Method for treating nickel smelting magnesium-containing wastewater

The invention provides a method for treating nickel smelting magnesium-containing wastewater, wherein the method is characterized by comprising the following steps: adding sodium sulfide to precipitate heavy metals, introducing tail gas to remove manganese ions, adding magnesium oxide to further remove manganese ions, concentrating, and carrying out spray drying to obtain a magnesium sulfate product. The heavy metal ion removal efficiency is high, and impurities such as manganese can be removed by utilizing heat energy and oxygen in the industrial tail gas; the tail gas can be subjected to cooling, dust removal and purification treatment; the cost of extra investment of dust removal equipment for tail gas treatment is saved; through addition of the magnesium oxide, impurity ions are effectively removed, and a magnesium-containing liquid is concentrated and dried to finally obtain the high-quality magnesium sulfate solid product. The method has the advantages of simple process flow, high production efficiency,