… have been further treated to eliminate impurities (e.g., treatment with acids or alkalis, with selective solvents, … earths, etc., or by re-distillation), provided this treatment does not produce separate chemically defined …
… a kind used, mainly in the extractive industries, for the treatment (sorting, screening, separating, washing, … Certain machines of the kind normally used for the treatment of mineral products can, as a secondary use, also …
