0812 Operation of gravel and sand pits/ mining of clays and kaolin

081211 Natural sands 081212 Granules, chippings and powder/ pebbles, gravel 081213 Mixtures of slag and similar industrial waste products, whether or not incorporating pebbles, gravel, shingle and flint for construction use 081221 Kaolin and other kaolinic clays 081222 Other clays, andalusite, kyanite and sillimanite/ mullite/ chamotte or dinas earths