Polyacrylamide is used in the mining and processing of coal, gold, silver, copper, iron, zinc, uranium, nickel, phosphorus, potassium, manganese and other minerals and tailings treatment processes. The main purpose is to improve the efficiency and recovery rate of solid-liquid separation; Among them, in the coal industry, the sedimentation and clarification of coal slurry and tailings, the solid-liquid separation in the process of tailings filtration and centrifugation; in gold or silver or copper mines, the sedimentation agent added by the thickener before the filter tank; in the PH value In lower (less than 4) mineral liquids, such as lead-zinc ore, used as sedimentation additives, etc.;
The mining industry consumes large amounts of water for:
(1) The main principle of ore washing and flotation is to use the difference in the physical and chemical properties of the mineral surface to make one or a group of minerals in the ore selectively attach to the bubbles and float to the surface of the ore, which will be useful Minerals are separated from gangue minerals. Many minerals such as iron, coal, phosphate, zinc, uranium, sand, etc. use this process. At this time, flocculants can be used to:
1. Separate water from gangue to facilitate water reuse;
Dewatering a pair of sludge generated by gangue sedimentation;
-If the useful mineral is suspended in the water, separate it from the water.
(2) During the process, metal minerals are sometimes dissolved in acid or alkali. At this time,
Flocculants are used to flocculate and separate undissolved impurities, and metals are recovered in the form of hydroxides or salts. Non-ionic or anionic flocculants are commonly used in the above processes. Non-ionic flocculants are often used in acidic or highly salty solutions.
- Tailings treatment
The tailings wastewater mainly includes beneficiation drainage, tailings slurry and mine drainage. There are more suspended solids in the tailings wastewater, and the content of usable minerals in the suspended solids is less. The current technology can no longer be further separated and become the final tailings wastewater. At present, the tailings are mostly treated by thickener plus sludge dewatering filter press (such as belt filter press, plate and frame filter press, ceramic filter, etc.). The suspended solids become mud cake after being processed by the filter press. The press-filtered water enters the beneficiation system again for recycling. Treatment process of beneficiation tailings wastewater: After the beneficiation wastewater is coagulated with an inorganic flocculant, the fine particles in the suspended solids coagulate into a slightly larger coarse particle suspension, and then enter the sedimentation tank after the flocculation reaction with the polyacrylamide flocculating precipitant, and the sediment After passing through the thickener in the sedimentation tank, the concentrated mud is pumped out by the mud pump, and polyacrylamide is added again for the secondary flocculation reaction, and then it enters the filter press (mostly uses a belt filter press, which is more efficient) for mud-water separation. The separated water enters the circulation system and the mud is discharged for landfill or utilization. Most tailings wastewater uses anionic polyacrylamide with a molecular weight of 15 million or 18 million for treatment, and a few use non-ionic polyacrylamide with a molecular weight of 12 million. The principle of polyacrylamide in the treatment of tailings wastewater: The long molecular chain of polyacrylamide captures and adsorbs suspended substances in water into coarse particles through mechanisms such as adsorption bridging, net capture, and electric neutralization. Large particles have a large specific gravity and can quickly move in water. Settling, so as to achieve the effect of separating suspended matter and water, secondary flocculation is to connect the coarse particles to flocculate the second time to make the flocs larger, thereby increasing the working efficiency of the filter press.
Post time: Mar-27-2021