GB1288806A - - Google Patents

Abstract

1288806 Clay refining agent MIZUSAWA KAGAKU KOGYO KK 26 Sept 1969 [1 Oct 1968 14 Aug 1969] 47618/69 Heading C1A An agent suitable for refining oily substances comprises granules or small aggregates of an acid-treated clay consisting predominantly of montmorillonite having a specific surface area of at least 120 sq. m./gm., a pore volume of at least 0À7 ml./gm., and a particle size of 0À1-5 mm.; and the montmorillonite may be mixed with a minor amount of a kaolinite clay, e.g. halloysite. The small aggregates may have dispersed therein 0À5-20 wt. per cent, based on the total weight of the agent, of an inorganic solid insoluble in water or acid, e.g. an anhydrous silicic acid, an insoluble silicate, an alumina, an insoluble titanium compound, a carbonaceous substance or an insoluble sulphate. The agent may be prepared by contacting the clay, containing acid-soluble basic constituents, with 0À2-1 equivalent, based on the total basic constituents, of an acid (e.g. H 2 SO 4 , HCl, HNO 3 , oxalic or acetic acid) in an amount that the ratio by weight of clay (dry basis) to acid is 1 : 0À3-2À5, and forming a small aggregated solid therefrom, and then extracting the basic constituents by treating the solid product with an aqueous medium having a pH less than 1, and then recovering the product having the desired characteristics. The fats or oils which may be refined by contact with the product include animal and vegetable oils and fats, crude fatty acids, plasticizers or petroleum products. In example VI a 7% (as SiO 2 ) sodium silicate solution is used in a purification step before acid treatment, to provide 2% silicate (as SiO 2 ) in the mixture, as a disintegration preventive step. Other methods of preparation of the granules include kneading a soluble salt, e.g. a sulphate (5-50 parts by weight) with acid treated powdery clay (100 parts) in the presence of water or aqueous acid. The mixture is then moulded into small aggregates of suitable diameter or is moulded into small aggregates of such size while heating them to 100-300‹ C. so the salt is uniformly dispersed in the particle interiors. These aggregates are then dipped in water or aqueous acid to lixiviate the soluble salts. Another method is to mix the acid-treated montmorillonite or the intermediate acid-treated product with a soluble inorganic salt and an aqueous solution of a mineral acid and then forming this mixture into granules.