摘要 |
1392197 Modified clays SNAM PROGETTI SpA 17 March 1972 [9 April 1971] 12703/72 Heading C1A [Also in Divisions B1 and C5] The surface of catalyst support material having a crystal matrix in the form of non- porous planar layers is provided with identical centres of controlled acidity by subjecting the material (which may be a natural or synthetic clay type mineral such as a beidellite-type smectite, for example beidellite or nontronite, or a semi-expandable vermiculite-type mineral, for example vermiculite, hydrobiotite or illite), either to heating at a temperature of from 350‹ to 450‹ C. or to cation exchange with ammonium ions and subsequent heating at a temperature of from 300‹ to 600‹ C. or to cation exchange with ions of Groups IIIb, IVb, VIb, VIIb or VIII metal, for example lanthanum, cerium, titanium or manganese. As exemplified, beidellite is subjected to cation exchange with lanthanum ions using lanthanum nitrate solution (Example 1), and vermiculite is subjected either to cation exchange with lanthanum ions using lanthanum nitrate solution (Example 2), or to cation exchange with ammonium ions, using ammonium acetate or nitrate solution, and subsequent heating at 450‹ C. (Example 3); also disclosed is vermiculite cation exchanged with titanium ions (Examples 5, 6, 7). A further material the surface of which has identical centres of controlled acidity is stated to be metakaolinite obtained by heating kaolinite at a temperature of from 350‹ to 450‹ C., for example 420‹ C. (Example 4). |