The flotation !

If you always wondered how it is possible to divide the coal from the waste material - here is the answer: By using the flotation. Because of the fact that the coal has a lower specific weight than the waste material, it swims on the water's surface. In contrary to that the rocks etc. sink down to the bassin's ground. So finally the coal just has to be skimmed of from the surface. That is the task of the machine visible in the photo.

Special thanks to Arno Hoffmann for sending me the CD with the photos. If the - pitily unknown - photographer does not want the pictures to be published here, please send me an e-mail.