METHOD FOR MANUFACTURING CAUSTIC SODA OR POTASH AND HYDROCHLORIC ACID, AND APPARATUS THEREFOR

摘要

A method for manufacturing sodium or potassium hydroxide and hydrochloric acid starting from sodium or potassium chloride and water. The method comprises steps of heating (94÷96) said chloride above its point of fusion, (97) bubbling vapour through said chloride and hydrolysis reaction, above said point of fusion, and contemporary collecting of gaseous hydrochloric acid produced, said vapour being preferably generated in situ by evaporation of distilled water, (98) cooling said hydroxide at a final temperature comprised not exceeding said point of fusion, (99) collecting said liquid hydroxide preferably by pressurizing the reaction zone. The step of bubbling is carried out in a reaction chamber after a step of (92) preheating said chamber, into which said chloride is preferably fed in solid state. Said distilled water is advantageously generated and heated by means of process heat recovery. An apparatus adapted to executing said method, comprising a reaction chamber having parts to contact with the fluids of process made of a material selected from the group comprised of : graphite and pyrolytic graphite, or a combination of said material.