ALEXANDRIA, Va., Aug. 20 -- United States Patent no. 12,391,549, issued on Aug. 19, was assigned to GREEN FINE TECHNOLOGY CORP. (Taoyuan, Taiwan) and GREEN ADVANCED TECHNOLOGY LTD. (Taoyuan, Taiwan).
"Method for preparing electronic grade inorganic acids from waste acid solution" was invented by Ching-Jung Kan (Taoyuan, Taiwan).
According to the abstract* released by the U.S. Patent & Trademark Office: "A method for preparing electronic grade inorganic acids includes: introducing alkali metal salts into a waste acid solution containing hydrofluoric acid, nitric acid and water to obtain hydrogen fluoride vapor, and a distillation residue mixture containing nitric acid, water and the alkali metal salts; subjecting the first distillation res...