Method for increasing magnesite flotation recovery rate

The invention discloses a method for increasing the magnesite flotation recovery rate. The method comprises the steps that reverse flotation silicone-removing work is conducted on crude ore pulp, foamsubjected to reverse flotation fine selection is fused together for reverse flotation fine scavenging, underflow subjected to reverse flotation fine scavenging returns to the first reverse flotationfine selection or reverse flotation coarse selection, underflow subjected to last reverse flotation fine selection is subjected to direct flotation calcium-lowering work, underflow subjected to directflotation coarse selection is subjected to direct flotation scavenging, foam subjected to direct flotation coarse selection is subjected to two to four times of direct flotation fine selection, foamsubjected to the last direct flotation fine selection is magnesite concentrate, underflow subjected to the first direct flotation fine selection is subjected to direct flotation fine scavenging, foamof direct flotation fine scavenging returns to direct flotation coarse selection or direct flotation scavenging, and other underflow subjected to direct flotation fine selection and foam subjected todirect flotation scavenging return to the previous work in sequence. Silicone and calcium impurities can be efficiently removed, the magnesite flotation recovery rate is increased by a large margin, and application of a flotation silicone-removing calcium-lowering technology of low-grade magnesite in the industry can also be achieved.