Yadong Zhang is a first year PhD student at China University of Mining and Technology, and his Major is in Mineral Processing Engineering. He has published two articles in Powder Technology and Journal of China Coal Society, respectively
Dry beneficiation of fine coal needs to be upgraded because of the poor efficiency of separation technology. Under this condition, it is extremely urgent to develop an advanced process in the field of fine coal cleaning. The vibrated fluidized bed(VFB) that introduces an external vibration force to the conventional fluidized bed was applied as a successful clean dry coal preparation technology. The pressure fluctuation signals in the VFB were measured by the pressure transmitters and the hidden information in the pressure signals of the VFB was extracted with the mathematical tools in both time and frequency domains. The objective of this work was to investigate the changes of the pressure signal components in different operating factors and to evaluate the separation performance of fine coal in a Φ110 mm×800 mm VFB with the -0.3+0.074 mm magnetite powder under optimum operating condition. The experimental results indicated that the energy and power spectra of the pressure signals were obtained. The gas velocity, frequency and amplitude of the vibration have an significant effect on the pressure fluctuation of the VFB, the gangue of high ash could be removed by a VFB and got clean coal whose ash content reached 10.57% and reduced by about 24.00% compared with 34.57% of raw coal and gangue ash reached 55.00% above under the optimal technique.
Bo Lv is studying for a PhD from China University of mining and technology. He is devoted to researching dry separation technology and application. He has published more than four papers in reputed journals in china. Zhenfu Luo is a Professor, Doctoral tutor and Editor of the Journal of China University of Mining & Technology, mainly engaged in dry mineral processing theory and technology development, fluidized dry sorting technology and equipment research. He has published more than 70 papers in reputed journals.
Adopting air dense medium fluidized bed, fine coal particles in the size range of 3-6 mm were separated in experimental study. The experimental results showed that most of the high density of fine coal were accumulation in the lower part of the bed, while low-density fine coal tend to gather in the upper bed. This increase was mainly due to plasmid degree in composition and fluidization conditions to achieve the minimum separation of particles, resulting in deterioration of separation efficiency.Currently the air dense medium fluidized bed dry coal preparation technology has been successfully achieved for 50~6 mm grain size sorting of coal, But it is still not clear for 6~0 mm fine coal. It is necessary to fine-grained level for dry separation of test.