In the process of washing and beneficiation of lead-zinc ore, a large amount of tailings slurry will be produced. Because the tailings directly carry pollutants such as heavy metals and residual beneficiation agents, it is easy to cause pollution to the environment. Therefore, tailings mud must be properly disposed of in a timely manner. At present, the main treatment method is that the tailings mud is subjected to precipitation and concentration, and the clarified liquid is reused. After the concentration, the tailings are added to a belt filter press with a sludge dewatering agent for polyacrylamide chemical pressure filtration and dehydration. After dehydration, the moisture content of the filter cake is low. , can realize dry row, dry heap or comprehensive utilization.
At present, the main methods of treating lead-zinc beneficiation wastewater include coagulation sedimentation method, oxidation method, adsorption method, biological method, etc., and the coagulation sedimentation method and adsorption method are widely used because of their simple process and low cost. Commonly used coagulants are polyacrylamide and polyaluminum chloride.
After the anionic polyacrylamide is dissolved in water, hydrated complex ions are formed when the metal cations and highly polar water molecules undergo hydration. High-charged complex ions with different degrees of polymerization are generated, and at the same time, the hydrolysis reaction of the polymer is constantly going on, resulting in low-charged complex ions with different degrees of polymerization. Through the compression of the electric double layer and the charge neutralization effect of the complex ions with low polymerization degree and high charge, the adsorption and bridging effect of complex ions with high polymerization degree and low charge, and the net trapping effect of hydrated hydroxide precipitation, under appropriate reaction conditions, Generate larger flocculent alum, adsorb heavy metal ions and suspended solids and other pollutants in the wastewater on the surface of the alum, and finally form a precipitate to achieve the purpose of water purification!
Post time: Feb-03-2023
