# US 5,707,910 A · Alumina-magnesia oxide, method of making the same, and fine pulverulent body of the same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,707,910 A - Document ID: US5707910A - Status: Granted - Kind: A - Application number: 08/623,165 - Filed: 1996-03-28 - Granted: 1998-01-13 - Earliest claimed: 1995-03-28 - Assignees: Taimei Kagaku Kogyo Kabushiki Kaisha - Inventors: Tokio Kamiyanagi; Takayuki Fujita; Noriho Harumiya - Web page: https://patentgrep.com/patent/US5707910A ## CPC - C01F 7/162: Magnesium aluminates - C01P 2002/70: defined by measured X-ray, neutron or electron diffraction data - C01P 2004/34: hollow - C01P 2004/61: Micrometer sized, i.e. from 1-100 micrometer - C01P 2006/10: Solid density - C01F: COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts of peroxyacids C01B15/00; sulfides or polysulfides of magnesium, calcium, strontium, or barium C01B17/42; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds other than ammonia or cyanogen containing nitrogen and non-metals and optionally metals C01B21/082; amides or imides of silicon C01B21/087}; metal {imides or} amides C01B21/092, {C01B21/0923}; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanic acid C01C3/14; salts of cyanamide C01C3/16; thiocyanates C01C3/20; {double sulfates of magnesium with sodium or potassium C01D5/12; with other alkali metals C01D15/00, C01D17/00}) - C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS ## Abstract An object of the present invention is to provide an alumina-magnesia oxide which can be fine pulverulent bodies by pulverizing. In the alumina-magnesia oxide of the present invention includes: 70-73 WT % of alumina component, which is converted into alumina (Al.sub.2 O.sub.3); and 27-30 WT % of magnesia component, which is converted into magnesia (MgO). The alumina-magnesia oxide is formed into a pulverulent body, which is a hollow grain having loosed bulk density of 0.15 g/cm.sup.3 or less and average grain diameter of 10 .mu.m or more. ## Claims ### Claim 1 An alumina-magnesia oxide, being made from a basic aqueous solution including an aluminum salt comprising poly aluminum chloride and a magnesium salt comprising magnesium chloride wherein said basic aqueous solution satisfies the following molar ratio formulas: Mg/Al=0.46-0.55; and Cl/Al=1.3-3.7, in which the total concentration of the aluminum salt and the magnesium salt, which are converted into oxides, is 12-20 WT %, said alumina-magnesia oxide, including: 7- 73WT % of an alumina component, which is converted into a alumina (Al.sub.2 O.sub.3); and 27-30 WT % of a magnesia component, which is converted into magnesia (MgO), wherein said alumina-magnesia oxide is formed into a pulverulent body, which is a hollow grain having a loose bulk density of 0.15 g/cm.sup.3 or less and an average grain diameter of 10 .mu.m or more. ### Claim 2 (depends on 1) The alumina-magnesia oxide according to claim 1, wherein said alumina-magnesia oxide mainly has a spinel crystal form. ### Claim 3 A method of making alumina-magnesia oxide, comprising of the steps of: spraying an aqueous solution of an aluminum salt and a magnesia salt in an oxidizing atmosphere; and roasting said sprayed aqueous solution so as to form an alumina-magnesia oxide mainly having a spinel crystal form, wherein said aqueous solution is a basic aqueous solution including an aluminum salt and magnesium salt in which total concentration of the aluminum salt and magnesium salt, which are converted into oxides, is 12-20 WT %, and wherein said alumina-magnesia oxide is formed into a pulverulent body, which is a hollow grain. ### Claim 4 (depends on 3) The method according to claim 3, wherein the magnesium salt comprises magnesium chloride and the aluminum salt comprises poly aluminum chloride, and wherein said basic aqueous solution satisfies the following molar ratio formulas: Mg/Al=0.46-0.55; and Cl/Al=1.3-3.7. ### Claim 5 (depends on 3) The method according to claim 3, wherein said aluminum salt is poly aluminum chloride. ### Claim 6 A fine alumina-magnesia oxide pulverulent body being made from a basic aqueous solution including an aluminum salt and a magnesium salt in which the total concentration of the aluminum salt and the magnesium salt, which are converted into oxides, is 12-20 WT %, said fine alumina-magnesia oxide pulverulent body, including: 70-73 WT % of an alumina component, which is converted into alumina (Al.sub.2 O.sub.3); and 27-30 WT % of an magnesia component, which is converted into magnesia (MgO), wherein said fine pulverulent body is formed by pulverizing a hollow alumina-magnesia oxide grain including said alumina component and said magnesia component, and wherein the diameter of said fine pulverulent body is 1 .mu.m or less. ### Claim 7 (depends on 6) The fine alumina-magnesia oxide pulverulent body according to claim 6, wherein the loose bulk density of said pulverulent body is 0.5 g/cm.sup.3 or more. ### Claim 8 (depends on 6) The fine alumina-magnesia oxide pulverulent body according to claim 6, wherein said hollow alumina-magnesia oxide grain has an average grain diameter of 10 .mu.m or more.