Flotation process suitable for reducing magnesium oxide content in nickel concentrate and improving nickel recovery rate of low-grade copper-nickel ore

The invention discloses a flotation process suitable for reducing the content of magnesium oxide in nickel concentrate and improving the nickel recovery rate of low-grade copper-nickel ore. The method comprises the steps of raw ore grinding, copper and nickel mixing primary quick separation, copper and nickel mixing secondary quick separation, copper and nickel mixing roughing, copper and nickel mixing primary scavenging, copper and nickel mixing secondary scavenging, copper and nickel mixing tertiary scavenging, middling re-separation, copper and nickel mixing primary concentration, copper and nickel mixing secondary concentration, copper and nickel mixing fine scavenging, copper and nickel mixing blank concentration, copper and nickel separation and the like. And nickel concentrate and copper concentrate are finally obtained. The method can solve the problem that the content of magnesium oxide is too high to influence downstream smelting industry equipment when the nickel metal is recovered from the low-gra