Research On Numerical Simulation And Experiment Of A New Type Coarse-Coal-Slime Separator

With the improvement of coal mining mechanization, the content of the slime is increasingly high, how to separate the coarse coal slime is not only a hot issue in the current coal preparation technology research, but also a technical bottleneck which affects the clean coal production rate in the coal preparation plant. The teeter bed separator has the shortcomings of narrow particle size sorting range, the thesis introduces the rising bubble stream in the rising water, and a new coarse slime separator was designed with this theory, which widened the separation density between coarse particles with low density and fine particles with high density to a certain extent, thus strengthened the separation effective in the coarse particles with low-density, meanwhile weaken the influence of particle size sorting effect, and it realized wide grain size sorting ultimately.It can be found that the interaction between the bubble and the particle can be enhanced due to larger turbulence intensity in the outlet and above the inflation port; and the circular flow which can be seen in the velocity field above feed inlet will improve the separation effect further on the wide grain size slime by studied on slime separation internal flow field numerical simulation in this thesis.The thesis based on the two coal samples coming from Tunlan mine and Xiqu mine, in order to study the rising rate of water flow, inflation rate, feed concentration, feed speed and water/gas hybrid feeding speed of the effect of separation, the different experimental conditions of without and adding collecting agent and modification structure are selected. The results can be seen without collector, the best experimental conditions:rising water speed, inflatable speed, feed speed and water/gas mixture into the feed speed are8.5×10-3,2×10-3,1.4×10-2and4.5×10-3m/s respectively; feed concentration is300g/L. With the same conditions, the separation effect with collector is better than without collector, it also illustrate that adding collector can enhance the coarse coal slime separation. The results can be found that the original design is better than modification on coarse coal particle separation, which verified the reasonable of the original structural design.The effects of separation are evaluated by float and sink tests of products with the optimal test conditions in the thesis. The results show that the actual separation density around1.4g/cm3in Tunlan coal samples, and the E value is about0.045,I value is around0.1, as can be seen from the organic efficiency in various size fraction, the better separation effect size fraction is0.25-1mm; the actual separation density of Xiqu coal samples is about1.45g/cm3, and E value is about0.1, while I value around0.2, the better separation effect size fraction is also the0.25-1mm.