A process for the separation and enrichment of rhenium from a solution containing rhenium

Abstract

The present application relates to a kind of methods for separating and enriching rhenium from rhenium-containing solution, belonging to the technical field of scattered metal metallurgy, to solve at least one of the problems in the prior art rhenium recovery method, such as low recovery rate, large acid-base consumption, poor selectivity, etc.The method of the present application realizes the selective separation of rhenium and impurity ions and the synchronous enrichment of rhenium in the rhenium-containing solution by coupling electric field forced phase migration and selective rhenium extraction with organic reagent, so as to realize continuous selective rhenium extraction and rhenium enrichment without consuming large amounts of acid and alkali for stripping and regeneration of organic reagent.The organic reagent described in the present application is equivalent to a selective separation membrane, which can effectively separate rhenium and impurity ions, and the amount of organic reagent can be greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of rare dispersed metal metallurgy, and in particular to a method for separating and enriching rhenium from a rhenium-containing solution. Background Technology

[0002] Rhenium possesses characteristics such as high melting point, high hardness, corrosion resistance, and excellent ductility, making it widely used in defense, aerospace, petrochemical, and electronics manufacturing, especially as a crucial raw material for turbine blades and nozzles in aero-engines. As one of the rarest and most dispersed metallic elements in nature, rhenium has an abundance of only about 10 in the Earth's crust. -9 There are almost no independent minerals available for mining. Due to its chalcophile properties, rhenium is often found in minerals such as molybdenite and bornite, and nearly 80% of rhenium products come from byproducts in molybdenum or copper metallurgy.

[0003] Due to the complex mineral composition and extremely low rhenium content, the extraction of rhenium as a byproduct from molybdenum or copper metallurgy involves complex separation and enrichment processes. In particular, the similarity in properties between rhenium and molybdenum makes their separation a persistent challenge in the industry. Currently, methods for recovering rhenium from molybdenum or copper metallurgy mainly include precipitation, ion exchange, and solvent extraction. Precipitation methods achieve selective separation of target ions and impurity ions based on the difference in solubility products. Selective precipitation of rhenium from molybdenum-rhenium solutions primarily utilizes precipitants such as potassium salts or methyl violet and ReO4. - This generates KReO4 or ZReO4 with low solubility. Chemical precipitation for rhenium extraction from molybdenum-rhenium solutions has advantages such as simple process and convenient operation, but the separation effect is poor and the rhenium yield is low. Ion exchange is based on the interaction between the active groups in the resin and ReO4. - Ion exchange occurs through interaction, and then ReO4 is removed using a desorbent. - Desorption is performed to separate rhenium from molybdenum. Ion exchange has the advantages of simple process and low environmental pollution, but the separation coefficient of rhenium from impurity ions, the selectivity of resin and recyclability need to be improved.

[0004] Solvent extraction is the main method for extracting rhenium industrially. Its basic principle is based on the difference in partition coefficients between rhenium and molybdenum compounds in organic and aqueous phases, thereby achieving their separation. Although solvent extraction has advantages such as mature technology, high efficiency, and low energy consumption, it also has problems such as large amounts of extractant, generation of large amounts of high-salt wastewater, and extractant loss during the solvent extraction process. Summary of the Invention

[0005] In view of the above analysis, the present invention aims to provide a method for separating and enriching rhenium from a rhenium-containing solution, in order to solve at least one of the problems of low recovery rate, large acid and alkali consumption, and poor selectivity in existing rhenium recovery methods.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A method for separating and enriching rhenium from a rhenium-containing solution includes the following steps:

[0008] (1) A rhenium-containing solution is added to the cathode chamber, and a supporting electrolyte is added to the anode chamber. Under the action of an electric field, the ReO4 in the rhenium-containing solution... - A directional migration occurs, from the cathode chamber through the organic phase chamber into the supporting electrolyte in the anode chamber, wherein an organic reagent saturated with rhenium is added to the organic phase chamber;

[0009] (2) When the concentration of rhenium-containing solution in the cathode chamber is <0.1 mg / L, replace it with a new rhenium-containing solution and continue electrochemical enrichment;

[0010] (3) Repeat step (2) until the rhenium concentration in the anode chamber is >1 g / L, then stop electrolysis and obtain a rhenium-rich solution at the anode.

[0011] Furthermore, in step (1), the organic reagent for saturating the extraction of rhenium is to pre-extract rhenium in a perrhenate solution until the organic reagent is saturated.

[0012] Furthermore, the organic reagent includes an extractant and a diluent, wherein the volume fraction of the extractant in the organic reagent is 2.5% to 90%.

[0013] Furthermore, the extractant is at least one of TBP, N235, TOPO, N263, 2-octanol, isoamyl alcohol, and cyclohexanone, and the diluent is kerosene or sulfonated kerosene.

[0014] Furthermore, in step (1), the current density in the electric field is 1–30 mA / cm². 2 .

[0015] Furthermore, step (3) also includes taking out the rhenium-rich solution, evaporating and concentrating it, and then adding a precipitant to obtain perrhenate.

[0016] Furthermore, the evaporation concentration is increased to a rhenium concentration > 10 g / L.

[0017] Furthermore, the precipitant is a soluble potassium salt or ammonium salt.

[0018] Furthermore, the rhenium-containing solution is at least one of the following: leachate obtained from hydrometallurgical refining of rhenium-molybdenum concentrate, flue gas leaching solution obtained from pyrometallurgical refining of rhenium-molybdenum concentrate, and waste acid obtained from pyrometallurgical refining of rhenium-copper concentrate.

[0019] Furthermore, the pH of the rhenium-containing solution is 0.1 to 14.

[0020] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0021] (1) The method of the present invention achieves selective separation of rhenium and impurity ions and simultaneous enrichment of rhenium in a rhenium-containing solution by using a coupled electric field to force interphase migration and selective extraction of rhenium with organic reagents. The method of the present invention can achieve continuous selective extraction and enrichment of rhenium without consuming a large amount of acid and alkali for back-extraction and regeneration of organic reagents. The organic reagent described in the present invention is equivalent to a selective separation membrane, which can effectively separate rhenium and impurity ions, and the amount of organic reagent used can be greatly reduced.

[0022] (2) In the method of the present invention, under the action of an electric field, an oxygen evolution or chlorine evolution reaction occurs at the anode, requiring the replenishment of anions in the organic phase chamber to maintain the electroneutrality of the anolyte. The organic reagent saturated with rhenium in the organic phase chamber releases ReO4. - Furthermore, under the influence of the electric field, the anions migrate to the anode chamber; while in the rhenium-containing solution, the anions need to migrate from the cathode chamber to the organic phase chamber to maintain the electroneutrality of the organic reagents, since the organic reagents in the organic chamber only selectively react with ReO4. - The reaction occurs, therefore the ReO4 in the rhenium-containing solution in the cathode chamber... - Under the influence of an electric field, it continuously migrates from the cathode chamber to the organic phase chamber. This is due to the presence of ReO4 in the rhenium-containing feed solution. - The organic reagents continuously migrate into the organic phase chamber, and the organic reagents in the organic phase chamber need to release ReO4. - To maintain the electroneutrality of the anodic region, thereby forcing the ReO4 loaded in the organic phase... - It continues to migrate towards the anode chamber and accumulates there. When the entire system reaches dynamic stability, under the continuous drive of the electric field, ReO4... - Rhenium is selectively extracted at the interface between the cathode chamber and the organic phase chamber and released at the interface between the anode chamber and the organic phase chamber, thereby achieving simultaneous separation and enrichment of rhenium and enhancing the separation and enrichment process.

[0023] (3) The method of the present invention can also recover rhenium in the form of perrhenate precipitate. The rhenium-rich solution in the anode chamber needs to be evaporated and concentrated, and then a precipitant is added to precipitate rhenium. The precipitant needs to form a perrhenate with low solubility with the perrhenate ion.

[0024] (4) The method for separating and enriching rhenium provided by the present invention is simple to operate, can be continuously produced, generates no pollutants, and is easy to implement in industrial applications.

[0025] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0026] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0027] Figure 1 This is a process flow diagram of separating and enriching rhenium from a rhenium-containing solution according to the present invention;

[0028] Figure 2 The curves showing the change of rhenium concentration in the cathode and anode chambers with electrolysis time in Example 1 of the present invention are shown. Detailed Implementation

[0029] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0030] A specific embodiment of the present invention, such as Figure 1 As shown, a method for separating and enriching rhenium from a rhenium-containing solution is disclosed, comprising the following steps:

[0031] (1) A rhenium-containing solution is added to the cathode chamber, and a supporting electrolyte is added to the anode chamber. Under the action of an electric field, the ReO4 in the rhenium-containing solution... - A directional migration occurs, from the cathode chamber through the organic phase chamber into the supporting electrolyte in the anode chamber, wherein an organic reagent saturated with rhenium is added to the organic phase chamber;

[0032] (2) When the concentration of rhenium-containing solution in the cathode chamber is <0.1 mg / L, replace it with a new rhenium-containing solution and continue electrochemical enrichment;

[0033] (3) Repeat step (2) until the rhenium concentration in the anode chamber is >1 g / L, then stop electrolysis and obtain a rhenium-rich solution at the anode.

[0034] The method of this invention, under the action of an electric field, can achieve continuous selective extraction and enrichment of rhenium without consuming large amounts of acid and alkali for back-extraction and regeneration of organic reagents. The organic reagent described in this invention acts as a selective separation membrane, enabling effective separation of rhenium from impurity ions, and significantly reducing the amount of organic reagent used. The method of this invention achieves selective separation of rhenium from impurity ions and simultaneous enrichment of rhenium in rhenium-containing solutions by coupling an electric field to force interphase migration and using organic reagents for selective rhenium extraction.

[0035] In one specific embodiment, in step (1), the organic reagent for saturating the extraction of rhenium is to pre-extract rhenium in a perrhenate solution until the organic reagent is saturated.

[0036] It should be noted that the organic reagent described is an organic reagent that can selectively extract rhenium without interacting with other impurity ions.

[0037] Preferably, the perrhenate is sodium perrhenate or ammonium perrhenate.

[0038] The organic reagents include extractants and diluents.

[0039] In the method of this invention, under the action of an electric field, an oxygen evolution or chlorine evolution reaction occurs at the anode. Anions need to be added to the organic phase chamber to maintain the electroneutrality of the anolyte. The organic reagent saturated with rhenium in the organic phase chamber releases ReO4. - Furthermore, under the influence of an electric field, the ions migrate to the anode chamber; while in the rhenium-containing solution, anions need to migrate from the cathode chamber to the organic phase chamber to maintain the electroneutrality of the organic reagents, since the organic reagents in the organic chamber only selectively react with ReO4. - The reaction occurs, therefore the ReO4 in the rhenium-containing solution in the cathode chamber... - Under the influence of an electric field, it continuously migrates from the cathode chamber to the organic phase chamber. This is due to the presence of ReO4 in the rhenium-containing feed solution. - The organic reagents continuously migrate into the organic phase chamber, and the organic reagents in the organic phase chamber need to release ReO4. - To maintain the electroneutrality of the anodic region, thereby forcing ReO4 in the organic phase... - It continues to migrate towards the anode chamber and accumulates there. When the entire system reaches dynamic stability, under the continuous drive of the electric field, ReO4... - Rhenium is selectively extracted at the interface between the cathode chamber and the organic phase chamber and released at the interface between the anode chamber and the organic phase chamber, thereby achieving simultaneous separation and enrichment of rhenium and enhancing the separation and enrichment process.

[0040] In one specific embodiment, the extractant has a volume fraction of 2.5% to 90% in the organic reagent, for example, 2.5%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, or 90%.

[0041] Preferably, the extractant is at least one selected from TBP (tributyl phosphate), N235 (trialkyl tertiary amine), TOPO (trioctylphosphine oxide), N263 (trioctylmethylammonium chloride), 2-octanol, isoamyl alcohol, and cyclohexanone.

[0042] Preferably, the diluent is either kerosene or sulfonated kerosene.

[0043] In one specific embodiment, in step (1), the supporting electrolyte is sodium hydroxide or a soluble sodium salt.

[0044] Preferably, the soluble sodium salt is at least one of sodium sulfate, sodium bisulfate, or sodium nitrate.

[0045] It should be noted that, in order to obtain a rhenium-rich solution with low impurity content and high concentration in the anode chamber, the supporting electrolyte selected in this invention must have high solubility of perrhenate ions, that is, the perrhenate salt formed by perrhenate ions and supporting electrolyte cations must have high solubility; in addition, in order to minimize the generation of corrosive gases such as chlorine during the electrolysis process, the selected supporting electrolyte should be a chlorine-free salt.

[0046] In one specific embodiment, the concentration of the supporting electrolyte is 1–2 mol / L, for example, 1 mol / L, 1.1 mol / L, 1.2 mol / L, 1.3 mol / L, 1.4 mol / L, 1.5 mol / L, 1.6 mol / L, 1.7 mol / L, 1.8 mol / L, 1.9 mol / L, or 2 mol / L. If the concentration is too low, the conductivity of the supporting electrolyte will be poor; if the concentration is too high, it will be uneconomical and increase the difficulty of subsequent processing.

[0047] In one specific embodiment, in step (1), the rhenium-containing solution is at least one of the following: leachate obtained by hydrometallurgical refining of rhenium-molybdenum concentrate, flue gas leaching solution obtained by pyrometallurgical refining of rhenium-molybdenum concentrate, and waste acid obtained by pyrometallurgical refining of rhenium-copper concentrate.

[0048] Specifically, the pH of the rhenium-containing solution is 0.1 to 14, for example, 0.1, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, and the rhenium concentration in the rhenium-containing solution is >10 mg / L.

[0049] In one specific implementation, in step (1), the current density in the electric field is 1–30 mA / cm². 2 For example, 1mA / cm 2 2mA / cm 2 3mA / cm 2 4mA / cm 2 5mA / cm 2 6mA / cm 2 7mA / cm 2 8mA / cm 2 9mA / cm 2 10mA / cm 2 11mA / cm 2 12mA / cm 2 13mA / cm 2 14mA / cm 2 15mA / cm 2 16mA / cm 2 17mA / cm 2 18mA / cm 2 19mA / cm 2 20mA / cm 2 21mA / cm 2 22mA / cm 2 23mA / cm 2 24mA / cm 2 25mA / cm 2 26mA / cm 2 27mA / cm 2 28mA / cm 2 29mA / cm 2 30mA / cm 2 .

[0050] In order to induce perrhenate ions in the rhenium-containing solution in the cathode chamber to migrate directionally into the organic phase chamber and the anode chamber, a voltage needs to be applied between the cathode and anode to provide an electric field. At the same time, a certain current density needs to be controlled to avoid the problem that the migration rate is low due to the current density being too low, or that the impurity ions migrate in large quantities due to the current density being too high, which would reduce the rhenium separation effect.

[0051] It should be noted that, in order to achieve stable and continuous electrochemical separation and enrichment of rhenium in this invention, the selected cathode and anode must be corrosion-resistant and stable electrodes, and have a low hydrogen evolution or oxygen evolution overpotential.

[0052] Specifically, the anode is one of graphite, carbon fiber cloth, platinum, etc., and the cathode is one of graphite, titanium, copper, platinum, and stainless steel.

[0053] It should be noted that, in order to prevent the organic reagents from being lost due to direct contact with the rhenium-containing solution or supporting electrolyte, and to reduce the amount of organic reagents used, a diaphragm is required to divide the electrolytic cell into a cathode chamber, an organic phase chamber, and an anode chamber. Furthermore, because the organic phase chamber contains organic reagents that selectively extract rhenium, the diaphragm used does not necessarily need to possess special ion selectivity.

[0054] Specifically, the membrane is either a porous membrane or an ion exchange membrane.

[0055] Preferably, the porous membrane is at least one of modified asbestos membrane, polytetrafluoroethylene membrane, and polyvinyl chloride membrane;

[0056] The ion exchange membrane is at least one of polyvinyl chloride semi-homogeneous membrane, polysulfone homogeneous membrane, and polyvinylidene fluoride homogeneous membrane.

[0057] In one specific embodiment, step (3) further includes taking out the rhenium-rich solution, evaporating and concentrating it, and then adding a precipitant to obtain perrhenate.

[0058] Specifically, the evaporation concentration is increased to a rhenium concentration > 10 g / L.

[0059] In one specific embodiment, the precipitant is a soluble potassium salt or ammonium salt, preferably, the precipitant is at least one selected from potassium chloride, potassium sulfate, potassium nitrate, ammonium chloride, and ammonium sulfate.

[0060] It should be noted that in order to recover rhenium in the form of perrhenate precipitate, the rhenium-rich solution in the anode chamber needs to be evaporated and concentrated, and then a precipitant is added to precipitate rhenium. The precipitant needs to form a perrhenate with low solubility with the perrhenate ion.

[0061] In the method of this invention, the enrichment factor of rhenium in the rhenium-rich solution reaches ≥4 times, for example, 4 times, 5 times, 10 times, 15 times, 20 times, 25 times, 30 times, 35 times, 40 times, 45 times, 50 times, 55 times, or 60 times, and the separation coefficient of rhenium from molybdenum is ≥60, for example, 60, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, or 14 times. 00, the separation coefficient of rhenium and sulfur is ≥400, for example, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100.

[0062] The technical solution of the present invention will be further explained below with reference to specific embodiments. All raw materials used in the present invention are commercially available.

[0063] Example 1

[0064] This embodiment discloses a method for separating and enriching rhenium from a rhenium-containing solution, wherein the rhenium-containing solution is a leaching solution of flue dust obtained from the pyrometallurgical refining of rhenium-molybdenum concentrate, and includes the following steps:

[0065] (1) Two modified asbestos porous membranes are used to divide the electrolytic cell into a cathode chamber, an organic phase chamber and an anode chamber. 500 mL of flue dust washing liquid obtained by pyrometallurgical smelting of rhenium-molybdenum concentrate (pH 0.1, specific composition as shown in Table 1) is added to the cathode chamber. 500 mL of 1 mol / L sodium sulfate solution is added to the anode chamber as a supporting electrolyte. TBP extractant, which has been pre-saturated with pure ammonium perrhenate solution to extract rhenium, is added to the organic phase chamber. Sulfonated kerosene is used as a diluent and the volume fraction of TBP is 90%.

[0066] Graphite anodes and cathodes are inserted into the cathode chamber and anode chamber, respectively, and then the current density is controlled to be 1 mA / cm² by an external power supply. 2 Rhenium is enriched by electrochemical separation. Under the action of an electric field, perrhenate anions in the rhenium-containing solution in the cathode chamber undergo directional migration and are enriched in the supporting electrolyte in the anode chamber.

[0067] (2) When the rhenium concentration in the rhenium-containing solution in the cathode chamber drops to 0.1 mg / L (the rhenium extraction rate is 99.98%), a new rhenium-containing solution is replaced to continue electrochemical separation and enrichment, while the rhenium concentration in the rhenium-rich solution in the anode chamber continues to rise.

[0068] (3) Repeat step (2) until the rhenium concentration in the rhenium-rich solution in the anode chamber reaches 2.12 g / L. Stop electrolysis, take out the rhenium-rich solution, evaporate and concentrate 500 mL of the 2.12 g / L rhenium-rich solution until the rhenium concentration reaches 30.36 g / L, add potassium chloride as a precipitant to precipitate rhenium, thereby obtaining 1.51 g of potassium perrhenate product.

[0069] In step (2), after the initial electrolysis is completed, i.e., 3.5 hours later, samples are taken to analyze the ion concentrations in the cathode and anode chambers. The concentrations of rhenium, molybdenum, and sulfur in the rhenium-containing solution in the cathode chamber are 0.1 mg / L, 3647 mg / L, and 3572 mg / L, respectively. The concentrations of rhenium, molybdenum, and sulfur in the supporting electrolyte in the anode chamber are 497 mg / L, 41 mg / L, and 6 mg / L, respectively. The separation coefficients of rhenium from molybdenum and sulfur reach 89.79 and 595.14, respectively, demonstrating good separation performance.

[0070] Table 1. Main components of leaching solution from rhenium-molybdenum concentrate pyrometallurgical dust.

[0071] Element Mo Re S Fe Concentration (mg / L) 3689 498 3578 1236

[0072] The main components of the rhenium-rich solution in step (3) were Re: 2.12 g / L, Mo: 0.21 g / L, and S: 0.03 g / L. In addition, compared with the concentration of rhenium in the raw material (498 mg / L), the concentration of rhenium in the rhenium-rich solution reached 2120 mg / L, and the enrichment factor of rhenium reached 4.3 times.

[0073] The rhenium concentration in the cathode and anode chambers as a function of electrolysis time is shown in the following curves. Figure 2 As shown in the figure, during the electrochemical separation and enrichment of rhenium, the rhenium concentration in the rhenium-containing solution in the cathode chamber gradually decreased with the extension of electrolysis time, while the rhenium concentration in the supporting electrolyte in the anode chamber continuously increased. After 15 hours of electrolysis, the rhenium concentration in the supporting electrolyte in the anode chamber reached 2120 mg / L. Furthermore, the results in the figure indicate that continuous enrichment of rhenium can be achieved by replacing the rhenium-containing solution.

[0074] Example 2

[0075] This embodiment discloses a method for separating and enriching rhenium from a rhenium-containing solution, wherein the rhenium-containing solution is a leachate obtained from the hydrometallurgical refining of rhenium-molybdenum concentrate, and includes the following steps:

[0076] (1) The electrolytic cell was divided into a cathode chamber, an organic phase chamber and an anode chamber by using a polytetrafluoroethylene porous membrane and a polyvinyl chloride porous membrane respectively. 1500 mL of leachate obtained by hydrometallurgical refining of rhenium-molybdenum concentrate (pH 14, specific composition as shown in Table 2) was added to the cathode chamber. 1500 mL of 2 mol / L sodium bisulfate solution was added to the anode chamber as the supporting electrolyte. N235 extractant, which was pre-saturated with pure sodium perrylate solution to extract rhenium, was added to the organic phase chamber. Kerosene was used as the diluent and the volume fraction of N235 was 2.5%.

[0077] A titanium anode and a platinum cathode are inserted into the cathode chamber and anode chamber, respectively, and then the current density is controlled to be 30 mA / cm² by an external power supply. 2 Rhenium is enriched by electrochemical separation. Under the action of an electric field, perrhenate anions in the rhenium-containing solution in the cathode chamber undergo directional migration and are enriched in the supporting electrolyte in the anode chamber.

[0078] (2) When the rhenium concentration in the rhenium-containing solution in the cathode chamber drops to 0.1 mg / L (the rhenium extraction rate is 99.55%), a new rhenium-containing solution is replaced to continue electrochemical separation and enrichment, while the rhenium concentration in the rhenium-rich solution in the anode chamber continues to rise.

[0079] (3) Repeat step (2) until the rhenium concentration in the rhenium-rich solution in the anode chamber reaches 1.29 g / L. Stop electrolysis, take out the rhenium-rich solution, evaporate and concentrate 1500 mL of the 1.29 g / L rhenium-rich solution until the rhenium concentration reaches 32.54 g / L, add potassium sulfate as a precipitant to precipitate rhenium, thereby obtaining 2.61 g of potassium perrhenate product.

[0080] In step (2), after the initial electrolysis is completed, i.e., 2 hours later, samples are taken to analyze the ion concentrations in the cathode and anode chambers. The concentrations of rhenium, molybdenum, and sulfur in the rhenium-containing solution in the cathode chamber are 0.1 mg / L, 26549 mg / L, and 18556 mg / L, respectively. The concentrations of rhenium, molybdenum, and sulfur in the supporting electrolyte in the anode chamber are 21.7 mg / L, 20 mg / L, and 6 mg / L, respectively. The separation coefficients for rhenium, molybdenum, and sulfur reach 1310 and 3051, respectively, demonstrating good separation performance.

[0081] Table 2. Main components of leachate from hydrometallurgical processing of rhenium-molybdenum concentrate.

[0082] Element Mo Re S Fe Concentration (mg / L) 26569 22 18563 0.2

[0083] The main components of the rhenium-rich solution in step (3) were: Re: 1.29 g / L, Mo: 1.39 g / L, and S: 0.36 g / L. Compared with the concentration of rhenium in the raw material (22 mg / L), the concentration of rhenium in the rhenium-rich solution reached 1290 mg / L, and the enrichment factor of rhenium reached 58.6 times.

[0084] Example 3

[0085] This embodiment discloses a method for separating and enriching rhenium from a rhenium-containing solution, wherein the rhenium-containing solution is a waste acid solution obtained from the pyrometallurgical refining of rhenium-containing copper concentrate, and includes the following steps:

[0086] (1) The electrolytic cell was divided into a cathode chamber, an organic phase chamber and an anode chamber by using a polyvinylidene fluoride homogeneous membrane and a polyvinyl chloride semi-homogeneous membrane respectively. 2000 mL of waste acid solution (pH 1.25, specific composition as shown in Table 3) was added to the cathode chamber. 2000 mL of 1.5 mol / L sodium hydroxide solution was added to the anode chamber as the supporting electrolyte. TOPO and 2-octanol, which were pre-saturated with pure ammonium perrhenate solution to extract rhenium, were added to the organic phase chamber. Sulfonated kerosene was used as the diluent. The volume fractions of TOPO and 2-octanol were 50% and 20% respectively.

[0087] A platinum anode and a stainless steel cathode are inserted into the cathode chamber and anode chamber, respectively, and then the current density is controlled to be 10 mA / cm² by an external power supply. 2 Rhenium is enriched by electrochemical separation. Under the action of an electric field, perrhenate anions in the rhenium-containing solution in the cathode chamber undergo directional migration and are enriched in the supporting electrolyte in the anode chamber.

[0088] (2) When the rhenium concentration in the rhenium-containing solution in the cathode chamber drops to 0.1 mg / L (the rhenium extraction rate is 99.95%), a new rhenium-containing solution is replaced to continue electrochemical separation and enrichment, while the rhenium concentration in the rhenium-rich solution in the anode chamber continues to rise.

[0089] (3) Repeat step (2) until the rhenium concentration in the rhenium-rich solution in the anode chamber reaches 1.57 g / L. Stop electrolysis, take out the rhenium-rich solution, evaporate and concentrate 2000 mL of the 1.57 g / L rhenium-rich solution until the rhenium concentration reaches 32.54 g / L, add potassium sulfate as a precipitant to precipitate rhenium, thereby obtaining 4.20 g of potassium perrhenate product.

[0090] Table 3. Main components of the acidic solution obtained from the pyrometallurgical refining of rhenium-copper concentrate.

[0091] Element Mo Re S Cu Concentration (mg / L) 589 219 26357 1131

[0092] The composition of the main impurity ions in the rhenium-rich solution in step (3) was analyzed (Mo: 23 mg / L, S: 0.46 g / L). The separation coefficients of rhenium from molybdenum and sulfur were calculated to be 184 and 410, respectively, demonstrating good separation effect between rhenium and impurity ions. In addition, compared with the concentration of rhenium in the raw material (219 mg / L), the concentration of rhenium in the rhenium-rich solution reached 1570 mg / L, and the enrichment factor of rhenium reached 7.2 times.

[0093] Example 4

[0094] This embodiment discloses a method for separating and enriching rhenium from a rhenium-containing solution, wherein the rhenium-containing solution is a leaching solution of flue dust obtained from the pyrometallurgical refining of rhenium-molybdenum concentrate, and includes the following steps:

[0095] (1) The electrolytic cell was divided into a cathode chamber, an organic phase chamber and an anode chamber by using a polysulfone homogeneous membrane and a polyvinylidene fluoride homogeneous membrane respectively. 5L of flue dust washing liquid obtained by pyrometallurgical smelting of rhenium-molybdenum concentrate (pH 0.1, specific composition as shown in Table 1) was added to the cathode chamber. 5L of 1.5mol / L sodium nitrate solution was added to the anode chamber as the supporting electrolyte. N263 extractant, which was pre-saturated with pure ammonium perrhenate solution to extract rhenium, was added to the organic phase chamber. Sulfonated kerosene was used as the diluent and the volume fraction of N263 was 30%.

[0096] A titanium anode and a copper cathode are inserted into the cathode chamber and anode chamber, respectively, and then the current density is controlled to be 15 mA / cm² by an external power supply. 2 Rhenium is enriched by electrochemical separation. Under the action of an electric field, perrhenate anions in the rhenium-containing solution in the cathode chamber undergo directional migration and are enriched in the supporting electrolyte in the anode chamber.

[0097] (2) When the concentration of rhenium in the rhenium-containing solution in the cathode chamber (i.e., the rhenium-poor solution) drops to 0.1 mg / L (the rhenium extraction rate is 99.98%), a new rhenium-containing solution is replaced to continue electrochemical separation and enrichment, while the concentration of rhenium in the rhenium-rich solution in the anode chamber continues to rise.

[0098] (3) Repeat step (2). When the rhenium concentration in the rhenium-rich solution in the anode chamber reaches 2.53 g / L, stop electrolysis, take out the rhenium-rich solution, evaporate and concentrate 5 L of the 2.53 g / L rhenium-rich solution until the rhenium concentration reaches 36.83 g / L, add ammonium chloride as a precipitant to precipitate rhenium, thereby obtaining 13.33 g of ammonium perrhenate product.

[0099] The composition of the main impurity ions in the rhenium-rich solution in step (3) was analyzed (Mo: 0.16 g / L, S: 0.05 g / L). The separation coefficients of rhenium from molybdenum and sulfur were calculated to be 117.1 and 363.5, respectively, demonstrating good separation performance. In addition, compared with the concentration of rhenium in the raw material (498 mg / L), the concentration of rhenium in the rhenium-rich solution reached 2530 mg / L, and the enrichment factor of rhenium reached 5.1 times.

[0100] Example 5

[0101] The method for separating and enriching rhenium from a rhenium-containing solution in this embodiment is the same as that in Example 1, except that in step (1), the organic reagent in the organic phase chamber is isoamyl alcohol, the extractant for pre-saturating rhenium extraction in pure ammonium perrylate solution, and the diluent is kerosene. The volume fraction of isoamyl alcohol is 50%, and the current density is 5 mA / cm². 2 Rhenium was then electrochemically separated and enriched.

[0102] After electrochemical separation and enrichment, the rhenium concentration in the rhenium-depleted solution in the cathode chamber was 0.1 mg / L (rhenium extraction rate was 99.98%), and 500 mL of rhenium-rich solution with a concentration of 2.35 g / L was obtained in the anode chamber. This solution was concentrated to 31.23 g / L by evaporation and then ammonium sulfate was added to precipitate rhenium to obtain 1.16 g of ammonium perperurate.

[0103] In step (3), the concentrations of the main impurity ions in the rhenium-rich solution were 0.26 g / L for Mo and 0.041 g / L for S. The separation coefficients of rhenium from molybdenum and sulfur were calculated to be 66.9 and 411.8, respectively, demonstrating good separation performance. In addition, compared with the rhenium concentration in the rhenium-containing solution (498 mg / L), the rhenium concentration in the rhenium-rich solution reached 2350 mg / L, and the enrichment factor of rhenium reached 4.7 times.

[0104] Example 6

[0105] The method for separating and enriching rhenium from a rhenium-containing solution in this embodiment is the same as that in Example 1, except that in step (1), the organic reagent in the organic phase chamber is cyclohexanone, an extractant for pre-saturating rhenium extraction in pure ammonium perrylate solution, and the diluent is sulfonated kerosene, with a volume fraction of 60% for cyclohexanone; the current density is 8 mA / cm². 2 Rhenium was then electrochemically separated and enriched.

[0106] After electrochemical separation and enrichment, the rhenium concentration in the rhenium-depleted solution in the cathode chamber was 0.05 mg / L (rhenium extraction rate of 99.99%), while 500 mL of a rhenium-rich solution with a concentration of 2.86 g / L was obtained in the anode chamber. This solution was concentrated to 32.59 g / L by evaporation, and then potassium chloride was added to precipitate rhenium to obtain 1.92 g of potassium perrhenate. The concentrations of the main impurity ions in the rhenium-rich solution were Mo 0.19 g / L and S 0.025 g / L. The separation coefficients of rhenium from molybdenum and sulfur were calculated to be 111.5 and 821.9, respectively, demonstrating good separation effects of rhenium and molybdenum, and rhenium and sulfur. In addition, compared with the rhenium concentration in the rhenium-containing solution (498 mg / L), the rhenium concentration in the rhenium-rich solution reached 2860 mg / L, and the rhenium enrichment factor reached 5.7 times.

[0107] Example 7

[0108] The method for separating and enriching rhenium from a rhenium-containing solution in this embodiment is the same as that in Example 3. The difference is that in step (1), the pH of the rhenium-containing solution is adjusted to 3, 6, and 9 by sodium hydroxide, and the rhenium-containing solutions with different pH values ​​are obtained by filtration, and then the rhenium is enriched by electrochemical separation.

[0109] After electrochemical separation and enrichment, the ion concentrations in the rhenium-poor and rhenium-rich solutions were separated, and the separation coefficient and enrichment factor were calculated. The results are shown in Table 4.

[0110] Table 4. Electrochemical separation and enrichment of rhenium from rhenium-containing solutions at different pH values.

[0111]

[0112] As shown in Table 4, the electrochemical separation and enrichment method for rhenium provided by this invention has good separation and enrichment effects at different pH levels, indicating that the method has a wide range of applicability to raw materials.

[0113] Comparative Example 1

[0114] The method for separating and enriching rhenium from a rhenium-containing solution in this comparative example is the same as that in Example 2, except that in step (1), the organic reagent added to the organic phase chamber is replaced with a 2 mol / L sodium sulfate solution.

[0115] After electrolysis for 3.5 hours, the ion concentrations in the cathode and anode chambers were analyzed. The concentrations of rhenium, molybdenum, and sulfur in the rhenium-containing solution in the cathode chamber were 20 mg / L, 24454 mg / L, and 17648 mg / L, respectively. The concentrations of rhenium, molybdenum, and sulfur in the supporting electrolyte in the anode chamber were 2 mg / L, 2115 mg / L, and 915 mg / L, respectively.

[0116] The results show that without the addition of an organic extraction system that selectively extracts rhenium in the organic phase chamber, relying solely on electric field drive cannot achieve effective separation of rhenium and impurity ions, nor can it enrich rhenium.

[0117] Comparative Example 2

[0118] The method for separating and enriching rhenium from a rhenium-containing solution in this comparative example is the same as that in Example 1, except that in step (1), the current density is 60 mA / cm². 2 Rhenium was enriched by electrochemical separation.

[0119] After electrolysis for 2 hours, the ion concentrations in the cathode and anode chambers were analyzed. The concentrations of rhenium, molybdenum, and sulfur in the rhenium-containing solution in the cathode chamber were 50 mg / L, 2463 mg / L, and 3426 mg / L, respectively. The concentrations of rhenium, molybdenum, and sulfur in the supporting electrolyte in the anode chamber were 448 mg / L, 1226 mg / L, and 152 mg / L, respectively. The separation coefficients of rhenium from molybdenum and sulfur were 20.3 and 57.9, respectively, which were significantly lower than those in Example 1.

[0120] The results indicate that a suitable current density needs to be controlled during electrochemical separation and enrichment of rhenium to achieve better separation results.

[0121] Comparative Example 3

[0122] The method for separating and enriching rhenium from a rhenium-containing solution in this comparative example is the same as that in Example 1, except that the volume fraction of TBP in step (1) is 2%.

[0123] Electrolysis was performed for 3.5 h, and the ion concentrations in the cathode and anode chambers were analyzed. The concentrations of rhenium, molybdenum, and sulfur in the rhenium-containing solution in the cathode chamber were 30 mg / L, 1763 mg / L, and 3526 mg / L, respectively. The concentrations of rhenium, molybdenum, and sulfur in the supporting electrolyte in the anode chamber were 468 mg / L, 1926 mg / L, and 52 mg / L, respectively. The separation coefficients of rhenium from molybdenum and sulfur were 1.79 and 64, respectively, which were significantly lower than those in Example 1.

[0124] The results show that the volume fraction of the extractant can only achieve good separation results within the scope of this invention.

[0125] Comparative Example 4

[0126] The method for separating and enriching rhenium from a rhenium-containing solution in this comparative example is the same as that in Example 1, except that in step (1), the extractant added to the organic phase chamber is not pre-saturated with ammonium perrhenate solution to extract rhenium, that is, only organic reagent TBP is added as the extractant, wherein sulfonated kerosene is used as the diluent and the volume fraction of TBP is 90%.

[0127] Because the organic extractant that was not pre-saturated for rhenium extraction had extremely poor conductivity, the electrolysis process was subject to extremely high voltage, which prevented effective electrolysis and thus failed to separate rhenium from impurity elements.

[0128] By comparing Examples 1, 2, 1, and 2, it can be seen that the good separation and enrichment effect of the method for separating and enriching rhenium from a rhenium-containing solution provided by the present invention is achieved by the coupling of appropriate electric field driving and organic reagent extraction.

[0129] The above description is only a preferred embodiment of the present invention, but the scope of protection 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 scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A process for separating and concentrating rhenium from a solution containing rhenium, characterized by, The method comprises the following steps: (1) adding a solution containing rhenium to the cathode compartment and a supporting electrolyte to the anode compartment, under the action of an electric field, ReO4 - migrates from the cathode compartment through an organic phase compartment, into which a saturated rhenium-extracting organic reagent is added, into the supporting electrolyte in the anode compartment; (2) when the concentration of the rhenium-containing solution in the cathode chamber is less than 0.1 mg / L, a new rhenium-containing solution is used to continue the electrochemical enrichment; (3) repeating step (2) until the concentration of rhenium in the anode chamber is greater than 1 g / L, and then stopping the electrolysis, and obtaining a rhenium-rich solution from the anode.

2. The method for separating and enriching rhenium from a rhenium-containing solution according to claim 1, characterized in that, In step (1), the saturated rhenium-extracting organic reagent is pre-extracted with rhenium in a perrhenate solution until the organic reagent is saturated with rhenium extraction.

3. The method for separating and enriching rhenium from a rhenium-containing solution according to claim 2, characterized in that, The organic reagent comprises an extractant and a diluent, and the volume fraction of the extractant in the organic reagent is 2.5-90%.

4. The method for separating and enriching rhenium from a rhenium-containing solution according to claim 3, characterized in that, The extractant is at least one of TBP, N235, TOPO, N263, sec-octyl alcohol, iso-amyl alcohol and cyclohexanone, and the diluent is one of kerosene and sulfonated kerosene.

5. The method for separating and enriching rhenium from a rhenium-containing solution according to claim 1, characterized in that, In step (1), the current density in the electric field is 1 to 30 mA / cm 2 .

6. A process for the separation and concentration of rhenium from a solution containing rhenium according to any one of claims 1 to 5, characterized in that, In step (3), the rhenium-rich solution is taken out, evaporated and concentrated, and then a precipitant is added to obtain a perrhenate.

7. The method for separating and enriching rhenium from a rhenium-containing solution according to claim 6, characterized in that, The evaporation concentration is greater than 10 g / L.

8. The method for separating and enriching rhenium from a rhenium-containing solution according to claim 6, characterized in that, The precipitant is a soluble potassium salt or an ammonium salt.

9. A process for the separation and concentration of rhenium from a solution containing rhenium according to any one of claims 1 to 5, characterized in that, The rhenium-containing solution is at least one of a leaching solution obtained by wet smelting of a rhenium-containing molybdenum concentrate, a leaching solution obtained by leaching of fume dust from fire smelting of a rhenium-containing molybdenum concentrate, and a polluted acid obtained by fire smelting of a rhenium-containing copper concentrate.

10. The method for separating and enriching rhenium from a rhenium-containing solution according to claim 9, characterized in that, The pH of the rhenium-containing solution is 0.1-14.

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