氟硅酸制取氢氟酸研究进展

Research Progress in the Preparation of Hydrofluoric Acid from Fluorosilicic Acid

磷肥副产的氟硅酸蕴含非常大的氟资源,且随着萤石资源的逐渐枯竭,以氟硅酸为原料制备氢氟酸的工艺将成为未来的主要工艺路线。着重概述了利用氟硅酸制取氢氟酸工艺的研究现状,并将其生产工艺分为直接法和间接法。其中直接法又分为氟硅酸直接热解法和浓硫酸分解法;间接法是将氟硅酸转化成氟化钙、氟硅酸镁、氟化氢铵和氟化氢钾等含氟盐,再将其热解或与浓硫酸反应制备氢氟酸。

Fluorosilicic acid,a by-product of phosphate fertilizer,contains a lot of fluorine resources.With the gradual depletion of fluorspar,the preparation of hydrofluoric acid from fluorosilicic acid will be the main process in the future.In this paper,the research status in the preparation of hydrogen fluoride from fluorosilicic acid is summarized,and the production method is divided into direct method and indirect method.The direct way includes two methods:direct pyrolysis of fluorosilicic acid and decomposition of concentrated sulfuric acid.Transforming fluorosilicic acid into fluorine-containing salts such as calcium fluoride,magnesium fluorosilicate,ammonium hydrogen fluoride and potassium hydrogen fluoride is the indirect method.Following pyrolysis or reaction with concentrated sulfuric acid,these fluorine-containing salts can be converted to hydrofluoric acid.