TY - JOUR
T1 - Recycle of synthetic calcium fluoride and waste sulfuric acid to produce electronic grade hydrofluoric acid
AU - Lin, Min Fa
AU - Wu, Jhong Lin
AU - Chang, Ken Lin
AU - Lee, Wen Jhy
AU - Chang, Chih Ping
AU - Lin, Yung Chang
AU - Chen, Po Han
N1 - Funding Information:
This research was funded by the Southern Taiwan Science Park Bureau, Ministry of Science and Technology of Taiwan (106-2218-E-110-009-MY2 and 108-2221-E-110-051), and TEEP@Asia Plus 2018-2019, Taiwan.
Publisher Copyright:
© 2020, Springer-Verlag GmbH Germany, part of Springer Nature.
PY - 2021/8
Y1 - 2021/8
N2 - An innovative method for utilizing synthetic calcium fluoride (CaF2), recovered from fluoride-containing semiconductor wastewater, and waste sulfuric acid (H2SO4) to produce hydrofluoric acid (HF) was investigated. The research was set to study the low-temperature production of HF via reaction of synthetic CaF2 and waste H2SO4. The impact of four factors, including H2SO4 concentration, total volume (H2SO4 + H2O)/CaF2 ratio, drying temperature of synthetic CaF2, and reaction carried out under different temperature, on HF productivity was investigated in this study. HF yield increased with increasing H2SO4 concentration and total volume/CaF2 ratio under room temperature. Generally, reactions carried out under low-temperature (< 100 °C) had a positive impact on HF yield. The higher temperature led to an increase in absorbed-HF but a decrease in total-HF. The reaction of commercial CaF2 and 70% H2SO4 had a higher absorbed-HF yield of 61.7% than synthetic CaF2 and 70% waste H2SO4, which had a yield of 36%. This was due to the higher purity of the commercial CaF2 and fewer interference ions in H2SO4. HF productivity was lowered by CaSO4, which hindered the reaction of reactants and also the generation of fluorosulfuric acid.
AB - An innovative method for utilizing synthetic calcium fluoride (CaF2), recovered from fluoride-containing semiconductor wastewater, and waste sulfuric acid (H2SO4) to produce hydrofluoric acid (HF) was investigated. The research was set to study the low-temperature production of HF via reaction of synthetic CaF2 and waste H2SO4. The impact of four factors, including H2SO4 concentration, total volume (H2SO4 + H2O)/CaF2 ratio, drying temperature of synthetic CaF2, and reaction carried out under different temperature, on HF productivity was investigated in this study. HF yield increased with increasing H2SO4 concentration and total volume/CaF2 ratio under room temperature. Generally, reactions carried out under low-temperature (< 100 °C) had a positive impact on HF yield. The higher temperature led to an increase in absorbed-HF but a decrease in total-HF. The reaction of commercial CaF2 and 70% H2SO4 had a higher absorbed-HF yield of 61.7% than synthetic CaF2 and 70% waste H2SO4, which had a yield of 36%. This was due to the higher purity of the commercial CaF2 and fewer interference ions in H2SO4. HF productivity was lowered by CaSO4, which hindered the reaction of reactants and also the generation of fluorosulfuric acid.
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U2 - 10.1007/s11356-020-09867-x
DO - 10.1007/s11356-020-09867-x
M3 - Article
C2 - 32729035
AN - SCOPUS:85088829505
SN - 0944-1344
VL - 28
SP - 40633
EP - 40639
JO - Environmental Science and Pollution Research
JF - Environmental Science and Pollution Research
IS - 30
ER -