Refractory building and construction materials, not of metal; refractory ceramic compounds, namely, refractory casting compounds, not of metal, refractory concrete, and refractory gunning, repair and ramming compounds, not of metal; refractory ceramic work pieces being refractory shapes, not of metal, including ceramic refractory blocks, not of metal, and refractory ceramic tiles; refractory mouldings, not of metal, namely, ceramic mouldings for use in refractory furnaces, and refractory cera...