GB255904A - Improvements in the manufacture and production of active adsorbent and catalytic masses - Google Patents

Abstract

255,904. I. G. Farbenindustrie Akt.- Ges. July 27, 1925, [Convention date]. Grant of Patent opposed. Purifying liquids. - In preparing liquidrefining products comprising catalytic materials precipitated on a colloidal support, the support, whether in the form of sol or jelly, is intimately mixed with the catalytic materials or with substances giving rise thereto, whereafter the mixture, which may be washed at any convenient stage, is dried. Gel-forming irreversible colloids, particularly silica, alumina, and iron oxide, are used as supports, and the admixed substances, which may be added in solution or in finely divided solid, preferably colloidal, form, may comprise metal compounds decomposed at raised temperatures, such as acetates, nitrates, carbonates, or ammonium compounds. When the support is taken in the sol form, the catalytic materials may be added without first purifying the sol, and when several materials are to be added, some may be added to the components used in making the sol. The sol is allowed to set to a jelly before washing and drying, and by suitably controlling the additions, it may be made to set directly after the additions have been made or after standing, with or without heating. When the support is taken in the jelly form, it is preferably purified, it may be by pressure, and is then suspended in water or a suitable solution, whereafter the catalvtic materials are added separately or together; one or more of the materials may, however, be added to the components used in making the jelly. The jelly, whether or not containing the catalytic materials, may be pressed before drying and may be mechanically treated, as in a ball mill, with the addition, it may be, of catalytic materials. Further additions may be made to the final products, and if the products contain metal oxides, these may be reduced. The adsorbing power of the products may be increased by removing the included additions or their decomposition products, such as metal oxides, for example by treatment with nitrogen oxides and water vapour. According to one example, a silica sol prepared by treating sodium silicate with sulphuric acid is treated at once with copper sulphate solution. After standing for some time, or on heating, the mixture sets to a jelly which is partially washed, dried at 100‹ C., saturated with water vapour, and completely washed, whereafter it is dried at 150-300‹ C. The copper oxide can be removed from the product by treating it with acids, preferably after saturation with water vapour. According to another example, sodium silicate is treated with acetic acid so as to produce, after a time, a jelly, which is washed and then slightly pressed until it contains 94.5 per cent of water. To the jelly suspended in water is added a solution of uranyl nitrate, mercurous nitrate, or ammonium vanadate, and the mixture is stirred and allowed to settle. The jelly is drawn off, slightly washed, and dried slowly at 50-200‹ C. On heating to higher temperatures the added substances decompose and products containing oxide of uranium, mercury, or vanadium may be obtained, and on heating to still higher temperatures the product may contain mercury. Specifications 212,034 and 220.771, [both in Class 1 (i), Chemical processes &c.], are referred to.