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I. Corrosion mechanism: Acidic sulfate wastewater is rich in H⁺ ions, which can interact with metals in two ways: Chemical corrosion: As oxidizing agents, H⁺ ions directly oxidize metallic elements into metal ions, while being reduced to hydrogen gas. The general reaction formula is: Metal + 2H⁺ → Metal ions + H₂↑. Electrochemical corrosion: Impurities on the metal surface can form microcells, accelerating the anodic dissolution of the metal and thereby greatly increasing the corrosion rate. II. Corrosion resistance of common metals: Carbon steel: It suffers severe corrosion in low-concentration acidic sulfate waste solutions; the corrosion rate decreases significantly when the mass fraction of sulfuric acid exceeds 60%. Stainless steel: Ordinary 304 and 316L exhibit only moderate corrosion resistance at low temperatures and low concentrations; the corrosion rate increases rapidly in high-temperature environments. Nickel-based alloy (Nickel201): It performs excellently in weakly reducing acidic sulfate environments and is a commonly used corrosion-resistant material in such conditions. Lead and lead alloys: They maintain good stability at normal concentrations, with their corrosion resistance decreasing significantly only in high-temperature and high-concentration environments. III. Reaction Products: For metals that are ranked above hydrogen in the metal activity series (such as iron and zinc), the reaction produces the corresponding metal sulfates along with hydrogen gas ； If oxidizing agents are present in the waste liquid, metal sulfates in higher oxidation states may also be formed, further accelerating corrosion. IV. Common protection methods: Select appropriate materials wisely – give priority to nickel-based alloys, titanium alloys, and corrosion-resistant lead materials as alternatives to ordinary carbon steel. Covering protective layer: Physical separation of the metal from waste liquids is achieved through coatings or platings, thereby blocking the pathways for corrosion to occur. Electrochemical protection: Sacrificial anode or impressed current cathodic protection methods are used, with the metal to be protected acting as the cathode to prevent oxidation. Add a corrosion inhibitor: A small amount of corrosion inhibitor is added to the waste liquid, where it inhibits electrode reactions through adsorption or film formation, thereby reducing the corrosion rate.