| 摘要 |
1,272,646. Mullite particles. UBE INDUSTRIES Ltd. 16 Sept., 1969 [17 Sept., 1968], No. 45686/69. Heading C1A. Spherical particles predominantly of mullite and having a particle diameter of 0À5-10 mm. are recovered from a fluidized bed (with forced circulation flow of the solid particles therein) operating at a temperature in the range 1200- 1600‹ C. and to which has been fed (A) a powdered material containing Al 2 O 3 and SiO 2 (or compounds decomposable thereto) in respective proportions of 40-80 wt. per cent and 58- 15 wt. per cent, and 2-5 wt. per cent MgO (or compound capable of forming MgO under the conditions), and (B) a solid seed material having a particle diameter of 0À05-8À0 mm. and consisting essentially of SiO 2 , Al 2 O 3 and MgO, whereby to make particles (A) adhere to (B). (A) may be introduced at 1-10 parts by wt. per part by wt. (B); and a liquid fuel may be introduced to the bed along with an O 2 -containing gas to effect the burning at the required temperature. For (B), particles of (A) of the required size, or the smaller product particles, may be used. |
