Manufacture of refractory products

This class includes the manufacture of intermediate products from mined or quarried non-metallic minerals, such as sand, gravel, stone or clay.

This class includes: - manufacture of refractory mortars, concretes etc. - manufacture of refractory ceramic goods: • heat-insulating ceramic goods of siliceous fossil meals • refractory bricks, blocks and tiles etc. • retorts, crucibles, muffles, nozzles, tubes, pipes etc.