Flotation process design based on energy input and distribution

•A new concept for flotation process design was proposed.•The design of new flotation process was based on energy input and distribution.•High energy input was required to recover difficult-to-float materials.•Low energy input was required to recover easy-to-float materials.•High flotation efficiency index was obtained by increasing power input step by step.

Energy-saving ability and high flotation efficiency are two important factors in the flotation process. In this investigation, a new concept for the flotation process design based on energy input and distribution was proposed, low energy was inputted early to recover easy-to-float materials, whereas high energy was inputted late to recover difficult-to-float materials. The flotation tests were conducted in an XFD 0.75 L laboratory-scale flotation machine. A comparison of flotation performance using constant power input and gradually increased power input was investigated. The flotation results indicated that low ash content, high flotation efficiency index, and energy-saving ability could be obtained by increasing power input step by step in the flotation process. The flotation process design based on different shaft speeds (1500, 1500, 1800, 1800, and 2400 r/min in different flotation periods) and an energy consumption of 1720.8 J is suitable for flotation performance of the coal samples in this study.