Analysis of characteristics of the design of Xingmei Coal Preparation Plant′s coal washing process

In design of the Xingmei silicon coal preparation plant, multiple new ideas and innovative design concepts are introduced. In view of the properties of the raw coal treated, and based on result of market survey, and the availability of advanced coal washing technologies and equipment, the plant opts to use the 3-product heavy medium cyclone as both primary and secondary washing equipment, treat the coarse slime with TPS teetered-bed separator, and treat the coarse coal through pre-removal of gangue using intelligent dry separator. The technological processes and the equipment selected for use as well as layout of systems are introduced. The washing systems prove to be advanced and well-appointed in technology, enabling the plant to effectively separate the raw coal at an ultra-low separation density to produce ultralow-ash clean coal and silicon coal products. Thanks to the flexibility and high adaptability of the systems, it is possible to produce through flexible selection either silicon coal + coking coal products or ultralow-ash clean coal + coking coal products or silicon coal + ultralow-ash clean coal + coking coal products, or only coking coal product. The quality of products can be fully assured. For treating the 25～3 mm coal, the yield is greater than 85% with the yield of Fe₂O₃ being less than 0.2%. While ensuring the social benefits, the economic benefit is maximized. The cost for treating each ton of coal is estimated to be 18.2 yuan and the annual profit that can be gained amounts to 107.315 5 million yuan on average (static investment payback period: 3.89 years). The silicon coal product currently available on market is mainly produced with power coal through removal of gangue at a high separation density. The silicon coal washing process applied in Xingmei Plant is the first of its kind both at home and abroad, which is suitable for use in other plants treating the raw coal with similar properties.