Operational Factor Optimization of Fine Lignite Cleaning Through a Dry Vibrated Fluidized Bed Separation

摘要

Efficient cleaning of fine lignite is difficult through conventional coal-separation technology. This study focused on the dry cleaning of fine lignite using vibrated fluidized bed separation. Various operational factors that influence the segregation efficiency of fine lignite include the initial bed height, fluidization number, vibrational amplitude, and frequency. The factors were optimized using response surface methodology, which was based on the Box-Behnken design. Results indicated that the satisfied segregation efficiency could be achieved under suitable operational conditions. The optimum segregation index was obtained when the initial bed height, fluidization number, vibrational amplitude, and frequency were optimally set to 80 mm, 1.5, 2.0 mm, and 16 Hz, respectively. In this case, the favorable recovery efficiency of clean coal was achieved as well. A mathematical quadratic model was established to predict the relationship between the segregation index and operational factors. Predicted results of the segregation index obtained under the optimized conditions by the model were consistent with the experimental results.