… broken or crushed stone, of a kind commonly used for concrete aggregates, for road metalling or for railway or other ballast, shingle and flint, whether or not heat-treated; macadam of slag, dross or …
Explanatory notes
… broken or crushed stone, of a kind commonly used for concrete aggregates, for road metalling or for railway or other ballast, shingle and … of flint are used in ball mills for crushing lime, cement, etc. Flint is, however, mainly used, after crushing, in the …