Sand mill

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In historical times, sand mills or gypsum mills were used in particular for the production of mineral building materials and house sand or abrasive sand in the appropriate grain size . They are particularly common in the red sandstone areas of southern Germany.

A large millstone made of red sandstone is typical of sand mills , with which the plaster of paris or sand chunks scattered on the grinding process were ground into a fine powder. Modern process engineering uses ball mills and air separators for fine grinding and sorting.

Sand mills as children's toys

These popular toys consist of a vertical funnel and a rotor positioned underneath. Pouring sand into the funnel drives the rotor; depending on the wind conditions, the rotor also acts as a wind sifter. The addition of water-containing silt or silt leads u. U. for temporary clogging of the sand mill.