ceramic refractory workpieces; namely, bricks, plates, bottoms and ceilings of furnaces, tubes, immersion pipes, plugs, tuyeres, and well nozzles; tapping spouts, spreader conduits for metallurgical purposes; ceramic refractory workpieces for the construction of intermediate walls in metallurgical vessels

ceramic refractory workpieces; namely, bricks, plates, bottoms and ceilings of furnaces, including tubes, immersion pipes, plugs, tuyeres, and well nozzles; tapping spouts, spreader conduits for metallurgical purposes; ceramic refractory workpieces for the construction of intermediate walls in metallurgical vessels