Study on dissociation characteristics and enhanced gravity separation of coking coal middlings

ABSTRACT

This work innovatively introduced EGS technology into the re-separation process of coking coal middlings based on the dissociation characteristics. The EGS separation characteristics were compared with conventional FF and a novel pre-desliming EGS technology was proposed to achieve clean and efficient separation of coking coal middlings. The density composition and washability of the coking coal middlings crushed under the upper limit size of 6, 3, 1, and 0.5 mm show that the dissociation of the coking coal middlings has been basically completed when crushing to −0.5 mm. The clean coal ash can be reduced to 13.37% with a yield of 42.46% through the pre-desliming EGS technology. The optimal combustible recovery of 71.84% and ash removal rate of 81.36% can be obtained by EGS and pre-desliming EGS methods, respectively, which indicates the superiority of EGS compared to conventional FF. The pre-desliming EGS technology has already demonstrated its great potential in the re-separation of coking coal middlings with the advantages of low-cost, no-pollution and high-efficiency.

KEYWORDS:

• Coking coal middlings
• dissociation characteristics
• enhanced gravity separation
• separation performance
• deashing

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China under Grant No. 51874303.