Study on feasibility of upgrading cake product of filter press through flotation process at Xiegou Mine Coal Preparation Plant

The trouble confronting the plant is that the cake product of filter press can hardly be used as a blend of washed coal due to its high moisture, and its stockpiling or dumping outside the plant adds pressure to environmental protection. To tackle this problem, a study is made on the feasibility of upgrading the cake product through flotation process, based on result of sieve analysis, float-and-sink analysis, timed-release analysis and batch-flotation test. Study result indicates that: the flotation process is deteriorated due to the presence of the < 0.045 mm high-ash fine slime whose yield is as high as 67.81%; it is impossible to produce a concentrate product with an ash of less than 11.0% through just a single flotation process, and the concentrate thus obtained cannot be directly mixed with clean small coal product; and through increase of dosage of flotation reagent, a tailing product with an ash of over 60% can be produced, which can be directly discarded, and the concentrate can be all mixed with clean coal, making it possible to dispense with the slime handling system. Calculation shows that adding the flotation system is theoretically feasible as evidenced by the rise of yield of clean coal by 3.5 percentage points. Compared with the existing washing system with no use of flotation circuit, the revenue obtained through selling each ton of raw coal can be increased by 7.06 yuan.