Production of hydrogen fluoride

Abstract

Abstract In the production of hydrogen fluoride and metal sulfates by the reaction of sulfuric acid and a metal fluoride, e.g. fluorspar, wherein the fluorspar is preheated, the improvement which comprises effecting the preheating by continuously heating the metal fluoride to about 500* to 800*C in a gas/solid suspension with a gas charge of about 0.2 to 4 kg/Nm3 and then reacting the preheated metal fluoride with sulfuric acid at a temperature of about 100* to 500*C. The preheating is preferably effected in counterflow with hot combustion gases, the preheater either having alternating constricted and widened zones or allowing the fluorspar to be alternately suspended in and separated from the gas passing through the preheater. The sulfuric acid is conveniently added to the fluorspar at a plurality of points prior to entry into the main reactor. In addition, an alkaline substance such as calcium oxide or hydroxide which reacts exothermically with sulfuric acid may be added to the preheater or thereafter so as to provide additional heat for the main reaction. The sulfuric acid may contain sulfur trioxide or oleum, preferably in appropriate amount to react with the by-product water formed from the exothermic reaction of the calcium or hydroxide.

Inventors

• 👤 Werner Schabacher
• 👤 Hans Guth
• 👤 Hermann Rohe
• 👤 Wolfgang Keller

Bibliographic Details