Patent · US Expired

Recovery of spent pickle liquor and iron metal

US4149946A · kind A · utility

12Cited by
4References
15Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 21, 1978
Grant dateApr 17, 1979
Priority date
Expiry dateMar 21, 1998

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02P10/20
  • WIPO fieldSurface technology, coating
  • WIPO sectorChemistry

Abstract

Spent sulfuric acid pickle liquor containing ferrous ion is regenerated and iron metal is recovered therefrom by electrolysis in a cell having an anode in an anode chamber and a cathode in a cathode chamber separated by a cation-selective membrane. The spent pickle liquor is placed in the cathode chamber, aqueous ammonium sulfate solution is placed in the anode chamber, and electrical current is passed through the cell. Iron plates out on the cathode. Ammonium ion passes through the membrane into the cathode chamber to form aqueous ammonium sulfate solution therein, and the ammonium sulfate anolyte is converted to sulfuric acid solution useful for pickling. Ammonium sulfate solution from the cathode chamber is recycled to the anode chamber and the process is repeated with fresh spent pickle liquor.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.