What are the treatment methods for industrial waste acid?

Currently, the main methods of concentrating sulfuric acid include the following methods: vacuum concentration, pot concentration, combustion concentration, etc. Compared with other concentration methods, dilute sulfuric acid vacuum concentration has obvious advantages. First, the operating environment is good, which completely avoids the pollution of acid smoke and has almost no emissions of three wastes; secondly, a variety of anti-corrosion materials with superior performance are used to avoid frequent replacement of equipment after corrosion, greatly reducing labor intensity; thirdly, the concentration system is continuously operated, with few operators and low energy consumption; fourthly, the investment is saved, compared with similar devices introduced abroad, nearly half of the investment is saved. The waste sulfuric acid with low concentrations and different organic and inorganic impurities discharged from various industrial systems is increased to about 90% after evaporation and washing. Its characteristics are that the waste acid is treated and removed from the impurities of organic and inorganic salts, absorbs part of the heat energy from the finished acid through a hot and cold acid exchanger, and enters the evaporator for vacuum concentration to reach the required concentration of the finished acid. The acid steam coming out of the evaporator enters the scrubber for washing. Calculated with the same processing capacity, the operating cost of vacuum concentration is 59% of the pot concentration and 62% of the hot air concentration. Although the investment in vacuum concentration is higher than that of pot and hot air concentration, the vacuum concentration yield is high, the energy consumption is low, the wastewater emissions are fully met, and the area covers a small area.