New mineral separation method suitable for separation of hard-separation micro-fine particle magnetic iron ores

The invention discloses a new mineral separation method suitable for separation of hard-separation micro-fine particle magnetic iron ores. The new mineral separation method adopts a process comprising the steps of carrying out two-stage grinding on raw ores, carrying out low-intensity magnetic separation, obtaining ore concentrate through reverse flotation and single-stage roughing, regrinding middlings, carrying out the low-intensity magnetic separation and carrying out the reverse flotation; two-stage low-intensity magnetic separation ore concentrate is obtained through the process by adopting a method comprising the steps of stage grinding and stage low-intensity magnetic separation tailings discarding; qualified iron ore concentrate can be obtained in advance by carrying out a cationic collector reverse flotation technology on the two-stage low-intensity magnetic separation ore concentrate under the situation that the granularity is roughened; a regrinding and low-intensity magnetic separation technology is carried out on reverse flotation middlings, the cationic collector reverse flotation technology is carried out on three-stage low-intensity magnetic separation ore concentrate, and thus the iron concentrate grade is increased. According to the new mineral separation method disclosed by the invention, ore concentrate is obtained in advance as the reverse flotation is carried out by independently adopting a cationic collector under the situation that a depressor DF is not added, adding points of medicament are reduced, the manual operation difficulty is reduced, and the cost of mineral separation medicament is reduced; since the ore concentrate is obtained in advance through the reverse flotation, three-stage ball milling material amount is reduced, the ore grinding cost is greatly reduced, and the effect of extracting iron and reducing the energy can be achieved.