Beneficiation of fine coal using the free jet flotation system

摘要

The free jet flotation cell was developed by BerlinTechnical University in 1985. It works as the free jet principleand is able to treat particles below 53 microns. The bituminuouscoal sample with 44.92 percent ash was obtained from the feedto the fine coal thickener at Zonguldak Central Coal Washerybelonging to TTK (Turkish Hard Coal Enterprise). In theconventional flotation tests, a mixture of 90 percent keroseneand 10 percent iso-octanol in the amount of 400 g/t was used ascollector. In the optimum conventional flotation conditions, thefloated coal had about 10 percent ash with a combustiblerecovery of 50 percent. The flotation tests were carried outsystematically in a 33 liter free jet type flotation cell and theoptimum parameters have been determined. In the optimum freejet type flotation conditions, the floated coal had 10.21 percentash with a combustible recovery of 42.2 percent where 3 timescleaning was done without any collector after rougher flotationwhere 400 g/ton collector was used (90 percent kerosene and 10percent iso-octanol). The result of free jet flotation testsappeared to be satisfactory, as the combustible recovery in thefloated coal could be raised to 68 percent by circulation of the middlings no 1.