| 摘要 |
<p>1344870 Spheroidizing ceramic material COORS PORCELAIN CO 18 June 1971 [22 Sept 1970] 28649/71 Heading B5A [Also in Division C1] Ceramic spheres are made by forming a bed of finely powdered wax, depositing drops of ceramic slip on to the bed, drying the drops at least partially to set the spheres, separating the dried drops from the wax and firing them. Suitable materials for the slip are an aqueous slurry of a powdered alumina, (preferably comprising between 50 and 100% alumina), or zirconia together with such other ingredients as clay, talc, barium carbonate and whiting and antifoam, wetting and dispersing agents, and a thickening agent, e.g. magnesium sulphate. The wax must have a high melting point, e.g. ethylene diamine bis-stearamide. The bed is deposited from a hopper 20 on to a moving belt, levelled off and drops of the slip are discharged from nozzles 48, dried by a radiant heater separated from the wax powder at 36, screened and fired, the separated wax powder being returned to the hopper. Specification 1,344,869 is referred to.</p> |
