a steelmaking additive.
The idea for the new technology was born when researchers discovered an affinity between fluorite, used for filtering out sulfur and phosphorus impurities during steelmaking processes ,and calcium fluoride (CaF2), which makes up 50% to 60% of the sewage sludge discharged from semiconductor plants.
In August 2020, Hyundai Steel, Samsung Electronics, and Pos Ceramics (known for its recycling technology) formed a tech-alliance to explore ways to reuse sewage sludge, and in April 2021, the group succeeded in producing steelmaking materials from 30 tons of fluorite substitutes.
The new technology was verified by the Korea Environment Corporation (K-eco) in June 2021 and further verified by the National Institute of Environmental Research (NIER) in August 2021 before being officially approved on August 31.
The NIER considers the technology to be the most important development since the Environmental Assessment of Recycling (EAoR) established in July 2016. The organization also pledged to utilize the EAoR platform to provide full technical and administrative support for recycling technologies, so that they would not be unduly hindered by technological or regulatory obstacles.
Currently, Korea imports all of its fluorite from South America, China, and other countries. Hyundai Steel imports and uses around 20,000 tons of fluorite each year, and by the end of October 2021 aims to replace half of its fluorite with recycled sewage sludge, gradually increasing its replacement rate over time.
The new technology is expected to prevent sewage sludge from ending up at cement factories so that it can instead be used as a valuable resource for numerous Samsung Electronics manufacturing processes and as a replacement for a percentage of the fluorite used by Hyundai Steel.
Hyundai Steel sees the new recycling technology as a source for resource creation and an important asset for helping the company become the world’s top green steelmaker. The company is determined to overcome the challenges of limited resources by creating a virtuous cycle of resources and energy, powered by breakthroughs in environmental and energy technology.