GB222159A - Improvements in the manufacture of adsorbent materials - Google Patents

Abstract

Calcium salts having adsorbent properties suitable for the treatment of liquids such as sugar solutions or oils and of gases and vapours are prepared by converting calcium oxide or hydroxide into an insoluble salt by treatment with an acid in presence of an alkali metal hydroxide or salt or with a large excess of an alkali salt with subsequent treatment of the solution remaining by an acid to regenerate the alkali salt. The calcium salts mentioned are the carbonate, sulphite, sulphate, phosphate, oxalate and tartrate the particular description relating to the production of carbonate. Milk of lime mixed with a solution of potassium or sodium carbonate or hydrate is treated with carbon dioxide at 90 DEG C. or higher. The precipitate may be washed with various liquids; for instance for use in the treatment of oils it may be washed with soda solution benzine or alcohol, and the precipitate may be used wet or wholly or partially dried; and various substances may be admixed with it such as amylum, gelatine, casein, tannin, or soda which prevents the particles from adhering to each other and facilitate their contact with the liquid to be treated. Alternatively finely divided lime or milk of lime, together with caustic alkali or alkali carbonate is distributed in a chamber into which carbon dioxide is admitted together with steam or superheated steam preferably under pressure; calcium sulphite may be made by employing sulphur dioxide in this process, and calcium sulphate by employing sulphur dioxide and sufficient superheated steam. Alternatively a large excess of sodium carbonate is added to milk of lime, an excess of 25 or 50 per cent being suitable; and before or after the separation of the precipitate the solution is treated with carbon dioxide, or flue gases to convert the caustic soda formed into carbonate for re-use. Specifications 183,485 and 184,473, [both in Class 46, Filtering &c.], are referred to.ALSO:Calcium salts having adsorbent properties suitable for the treatment of liquids such as sugar solutions or oils and of gases and vapours are prepared by converting calcium oxide or hydroxide into an insoluble salt by treatment with an acid in presence of an alkali metal hydroxide or salt or with a large excess of an alkali salt with subsequent treatment of the solution remaining by an acid to regenerate the alkali salt. Calcium oxalate and tartrate are mentioned, the particular description relating to the production of carbonate.ALSO:Calcium salts having adsorbent properties suitable for the treatment of liquids such as sugar solutions or oils and of gases and vapours are prepared by converting calcium oxide or hydroxide into an insoluble salt by treatment with an acid in presence of an alkali metal hydroxide or salt or with a large excess of an alkali salt with subsequent treatment of the solution remaining by an acid to regenerate the alkali salt. The calcium salts mentioned are the carbonate, sulphite, sulphate, phosphate, oxalate, and tartrate, the particular description relating to the production of carbonate. Milk of lime mixed with a solution of potassium or sodium carbonate or hydrate is treated with carbon dioxide at 90 DEG C. or higher. The precipitate may be washed with various liquids; for instance, for use in the treatment of oils it may be washed with soda solution benzine or alcohol, and the precipitate may be used wet or wholly or partially dried; and various substances may be admixed with it such as amylum, gelatine, casein, tannin, or soda, which prevent the particles from adhering to each other and facilitate their contact with the liquid to be treated. Alternatively, finely divided lime or milk of lime, together with caustic alkali or alkali carbonate, is distributed in a chamber into which carbon dioxide is admitted, together with steam or superheated steam, preferably under pressure. Calcium sulphite may be made by employing sulphur dioxide in this process, and calcium sulphate by employing sulphur dioxide and sufficient superheated steam. Alternatively, a large excess of sodium carbonate is added to milk of lime, an excess of 25 or 50 per cent being suitable; and before or after the separation of the precipitate the solution is treated with carbon dioxide or flue gases to convert the caustic soda formed into carbonate for re-use. Specifications 183,485, [Class 46, Filtering &c.], and 184,473 are referred to.ALSO:Calcium salts having adsorbent properties suitable for the treatment of liquids such as sugar solutions or oils and of gases and vapours are prepared by converting calcium oxide or hydroxide into an insoluble salt by treatment with an acid in presence of an alkali metal hydroxide or salt or with a large excess of an alkali salt with subsequent treatment of the solution remaining by an acid to regenerate the alkali salt. The calcium salts mentioned are the carbonate, sulphite, sulphate, phosphate, oxalate and tartrate, the particular description relating to the production of carbonate. Milk of lime mixed with a solution of potassium or sodium carbonate or hydrate is treated with carbon dioxide at 90 DEG C. or higher. The precipitate may be washed with various liquids; for instance for use in the treatment of oils it may be washed with soda solution, benzine or alcohol, and the precipitate may be used wet or wholly or partially dried; and various substances may be admixed with it such as amylum, gelatine, casein, tannin, or soda which prevent the particles from adhering to each other and facilitate their contact with the liquid to be treated. Alternatively, finely-divided lime or milk of lime, together with caustic alkali or alkali carbonate is distributed in a chamber into which carbon dioxide is admitted together with steam or superheated steam preferably under pressure; calcium sulphite may be made by employing sulphur dioxide in this process, and calcium sulphate by employing sulphur dioxide and sufficient superheated steam. Alternatively, a large excess of sodium carbonate is added to milk of lime, an excess of 25 or 50 per cent being suitable; and before or after the separation of the precipitate the solution is treated with carbon dioxide or flue gases to convert the caustic soda formed into carbonate for re-use. Specifications 183,485 and 184,473, [Class 46, Filtering &c.], are referred to.