HS 6903: Other refractory ceramic goods (for example, retorts, crucibles, muffles, nozzles, plugs, supports, cupels, tubes, pipes, sheaths, rods and slide gates), other than those of siliceous fossil meals or of similar siliceous earths

Notes 1. This Chapter applies only to ceramic products which have been fired after shaping: 1. 6904 to 6914 apply only to such products other than those classifiable in 6901.00.00 to 6903; 2. Articles heated to temperatures less than 800 °C for purposes such as curing of resins, accelerating hydration reactions, or for the removal of water or other volatile components, are not considered to be fired. Such articles are excluded from Chapter 69; and 3. Ceramic articles are obtained by firing inorganic, non‑metallic materials which have been prepared and shaped previously at, in general, room temperature. Raw materials comprise, inter alia, clays, siliceous materials including fused silica, materials with a high melting point, such as oxides, carbides, nitrides, graphite or other carbon, and in some cases binders such as refractory clays or phosphates. 1. This Chapter does not cover: