A study on the low-temperature wet synthesis of hydrofluoric acid from synthetic calcium fluoride and waste sulfuric acid. Issue 1 (March 2020)

• Record Type: Journal Article
• Authors: Lin, Min-Fa; Chang, Chih-Ping; Chang, Ken-Lin; Lee, Wen-Jhy; Wu, Jhong-Lin; Chen, Po-Han
• Is Part Of: IOP conference series. Volume 463:Issue 1(2020)
• Publication Date: 2020-03
• Subjects: HF productivity -- Synthetic CaF2 -- Waste sulfuric acid; Earth sciences -- Periodicals; Environmental sciences -- Congresses; Environmental sciences -- Periodicals; 550.5
• DOI: 10.1088/1755-1315/463/1/012098
• Languages: English
• ISSNs: 1755-1307

Abstract

Abstract: An innovative method for utilizing synthetic calcium fluoride (CaF2 ), recovered from fluoride-containing semiconductor wastewater, and waste sulfuric acid (H2 SO4 ) to produce hydrofluoric acid (HF) was investigated. The research was set to study the low-temperature production of HF via the reaction of synthetic CaF2 and waste H2 SO4 . The impact of H2 SO4 concentration and total volume (H2 SO4 + H2 O)/CaF2 ratio, drying temperature of synthetic CaF2 on HF productivity were investigated in this study. HF yield increased with increasing H2 SO4 concentration and total volume/CaF2 ratio under room temperature. In addition, the HF produced in the reactions involving the 105 °C-dried synthetic CaF2 were higher than the 600 °C-dried synthetic CaF2 ones. The study will not only find uses for this semiconductor wastes but also provide a greener alternative to the current commercial production of HF.