探讨了细粒煤的粘附机理，通过试验证实了外在水分是造成筛分过程中细粒煤粘附的首要因素。对粘附力和粘附厚度的影响因素进行了研究，提出了潮湿细粒物料的粘附模型及解决筛孔堵塞的几种方法，为筛分机的设计和应用提供理论依据。

Dry beneficiaion technology with an air dense medium fluidized bed is brielty introduced. Systems for the dry separation of fine coal consisting of a magnetically fluidized bed (MFB) as separation medium are deseribed. The magnetic stabilization produces homogeneity and stability of the fluidized bed and thus eohances the separation efficiency by preventing remixing of the feedstock to be separated. Experimnts have been conducted in a 100-mm inner diamcter cylinder and results show that a uniform and stable MFB can be formed and fine coal(6mm size) can be separaed efficiently.

Coal dry beneficiation with gas-solid fluidized beds belongs to dry dense medium separation. It is important for us to study the rheological behaviors of gas-solid fluidized beds. In this paper, the viscosity of fluidized beds was measured by the solid-settling experiments. The rheological characteristics of fluidized beds can be described with Bingham fluid model. The effective viscosity of fluidized beds can be calculated. the plastic viscosity and yield stress of fluidized beds can be obtained by linear regression analysis of the experimental data. The calculated results agree with the experimental data well.

This paper established the mechnaics model of flip-flow screen. Based on theory analysis, the authors obtained the elastic dynamic differential equation of screen surface, the distribution formula of acceleration along screen surface, the acceleration formula and the numerical solution. All the formulas were tested by experiments. Based on the above, the authors designed the model flip-flow screen and did the pilot experiments. All the results obtained will instruct us in designing flip-flow screen and applying it in industry.