Samsung Electronics, along with Hyundai Steel and recycling company Steel Ceramic, has jointly developed a new technology that can reuse wastewater sludge (precipitates) generated in semiconductor manufacturing processes in steel mills. The three companies signed a technology agreement on wastewater sludge recycling in August 2020 and succeeded in producing steel materials using 30 tons of fluorite – replaced products at Hyundai Steel’s Dangjin Steel Mill through joint research and development.
The new technology was finally approved on August 31, 2021 after the first evaluation by the Korea Environmental Corporation in June and the final evaluation by the National Institute of Environmental Research in August 2021.
The researchers focused on the fact that calcium fluoride (CaF2), which accounts for 50-60% of semiconductor wastewater sludge, is a similar component to fluorescence. In the steel-making process, fluorescent stone is used to more easily remove impurities in iron such as sulfur (S) and phosphorus (P).
Wastewater sludge is a precipitate from the wastewater treatment process generated during the semiconductor process and accounts for more than half of the total waste. The wastewater sludge from Samsung Electronics’ semiconductor plant has so far been sent to all cement plants and recycled only as cement raw materials. However, with the development of new technologies by the three companies, the scope of use of semiconductor waste has expanded. Accordingly, wastewater sludge is expected to be used as a substitute for fluorite, a mineral that has relied entirely on imports from South America and China. Hyundai Steel imports and uses about 20,000 tons of fluorite annually, and plans to replace about 10,000 tons with wastewater precipitate recyclables as early as the end of next month and increase future usage.
With this technology development, Samsung Electronics expects to expand the field of recycling wastewater sediment that has been sent to cement plants and contribute to reducing Hyundai Steel’s purchase cost of fluorite.