ABSTRACT
Dense medium cyclone is effective in beneficiation of fine coal with great separation precision. Small-diameter cyclones (usually 150 mm to 350 mm) are preferred in industrial applications. But the handling capacity of a small cyclone is low, which brings about the problems of maintain and operation. The separation efficiency of large-diameter cyclones with greater handling capability in fine coal treatment is questionable. In this study, the cylindrical section of a 710/500 mm three-product cyclone was adopted to treat 0.75–0.125 mm fine coal, where the cylinder-cone cyclone was a surge section. Influence of inlet pressure and feed rate were studied in an industrial environment. According to the results, the separation efficiency was sharp at relatively low feed pressures (110 KPa to 160 KPa). The separation effect increased with the feed rate. The favorable Ecart probable (Ep) value of 0.054 was obtained at an inlet pressure of 120 KPa and a feed rate of 42 t/h. Results of the studies showed that large-diameter cyclones will be applicable for fine coal treatment. These results will be significant for fine coal with a high content of near-density material.
Acknowledgment
The authors are grateful to Shaowen Huang and Pengshuai Wang for their diligent work in conducting the industrial tests and sample analysis.
Funding
This work was supported by the National Natural Science Foundation of China (NSFC, Grant No. 51474213), the National Natural Science Foundation of China (NSFC, Grant No. 51374205), and the Graduate Education Innovation Project of Jiangsu Province (No. KYLX_1409). We also want to thank the support of the Fundamental Research Funds for the Central Universities (Grant No. 2014XT05) and A Priority Academic Program Development of Jiangsu Higher Education Institutions.