Patent ID: 11959046

Abstract:
A method of creating a protective coating on an alkali metal hydroxide-containing solid is provided. The method includes providing carbon dioxide to an alkali metal hydroxide-containing solid and allowing the alkali metal hydroxide and carbon dioxide to react thereby forming a carbonate or bicarbonate-containing layer on the exterior of the solid wherein the carbonate or bicarbonate-containing layer is non-hygroscopic and water soluble, and wherein greater than 80% of the hydroxide in the hydroxide-containing solid does not react with the carbon dioxide, and further wherein the alkali metal hydroxide-containing solid is substantially free of lithium hydroxide. A method of testing for the presence of carbonate-containing coating on an alkali metal hydroxide containing solid is also provided. The method includes exposing the coated solid to 95 weight percent ethanol, collecting the ethanol effluent and testing the effluent for alkali metal hydroxide. A suitably coated solid does not have dissolved alkali metal hydroxide in the ethanol effluent or is substantially free of alkali metal hydroxide.