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:
このコード6903.10.00.00
参考日本語訳
遊離炭素の含有量が全重量の50%を超えるもの
Containing by weight more than 50 percent of free carbon