| With the development of economy and the enlargement of environmental protection behavior, it is imperative enough for the ore dressing enterprise to reduce discharging and develop recycling process. The main pollution from the ore dressing enterprise is the abandon gangues and the waste water in floating process. Wastewater in the floating process mainly roots in the ore wash of stave work, rubbing work graduation, classification, various froth concentrating works, product concentration dehydration, debris overflow, wet dust removal and accident discharge. There are some characteristics of the beneficiation wastewater: the SS is high, the heavy metal density is high, and the concentration of COD is high and the toxicity of water flotation reagents. Thus, the beneficiation wastewater which is discharged into environment without treatment has been a serious environmental problem. In addition, the flotation process waste water has not had the adverse effect after the cleaning treatment direct sales commission to ore mineral's classification target, the main performance reduces for the froth concentrate product's quality with the metal content increases mutually. Therefore, how to disposal and reuse the flotation process wastewater has been a main problem that the ore dressing enterprise faces.So far, the methods of the flotation process wastewater treatment in the domestic and foreign country are: flocculation precipitation method, ion mineral separation process, adsorption law and so on. The natural precipitation processing method is used widely in ore dressing plants in our country. However, the water still could not achieve the emissions or the recycle standard according to this method. This experimentation is take some ore dressing plant flotation process waste water as the object of study, through the sample analysis determined that its main contamination index is: Heavy metals and COD. Unifies the predecessor research results, decided that uses the flocculent precipitate craft to carry on processing primarily, and has carried on the sewage treatment experiment in the laboratory.To inspect the processing effect of flocculent precipitate to this wastewater, first the flocculent precipitate experiment about the tailings wastewater has been carried out. Through the experiment the best flocculent PAC had been determined; the input is 30-40 mg/L. While putting the flocculation to the water, the pH should be adjusted to 10-11. After the flocculation, besides the Zn and COD, other heavy metals have all achieved the index of upstream of the waters. Therefore, further method to removes COD needs to be found.In order to find out whether the scoria can help to remove COD or not, as well as the changes of water index though the scoria layer, the scoria leaching experiment has been designed. The experimental results showed that after the wastewater though the scoria layer; COD can be reduce by 40%---50%. But the heavy metals Zn and Mn of the scoria have dissolved in different degrees: Mn has risen from 1.94 mg/L before to 15.1 mg/L after; the Zn has risen from 0.71mg/L before to 2.00mg/L after. According to the experiment results, to establish wells which are used to collect the wastewater has been decided. The tailings'wastewater enters to the wells through the nature infiltration. This makes the tailings'wastewater collecting easier; meanwhile, COD can be removed more. The elevator heavy metals can be wiped out through the flocculent precipitate.To remove COD more and more, the aeration experiment has been designed. After aeration to the filtered water, the aeration can accelerate the COD elimination has been discovered. The temperature and the aeration time help to remove COD. The experimental results showed that along with aeration time's extension, COD get less and less, moreover the higher the sewage temperature is, the COD drops faster. Under the normal temperature, aerate 0.5 hour, the COD of wastewater drops from 43.98 mg/L to 35.47 mg/L. According to the practical project, the aeration time has been decided for 0.5 hour. In technological designing, aeration tank has been taken into account, in order to assume the function of aeration and the adjustment water volume.The flocculent precipitate experiment has been carried out to the wastewater that after aeration. The experiment discovered that different heavy metals have different elimination. To strengthen the security and anti-shocking qualities of the techniques, the limestone has been decided to be used in the filter, for the reason that the limestone has different elimination functions to many kinds of heavy metals. The final water index are: the Pb2+ reduces to 0.1mg/L, Zn2+ 0.2 mg/L, Cd2+ 0.025 mg/L, Fe3+ 0.1 mg/L, Mn2+ 0.72mg/L, Cu2+ 0.019 mg/L, As 0 mg/L, COD is less than 12 mg/L. To compare this index with that index which had been used in the succeeded running of similar Lead-Zinc mine processing, the index can totally satisfied the reusing requests.On this basis, the entire craft has been decided: after collecting, the tailing wastewater will be pumped to drop-aeration container, after aeration, the pH will be adjusted to 10~11, after that comes to the flocculent precipitate experiment, then go to the container after filter. The design of mainly constructions has been carried out.The whole craft is divided into the drop-aeration (also adjustment) part, the flocculent precipitate part, the filter tank part and the water storage and so on, four major parts. The water aeration tank has been designed four dropping variances, each dropping variance is 0.5 meter, the distribution tank has been set in the top, and the accumulating tank at the bottom. The fluid and the drop help to increase the area and time of aeration, which helps with the aeration in natural ways. Through the inspection, the star products of Source Waterway are recommended in the flocculent precipitate part, the V precipitation equipment (or sloping plate sedimentation pond) is recommended in the precipitation part. The experiment advised to take the designs of ordinary quick filter tank into account when designing the filter tank, the limestone is advised to use as the filter material.After the economical feasibility analysis of the entire craft, the entire building cost 924300 Yuan, a ton water needs 1.09 Yuan electricity, a ton water costs 1.38 Yuan, which tally with the professional water treatment cost of present water treatment, the entire projects cost is acceptable to the factory. Through the scene investigation, the original ore will be built on the hillside, the entire craft can be carried out next to the mountain, and the difficulty of the project is not big. The entire plan is basic feasible.
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