Improved process of separating fine coal of low ash content by froth flotation

摘要

605,179. Froth flotation. DE DIRECTIE VAN DE STAATSMIJNEN IN LIMBURG. Dec. 17 1945, No. 34180. Convention date, Aug. 25,1944. [Class 82(ii)] In a process of washing coal by froth flotation in a series of flotation cells in which tailings from a preceeding cell are led to a following cell, the liquid level in the first cell or cells is maintained so low that only part of the froth layer is collected and sent to filters for dewatering and the liquid level in the remaining cells maintained so high that liquid and froth is collected and returned to the first cell or cells. As shown, froth b from cell 1 is led to a rotary drum filter 5. The tailings c from cell 1 and each succeeding cell are led to the next cell in series and froth and some liquid e from cell 2 and each succeeding cell are returned to cell 1. In a modification, Fig. 3, not shown, several cells take the place of the first cell and froth and liquid is returned to these cells from succeeding cells.