| 摘要 |
1,247,200. Mouldings incorporating pitch or tar. KUREHA KAGAKU KOGYO K.K., and K. UMEYA. 30 Dec., 1968 [29 Dec., 1967], No. 61713/68. Heading B5A. [Also in Divisions C1, C3 and C5] An article, e.g. a firebrick or an electrode, is made by compression moulding a mixture of a pitch obtained by heating a liquid hydrocarbon and a powdered refractory material, e.g. dolomite, magnesia, calcium oxide, thoria, chromium oxide, yttria, alumina, silica, mullite, carbon, silicon carbide, silicon boride, or silicon nitride. The pitch may be pulverized and mixed with the refractory powder at a temperature below the softening point of the pitch, the mixture kneaded with a coal tar fraction or a petroleum fraction, and then moulded, or the heated pitch may be flowed on to the heated refractory powder, and the mixture kneaded, and charged to a mould. |
