Advanced Physical Fine Coal Cleaning Microbubble Flotation. Topical Report No. 1. GHH-Bergbau Forschung Microbubble Coal Flotation Machine

摘要

In conventional coal flotation, it is usual to use mechanically agitated cells. The agitator generates the air bubbles, mixes the slurry and air bubbles to bring about ''bubble-particle'' collisions. The average bubble size ranges between 500 and 1000 micrometers in diameter. Conventional flotation suffers from the following disadvantages: poor recovery with fine particles below 140 mesh due to inadequate bubble-particle encounter, or poor collision efficiency; comtamination of concentrates due to physical entrapment of ash particles in the froth; and loss of yield due to coal dropping off from the bubbles due to the agitated environment in the cell. The GHH-Bergbau Forschung (GHH-BF) microbubble flotation unit addresses the above noted drawbacks of conventional flotation and more effecitvely than other microbubble flotation systems. The innovations introduced by the GHH-BF unit in coal flotation, which are particularly relevant to the production of ultra clean coal, are briefly discussed. 1 ref., 1 fig. (ERA citation 11:010857)