Method for preparing lithium chloride from magnesium sulfate subtype salt lake brine

A method for preparing lithium chloride from magnesium sulfate subtype salt lake brine relates to the technical field of lithium chloride preparation, and comprises the following steps: purification and impurity removal: filtering salt lake brine, and standing to remove impurities such as silt and precipitates; removing sulfate ions: adding barium carbonate powder into the brine filtrate, stirring, heating, standing and precipitating to obtain a lithium-containing solution; removing other impurity ions: adjusting the pH value of the lithium-containing solution, stirring, standing and precipitating to obtain lithium chloride, a sodium chloride solution and filter residues; evaporating lithium chloride and water accounting for 90% +/-2% of the mass of the sodium chloride solution to a co-saturation point, and separating out a large amount of sodium chloride to obtain a high-concentration lithium chloride solution; and concentrating and drying: adjusting the pH value of the high-concentration lithium chloride so