Preparation of hydrogen fluoride from fluorspar or calcium fluoride containing waste material
AssigneeSolvay Fluor GmbH
InventorsHelmut Grass, Matthias Hengst, Johannes Eicher
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Abstract
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.
Claims15
A process for the preparation of hydrogen fluoride comprising reacting calcium fluoride substantially in the form of fines as starting material with sulfuric acid in a reaction mixture with the proviso that the content of sulfuric acid in the reaction mixture is kept in an amount of equal to or less than 20% by weight of the total weight of the reaction mixture.
Dependencies are inferred from the claim text.