Manufacture of refractory products

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