Stone processing wastewater mainly contains stone powder (SiO2, Cao and CaCO3, etc.), a small amount of diamond particles, abrasive particles and washing mud. Compared with mill wastewater, the water quality of sawing machine and trimming machine wastewater is more similar, and the particles in the wastewater are larger and contain a small amount of organic coolant (mainly saponification, archaea oil, etc.). According to the investigation and water quality analysis, the characteristic pollutant of the wastewater is SS. The particles in the wastewater are fine (particle size ≤ 200 mesh), suspended and colloidal, with high dispersion. If it is discharged without treatment, the color of the polluted wastewater is gray, which is harmful to the aquatic plants of fish and shrimp. The aquatic animals and plants in the polluted river will be significantly reduced. The polluted wastewater is also harmful to the land, and it will pollute the groundwater, thus affecting human health. In addition, the stone powder flowing into the river reservoir will block the water bottom, increase the silt at the bottom, and reduce the fluidity of the water body.

Because of the great harm of stone sewage, it must be strictly controlled to meet the discharge standard before discharge. In view of the pollution of Dali stone and artificial stone, because of its high turbidity, the effect of using anionic polyacrylamide is better, which can quickly flocculate and precipitate lime powder and other substances, and its substances can also be recycled.