Cyclochrome—The Recycle of Sodium Dichromate in Sodium Chlorate Manufacture

  • R. E. Alford

Abstract

Sodium dichromate is used in the electrochemical manufacture of sodium chlorate to both buffer the electrolyte and to minimize undesirable cathodic reactions.

Increasing quantities of chlorine dioxide are being produced from chlorate solutions as the use of environmentally undesirable chlorine is reduced in pulp mill bleaching operations. Such processes result in the contamination of mill effluents with chromium species which cause environmental concerns.

Several processes are known for dichromate removal, but they are expensive to operate. This paper will discuss a process utilizing ammonia and sodium hypochlorite, both generally available at sodium chlorate producing plants, to recover dichromate at a reagent cost less than the value of the recovered dichromate.

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References

  1. 1.
    Hisinger & Berzelius, Neuses. Alg, J. Chem., I 115–149Google Scholar
  2. 2.
    British Patent 13,785 (1851)Google Scholar
  3. 3.
    Lindbergh & Simonsson Dept. of Applied Electrochemistry, StockholmGoogle Scholar
  4. 4.
    U.S. Patent 3843759Google Scholar
  5. 5.
    U.S. Patent 4268486, Canadian Patent 1139090Google Scholar
  6. 6.
    German Patent 3032131Google Scholar
  7. 7.
    U.S. Patent 4259297Google Scholar
  8. 8.
    U.S. Patent 4699701Google Scholar
  9. 9.
    U.S. Patent 3835001Google Scholar

Copyright information

© SCI 1992

Authors and Affiliations

  • R. E. Alford
    • 1
  1. 1.Manager, Research & Technology Department Chemetics International Company Ltd. VancouverBritish ColumbiaCanada

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