초록 ▼

Contaminated sulfuric acid which may contain water, organic compounds and inorganic salts is converted to almost pure concentrated sulfuric acid by passing the acid through a Pauling plant and distilling the concentrated contaminated acid. Addition of nitric acid improves the decomposition of organi

Contaminated sulfuric acid which may contain water, organic compounds and inorganic salts is converted to almost pure concentrated sulfuric acid by passing the acid through a Pauling plant and distilling the concentrated contaminated acid. Addition of nitric acid improves the decomposition of organic compounds and ammonium salts of the contaminated acid.

대표청구항 ▼

A two-step process for the continuous regeneration of contaminated aqueous 65 to 95% sulfuric acid to obtain essentially pure 95 to 98% sulfuric acid, which comprises adding to said contaminated sulfuric acid a hexavalent chromium compound as a corrosion inhibitor and in a first step continuously fe

A two-step process for the continuous regeneration of contaminated aqueous 65 to 95% sulfuric acid to obtain essentially pure 95 to 98% sulfuric acid, which comprises adding to said contaminated sulfuric acid a hexavalent chromium compound as a corrosion inhibitor and in a first step continuously feeding said contaminated 65 to 95% sulfuric acid containing metal salt contaminants and a small amount of up to 4% by weight organic impurities, calculated as carbon, to a cast iron dephlegmator mounted on an external heated vessel containing concentrated boiling sulfuric acid at atmospheric pressure, removing overhead water vapor and volatile organic contaminants, continuously withdrawing as a bottoms product 95 to 98% concentrated contaminated acid and continuously feeding the withdrawn acid, in a second step, to a cast iron distillation unit in which boiling concentrated sulfuric acid is maintained, continuously removing and recovering overhead essentially pure 95 to 98% concentrated sulfuric acid and withdrawing and removing from the distillation step nonvolatile metal salt contaminants as a bottoms product.