Prevention of corrosion of exhaust gas introducing pipe and removal of fluorine in washing liquid

Abstract

Abstract PURPOSE:To prevent the corrosion of an exhaust gas introducing pipe and to remove the fluorine component in a washing liquid by precipitating the same as a spinel compound, by adding a Ca-salt so that the pH of the washing liquid is held to an alkaline side and a Ca-concn. and the mole ratio of Ca/F2 are brought to specific values or more. CONSTITUTION:The pH of a washing liquid for washing a fluorine-containing exhaust gas is held to an alkaline side and a Ca-Salt is added so that Ca in the washing liquid is 20ppm or more and the mole ratio of Ca/F2 reaches 1 or more to prepare the washing liquid. This liquid is sprayed into the exhaust gas introducing pipe of a washing tower and a film is formed on the surface of the introducing pipe to prevent the corrosion of said pipe. A ferrous salt of an inorg. acid is added to the fluorine-containing washing liquid to be reacted with fluorine therein and, after the addition of alkali, oxidizing treatment is applied to the treated liquid to form a spinel compound. A Ca-salt is added to this waste liquid so as to adjust the Ca/F2 mole ratio to 1 or more and the formed precipitated product is separated.

Inventors

• 👤 Saburo Hayashi
• 👤 三郎 林

Bibliographic Details