The beneficiation wastewater contains a lot of harmful components, if directly discharging them will pollute the environment, and the direct reuse will have an adverse effect on the flotation machine. The study found that reusing the different proportions of backwater and the environmental backwater will lower the grade and recovery rate of copper concentrate, while the recovery rate of associated elements also decreased. Therefore, it is necessary to carry out the further physical and chemical treatment to meet the standardized discharge and recycling of wastewater.
In view of the dispose of copper sulfur ore dressing wastewater, traditionally, we give priority to the natural precipitation, flocculation precipitation, and neutralization precipitation method, nowadays, the oxidation process, membrane separation technique, biological method and a series of new methods are gradually applied from laboratory to the practice.
Oxidation method includes biological oxidation and chemical oxidation. This method is mainly used to eliminate the residual potions in flotation tailings, and the chemical oxidation method is usually used to deal with flotation tail water. For example, Japanese uses the bacterial oxidation to treat acid wastewater from mines. In China, people often make the sulfur of Xanthate oxidized to sulfates by using the active chlorine or ozone, using the potassium permanganate to oxidize the black catching agent and make the phosphoric acid oxidized into phosphate anion.
(2)Membrane separation technique
As a new separation purification and enrichment method, membrane separation technology is characterized by low energy consumption, high separation efficiency, no secondary pollution and simple process compared with the traditional separation operating. Therefore, it has been widely used in water treatment, biochemical industry, food industry, papermaking industry and pharmaceutical industry.
Using the biological method can realize the purpose of purifying wastewater through the interaction between biological organisms or their metabolites and metal ions. The advantages of using the biological method to dispose of Xanthate are low-cost and environment-friendly. The disadvantage is that it is only effective in treating low-concentrations Xanthate wastewater, and the optimum pH value of the pseudomonas aeruginosa degrading Xanthate is 8.0. If the beneficiation wastewater is acidic or its pH value is up to 11.0, the dispose effect by using biological method is not ideal.
(1) Natural precipitation
Natural precipitation is to put the beneficiation wastewater into the tailings dam, with the help of the large size and capacity natural conditions of tailings dam, the wastewater is stored for a long time, until the natural sedimentation of suspended substance in wastewater and the natural oxidization of the easily decomposed substances, the wastewater purification can be realized.
(2) Flocculation precipitation
Flocculation precipitation mainly aimed at the beneficiation wastewater of containing a large amount of suspended particles and difficult to be natural sedimentation, to improve the precipitation effect, adding suitable amount of inorganic coagulant or high-polymer flocculant to make the dispersed particles under the interaction of molecular force become the floc and collide with each other in the process of subsidence condensation, then its size and quality constantly gets bigger, so as to accelerate the subsidence process.
(3) Neutralization precipitation
Lime neutralization precipitation is the most widely used method in the dispose of copper sulfur ore wastewater, its dispose process is adding the lime milk to neutralize and remove iron at the first stage; adding the sulfur-containing wastewater or sodium sulfide to sink copper at the second stage; adding the lime to neutralize the acid-base wastewater at the last stage. After disposing, the standard overflow is returned to the production, and the sediment is sent to the tailings reservoir.
Due to the insufficient attention of ore dressing plant to the mine wastewater, serious environmental pollution has been caused, therefore, adopting the appropriate methods for ore dressing wastewater treatment is very important. Carrying on the corresponding treatment on the mine wastewater timely, can not only reduce the wastewater treatment cost, also can avoid the pollution to the environment, what's more, it can provide technical support for the comprehensive utilization of mine wastewater purification and recycling in the future.