CN103305693B - A kind of method of preventing vanadium-chromium extraction sepn process interphase impurity - Google Patents

Abstract

The invention discloses a method for preventing interface dirt in the extraction and separation process of vanadium chromium, which is characterized in that impurities such as phosphorus, silicon, calcium and iron in the extracted liquid are removed deeply before extraction; high-efficiency compound amine extractant, demulsifier and The mixed solution of the diluent extracts the purified extracted liquid. During the extraction process, the pH value of the extracted liquid is adjusted, and the extraction temperature, time, concentration of the extractant and the concentration of the demulsifier are controlled. This method reduces the solid particles that may cause emulsification in the solution through deep removal of impurities, and reduces the stability of the emulsified interface at the end of the extraction by adding a demulsifier, thereby reducing the probability of inorganic salts crystallizing at the interface to form a solid interface film. This method can effectively eliminate the interface dirt in the vanadium-chromium extraction and separation process, improve the phase separation speed of the extraction equilibrium, reduce the loss of the organic phase, save the operating cost, and ensure the long-term circulation of the extraction system.

Description

A method for preventing interface dirt in vanadium-chromium extraction and separation process

technical field

The invention belongs to the field of interface dirt prevention in metal extraction, and in particular relates to a method for preventing interface dirt from occurring in the extraction and separation process of vanadium and chromium.

Background technique

With the continuous deepening of environmental protection awareness, the recycling of toxic and harmful substances has become a research hotspot in current scientific research. Heavy metal resources, especially the mining of low-grade ores and the recovery and recycling of a large number of heavy metals have attracted more and more attention. Chromium-containing vanadium slag contains a large amount of rare metals vanadium and chromium. If it is not properly treated, it will pose a great threat to the ecological environment and people's health. Therefore, the vanadium and chromium in it are separated and recovered for recycling. deep meaning.

The separation of vanadium and chromium is a very difficult subject, but after a lot of in-depth research, researchers have found that primary amines can quantitatively extract vanadium from near-neutral solutions according to the solvation mechanism, leaving chromium in the raffinate, So as to achieve the purpose of vanadium chromium separation. However, the experiment of primary amine extraction and separation of vanadium and chromium is usually carried out in the laboratory. The test reagents used by the researchers are all analytical grade drugs. Once the actual material liquid is used as the water phase, the problem of interface contamination will appear.

Interface fouling is a difficult problem often encountered in hydrometallurgical processes, which mainly consists of aqueous phase, organic phase and irregular fine particles. The appearance of dirt at the interface during the extraction process will bring many adverse effects to the entire extraction process. It will seriously prolong the phase separation time, make the separation of vanadium and chromium incomplete, and cause the loss of extraction agent, increase production costs, and seriously Or it will cause the whole workshop to stop, so that the extraction-reextraction cannot be circulated. However, dealing with interface fouling is a more challenging problem, because there are many influencing factors of interfacial fouling, such as aqueous phase composition, organic phase composition, external environment and the type of agitator will all promote the system to generate interfacial fouling, and interfacial fouling It is a stable heterogeneous emulsification system, its composition will be different with the change of the system, even in the same system, the composition of the interface dirt produced at different times is different, which is the interface dirt The elimination of the posed greater difficulties.

Chinese patent CN1048889A discloses a preventive method involving interface emulsification in the separation and purification process of metal yttrium, which is characterized in that sulfide and chloride precipitants are used to remove impurities before extraction; The emulsified layer is settled and centrifuged, and then the different substances in the emulsified layer are separated; CN202671624U utility model patent discloses a device for efficiently separating the emulsified layer; CN101565776A discloses a method for eliminating emulsions in the extraction system of amines and phosphorus, Its feature is to add metal cleaning aids with brand names of CSP-925, CSQ-926 or GEA-746 in the extracted liquid in advance, and extract after stirring, settling, and filtering to remove impurities under certain conditions; US Patent US6500232 also The method of eliminating the interface dirt in the solvent extraction process has been reported, and the patent provides a special device to remove the interface dirt in the extraction process, although this method of separating the emulsified layer is suitable for the elimination of interface dirt in various systems , but it is necessary to add another equipment and add an operation, which will increase the operating cost, and it cannot fundamentally eliminate the interface dirt, but only solve the problem to ensure the normal operation of the process.

The applicant has conducted long-term and in-depth research on the interface dirt that occurs during the extraction and separation of vanadium and chromium, and found that the interface dirt is composed of solid particles, water phase, and organic phase. Solid particles are the primary reason for its formation and stability, and the interface There are a large number of dispersed phase droplet interfaces in the region, and the aggregated solid particles will become crystallization active centers, which will reduce the surface energy barrier for the nucleation of inorganic salt sodium sulfate with a higher concentration in the water phase, catalyze heterogeneous nucleation, and form crystallization Sodium sulfate crystals of water. At the same time, the electric field of the electric double layer formed by the adsorption of fine particles on the emulsified interface in the interface region will reduce the solubility of sodium sulfate at the interface and cause it to crystallize and precipitate at the interface.

Based on the above mechanism research, the prevention method of the system interface contamination is proposed, but there are no relevant literature reports at home and abroad.

Contents of the invention

The technical problem to be solved by the present invention is: to overcome the deficiencies in the prior art, to provide a method for preventing the interface dirt in the extraction and separation process of vanadium chromium, which can effectively eliminate the interface dirt in the extraction and separation process of vanadium chromium, without increasing too much In the case of operating costs, prevent interface contamination, or make it appear as little as possible, so as to speed up the extraction and separation process, reduce the loss of extractant during operation, and ensure the normal operation of the production process.

The technical solution of the present invention is: a method for preventing interface dirt in the extraction and separation process of vanadium chromium, which is characterized by the following steps: (1) deep removal of impurities in the extracted liquid before extraction, after deep removal of impurities in the extracted liquid, The total amount of impurities is controlled below 0.1g/L; (2) The mixed solution of high-efficiency compound amine extractant, demulsifier and diluent is used to extract the extracted liquid after impurity removal, and obtain the organic phase loaded with vanadium and containing chromium and a small amount of The raffinate of vanadium has fast phase separation in the extraction process, and no intermediate phase is produced under optimal operating conditions. During the extraction process, the pH value of the feed liquid is adjusted, and the extraction temperature, time, concentration of the extractant and the concentration of the demulsifier are controlled; the complex amine is a mixture of primary and tertiary amines. The concentration is 1-10%; the extraction process adjusts the pH range of the extracted liquid to 2-6; the extraction temperature is 10-90°C; the extraction time is 1-30 minutes; the volume percentage concentration of the demulsifier is 1 -10%. According to claim 1, the method for preventing interface dirt in the extraction and separation process of vanadium chromium is characterized in that: in step (1), the impurities in the extracted liquid are deeply removed before extraction, and after the impurities in the extracted liquid are deeply removed, the impurities The total amount is controlled below 0.07g/L; particularly preferably, the total amount of impurities is controlled below 0.05g/L. The method for preventing interface dirt in the extraction and separation process of vanadium chromium according to claim 1, characterized in that: the primary amines described in step (2) include N1923, Primene JMT, Primene81R or 7101 and other organic fatty primary compounds with carbon chains exceeding 13 Amines and their mixtures. The method for preventing interface contamination in the extraction and separation process of vanadium and chromium according to claim 1, wherein the tertiary amines include medium and long chain fatty tertiary amines such as N235, TOA, 7301 or Alamine336 and mixtures thereof. The method for preventing interface dirt in the extraction and separation process of vanadium chromium according to claim 1, characterized in that: the demulsifier in step (2) is an oil-soluble demulsifier, preferably polyether, including amine as the initiator The polyether of polyether, polyether with phenolic formaldehyde as initiator and the polyether with alcohol as initiator etc., especially preferably be the polyether of commodity number PAG and OSP series. The method for preventing interface contamination during the extraction and separation of vanadium and chromium according to claim 1, characterized in that: the pH range of the extracted liquid is adjusted to be 3-6 during the extraction in step (2). The method for preventing vanadium-chromium extraction and separation process interface dirt according to claim 1, characterized in that: the volume percentage concentration of primary amine in the compound amine extractant described in step (2) is 10-30%, and the volume percentage of tertiary amine The concentration is 1‐5%. The method for preventing interface contamination in the extraction and separation process of vanadium chromium according to claim 1, characterized in that: the volume percentage concentration of the demulsifier in step (2) is 0.1-1.5%. The method for preventing interface contamination during vanadium-chromium extraction and separation process according to claim 1, characterized in that: the diluent in step (2) includes sulfonated kerosene, toluene, n-hexane, petroleum ether, tetrachloromethane, benzene , n-octanol, xylene; particularly preferably sulfonated kerosene, n-hexane, toluene. The method for preventing interface contamination in the vanadium-chromium extraction and separation process according to claim 1, characterized in that: the extraction temperature in step (2) is 10-30°C; the extraction time is 1-15 minutes.

The present invention uses compound amine-type extractant, demulsifier and diluent to extract and separate the material liquid after the deep removal of impurities in the chromium-containing vanadium slag leachate. The extraction rate of vanadium is as high as 95.80%, while the extraction rate of chromium is only 3.64%. In the second round of extraction, there is still no interface dirt, and the extraction rates of vanadium and chromium are 96.90% and 3.35% respectively; after carrying out the third round of extraction after loading organic phase extraction, there is no interface dirt, and the extraction rates of vanadium and chromium are respectively 96.12% and 3.14%; the fourth extraction was carried out after the loaded organic phase extraction, there was no interface dirt, and the extraction rates of vanadium and chromium were 96.15% and 3.74%, respectively. The invention effectively eliminates the interface dirt in the extraction and separation process of vanadium and chromium, and ensures a good extraction rate of vanadium and a continuous low extraction rate of chromium, and can still separate vanadium and chromium well; four rounds of extraction have no interface pollution The appearance of the compound indicates that the extraction system is stable and the extraction and separation effect is good.

The advantage of the present invention compared with prior art is:

(1) The complex amine-demulsifier-diluent extraction and separation system in the present invention achieves the purpose of preventing interface dirt during the extraction process of vanadium and chromium, and extracting and separating vanadium and chromium with the new system not only effectively prevents interface dirt, but also ensures Good vanadium-chromium separation effect, and the four rounds of organic phase extraction can ensure a high extraction rate, truly preventing interface contamination while ensuring the vanadium-chromium separation effect.

(2) The invention does not need to add any additional equipment, the operation is simple and easy, and the equipment cost is saved.

(3) No additional operations are required, saving labor.

(4) Fundamentally prevent interface dirt, which is superior to the method of removing interface dirt, and reduces the loss of extractant.

(5) Improve the phase separation effect of the organic phase.

specific implementation plan

The present invention is described in detail below with specific examples. But the following embodiments are only limited to explain the present invention, and the protection scope of the present invention should include the entire content of the claims, not only limited to the present embodiment.

Example 1:

Taking the material liquid after deep removal of impurities in the chromium-containing vanadium slag leachate as the extraction liquid, the organic phase was prepared with the primary amine N1923, the tertiary amine TOA, the demulsifier with the commodity number PAG, and the diluent cyclohexane, and the extraction and separation test was carried out. The pH values of the feed liquid were adjusted to 3.20, 4.20, 5.20, and 6.00 respectively, the volume percentage concentration of the extraction agent primary amine was selected as 15%, the volume percentage concentration of the tertiary amine was 5%, the volume percentage concentration of the demulsifier was 1%, and the extraction temperature was room temperature at 25 ℃, mix the aqueous phase and the organic phase in a separatory funnel, then fix the separatory funnel on a Conrad shaker and shake for 15 minutes, remove the shaker and let the layers stand for 30 minutes, then take out the gap between the aqueous phase and the organic phase Use a graduated cylinder of appropriate specifications to measure the volume of the interface dirt, and then divide the volume of the measured interface dirt by the sum of the volumes of the initial aqueous phase and the organic phase, and record it as the generation rate of the interface dirt; then use Pipette 1 milliliter of raffinate into a 100 milliliter volumetric flask, and add 1% by volume aqueous hydrochloric acid to constant volume, and measure the vanadium-chromium content in the raffinate with an inductively coupled plasma emission spectrometer. The results are shown in Table 1.

Table 1 The extraction rate of vanadium and chromium and the generation rate of interface dirt at different initial pH values of feed liquid

^* Interface dirt generation rate = interface dirt volume * 100% / (initial water phase volume + initial oil phase volume)

Example 2:

The material liquid after deep removal of impurities in the chromium-containing vanadium slag leaching liquid is used as the extraction liquid, and the organic phase is prepared with the primary amine N1923, the tertiary amine TOA, the demulsifier and the diluent cyclohexane, and the extraction and separation test is carried out. The volume percentage concentration of the demulsifier PAG 0.3%, 0.5%, 1%, and 1.5%, respectively, wherein the pH value of the feed liquid is adjusted to 5.20, the volume percentage concentration of the extraction agent primary amine is 15%, the volume percentage concentration of the tertiary amine is 5%, and the extraction temperature is room temperature 25°C. Mix the aqueous phase and the organic phase in a separatory funnel, then fix the separatory funnel on a Conrad shaker for 15 minutes, remove the shaker and let the layers stand for 30 minutes, then take out the interface between the aqueous phase and the organic phase Dirt, use a graduated cylinder of appropriate specifications to measure the volume of the interface dirt, and then divide the measured volume of the interface dirt by the sum of the volumes of the initial aqueous phase and the organic phase, and record it as the generation rate of the interface dirt; Take 1 milliliter of the raffinate and move it into a 100 milliliter volumetric flask, and add 1% hydrochloric acid aqueous solution to constant volume, and measure the vanadium-chromium content in the raffinate with an inductively coupled plasma emission spectrometer. The results are shown in Table 2.

Table 2 The extraction rate of vanadium and chromium and the generation rate of interface dirt at different demulsifier concentrations

^* Interface dirt generation rate = interface dirt volume * 100% / (initial water phase volume + initial oil phase volume)

Example 3:

Taking the material liquid after deep removal of impurities in the chromium-containing vanadium slag leachate as the extraction liquid, the organic phase was prepared with the primary amine N1923, the tertiary amine TOA, the demulsifier with the commodity number PAG, and the diluent cyclohexane, and the extraction and separation test was carried out. The diluents are kerosene, toluene, n-octanol, and cyclohexane respectively, the pH value of the feed liquid is adjusted to 5.20, the volume percentage concentration of the extractant is 15%, the volume percentage concentration of the tertiary amine is 5%, and the extraction temperature is room temperature 25°C. Mix the aqueous phase and the organic phase in a separatory funnel, then fix the separatory funnel on a Conrad shaker for 15 minutes, remove the shaker and let the layers stand for 30 minutes, then take out the interface between the aqueous phase and the organic phase Dirt, use a graduated cylinder of appropriate specifications to measure the volume of the interface dirt, and then divide the measured volume of the interface dirt by the sum of the volumes of the initial aqueous phase and the organic phase, and record it as the generation rate of the interface dirt; Take 1 milliliter of the raffinate and transfer it to a 100 milliliter volumetric flask, add 1% by volume aqueous hydrochloric acid to constant volume, and measure the vanadium-chromium content in the raffinate with an inductively coupled plasma emission spectrometer. The results are shown in Table 3.

The extraction rate of vanadium and chromium and the generation rate of interface dirt when table 3 is different diluents

^* Interface dirt generation rate = interface dirt volume * 100% / (initial water phase volume + initial oil phase volume)

Example 4:

The chromium-containing vanadium slag leaching liquid is used as the extraction liquid, and the primary amine N1923, the tertiary amine TOA, the demulsifier and the diluent cyclohexane are used to make the organic phase, and the extraction and separation test is carried out. The demulsifier PAG or OSP, Its volume percentage concentration is 1%, wherein the pH value of the feed liquid is adjusted to 5.20, the volume percentage concentration of the extractant is 15%, the volume percentage concentration of the tertiary amine is 5%, the extraction temperature is room temperature 25°C, and the aqueous phase and the organic phase are separated into Mix in a liquid funnel, then fix the separatory funnel on a Kang's oscillator and vibrate for 15 minutes, remove the oscillator and static layer for 30 minutes, then take out the interface dirt between the aqueous phase and the organic phase, and use a measuring cylinder of appropriate specifications Measure the volume of the interface dirt, and then divide the volume of the measured interface dirt by the sum of the volumes of the initial aqueous phase and the organic phase, and record it as the generation rate of the interface dirt; then use a pipette to take 1 ml of the raffinate into In 100 milliliter volumetric flasks, and adding volume percent is 1% hydrochloric acid aqueous solution, constant volume, measures vanadium chromium content in the raffinate with inductively coupled plasma emission spectrometer. The results are shown in Table 4.

Table 4 The extraction rate of vanadium and chromium and the generation rate of interface dirt at different demulsifier concentrations

^* Interface dirt generation rate = interface dirt volume * 100% / (initial water phase volume + initial oil phase volume)

In a word, the present invention can effectively eliminate the interface dirt in the extraction and separation process of vanadium and chromium, improve the extraction equilibrium phase separation speed, reduce the loss of organic phase, and save operating costs.

It should be noted that, according to the above-mentioned embodiments of the present invention, those skilled in the art can fully realize the full scope of the independent claims and dependent rights of the present invention, and the implementation process and method are the same as the above-mentioned embodiments; and the present invention is not elaborated Some of them belong to well-known technologies in the art.

The above are only some specific implementations of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be covered within the protection scope of the present invention.

Claims (8)

1. a method for preventing vanadium chromium extraction and separation process interface dirt, its feature may further comprise the steps: (1) Deeply remove the impurities in the extracted liquid before extraction, and after the deeply removed impurities in the extracted liquid, the total amount of impurities is controlled below 0.05g/L; (2) Use a mixed solution of high-efficiency compound amine extractant, demulsifier and diluent to extract the extracted liquid after impurity removal, and obtain an organic phase loaded with vanadium and a raffinate containing chromium and a small amount of vanadium; the pH of the feed liquid is adjusted during the extraction process value, control the extraction temperature, time, extractant concentration and demulsifier concentration; the complex amine is a mixture of primary amine and tertiary amine, the primary amine volume percentage concentration is 5-40%, and the tertiary amine volume percentage concentration is 1-10% The extraction process adjusts the pH range of the extracted liquid to 2-6; the extraction temperature is 10-90°C; the extraction time is 1-30 minutes; the volume percentage concentration of the demulsifier is 1-10%. 2. the method for preventing vanadium-chromium extraction separation process interface dirt according to claim 1, is characterized in that: primary amine described in step (2) comprises one or more in N1923, Primene JMT, Primene 81R or 7101 kind of mixture. 3. the method for preventing vanadium-chromium extraction separation process interface dirt according to claim 1, is characterized in that: described tertiary amine comprises one or more mixtures in N235, TOA, 7301, Alamine 336. 4. The method for preventing the interface dirt in the vanadium-chromium extraction and separation process according to claim 1, characterized in that: the demulsifier described in the step (2) is a polyether whose commodity code is PAG and OSP series. 5. The method for preventing interface dirt in the extraction and separation process of vanadium and chromium according to claim 1, characterized in that: the pH value of the extracted liquid is preferably adjusted to a range of 3-6 during the extraction described in step (2). 6. the method for preventing vanadium-chromium extraction and separation process interface dirt according to claim 1, is characterized in that: primary amine volume percent concentration is preferably 10-30% in the compound amine extractant described in step (2), tertiary The volume percent concentration of amine is preferably 1-5%. 7. the method for preventing vanadium-chromium extraction and separation process interface dirt according to claim 1, is characterized in that: diluent described in step (2) is sulfonated kerosene, toluene, normal hexane, sherwood oil, tetrachloromethane , benzene, n-octanol or xylene. 8. The method for preventing interface contamination during vanadium-chromium extraction and separation process according to claim 1, characterized in that: the extraction temperature in step (2) is preferably 10-30° C.; the extraction time is preferably 1-15 minutes.