Method of removing potassium hydroxide from crystallized potassium ferrate (VI)
AssigneeCarus Chemical Company
InventorsPeter G. Mein, Arno H. Reidies
Life of this patent
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Abstract
Potassium ferrate (VI), K.sub.2 FeO.sub.4, which has been crystallized from a concentrated aqueous solution of KOH is washed with an aqueous solution of a potassium salt of an inorganic acid to remove the residual KOH. The wash solution is at an alkaline pH and contains a high concentration of the potassium salt.
Claims12
The preparation of potassium ferrate (VI), K.sub.2 FeO.sub.4, in which the K.sub.2 FeO.sub.4 is crystallized from concentrated aqueous potassium hydroxide (KOH) solution, separated therefrom, and washed to remove residual KOH solution from the separated K.sub.2 FeO.sub.4 crystals, wherein the improvement comprises washing the separated K.sub.2 FeO.sub.4 crystals with an aqueous solution of a potassium salt of an inorganic acid to remove the residual KOH solution, said wash solution having a concentration of said potassium salt of at least 30% by weight, said potassium salt being stable in said wash solution in contact with said K.sub.2 FeO.sub.4, and said potassium salt providing a pH in said wash solution of greater than 9.0.
The preparation of potassium ferrate (VI), K.sub.2 FeO.sub.4, in which the K.sub.2 FeO.sub.4 is crystallized from concentrated aqueous potassium hydroxide (KOH) solution, separated therefrom, and washed to remove residual KOH solution from the separated K.sub.2 FeO.sub.4 crystals, wherein the improvement comprises washing the separated K.sub.2 FeO.sub.4 crystals with an aqueous solution of a potassium salt of an inorganic acid to remove the residual KOH solution, said wash solution having a concentration of said potassium salt of at least 40% by weight, said potassium ferrate VI being stable in contact with said potassium salt in said wash solution, and said potassium salt providing a pH in said wash solution of greater than 9.0.
The preparation of potassium ferrate (VI), K.sub.2 FeO.sub.4, in which the K.sub.2 FeO.sub.4 is crystallized from concentrated aqueous potassium hydroxide (KOH) solution, separated therefrom, and washed to remove residual KOH solution from the separated K.sub.2 FeO.sub.4 crystals, wherein the improvement comprises washing the separated K.sub.2 FeO.sub.4 crystals with an aqueous solution of a potassium salt of an inorganic acid to remove the residual KOH solution, said wash solution having a concentration of said potassium salt of from 45 to 70% by weight, said K.sub.2 FeO.sub.4 being stable in contact with said potassium salt in said wash solution, and said potassium salt providing a pH in said wash solution of from 10 to 12.
Dependencies are inferred from the claim text.