23201Manufacture of refractory products  

Includes

This class includes: - manufacture of intermediate products from mined or quarried non-metallic minerals (e.g. gravel, stone or clay) - manufacture of refractory mortars, concretes, etc. Manufacture of refractory ceramic goods, e.g.: - heat-insulating ceramic goods of siliceous fossil meals - refractory bricks, blocks and tiles, etc. - retorts, crucibles, muffles, nozzles, tubes, pipes, etc. This class also includes: - manufacture of refractory articles containing magnesium oxide, calcium magnesium oxide or chromite