FOERFARANDE FOER ATT RENA EN FOER ELEKTROLYS AVSEDD VATTENLOESNING AV EN ALKALIMETALLHALOGENID

摘要

In a process for purifying an aqueous solution of an alkali metal halide e.g. brine for electrolysis, the solution containing polyvalent ions including calcium ions, phosphate ion is added to the solution in an amount exceeding that which is consumed in the reaction of the phosphate ion with the calcium ions. The pH of the solution is adjusted to the alkaline region to precipitate at least the calcium ions in the solution and the precipitate is removed. Magnesium ions, if present, are also precipitated.