Problem:
The problem was how to reclaim magnetite from waste material and water after the flotation material had been used to raise the specific gravity of coal washing water.
Solution:
The solution was four of the widest
Wet Drum Separators ever built. At the Island Creek Coal Company's Gund and Vail Mines in Blue Creek, KY, USA, the 124-inch wide (3150 mm) drum separators reduced production costs and sped up coal preparation.