Abstract: It is found through sieve and float-and-sink analysis and laboratory experiment that the flotation feed of Shanjiaoshu Plant contains a high proportion of high-ash fine slime, making it difficult for the flotation system to produce a concentrate product with a required ash level and a high yield. Whereas, with the use of a cyclone microbubble flotation column, a high yield of concentrate product with an up-to-standard ash can be produced. As evidenced by field application of the flotation system renovated with the use of the flotation column, there have been seen a drop of concentrate ash by 1.4 percentage points, and a rise of yield of concentrate and recovery of combustible matters by respectively 4.7 and 6.75 percentage points. This not only averts the situation of producing a concentrate product with a substandard ash level and a low yield, a technical bottleneck in the case before renovation, but also creates a favorable economic benefit for the plant.