Improvements in the Treatment of Spent Iron Pickling or Cleaning Liquors or other Solutions containing Sulphate or Chloride of Iron, for obtaining Sulphate or Chloride of Iron or other useful products therefrom.

摘要

7832. Crossley, F. B. April 3. Mordants and fixing-agents.-Solutions containing chloride or sulphate of iron, such as spent pickling liquors, are treated to obtain either crystals of these salts or a mordant. In the latter case, the solution is heated with scrap iron or the like until it is only just acid and is of a strength of 60‹- 100‹ Tw. The liquor is then treated with sodium or potassium nitrate or with acetic acid, pyroligneous acid, or an acetate, such as calcium acetate. When acetic acid or an acetate is used, " black liquor" is obtained.