The invention provides a method for the Industrial purification of a low-grade polyvalent cation feed stream of purity P1, by the formation of a polyvalent cation- double-salt precipitate of purity P2 and a polyvalent cation solution with purity P3, wherein P2>P1>P3, said method comprising the steps of: a) forming, from said feed, a medium comprising water, polyvalent cation, a cation selected from the group consisting of ammonium, cations of alkali metals, protons and a combination thereof, and anions; which formed medium is further characterized by the presence of (i) a double- salt precipitate comprising a polyvalent cation, at least one of said cations and at least one of said anions; and (ii) a polyvalent cation solution; and wherein the concentration of said anions is higher then 10% and the ratio between the concentrations of said cation to said anion in said polyvalent cation solution is within Zone DS as herein defined; and b) separating at least a portion of said precipitate from said solution.
Inventors:
VITNER, Asher
Applicant:
JOMA INTERNATIONAL
ASHER VITNER LTD