1. Mineral processing of molybdenum ore and formation of molybdenum-selected sewage
Generally, the selection of molybdenum minerals is carried out by a flotation method. In the process of molybdenum selection, flotation reagents are added. In addition to being partially consumed in the ore sorting process, some of the remaining medicaments are discharged with the tailings. As rough adjustor (lime, sodium carbonate) added during the scavenger, inhibitor (water glass), collector (petroleum products such as oil and coal), foaming agent (# 2 oil). In addition to the addition of inhibitors (water glass) in the selection and separation process, there are also cyanide-containing processes (small cyanide, etc.), cyanide-free processes (sodium sulfide, amine sulfide, Nokes method, sodium hypochlorite method, etc.).
The remaining pesticides are mainly in tailings water, and the tailings water accounts for 60-70% of the total discharge. And contains a certain harmful metal ions, generally in the discharge process or for discharge into the tailings portion receiving stock utilization. If the poor management of emissions causes pollution to the environment and harms people, livestock, fish, agriculture and forestry, it must be dealt with in a timely manner.
Second, the nature and characteristics of molybdenum wastewater
The characteristics of the ore dressing wastewater are related to the composition of the ore pulp water quality, the process used and the nature of the added flotation agent. For example, the analysis results of a molybdenum ore dressing wastewater are shown in the table, and the analysis results of the molybdenum-tungsten ore beneficiation
Analysis results of a molybdenum ore dressing wastewater | ||||||||||
Measurement item | pH | BoD | CoD | SS | Oil | Mo | Cu | Pb | Ca | Cr |
Content (mg/L) | 8.8-9.8 | 269 | 100-400 | >50000 | May 12 | 0.55 | 0.008-0.02 | 0.2 | 0.001 | <0.05 |
Measurement item | V | Mn | AS | Hg | Co | Ni | F | |||
Content (mg/L) | <0.1 | 0.05 | Can't detect | Can't detect | mark | 0.48 | <0.1 | |||
Analysis result of tailings water in a molybdenum-tungsten ore beneficiation | |||||||||
Measurement item | pH | CoD | SS | Oil | Yellow medicine | Black medicine | Hg | Pb | Ca |
Content (mg/L) | 10.8 | 416.6 | >50000 | 5.4 | Undetectable | Undetectable | 0.06 | <0.01 | <0.002 |
Measurement item | Oxide wax | As | F | Zn | Cr | Cu | Do | ||
Content (mg/L) | 16.4 | 0.09 | 1.19 | 0.054 | 0.01 | 0.08 | 3.2 | ||
According to the investigation and measurement of ore dressing oxygen water, its water quality has the following characteristics:
(1) The pH of the tailing water of the beneficiation is generally 7-12, so most of the ions are precipitated as hydroxides in the alkaline, and the metal ions are less polluted by the tail water.(2) The organic and inorganic flotation reagents used in the beneficiation and the slime produced during the beneficiation process are the main reasons for the pollution of tailings water.
(3) According to the field inspection of the tailings of the concentrator and the analysis of tailings water, the turbidity of the water has a great relationship with the water glass added during the beneficiation process.
(4) The nature of the tailings water in the beneficiation changes with the changes of the time, temperature and pH. If the suspended solids, CoD, etc. are lowered, the dressing agent is gradually separated from the xanthate and the nigrosine.
Third, the common method of molybdenum sewage purification
At present, the use of tailings water is generally used. Reduce emissions, followed by recycling valuable metals to reduce the amount of harmful substances in the drainage to prevent environmental pollution.
The treatment method and treatment process of the tailings water for beneficiation are determined by factors such as the quality of the wastewater, the amount of water, the possibility of reuse, and the mode of discharge. There are many treatment methods, such as precipitation, oxidation, ion exchange, activated carbon adsorption, flotation and electrodialysis. Some people have applied chemical precipitation, ozone oxidation, activated carbon adsorption, etc. to treat the ore tailings water. :
1. Coagulation and sedimentation method for processing tailing water
The process of treating tailings water by coagulation sedimentation is shown in the figure below.
The tailings are mixed into the pH adjustment tank, and sulfuric acid (10%) is added to the tailings water to keep the pH of the tailings water at around 7. After concentration tail water tank settle for 30 minutes, the water main indicators, such as suspended solids, the CoD like decreased, and concentrated into the underflow tailings, iron salts and # 3 flocculant precipitate good effect, industrial effluent reached Emission standards can be effluxed or reused.
2. Oxidation treatment of flotation reagents in tailings
After the tailings water is treated by coagulation, the suspended solids in the water are basically removed, but some organic flotation agents added during the beneficiation process are difficult to remove. In addition, the sulfides in the concentrate water are not easily removed, and other methods are needed. Such as adsorption, oxidation, to purify. The oxidation method is a commonly used method, and generally can be classified into aeration oxidation, chemical oxidation, and auto-oxidation. Among them, aeration oxidation uses air as an oxidant, and has certain effects on the treatment of unstable compound wastewater containing sulfides. For the oxidation of chemicals, liquid chlorine, sodium hypochlorite and bleaching powder are generally used as oxidants. After treatment of water containing sulfide concentrates, the sulfide content is lower than the allowable content of industrial discharge standards. The disadvantage is that excess chlorine is harmful to water quality. The effect of the ozone oxidation method is better than the above two methods. Under appropriate conditions, the flotation reagents such as 2 # oil and sulfide can be completely oxidized, and the reaction product is harmless to the environment. The flow chart is as follows, currently in industrial scale. Mostly used for deep processing.
3. Treatment method of cyanide-containing wastewater in concentrator
Several methods commonly used in the industry to treat cyanide-containing wastewater are as follows:
(1) The alkaline oxidation method is designed according to the property that cyanide is easily oxidized and decomposed. The cyanide is first oxidized to cyanate in an alkaline solution, and its toxicity can be reduced to 1/1000 of cyanide, which is then further oxidized to nitrogen and carbon dioxide, which are all harmless substances. After treatment by this method, the purpose of detoxification can be achieved. Commonly used chlorine-based oxidizing agents are sodium hypochlorite, liquid chlorine, etc., and are widely used.
(2) Acid stripping method This is one of the early treatment methods for cyanide-containing wastewater in foreign countries. It is designed based on the instability of cyanide. It is reported that when the acid containing cyanide waste water is passed through the mineral acid to pH 2.8-3.5, the generated hydrogen cyanide is discharged into the atmosphere by stirring or direct blasting, or Adsorption with caustic soda. This method is currently used in cyanide recovery processes.
(3) Ozonation method This is a method for oxidative decomposition of cyanide by utilizing the oxidizing ability of ozone. The advantage is that the reaction product does not contain harmful components, and oxygen which is advantageous for improving water quality is generated, and the disadvantage is that it must be set. A suitable reaction device. It is still relatively rare to use this method to treat oxides.
(4) Iron Oxidation Method A method of removing insoluble cyanide salt by adding ferrous sulfate and then removing cyanide by solid-liquid separation. The disadvantage of this method is that the precipitate contains a large amount of cyanide and heavy metals must be treated.
(5) Biochemical method The cyanide is decomposed by the strain with strong ability to degrade cyanide to produce carbon dioxide and ammonia. It is a promising purification method.
(6) Ion exchange method A process of purifying a cyanide solution or a slurry with a strong basic anion resin is feasible. The advantage is that the treatment is thorough, the treated water can be recycled, and the cyanide can be recovered at a high concentration. The disadvantage is that it is not suitable for treating wastewater with too much displacement.
Double Glazing And Triple Glazing Sealing Robot
Double Glazing and triple glazing sealing robot is composed of three section:input section, sealing section, output section.This machine is controlled by the YASKAWA servo control system,with high efficiency and stable quality sealing performance, instead of Manual Insulating glass Sealant .but only can produce normla double glazing and triple glazing
Automatic Silicone Sealant Sealing Line,Vertical Insulating Glass Machine,Automatic Insulating Glass Sealing Line,Two Component Sealing Robot
JINAN WEILI MACHINE CO LTD , https://www.wlglassmachines.com