Abstract: In connection with the recycling of lead-acid batteries, lead-acid battery mud containing lead sulfate is desulfated by adding to the battery mud, which is maintained at a temperature less than 140.degree. F., an aqueous solution containing an ammonium reagent such as ammonium carbonate or ammonium bicarbonate. The ammonium reagent reacts with the lead sulfate to form an aqueous solution of ammonium sulfate and a lead carbonate precipitate. The aqueous solution of ammonium sulfate is then separated from the battery mud containing the lead carbonate precipitate.
Abstract: In connection with the recycling of lead-acid batteries, battery muds are desulfated by adding an aqueous solution of a treating agent comprising soluble alkali metal salts or alkali metal hydroxides to crushed battery components. The treating agent reacts with sulfuric acid and lead sulfate to form an aqueous solution of alkali metal sulfates and precipitated lead compounds. Following separation of the reacted battery mud and other crushed battery components, separation of the soluble alkali metal sulfates and solids such as PbO, PbO.sub.2, and precipitated lead compounds is effected.
Abstract: An efficient and inexpensive method for producing lead monoxide from lead sulfate bearing materials such as recycled battery mud is provided comprising:(a) reacting said material with an ammonium carbonate solution to convert lead sulfate to lead carbonate;(b) decomposing the lead carbonate to form impure lead monoxide;(c) reacting the impure lead monoxide with acetic acid to form a lead acetate solution;(d) contacting the lead acetate solution with carbon dioxide to produce insoluble lead carbonate; and(e) decomposing the lead carbonate to form lead monoxide.
March 3, 1980
Date of Patent:
May 26, 1981
NL Industries, Inc.
Eugene Striffler, Jr., Michael A. Kolakowski