Coal Ash Beneficiation and Utilization in Coal Separation Process
In recent years, coal production and consumption increased dramatically, especially in China. So, more and more attentions have been paid to coal preparation and coal ash utilization with the growing concern about the pollution by fly ash. The unburned carbon in fly ash significantly affects its utilization in many fields, especially in concrete production industry. Technologies such as flotation, triboelectrostatic separation and carbon burnout have been developed to remove carbon from coal ash. This paper introduces chemical compositions of a typical coal ash and a dry beneficiation method. For some kinds of fly ash, magnetically stabilized fluidized bed was studied to recover magnetic pearls from fly ash. The magnetic pearls are mainly composed of Fe3O2 and Fe3O4 and are mostly hollow spheres. The size distributions of three kinds of magnetic pearls are from 300 to 25 µm. A magnetic pearls fluidized bed and a magnetically stabilized magnetic pearls fluidized bed for coal dry separation are studied in the paper.
Magnetically stabilized fluidized beds for fine coal separation
Abstract Based on a prior study on air-fluidized dense media for 6–50-mm coal preparation, this paper presents results on magnetically stabilized fluidized bed (MSFB) on fine 1–6-mm coal preparation. Magnetic stabilization improves separation by lowering the lower size limit of separation and by preventing back mixing of the separated solids. This work addresses the fluidization media characteristics, the experimental system and separation results.
Crossflow Magnetically Stabilized Bed Chromatography
Abstract A device for continuous chromatographic separation of multicomponent feeds is described. It consists of a magnetically stabilized fluidized bed (MSB) in which bed solids move crossflow to the fluidizing fluid. Adsorbable components of the feed move in two directions; with the fluidizing carrier fluid to the bed surface, and with the solids across the bed to different positions depending on their sorption characteristics. The features that make the crossflow MSB chromatograph attractive are the ability to continuously separate feed mixtures into multiple products in a single vessel with no moving mechanical parts. The MSB is ideally suited for chromatographic operation. The fluid and solids move in plug flow, and the pressure drop is limited to the weight of solids per unit bed area, independent of the particle size and fluid throughput. Using tracer gases, the operation of a crossflow MSB chromatograph has been demonstrated. Increasing the height of the crossflow bed has been shown to improve the...