Formation of Double-Density Fluidized Bed and Application in Dry Coal Beneficiation

摘要

Currently utilized separators with air-dense medium fluidized bed can only produce two products with single-separating density. Two separators must be employed in series to generate three products, which leads to the complication of the technical system and on increase in construction investment and operation costs. Moreover, they are difficult to operate continuously owing to the problems of preparation and recovery of dense media. The double-density fluidized bed forms two separating areas with different densities in a fluidized cascade. In each separation area, the bed density is uniform and meets the needs for three-product separation of coal. Therefore, the coal can be separated into three products according to density. In this paper, the fluidized behavior of binary dense media was experimentally studied in different bed structure. The segregation and mixing process of binary dense media was analyzed. By use of the proper operation conditions and the specially designed bed structures, a double-density fluidized bed was formed for three-product separation of coal.