| abstract |
A process is disclosed for purifying aqueous solutions of metal hydroxides. n An aqueous solution of a metal hydroxide, such as sodium hydroxide, containing a complex of a heavy metal contaminant, such as mercury, is heated. n An oxidizing agent, such as hydrogen peroxide, is reacted with the solution to precipitate solid particles of an oxide of the heavy metal, for example, mercuric oxide, in a solution. The solid particles of mercuric oxide are separated from the solution by filtration. n The purified solution comprised of water and sodium hydroxide and containing less than about 0.3 part per million mercury by weight is sold commercially. The solid particles of mercuric oxide are landfilled or otherwise utilized. |