Treatment of phosphoric acid
AssigneeTriomf Fertilizer (Proprietary) Ltd.
InventorsCharles S. Williams, Jacobus J. Gerber
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Abstract
A method for the treatment of phosphoric acid containing one or more impurities comprising the ions of at least one of the metals from the group magnesium, iron and aluminium, including the step of heating the acid under such conditions of temperature, pressure, time and concentration as to cause at least some of these impurities, (and in the case where magnesium is the major constituent among such impurities, more than 60% (mass/mass) of such magnesium) to precipitate as a pyrophosphate of the relevant metal ion.
Claims11
A method for treatment of phosphoric acid having a concentration of from about 50 to about 72% P.sub.2 O.sub.5, and containing magnesium ions in solution as an impurity comprising heating the acid at a pressure between about 100 and about 500 p.s.i. to a temperature of from about 100.degree. C. to about 180.degree. C. and maintaining the acid at this temperature and pressure to cause more than 60% (mass/mass) of the magnesium to precipitate as the acid pyrophosphate.
Dependencies are inferred from the claim text.