FREMGANGSMAATE TIL RENSNING AV KORNEDE MATERIALER SOM VALSEBELEGG ELLER OLJEHOLDIGE MINERALER, FOR MEDFOERT FETE STOFFER, SPESIELT OLJE.

摘要

1. Process for the purification of granular materials such as rolling mill scale or oil-containing minerals from fatty substances such as especially oil which are entrained with said materials or minerals, wherein the materials are washed with a washing liquid containing solvents, separated therefrom, and then dried, and wherein the washing liquid freed from the fatty substances is returned into the process, characterised in that the materials, which are broken to grain sizes below 1 mm if appropriate, are subjected for the purpose of surface smoothing to mechanical stressing with solid bodies in which operation the mean grain size is only slightly reduced, and are then washed in a flotation system, that the materials are separated out from the under-course of the flotation system and then dried with removal of water, and that the overflow liquid discharged at the flotation system overflow and then freed from the fatty substances, and/or the washing liquor resulting after the flotation on separation of the granular materials, are/is returned into the process.