Abstract: Because of ageing of the XJN-14 flotation machine, a series of problems arise in its operation. To address these problems, a novel-type mechanically-agitated flotation machine is developed through optimum design according to requirements of the plant. Practical application of the machine shows that the machine can fully meet the production requirement. Under the conditions of treating a feed of the same property and maintaining the required ash of concentrate, there can be seen an increase of ash of tailings from 60% to over 65%, a rise of concentrate yield by 3.20 percentage points and an increase of yield of total clean coal product by 0.80 percentage point.