Recycles Sludge from Semiconductor Production Process
Samsung Electronics and Hyundai Steel have developed a new wastewater recycling technology to reuse sludge from the semiconductor manufacturing process for steelmaking, the two companies announced on Sept. 27.
Wastewater sludge is a precipitate from a wastewater treatment process and accounts for more than half of the total waste generated from a semiconductor process. The main ingredient of wastewater sludge is calcium fluoride, which is similar to fluorite used to remove impurities (sulfur and phosphorus) from metal in the steelmaking process. When put into melted iron and slag, calcium fluoride promotes the reaction of removing impurities by lowering the melting point.
Samsung Electronics, Hyundai Steel, and Pos Ceramics, a recycling company, signed an agreement in August 2020 to develop a wastewater sludge recycling technology. Hyundai Steel's Dangjin Steel Mill succeeded in producing steel products using 30 tons of fluorite replacements in April this year. The achievement of the three companies is considered a good example of ESG management activities that responds to the government's resources circulation policy.
Korea imports all fluorite it needs from overseas (South America, China and other countries). Hyundai Steel has imported about 20,000 tons of fluorite a year. It plans to halve fluorite imports starting from as early as the end of October. The steelmaker will reduce the cost of purchasing fluorite as it plans to gradually jack up the use of the fluorite replacement in the future. Samsung Electronics has thus far sent its wastewater sludge to cement factories, but can now recycle it in other fields.