Patent ID: 6758977
Filing Date: 2004-07-06
Classification: C02F,Y10S

Abstract:
A process for the partial purification of pond water such that said pond water can be further purified by the removal of essentially pure water without solids precipitation, comprising the steps of:adding a first compound to a quantity of pond water to cause precipitation by reaction with fluorides in said pond water to form an essentially insoluble fluoride salt; adding a second compound to said pond water, to increase the pH of the pond water, said second compound being a base or forming a base when water is present, said second compound having a cationic portion that causes phosphate salts thereof to remain soluble, allowing precipitates formed by adding the first and second compounds to the pond water to settle, separating the precipitates to obtain a clarified liquid portion holding said clarified liquid portion for a time period sufficient to allow any silicic acid present in the clarified portion to decompose into a hydrated silicon dioxide sludge, separating the hydrated silicon dioxide sludge and recovering a clear liquid; and adding a third compound to decrease the pH of the clear liquid, said added third compound being an acid or acid-forming compound such that the solubility of ions remaining in clear liquid is increased.