The industrial by-product gypsum can easily pollute the environment if not disposed of properly. Taking phosphogypsum as an example, phosphogypsum contains phosphate, sulfate, fluoride, heavy metals manganese and cadmium, and some phosphogypsum also contains radium. If it is not stacked according to the specification or there is a problem in the yard, some substances in the phosphogypsum can be dissolved in water and discharged into the environment, and the dissolved aqueous solution is obviously acidic.

When atmospheric precipitation occurs, phosphogypsum is leached by rainwater, and its harmful substances are easily leached out. These leaching water may flow into farmland, lakes, rivers, and may also seep into the ground. Therefore, soil, surface water, and groundwater will all be washed out. Pollution. In the long-term stacking process, the surface part of the phosphogypsum pile is dehydrated due to the sun, so that some toxic and harmful substances are evaporated into the air. When the wind speed is large enough, fine phosphogypsum particles can also cause dust pollution.

Calcium sulfite and excess chloride ions in desulfurized gypsum will pollute the air and groundwater. After sun exposure, volatile acid substances will increase the threat of acid rain; desulfurization gypsum particles will cause dust pollution, suspended particles with a diameter of less than 10mm will affect the human respiratory system, and some desulfurization gypsum have odor.

Like phosphogypsum, fluoride gypsum, citric acid gypsum, mirabilite gypsum, boron gypsum, etc. are all by-product gypsum obtained by acid hydrolysis of calcium-containing substances with sulfuric acid. Titanium gypsum is obtained by neutralizing waste acid with lime. These by-product gypsum will have different degrees of residual acid, and they are all muds with high moisture content. After long-term stacking, there will be waste water infiltration, and after drying, there will be Dust pollution.