Patent · US Expired

Electrolytic cell for electrowinning of metals

US4129494A · kind A · utility

15Cited by
4References
12Claims
0Family size

Inventor

Key dates

Filing dateMay 4, 1977
Grant dateDec 12, 1978
Priority date
Expiry dateMay 4, 1997

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC25C7/00
  • WIPO fieldSurface technology, coating
  • WIPO sectorChemistry

Abstract

Outlet weir of tank is lower than inlet and electrolyte is forced to flow in alternately downward and upward paths between anodes and cathodes at velocities in excess of 10 feet per minute and preferably 20 to 100 feet per minute. Cathodes (or anodes) are spaced from bottom of tank for flow underneath and anodes (or cathodes) have an upper edge of active area over which electrolyte flows, to produce upward and downward paths. Difference of electrolyte level between downward and upward flow cycles is at least 1/4 inch and not more than 6 inches, while spacing between adjacent electrodes is at least 1/4 inch and not more than 3 inches. Levels of upper edges of active areas may be consecutively lower and bottom of tank may slope downwardly to correspond. Electrolyte velocity eliminates or reduces ion-deficient film tending to form on electrode faces, with advantages including formation of more coherent, smooth and dense deposits, good quality deposits at higher current densities, reduction in voltage drop, improvement in cathode current efficiency, reduction in impurities in the cathode deposits, efficient electrowinning from very dilute solutions of metal and maintenance of slurry su…

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