GB626882A - Improvements relating to the recovery of metal compounds from solutions - Google Patents

Abstract

Solutions, particularly waste liquids, containing chromium, molybdenum, tungsten or uranium in the form of an oxygen-containing complex anion are brought into contact with an anion exchanger in salt form to cause exchange of the anionic complex, and this is then displaced by treatment with an acid, e.g. hydrochloric or sulphuric acid, or salt, e.g. sodium chloride, sulphate or carbonate, ammonium sulphate or chloride, or base, e.g. potassium, sodium or ammonium hydroxide. A mixture of salt and base may be employed. When acids are employed, reduction of the liberated compound, e.g. to the chromic state may occur. Using salts or bases, chromates, tungstates, &c., are produced. Excess recovery agent may be used, being subsequently distilled off in the case of ammonia, or recycled in the case of non-volatile agents. Suitable exchangers are aniline black, aromatic amine-formaldehyde resins and aliphatic amine resins such as those prepared from the polyalkylene polyamines. They are suitably employed in chloride or sulphate form. Specification 572,836 is referred to.ALSO:Solutions, particularly waste liquids, containing chromium, molybdenum, tungsten or uranium in the form of an oxygen-containing complex anion are brought into contact with an anion exchanger in salt form to cause exchange of the anionic complex, and this is then displaced by treatment with an acid, e.g. hydrochloric or sulphuric acid, or salt, e.g. sodium chloride, sulphate or carbonate, ammonium sulphate or chloride, or base, e.g. potassium, sodium or ammonium hydroxide. A mixture of salt and base may be employed. When acids are employed, reduction of the liberated compound, e.g. to the chromic state may occur. Using salts or bases, chromates, tungstates &c. are produced. Excess recovery agent may be used, being subsequently distilled off in the case of ammonia, or recycled in the case of non-volatile agents. Suitable exchangers are aniline black, aromatic amine-formaldehyde resins and aliphatic amine resins such as those prepared from the polyalkylene polyamines. They are suitably employed in chloride or sulphate form. Specification 572,836 is referred to.