Production of hydrogen fluoride from calcium fluoride-containing waste or fluorite

摘要

A process for the preparation of HF and anhydrite from reaction of calcium fluoride in the form of fines and sulfuric acid. The content of sulfuric acid is kept in a range where no agglomeration occurs. In such process, dust originating from natural fluorspar can be reacted, as well as synthetic calcium fluoride, e.g., from calcium fluoride and optionally calcium carbonate containing solids from treating a waste gas or waste water with basic calcium compounds to remove contained HF.