Liquid ferric sulfate manufacturing process
AssigneeGeneral Chemical Corporation
InventorsSteven Faigen, Joseph Hurd, Larry Knuth
Life of this patent
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Abstract
A process for the production of liquid ferric sulfate from finely-divided ferric oxide, sulfuric acid and water in a closed reaction vessel at temperatures ranging from about 130.degree. C. to about 150.degree. C. and pressures from about 30 psi to about 70 psi. The reaction time ranges from Four to eight hours and produces liquid ferric sulfate having at least 10% trivalent iron. Yield and efficiency are provided by controlling the specific gravity prior to the reaction and by counter current cycling the waste stream from the reaction through the dilution water and use of a polymeric settling agent to remove unreacted iron content from the digester output.
Claims10
In a process for making aqueous ferric sulfate solution that involves:
- (a) combining in a closed reaction vessel a mixture of finely-divided ferric oxide, concentrated sulfuric acid and water;
- (b) heating said mixture to a reaction temperature of from about 130° C. to about 150° C. and, at a pressure of from about 30 PSI to about 40 PSI while agitating said mixture and while controlling the rate of temperature increase at about 5° C. per fifteen minutes;
- (c) maintaining said mixture at a digestion temperature ranging from about 130° C. to about 150° C. and a pressure ranging from about 30 PSI to about 40 PSI for a period ranging up to from about three to eight hours while continuing said agitation;
- (d) lowering the temperature and pressure of said mixture;
- and
- (e) collecting said aqueous ferric sulfate solution as a product of the process, the improvement comprising water scrubbing waste gas from the reaction vessel and recycling the scrubbing water to the digestion process of step (c).
Dependencies are inferred from the claim text.