The mechanism of beneficiation with air dense fluidized bed has been theoretically studied in the paper. Focusing attention on the misplacing resources in separation process, the misplacing effects are divided into t...The mechanism of beneficiation with air dense fluidized bed has been theoretically studied in the paper. Focusing attention on the misplacing resources in separation process, the misplacing effects are divided into two parts called respectively as misplacing effect of viscosity and misplacing effect of motion. The proposed separation theory can reasonably explain the results of separation in different fluidization states. Experimental results in pilot and commercial plants showed that the air dense medium fluidized bed is a high efficiency dry cleaning technique. The dynamic stability of fluidized bed density is directly affected by the variation of fine coal content in fluidized bed and can be controlled in expected range through measurement of fluidized bed density and adjusting of split flow rate. With air dense medium fluidized bed, various coals of size 50—6 mm can be efficiently beneficiated. The separation density can be adjusted between 1.2—2.2 g/cm 3, and the probable error E p value is about 0.06.展开更多
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. Th...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.展开更多
为提高空气重介质流化床对入料煤水分的适应性，以热气代替常温空气改善流化床对褐煤的分选效果。采用可能偏差 E p为评价指标，研究了热态空气重介质流化床的干燥温度、干燥时间和风量对褐煤分选效果的影响。结果表明：干燥温度为30~5...为提高空气重介质流化床对入料煤水分的适应性，以热气代替常温空气改善流化床对褐煤的分选效果。采用可能偏差 E p为评价指标，研究了热态空气重介质流化床的干燥温度、干燥时间和风量对褐煤分选效果的影响。结果表明：干燥温度为30~50℃时，干燥温度越高，Ep越低；干燥时间为1~5 min 时，干燥时间越长，Ep越低，超过3 min 后，Ep降低缓慢；风量为8~12 m3/ h 时，风量增大，Ep先降低后升高。煤样表面水分越高，干燥温度、干燥时间和风量变化对 E p影响越显著。表面水分1％的褐煤，干燥温度50℃、干燥时间5 min、风量10 m3/ h 时，褐煤分选效果最好，Ep 可达到0.022 g / cm3。实验证明热态空气重介质流化床可用于分选潮湿褐煤。展开更多
文摘The mechanism of beneficiation with air dense fluidized bed has been theoretically studied in the paper. Focusing attention on the misplacing resources in separation process, the misplacing effects are divided into two parts called respectively as misplacing effect of viscosity and misplacing effect of motion. The proposed separation theory can reasonably explain the results of separation in different fluidization states. Experimental results in pilot and commercial plants showed that the air dense medium fluidized bed is a high efficiency dry cleaning technique. The dynamic stability of fluidized bed density is directly affected by the variation of fine coal content in fluidized bed and can be controlled in expected range through measurement of fluidized bed density and adjusting of split flow rate. With air dense medium fluidized bed, various coals of size 50—6 mm can be efficiently beneficiated. The separation density can be adjusted between 1.2—2.2 g/cm 3, and the probable error E p value is about 0.06.
基金Projects(51221462)supported by the National Natural Science Foundation of ChinaProject(2014QNA28)supported by the Fundamental Research Funds for the Central Universities,China
文摘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.
文摘为提高空气重介质流化床对入料煤水分的适应性，以热气代替常温空气改善流化床对褐煤的分选效果。采用可能偏差 E p为评价指标，研究了热态空气重介质流化床的干燥温度、干燥时间和风量对褐煤分选效果的影响。结果表明：干燥温度为30~50℃时，干燥温度越高，Ep越低；干燥时间为1~5 min 时，干燥时间越长，Ep越低，超过3 min 后，Ep降低缓慢；风量为8~12 m3/ h 时，风量增大，Ep先降低后升高。煤样表面水分越高，干燥温度、干燥时间和风量变化对 E p影响越显著。表面水分1％的褐煤，干燥温度50℃、干燥时间5 min、风量10 m3/ h 时，褐煤分选效果最好，Ep 可达到0.022 g / cm3。实验证明热态空气重介质流化床可用于分选潮湿褐煤。
