Department of Civil Engineering, National Taiwan University, Taipei, Taiwan.
Environmental Resource and Management Research Center, National Cheng Kung University, Tainan, Taiwan.
Environ Sci Pollut Res Int. 2021 Aug;28(30):40633-40639. doi: 10.1007/s11356-020-09867-x. Epub 2020 Jul 29.
An innovative method for utilizing synthetic calcium fluoride (CaF), recovered from fluoride-containing semiconductor wastewater, and waste sulfuric acid (HSO) to produce hydrofluoric acid (HF) was investigated. The research was set to study the low-temperature production of HF via reaction of synthetic CaF and waste HSO. The impact of four factors, including HSO concentration, total volume (HSO + HO)/CaF ratio, drying temperature of synthetic CaF, and reaction carried out under different temperature, on HF productivity was investigated in this study. HF yield increased with increasing HSO concentration and total volume/CaF 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 CaF and 70% HSO had a higher absorbed-HF yield of 61.7% than synthetic CaF and 70% waste HSO, which had a yield of 36%. This was due to the higher purity of the commercial CaF and fewer interference ions in HSO. HF productivity was lowered by CaSO, which hindered the reaction of reactants and also the generation of fluorosulfuric acid.
本研究旨在探索利用含氟半导体废水中回收的合成氟化钙（CaF）和废硫酸（HSO）生产氢氟酸（HF）的创新方法。该研究通过合成 CaF 与废 HSO 的反应，考察了低温下生产 HF 的情况。考察了 HSO 浓度、（HSO+H O）/CaF 总体积比、合成 CaF 的干燥温度以及在不同温度下进行反应等四个因素对 HF 产率的影响。本研究结果表明，在室温下，HF 产率随 HSO 浓度和总体积/CaF 比的增加而增加。一般来说，低温（<100°C）下的反应对 HF 产率有积极影响。温度升高导致吸收的-HF 增加，但总-HF 减少。商业 CaF 与 70%HSO 的反应比合成 CaF 和 70%废 HSO 的吸收-HF 产率高，为 61.7%，而后者的产率为 36%。这是因为商业 CaF 的纯度更高，HSO 中的干扰离子更少。硫酸钙会降低 HF 的生产力，因为它会阻碍反应物的反应和氟硫酸的生成。
