TSMC [Taiwan Semiconductor Manufacturing] promotes the circular economy and strives to convert waste generated from manufacturing processes into products that can be used by other industries. In September 2021, the first hydrofluoric acid waste regeneration system, which can convert hydrofluoric acid waste into high-purity cryolite, was successfully launched in Fab 15B. As of November 2021, the system has reduced the outsourcing of hydrofluoric acid waste by 500 tons and produced 150 tons of cryolite. TSMC plans to implement this system in other fabs in 2023, with the expectation that it will reduce outsourced hydrofluoric acid waste by about 46,000 tons and produce recycled products of about 12,000 tons per year, creating a benefit of more than NT$ 400 million per year.
Using Hydrofluoric Acid Waste as Raw Material in Cryolite Production to Maximize Resource Utilization Value
In order to be friendlier to the environment and enhance the reuse value of the hydrofluoric acid waste generated during the wafer processing and cleaning process, TSMC has been collaborating with suppliers to conduct research on hydrofluoric acid waste recycling technology since 2018. Through the analysis of waste liquid concentration, reprocessing technology, pharmaceutical preparation and sales channels, it was concluded that the synthesis of hydrofluoric acid waste into high-purity cryolite has the most advantage as a high-value waste resource.
Cryolite is mainly used as a flux in the aluminum industry which can save more than 25% of energy consumption in the process of electrolytic aluminum smelting. Since the global production of natural cryolite is scarce and almost completely mined, most cryolite is produced artificially. The general production process requires multiple raw materials and higher reaction temperature. TSMC uses hydrofluoric acid waste as raw material in cryolite production. According to the concentration requirements of the waste hydrofluoric acid, it cooperates with manufacturers to develop a reaction agent that can generate cryolite, and then works within the appropriate operating parameters to reduce the reaction temperature. The successful synthesis of hydrofluoric acid waste liquid into high-purity cryolite not only overcomes the limitation of equipment space required for diluting the waste liquid, but can be directly produced in the fab. The locally developed reagents also enhance the regeneration technology of the domestic circular economy industry.
Difference Between TSMC Regeneration Cryolite Process and General Cryolite Process
Through the establishment of in-fab resource regeneration and activation equipment, TSMC converts waste resources into high-quality fluxes required for electrolysis in aluminum production. In addition to improving its own waste reduction, this also further expands the circular economy and implements energy-saving and carbon reduction across industries, creating a sustainable move towards the common good.
TSMC Hydrofluoric Acid Waste Regeneration System Milestone