Experimental Study On Strengthing Separation Of Refractory Coarse Coal Slime In Teetered Bed Separator Based On Additional Pulsing Flow

In view of the problems of high concentrate ash content,low concentrate yield and poor performance in the separation of refractory coarse slime.with traditional teetered bed separator,the fluidization characteristics of two model particles in traditional teetered bed separator were studied,the stratification and separation laws in pulsatile teetered bed separator were investigated aiming at the poor performance of particles with different densities in traditional teetered bed separator.On this basis,the comparison tests of teetered bed separator and pulsatile teetered bed separator were carried out.Explore the feasibility of pulsation disturbance bed to strengthen the sorting of hard coal slime.The results show that the initial fluidization velocities of particles were related to the density and size distribution rather than the height of static bed layer.The bed expansion degree and initial fluidization velocity of mixed particle group were between that of small particles and large particles;two kinds of particles with different densities are mixed with each other.The difference of grain size leads to the difficulty of separating particles.separation under the condition of pulsating flow was investigated for this purpose.The smaller the pulsation amplitude,the greater the difference between expansion degree of particles under the same stationary flow when the pulsating period was certain;shorter pulsating period led to greater difference of expansion degree of particles.When the pulsating period was 1 second,the sampling results show that the yield of low-density particles and high-density particles at the overflow changed from 19.6% and 21.4% to 41.3% and 13.6%,Additional pulsating flow is conducive to promoting particle separation under conventional water..The separation performance of pulsatile teetered bed separator was better than that of traditional teetered bed separator under the same flow average flow velocity in the separation of refractory coarse slime.The separation precision of the coarse slime can be improved by adding the pulsating flow.When the average flow velocity was 10.61mm/s,pulsatile teetered bed separator(amplitude: 1.41 mm/s,period: 2s)can be used to separate coarse slime effectively,the concentrate ash content was 9.47% and the yield was 57.17%.With the increase of pulsating amplitude and pulsation period,both the possible deviation and the imperfection tended to increase.Lower pulsating amplitude was beneficial to the reduction of coarse particle ash content in the concentrate and shorter pulsation period can help promote the separation performance of fine particles.Based on the separation law and optimization method of refractory coarse slime,the optimum separation conditions were obtained by the comprehensive analysis of software.When the stable flow is 11.58 mm/s,the pulsating amplitude is 2.70 mm/s and the pulsating period is 2.41 s,the optimum concentrate ash content is 9.67% and the optimum yield is 60.32%.