Method for preparing magnesium sulfate from tailings produced in extraction of potassium of magnesium sulfate subtype salt lake brine

The invention relates to a method for preparing magnesium sulfate from tailings produced in extraction of potassium of magnesium sulfate subtype salt lake brine. The method comprises the following steps of 1, crushing tailings produced in extraction of potassium of magnesium sulfate subtype salt lake brine and grinding, 2, carrying out decomposition conversion of slurry obtained by grinding, and carrying out flotation to obtain the slurry subjected to size mixing, 3, carrying out roughing of the slurry subjected to size mixing to obtain rough concentrate slurry and rough tailing slurry, 4, carrying out scavenging of the rough tailing slurry to obtain scavenged concentrate slurry and scavenged tailing slurry, and carrying out solid-liquid separation of the scavenged tailing slurry to obtain tailings mainly containing sodium chloride and a filtrate A, 5, carrying out one-step concentration of the rough concentrate slurry to obtain concentrated concentrate slurry and concentrated tailing slurry ...