Comparison of coal separation characteristics based on different separating approaches in dry coal beneficiation flowsheet

Abstract

The separation characteristic of raw coal from Luoyang mining area, China, was investigated by applying a dry coal beneficiation flowsheet with the dense medium gas-solid fluidized bed as main separating equipment. The experimental and simulation results indicate that the dense medium gas-solid fluidized bed can provide uniform distribution and stable fluctuation of bed densities at various heights. Two types of different separating approaches were compared using the dry coal beneficiation flowsheet. Compared with obtaining cleaning coal in the first stage of the flowsheet, a higher yield of the cleaning coal and better separation efficiency can be achieved when discharging gangue in the first stage. Finally, the results indicate that 64.86% pure cleaning coal with an ash content of 11.77% and 13.53% middlings were obtained, and 21.61% gangue was removed in two successive separation stages with the probable errors of 0.05 and 0.07 g/cm³, respectively.

Keywords

separation characteristic / dense medium gas-solid fluidized bed / separating approach / numerical simulation / density stability

References

[1] HeinbergR, FridleyD. The end of cheap coal [J]. Nature Comment, 2010, 468: 367-369

[2] HanK-q, WangY-jun. Developing trend and expectation of energy consume in China [J]. Journal of China University of Mining and Technology, 2004, 33(1): 1-8

[3] World energy outlook 2010 [R]. International Energy Agency, 2010.

[4] LuY-xiangEnergy science & technology in China: A roadmap to 2050 [M], 2009, Beijing, Science Press

[5] SahuA K, BiswalS K, ParidaA. Development of air dense medium fluidized bed technology for dry beneficiation of coal-A review [J]. International Journal of Coal Preparation and Utilization, 2009, 29: 216-241

[6] MohantaS, RaoC S, DaramA B, ChakrabortyS, MeikapB C. Air dense medium fluidized bed for dry beneficiation of coal: Technological challenges for future [J]. Particulate Science and Technology, 2013, 31: 16-27

[7] van HouwelingenJ A, de JongT P R. Dry cleaning of coal: Review, fundamentals and opportunities [J]. Geologica Belgica, 2004, 7: 335-343

[8] HonakerR Q, SaracogluM, ThompsonE, BrattonR, LuttrellG H, RichardsonV. Upgrading coal using a pneumatic density based separator [J]. International Journal of Coal Preparation and Utilization, 2008, 28: 51-67

[9] MacphersonS A, IvesonS M, GalvinK P. Density based separations in the reflux classifier with an air-sand dense-medium and vibration [J]. Minerals Engineering, 2010, 23: 74-82

[10] SahuA K, TripathyA, BiswalS K. Study on particle dynamics in different cross sectional shapes of air dense medium fluidized bed separator [J]. Fuel, 2013, 111: 472-477

[11] EbrahimA, ShayanK, MoshfiqurR, JozefS, RajenderG. Evaluation of the performance of air dense medium fluidized bed (ADMFB) for low-ash coal beneficiation. Part 1: Effect of operating conditions [J]. Energy & Fules, 2013, 27: 5595-5606

[12] EbrahimA, ShayanK, MoshfiqurR, JozefS, RajenderG. Evaluation of the performance of air dense medium fluidized bed (ADMFB) for low-ash coal beneficiation. Part 2: Characteristics of the beneficiated coal [J]. Energy & Fuels, 2013, 27: 5607-5616

[13] GeorgeV F, MuhamadF, OshitaniJ. Copper ore density separations by float/sink in a dry sand fluidised bed dense medium [J]. International Journal of Mineral Processing, 2013, 121: 12-20

[14] ChenQ-r, YangY-fen. Development of dry beneficiation of coal in China [J]. Coal Preparation, 2003, 23: 3-12

[15] ZhaoY-m, LuoZ-f, ChenQ-ru. Fundamental and practical developments of dry coal cleaning in China: A review [J]. Coal Preparation Society of America Journal, 2004, 3: 14-18

[16] ZhaoY-m, LiG-m, LuoZ-f, LiangC-c, TangL-g, ChenZ-q, XingH-bo. Modularized dry coal beneficiation technique based on gas-solid fluidized bed [J]. Journal of Central South University of Technology, 2011, 18(2): 374-380

[17] ZhaoY-m, WeiL-bin. Rheology of gas-solid fluidized bed [J]. Fuel Processing Technology, 2000, 68: 153-160

[18] LuoZ-f, ChenQ-ru. Dry beneficiation technology of coal with an air dense-medium fluidized bed [J]. International Journal of Mineral Processing, 2001, 63: 167-175

[19] LuoZ-f, FanM-m, ZhaoY-m, TaoX-x, ChenQ-r, ChenZ-qiang. Density-dependent separation of dry fine coal in a vibrated fluidized bed [J]. Powder Technology, 2008, 187: 119-123

[20] LuoZ-f, ZhaoY-m, ChenQ-r, FanM-m, TaoX-xiang. Separation characteristics for fine coal of the magnetically fluidized bed [J]. Fuel Processing Technology, 2002, 79: 63-69

[21] HeJ-f, ZhaoY-m, LuoZ-f, ZhaoJ, DuanC-l, HeY-qun. Improving separation efficiency of 6-1 mm coal by introducing vibration energy to dense medium gas-solid fluidized bed [J]. Physicochemistry Problems of Mineral Processing, 2015, 51(1): 95-108

[22] HeJ-f, ZhaoY-m, HeY-q, LuoZ-f, DuanC-long. Numerical simulation and experimental verification of bubble size distribution in an air dense medium fluidized bed [J]. International Journal of Mining Science and Technology, 2013, 23(2): 387-393

[23] HeJ-f, HeY-q, ZhaoY-m, DuanC-l, YeC-ling. Numerical simulation of the pulsing air separation field based on CFD [J]. International Journal of Mining Science and Technology, 2012, 22(2): 201-207

[24] HonakerR Q, BimpongC. Alternative materials for dense medium separations [J]. International Journal of Coal Preparation and Utilization, 2009, 29: 173-191

[25] ObengD P, MorrellS. The JK three-product cyclone-performance and potential applications [J]. International Journal of Mineral Processing, 2003, 69: 129-142

[26] HeJ-fengNumerical simulation of multiphase fluid dynamic in air dense medium fluidized bed based on Euler-Euler model [D], 2012, Xuzhou, China University of Mining and Technology