Microgas Dispersion for Fine-Coal Cleaning. Technical Progress Report, March 1, 1981-August 31, 1981

摘要

The results of the flotation tests conducted demonstrate that the use of fine colloidal gas aphrons (CGA) bubbles is beneficial for fine coal flotation. As demonstrated with the ultrafine coal sample, the froth products of CGA flotation are almost twice as clean as those of the conventional flotation tests at 70% yield. The kerosene consumption was considerably higher, however, both in conventional and in CGA flotation. Attempts were made to coat the CGA bubbles with a film of kerosene and use them for flotation, hoping that this would reduce the oil consumption. However, no positive results have yet been obtained with this process. Another problem associated with CGA flotation is that the ash content of the froth products is relatively high when using a stable CGA, such as that prepared with Dowfroth M150. On the other hand, when using an unstable CGA, as is the case with MIBC, low ash clean coal products can be obtained, but at the expense of the yield. Two approaches are being investigated to correct this problem. A considerable amount of effort has been made to determine the surface charge of the CGA.