Patent ID: 9738542
Date: 2017-08-22
CPC Classifications: C01G

Claim:
1. A method for processing iron sulfate heptahydrate, comprising: a) providing a first mixture comprising an aqueous solution or suspension of iron sulfate heptahydrate; b) heating the first mixture in a first pressure vessel to a first temperature that is above the boiling temperature of the first mixture at atmospheric pressure, wherein the first pressure vessel is at a first pressure that corresponds to the first temperature and wherein solid iron sulfate monohydrate and a second solution are formed; c) separating the solid iron sulfate monohydrate from the second solution, optionally in a second pressure vessel, at a second temperature and second pressure to form a separated iron sulfate product that comprises solid iron sulfate monohydrate and an adhered portion of the second solution; d) feeding the separated iron sulfate product into a third pressure vessel at a third pressure, wherein the temperature of the separated iron sulfate product entering the third pressure vessel is above the boiling temperature of the second solution at the third pressure, wherein the third pressure is lower than then second pressure and wherein during step d) the temperature of the separated iron sulfate product drops to a third temperature that corresponds to the third pressure; wherein step d) results in an iron sulfate monohydrate product.