Method for recycling copper and iron in acid mine wastewater by high-polymer chelating-precipitating agent two-step process

Abstract

The invention discloses a method for recycling copper and iron in acid mine wastewater by a high-polymer chelating-precipitating agent two-step process, relates to a wastewater treatment method and provides a method for recycling copper and iron in acid mine wastewater by a high-polymer chelating-precipitating agent two-step process, and the method adopts the two-step process, is simple in process and free of secondary pollution, capable of changing the outlet slag into finished products and easily pressing and filtering the slag, so that the zero storage capacity is achieved, the outlet water can completely satisfy the standards and the outlet water can be recycled for mineral processing. The method comprises the following steps of: adding liquid caustic soda to the acid mine wastewater for entering a next stirring reaction slot after regulating the pH of the wastewater to 2.7; adding the high-polymer cheating copper-extracting agent for regulating the pH to 4.2-4.4; adding flocculating agent for carrying out sedimentation and solid-liquid separation, wherein the sediment is copper concentrate with 20%-30% of copper, and the liquid supernatant enters an ion-extracting reaction slot; the high-polymer cheating iron-extracting agent is added to regulate the pH to 8.2-8.5; and the flocculating agent is added for carrying out sedimentation and solid-liquid separation, wherein the sediment is iron concrete, and the liquid supernatant can reach the first-level emission standards and can be directly exhausted or recycled.

Description

technical field [0001] The invention relates to a wastewater treatment method, in particular to a method for recovering copper and iron in mine acid wastewater by a two-step method of a polymer chelating precipitant. Background technique [0002] Due to its low pH value, high acidity, and a large amount of heavy metals, acid mine wastewater will cause serious pollution to the water around the mining area. Among them, the national comprehensive treatment rate of copper mine wastewater is only 70%. About 30% of the waste water is discharged directly without treatment, and the operating rate of existing treatment devices is only 20%. The copper-containing acid waste water produced by mining and utilization has become one of the industries that cause the most serious pollution to the water ecological environment. one. Therefore, an efficient and environmentally friendly copper-containing acid wastewater treatment process is urgently needed. [0003] At present, there are main...

AI Technical Summary

Problems solved by technology

Chinese patent CN101974690A uses calcium hydroxide to separate rare earth elements, Chinese patent CN102786133A uses lime milk to recover copper and iron in acidic mines, but the lime neutralization method will bring a lot of sediment, and these sediments cannot be reused, because there is no tailings pond Occupies a large amount of storage capacity, that is, after being landfilled, there will be secondary pollution when encountering acid, and the effluent cannot be discharged stably and meet the standards

[0004] The sulfide method requires three stages of treatment. First, iron is precipitated with liquid caustic soda. In the second step, copper is precipitated with sulfide. In the third step, liquid caustic soda is used to adjust the pH to neutral to allow water to reach the standard. Chinese patent 201110408370 adopts sulfide Physical treatment of mine wastewater, but this process will produce a large amount of secondary pollution of hydrogen sulfide gas. Iron slag cannot be reused due to high water content, which also occupies the storage capacity of waste slag. Copper sulfide slag is difficult to separate from solid and liquid due to its extremely small particles.