A large amount of mineral processing wastewater is generated in mining production. These wastewaters have the characteristics of large discharge, complex composition, high suspended matter content, more harmful components and lower concentration. If the mineral processing wastewater is not treated in time, it will inevitably produce the surrounding environment Hazard also caused great waste of water resources. Coagulation method is one of the commonly used methods in water treatment, and it is often used in the treatment of ore dressing wastewater. Experience has shown that polyacrylamide flocculant is better for flotation agent for ore dressing wastewater treatment.
The application of Flocculant for tailings wastewater in the treatment of tailings wastewater will produce a large amount of high-concentration tailings wastewater. Such high-concentration tailings wastewater contains a large amount of mineral resources such as iron, copper, gold, and coal, and has certain usable value. Direct discharge will not only cause environmental pollution, but also waste these mineral resources. Therefore, it is very necessary to purify such high-concentration tailings wastewater. The treated wastewater can not only achieve the purpose of reuse, reduce the water pressure of mineral processing enterprises, but also recover the mineral resources in it, and increase part of the income for the enterprise. In the treatment of such high-concentration tailings wastewater, the treatment process used is mainly the chemical precipitation method, which uses the flocculation precipitation effect of the coagulant polyaluminum chloride and the flocculant polyacrylamide. So, how does polyacrylamide play a role in the treatment of such high-concentration tailings wastewater? What is its treatment effect?
Polyacrylamide is abbreviated as PAM, commonly known as flocculant or coagulant, and its molecular formula is: +CH2-CHn linear polymer, molecular weight is between 4-20 million, the appearance of solid product is white or slightly yellow powder, liquid is none The color is viscous colloid, easily soluble in water, and easily decomposed when the temperature exceeds 120℃.
The polyacrylamide molecule has a positive group (-CONH2), can adsorb and bridge with suspended particles dispersed in the solution, and has a strong flocculation effect, so it is widely used in water treatment and metallurgy, papermaking, petroleum, chemical industry , Textile, mineral processing and other fields.
Polyacrylamide is divided into: cationic polyacrylamide, anionic polyacrylamide, non-ionic polyacrylamide, zwitterionic polyacrylamide.
Polyaluminum ferric chloride is a polymer coagulant made by hydrolysis of aluminum salts, etc. The hydrolysis speed of polyaluminum ferric chloride is very fast, and the hydration is weak.
Application of polyacrylamide in the treatment of high concentration tailings wastewater
Second, the source, characteristics and treatment methods of high-concentration tailings wastewater
High-concentration tailings wastewater comes from production wastewater generated when crushing and ore sorting.
Such high-concentration tailings wastewater contains a large amount of substances mainly metal elements and soluble compounds in the ore, as well as the flotation agent added during the beneficiation. Mainly include: copper, aluminum, arsenic, zinc, mercury, phosphorus, chromium, cadmium and other metal ions, compounds such as cyanide, xanthate, medicinal herb, pine root oil, phenol, kerosene, diesel, etc.
There are three main methods for treating high-concentration tailings wastewater:
1. Physical law. Such as precipitation, flotation, filtration, blowing off, magnetic separation, etc.
2. Chemical method. Such as neutralization, redox, ion exchange, adsorption, extraction, etc.
3. Biochemical method. Such as aerobic biochemical treatment, anaerobic biochemical treatment, disinfection treatment, etc.
Application of polyacrylamide in tailings wastewater treatment
For flocculant for tailings wastewater, the main method currently adopted is to use a cyclone and a vibrating screen to remove sand, and then accelerate the solid suspended solids in the precipitation water by adding a chemical flocculant. In this process, the chemicals added are mainly coagulant polyaluminum chloride and flocculant polyacrylamide.