Under Black cleaning refers to the cleaning of grain prior to milling. First, iron parts are removed with the help of a magnet, then coarse impurities such as pieces of wood, large stones and the like are removed with a separator . a. as well as very fine impurities such as sand. Then husks are removed with the help of an aspirator . In a further step, stones are removed with a stone separator and, finally, with a trieur, foreign grain, weed seeds and broken grains are removed. In addition or as an alternative to the trieur, table separators (impact tables) are used that read out lighter goods such as ergot or foreign grain such as barley or oats from wheat or rye, as well as color sorters that read different colored goods such as ergot, weed seeds and z. Sometimes also remove stones.
- Erling, Peter (Hrsg.), Handbuch der Mehl- und Schälmüllerei , 2nd edition, Bergen / Dumme 2004, ISBN 3-86037-230-0