GB410940A - Improved production of finely distributed copper compounds - Google Patents

Abstract

Colloidal copper compounds are obtained in paste form by mixing, in the presence of a protective colloid, a copper salt solution with a solution of ions which will form a copper compound insoluble in the mixture. The precipitate is then washed until it is free from colloid and soluble salts and then concentrated until it contains the desired percentage of copper. If desired, a small quantity of a suitable colloid, alkali, alkali carbonate or mixtures thereof may be added. Suitable precipitating agents include alkali salts of inorganic acids, e.g. carbonates, bicarbonates, arsenites, borates, ferrocyanides or silicates; alkali salts of organic acids, e.g. oxalates, certain fatty or rosin acids; alkali hydroxides; ammonium hydroxides to form hydroxides or basic salts, and alkaline earth oxides or hydroxides. Protective colloids include gum, casein in alkaline solution, waste sulphite, cellulose liquor, gelatine, saponin or mixtures thereof. According to examples: (1) copper sulphate is treated with borax in the presence of concentrated sulphite cellulose lye and sodium carbonate is added to the moist paste obtained; (2) the sulphite cellulose lye is replaced by an alkaline solution of casein; (3) copper sulphate is treated with sodium carbonate in the presence of gum arabic and sodium carbonate is admixed with the final product. The products are stated to be useful for fungicidal purposes.ALSO:Colloidal copper compounds are obtained in paste form, suitable for use as fungicides, by mixing, in the presence of a protective colloid, a copper salt solution with a solution of ions which will form a copper compound insoluble in the mixture. The precipitate is then washed until it is free from colloid and soluble salts and then concentrated until it contains the desired percentage of copper. If desired, a small quantity of a suitable colloid, alkali or alkali carbonate or mixtures thereof may be added. Suitable precipitating agents include alkali salts of inorganic acids, e.g. carbonates, bicarbonates, arsenites, borates, ferrocyanides or silicates; alkali salts of organic acids, e.g. oxalates, certain fatty or rosin acids; alkali hydroxides; ammonium hydroxide to form hydroxides or basic salts, and alkaline earth oxides or hydroxides. Protective colloids include gum, casein in alkaline solution, waste sulphite cellulose liquor, gelatine, saponin or mixtures thereof. According to examples: (1) Copper sulphate is treated with borax in the presence of concentrated sulphite cellulose lye and sodium carbonate is added to the moist paste obtained. (2) The sulphite cellulose lye is replaced by an alkaline solution of caesin. (3) Copper sulphate is treated with sodium carbonate in the presence of gum arabic and sodium carbonate is admixed with the final product.