Treatment method for three-phase dirt in extraction system

Abstract

The invention provides a method for treating three-phase dirt in an extraction system. The method comprises the following steps: extracting and collecting the three-phase dirt in a soap conversion section extraction box; adding a P204 extraction agent into the three-phase dirt, heating and stirring to obtain a mixture of the three-phase dirt and the extraction agent; acid is added into the mixture of the three-phase dirt and the extraction agent for back extraction, and metal ions in the extraction agent are subjected to back extraction to obtain a back extraction mixture; performing phase splitting on the back extraction mixture to obtain a liquid phase containing an organic phase and a water phase and a deposition solid; the organic phase is used as a P204 no-load organic phase, the water phase is reused as feed liquid, and deposited solids are discharged out of a system for stockpiling. The treatment method for the three-phase dirt in the extraction system is easy and convenient to operate and simple in process, no other salt needs to be added, and the recovery rate of the feed liquid and the organic phase can be effectively increased.

Description

Technical Field

[0001] The present invention relates to the technical fields of extraction chemistry and chemical engineering, and particularly to a method for treating three-phase contaminants in an extraction system. Background Art

[0002] Lithium-ion batteries have the advantages of high working voltage, high specific energy, large capacity, low self-discharge, and good cycle performance, and are widely used in the fields of 3C products and new energy vehicles. Lithium nickel cobalt manganese oxide has developed into a key material for lithium-ion power batteries and has become the most promising cathode material for lithium-ion batteries, with broad market prospects. The extraction method is a relatively widely used method in the current production of lithium nickel cobalt manganese oxide precursors, with the advantages of high separation efficiency, large production capacity, good separation effect, high recovery rate, low reagent consumption, simple equipment, and easy automation and continuousization of the production process. As the most common impurity removal extractant in the nickel-cobalt extraction system, P204 has the advantages of low price and strong extraction ability. However, after long-term cyclic use, P204 is prone to generating a third-phase contaminant, which has a relatively serious negative impact on the operation of the extraction system. At the same time, a large amount of aqueous phase and organic phase are entrained in the third phase, which is one of the main reasons for the loss of the organic phase in the extraction system and has a great impact on the technical and economic indicators of the extraction system.

[0003] The common method for treating the third-phase contaminant at present is to let it stand still for a long time to automatically separate phases so as to recover the organic phase and the feed liquid. However, this method takes a long time and the separation effect is not good. There are also methods that choose to add a demulsifier to treat the third-phase contaminant, but using a demulsifier will cause the introduction of new elements, with both advantages and disadvantages. For example, the "Method for Treating Interphase Contaminants in the P204 Extraction System for Nickel-Cobalt Metallurgy" with the authorization announcement number CN113308603B selects ethanol as a dispersant to disperse the third-phase contaminant, and uses an anti-extraction agent and liquid alkali precipitation to achieve the effect of oil-water separation. However, precipitation with liquid alkali will lead to the introduction of a large amount of Na, resulting in the feed liquid being unable to be used continuously and only being treated as Na-containing wastewater, and the distillation operation for separating the organic phase and ethanol will increase the cost.

[0004] Therefore, there is an urgent need for a method for treating three-phase contaminants in an extraction system that is simple to operate, has a simple process, does not require the addition of any other salts, and can effectively improve the recovery rates of the feed liquid and the organic phase. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for treating three-phase contaminants in an extraction system that is simple to operate, has a simple process, does not require the addition of any other salts, and can effectively improve the recovery rates of the feed liquid and the organic phase.

[0006] To solve the above technical problem, the present invention provides a method for treating three-phase contaminants in an extraction system, including the following steps:

[0007] Extract and collect the three-phase dirt in the extraction tank of the saponification conversion section;

[0008] Add P204 extractant to the three-phase dirt, heat and stir to obtain a mixture of the three-phase dirt and the extractant;

[0009] Add acid for back-extraction to the mixture of the three-phase dirt and the extractant, and back-extract the metal ions in the extractant to obtain a back-extraction mixture;

[0010] Separate the phases of the back-extraction mixture to obtain a liquid phase containing an organic phase and an aqueous phase and deposited solids;

[0011] The organic phase is used as the P204 empty organic phase, the aqueous phase is reused as the feed liquid, and the deposited solids are discharged from the system for stacking.

[0012] Further, the three-phase dirt is the three-phase dirt in the P204 extraction system.

[0013] Further, the P204 extractant is the organic phase obtained in the back-extraction section of the P204 extraction system.

[0014] Further, the volume ratio of the P204 extractant added to the three-phase dirt to the three-phase dirt is 1:1 to 5:1.

[0015] Further, the stirring time of the heating and stirring is 30 min to 120 min, and the heating temperature is 40 °C to 70 °C.

[0016] Further, the hydrogen ion concentration in the acid added to the mixture of the three-phase dirt and the extractant is 1 M to 12 M.

[0017] Further, the acid added is hydrochloric acid or sulfuric acid.

[0018] Further, the volume ratio of the acid added to the mixture of the three-phase dirt and the extractant is 0.5:1 to 3:1.

[0019] Further, the time for the back-extraction is 5 min to 30 min.

[0020] Further, the method for separating the phases of the back-extraction mixture is direct static phase separation, and the static time is 30 min to 90 min.

[0021] A method for treating three-phase dirt in an extraction system provided by the present invention. The reagents used in the process of the treatment method are all common reagents in the P204 extraction system, without the need to purchase additional reagents, with low treatment costs and high economic benefits.

[0022] Moreover, the method for treating three-phase dirt in an extraction system provided by the present invention has relatively short back-extraction time and phase separation time during the treatment process, which can not only greatly shorten the process time, but also has relatively high treatment efficiency and recovery rate for the three-phase dirt.

[0023] Meanwhile, in the method for treating three-phase dirt in an extraction system provided by the present invention, since no other reagents such as demulsifiers are used during the treatment process, there is no risk of introducing other impurities into the P204 extraction system.

[0024] Therefore, the method for treating three-phase dirt in an extraction system provided by the present invention can economically, environmentally friendly, simply and efficiently recover the liquid material and organic phase entrained by the third-phase dirt, and greatly reduce the losses caused by the third-phase dirt to the P204 extraction system. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a flowchart of the method for treating three-phase dirt in the extraction system provided by the embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0026] See Figure 1 , the method for treating three-phase dirt in an extraction system provided by the embodiment of the present invention includes the following steps:

[0027] Step 1) Extract and collect the three-phase dirt in the extraction tank of the saponification conversion section.

[0028] Among them, the three-phase dirt is the three-phase dirt in the P204 extraction system. Specifically, a hose is placed into the extraction tank of the saponification conversion section of the P204 extraction system, with the hose nozzle in the middle of the aqueous phase and the organic phase. One end is connected to a pneumatic diaphragm pump, and then to a ton barrel. The compressed air pipe is connected to the pneumatic diaphragm pump to extract the three-phase dirt in the extraction tank of the saponification conversion section and collect and store it in the ton barrel.

[0029] Step 2) Add P204 extractant to the three-phase dirt and heat and stir to obtain a mixture of the three-phase dirt and the extractant.

[0030] Among them, in order to save resources, the P204 extractant added to the three-phase dirt is the organic phase obtained in the back-extraction section of the P204 extraction system.

[0031] Among them, in order to enable the P204 extractant to fully extract the three-phase dirt, the volume ratio of the P204 extractant added to the three-phase dirt to the three-phase dirt is controlled to be 1:1 to 5:1.

[0032] In order to enable the three-phase dirt to come into full contact with the extractant, increase the reaction area, and thus enhance the extraction effect of the P204 extractant on the three-phase dirt, after the P204 extractant is added to the three-phase dirt, the mixture is heated and stirred. The heating temperature is controlled at 40°C to 70°C, and stirring is carried out for 30 min to 120 min to obtain a mixture of the three-phase dirt and the extractant.

[0033] Step 3) Add acid to the mixture of the three-phase dirt and the extractant for back-extraction, that is, use H+ in the acid + to back-extract the metal ions in the extractant to obtain a back-extraction mixture.

[0034] Among them, in order to achieve a better back-extraction effect, the hydrogen ion concentration in the acid added to the mixture of the three-phase dirt and the extractant is 1 M to 12 M.

[0035] As a specific embodiment of the present invention, the added acid is hydrochloric acid or sulfuric acid.

[0036] Moreover, in order to fully back-extract the metal ions in the extractant, the volume ratio of the acid added to the mixture of the three-phase dirt and the extractant to the mixture of the three-phase dirt and the extractant is 0.5:1 to 3:1.

[0037] At the same time, in order to completely back-extract the metal ions in the extractant, the back-extraction time is controlled to be 5 min to 30 min.

[0038] Step 4) Separate the back-extraction mixture to obtain a liquid phase containing an organic phase and an aqueous phase and deposited solids.

[0039] Among them, the phase separation of the back-extraction mixture is relatively simple. The back-extraction mixture is directly allowed to stand for 30 min to 90 min to achieve phase separation, obtaining a liquid phase containing an organic phase and an aqueous phase and solids deposited at the bottom of the liquid phase.

[0040] In the treatment method of the three-phase dirt in an extraction system provided by the present invention, the back-extraction can be completed by controlling the back-extraction time within 5 min to 30 min during the treatment process, and the phase separation of the back-extraction mixture can be achieved by directly allowing the back-extraction mixture to stand for 30 min to 90 min. Therefore, both the back-extraction time and the phase separation time are relatively short, which can not only greatly shorten the process time, but also have relatively high treatment efficiency and recovery rate for the three-phase dirt.

[0041] Step 5) The organic phase obtained by phase separation of the back-extraction mixture is returned as the P204 empty organic phase to step 2) for use in the extraction of the three-phase dirt in the P204 extraction system, the obtained aqueous phase is returned as the feed liquid to the extraction system for reuse, and the deposited solids at the bottom of the liquid phase are discharged from the system and stockpiled for other uses.

[0042] A method for treating three-phase dirt in an extraction system provided by the present invention uses reagents that are common in the P204 extraction system and are recycled, eliminating the need to purchase additional reagents. Therefore, the treatment cost is low and the economic benefit is high.

[0043] Moreover, the method for treating three-phase dirt in an extraction system provided by the present invention does not require the use of other reagents such as demulsifiers during the treatment process. Therefore, there is no risk of introducing other impurities into the P204 extraction system.

[0044] Therefore, the method for treating three-phase dirt in an extraction system provided by the present invention can economically, environmentally friendly, simply and efficiently recover the liquid material and organic phase entrained by the third-phase dirt, greatly reducing the losses caused by the third-phase dirt to the P204 extraction system.

[0045] The following specifically describes the method for treating three-phase dirt in an extraction system provided by the present invention through examples.

[0046] Example 1

[0047] Take out 2 kg of the third phase in the saponification section of the P204 extraction system. In the third phase, the total content of Ni and Co is 1 wt%, and the organic phase is 10 wt%. Add 3 L of the unloaded P204 (i.e., P204 not loaded with the extracted substance) obtained from the stripping section of the extraction system (density 0.85 g / mL) to the reaction tank and mix it with the third phase. Heat up to 50 °C and stir for 30 min. Then add 1 L of hydrochloric acid with a hydrogen ion concentration of 5 mol / L to the reaction tank, continue to stir for 15 min, and then let it stand. After standing for 40 min, the upper organic matter in the reaction tank is used as the blank organic phase. A total of 2.713 kg of organic phase is recovered, and the recovery rate of the organic phase is 81.5%; the lower aqueous phase is discharged from the bottom and returned to the extraction system. A total of 16.7 g of Ni and Co are recovered, and the metal recovery rate is 83.5%. The bottom solids are discharged from the system for stacking.

[0048] Example 2

[0049] Take out 5 kg of the third phase in the saponification section of the P204 extraction system. In the third phase, the total content of Ni and Co is 0.3 wt%, and the organic phase is 15 wt%. Add 5 L of the unloaded P204 obtained from the stripping section of the P204 extraction system to the reaction tank and mix it with the third phase. Heat up to 40 °C and stir for 30 min. After stirring, add 2.5 L of hydrochloric acid with a hydrogen ion concentration of 1 mol / L to the reaction tank, continue to stir for 5 min, and then let it stand. After 30 min, the upper organic matter is recovered and used as unloaded P204. A total of 4.729 kg of P204 organic phase is recovered, and the recovery rate is 75.2%; the lower aqueous phase is discharged from the bottom and returned to the extraction system. A total of 12.53 g of Ni and Co are recovered, and the metal recovery rate is 83.53%. The solids are discharged from the system for stacking.

[0050] Example 3

[0051] Take out 3kg of the third phase of the extraction section of the P204 extraction system, of which: Ni and Co content total 3wt%, organic phase 12wt%, add 14L of the unloaded P204 obtained from the stripping section of the P204 extraction system into the reaction tank and mix with the third phase, heat to 70℃ and stir for 120min, add 8.5L of hydrochloric acid with a hydrogen ion concentration of 12mol / L into the reaction tank after stirring, continue stirring for 30min and then let stand. After 90min, recover the upper organic matter as unloaded P204 for further use, recover a total of 11.29L of P204 organic phase, with a recovery rate of 92.08%; the lower aqueous phase is discharged from the bottom and returned to the extraction system, recovering a total of 8.32g of Ni and Co, with a recovery rate of 92.44%, and the solid matter is discharged from the system for storage.

[0052] It can be seen from the above three embodiments that the method for treating three-phase pollutants in an extraction system provided by the present invention is not only easy to operate and has a simple process, but also can achieve a higher recovery rate of the feed liquid and the organic phase without adding any other salts.

[0053] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for treating three-phase dirt in an extraction system, characterized in that, The steps include: Extract and collect three-phase dirt in the extraction box of the soap transfer section; Adding P204 extractant to the three-phase pollutant, heating and stirring to obtain a mixture of the three-phase pollutant and the extractant; adding acid to the mixture of the three-phase pollutant and the extractant for stripping, stripping the metal ions in the extractant to obtain a stripping mixture; Separating the stripping mixture into a liquid phase containing an organic phase and an aqueous phase and a precipitated solid; The organic phase is used as the P204 no-load organic phase, the aqueous phase is reused as the feed liquid, and the deposited solids are discharged from the system for storage.

2. The treatment method for three-phase dirt in the extraction system according to claim 1, characterized in that: The three-phase sewage is the three-phase sewage in the P204 extraction system.

3. The treatment method of three-phase dirt in the extraction system according to claim 1, characterized in that: The P204 extractant is the organic phase obtained in the stripping section of the P204 extraction system.

4. The method for treating three-phase contaminants in the extraction system according to claim 1, wherein: The volume ratio of the P204 extractant added to the three-phase pollutant to the three-phase pollutant is 1:1 to 5:

1.

5. The treatment method of three-phase dirt in the extraction system according to claim 1, characterized in that: The heating and stirring time is 30 min to 120 min, and the heating temperature is 40° C. to 70° C.

6. The treatment method for three-phase dirt in the extraction system according to claim 1, characterized in that: The hydrogen ion concentration of the acid added to the mixture of the three-phase pollutant and the extractant is 1M to 12M.

7. The method for treating three-phase dirt in the extraction system according to claim 1, characterized in that: The added acid is hydrochloric acid or sulfuric acid.

8. The method for treating three-phase dirt in the extraction system according to claim 1, wherein: The volume ratio of the added acid and the mixture of the three-phase dirt and the extractant is 0.5:1 to 3:

1.

9. The method for treating three-phase dirt in the extraction system according to claim 1, characterized in that: The back extraction time is 5 min to 30 min.

10. The method for treating three-phase dirt in the extraction system according to claim 1, characterized in that: The method for separating the phases of the stripping mixture is to directly separate the phases by standing for a period of 30 to 90 minutes.

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