Cupric sulphite

The process patented by Jumau1 involves the extraction of the roasted ore with an ammoniacal solution of ammonium sulphate or sulphite. Sulphurous acid reacts with the solution thus formed, precipitating either cuprous sulphite or cupro-cupric sulphite ... 

Jumau s process (ut supra) for the electrolytic extraction of copper from its ores is also applicable to the production of pure copper from solutions of its compounds.8 The cupric sulphite or cupro-cupric sulphite precipitated from the copper solution by the action of sulphurous acid or a sulphide is decomposed by sulphuric acid into cupric sulphate and metallic copper. The metal thus liberated is pressed into a form suitable for an anode, and refined electrolytically. 

Cupric sulphite.—The normal sulphite is unstable, and has not been isolated. With solutions of cupric sulphate sodium sulphite gives a green precipitate of varying composition, but containing basic salts.6... 

Nugatory attempts to render the metal active by the addition of cupric chloride, sodium sulphite, alcohol, ferrous chloride, ferric chloride, colloidal platinum, chromic acid, potassium nitrite prolonged contact with metallic platinum variation of temp, between 0 and 50° previous treatment of the metal with chromic acid or potassium permanganate fusion with potassium nitrate heating on charcoal with sodium phosphate to give the metal a phosphorus content melting in the electric oven in an atm. of coal-gas using the metal as anode have all been made. 

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