Method for separating and enriching rhenium from rhenium-containing solution

Abstract

The invention relates to a method for separating and enriching rhenium from a rhenium-containing solution, belongs to the technical field of scattered metal metallurgy, and is used for solving at least one of the problems of low recovery rate, high acid and alkali consumption, poor selectivity and the like in the existing rhenium recovery method. According to the method, selective separation of rhenium and impurity ions in the rhenium-containing solution and synchronous enrichment of rhenium are achieved through forced interphase migration of the coupled electric field and selective rhenium extraction of the organic reagent, continuous selective rhenium extraction and rhenium enrichment can be achieved, and it is not needed to consume a large amount of acid and alkali for reverse extraction and regeneration of the organic reagent; the organic reagent is equivalent to a selective separation membrane, effective separation of rhenium and impurity ions can be achieved, and the dosage of the organic reagent can be greatly reduced.

Description

Technical Field

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

[0002] Rhenium has the characteristics of high melting point, high hardness, corrosion resistance and excellent ductility. It is widely used in national defense construction, aerospace, petrochemical industry and electronic manufacturing, especially as an indispensable key raw material for aircraft engine turbine blades and nozzles. Rhenium is one of the rarest and most dispersed metal elements in nature, with an abundance of only about 10 -9 , there are almost no independent minerals available for mining. Rhenium is often associated with minerals such as molybdenite and bornite due to its sulfide affinity, and nearly 80% of rhenium products come from by-products of molybdenum metallurgy or copper metallurgy.

[0003] Due to the complex mineral composition and extremely low rhenium content, the by-product rhenium products from molybdenum or copper metallurgy involve complex separation and enrichment processes. In particular, the separation of molybdenum and rhenium has always been a difficult problem in the industry due to the similar properties of rhenium and molybdenum. At present, the methods for recovering rhenium from molybdenum or copper metallurgy mainly include precipitation, ion exchange, solvent extraction, etc. The precipitation method is based on the difference between the solubility products of substances to achieve the selective separation of target ions and impurity ions. The selective precipitation of rhenium from molybdenum-rhenium solution mainly uses precipitants such as potassium salt or methyl violet and ReO4 - The chemical precipitation method for extracting rhenium from molybdenum-rhenium solution has the advantages of simple process and convenient operation, but the separation effect is poor and the yield of rhenium is low. The ion exchange method is based on the active groups in the resin and ReO4 - The interaction is carried out by ion exchange, and then the ReO4 - Desorption, thus achieving the separation of rhenium and molybdenum. The ion exchange method has the characteristics of simple process and low environmental pollution, but the separation coefficient of rhenium and impurity ions, the selectivity of the resin and the recycling regeneration need to be improved.

[0004] Solvent extraction is the main method for extracting rhenium in industry. Its basic principle is to separate rhenium compounds and molybdenum compounds based on their different distribution coefficients in organic and aqueous phases. Although solvent extraction for separating rhenium and molybdenum has the advantages of mature technology, high efficiency and low energy consumption, there are still problems such as large amount of extractant, large amount of high-salt wastewater and loss of extractant in 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, so as 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] In order to achieve the above object, the present invention adopts the following technical solution:

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

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

[0009] (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 replaced to continue electrochemical enrichment;

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

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

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

[0013] Furthermore, the extractant is at least one of TBP, N235, TOPO, N263, 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 to 30 mA / cm 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] Further, the rhenium concentration is evaporated to a concentration of >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 a leachate obtained from wet smelting of rhenium-containing molybdenum concentrate, a smoke leaching solution obtained from pyrometallurgy of rhenium-containing molybdenum concentrate, and a waste acid obtained from pyrometallurgy of rhenium-containing copper concentrate.

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

[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 the selective separation of rhenium from impurity ions and the simultaneous enrichment of rhenium in a rhenium-containing solution by coupling electric field forced phase migration 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 stripping and regeneration of organic reagents. The organic reagent of the present invention is equivalent to a selective separation membrane, which can achieve effective separation of rhenium from impurity ions, and the amount of organic reagent used can be greatly reduced.

[0022] (2) In the method of the present invention, oxygen or chlorine evolution occurs at the anode under the action of an electric field, and anions need to be added to the organic phase chamber to maintain the electrical neutrality of the anode liquid. The organic reagent saturated with rhenium in the organic phase chamber releases ReO4 - , and migrate to the anode chamber under the action of the electric field; while the anions in the rhenium solution need to migrate from the cathode chamber to the organic phase chamber to maintain the electrical neutrality of the organic reagent, because the organic reagent in the organic chamber only selectively reacts with ReO4 - Therefore, the ReO4 in the rhenium solution in the cathode chamber - Under the action of the electric field, it continuously migrates from the cathode chamber to the organic phase chamber. - Migrate to the organic phase chamber continuously, and the organic reagent in the organic phase chamber needs to release ReO4 - To maintain the electrical neutrality of the anode region, thus forcing the ReO4 loaded in the organic phase to - Continue to migrate toward the anode chamber and accumulate in the anode chamber. When the entire system reaches dynamic stability, under the continuous driving of the electric field, ReO4 - It is continuously 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 the synchronous separation and enrichment of rhenium and strengthening the separation and enrichment process;

[0023] (3) The method of the present invention can also recover rhenium in the form of perrhenate precipitation, which requires evaporating and concentrating the rhenium-rich solution in the anode chamber, and then adding a precipitant to precipitate rhenium, and the precipitant needs to form a perrhenate with lower 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 produced continuously, does not generate pollutants, and is easy to realize industrial application.

[0025] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0027] Figure 1 The present invention is a process flow chart for separating and enriching rhenium from a rhenium-containing solution;

[0028] Figure 2 1 is a curve showing the change of rhenium concentration in the cathode chamber and the anode chamber with electrolysis time in Example 1 of the present invention. DETAILED DESCRIPTION

[0029] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings 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 used to limit the scope of the present invention.

[0030] A specific embodiment of the present invention, 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) Add a rhenium-containing solution to the cathode chamber and a supporting electrolyte to the anode chamber. Under the action of the electric field, ReO4 - Directional migration occurs from the cathode chamber through the organic phase chamber into the supporting electrolyte in the anode chamber, and the organic phase chamber is added with an organic reagent for saturated extraction of rhenium;

[0032] (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 replaced to continue electrochemical enrichment;

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

[0034] The method of the present invention can realize continuous selective extraction and enrichment of rhenium under the action of electric field, without consuming a large amount of acid and alkali for stripping and regeneration of organic reagents; the organic reagent of the present invention is equivalent to a selective separation membrane, which can realize effective separation of rhenium and impurity ions, and the amount of organic reagent can be greatly reduced. The method of the present invention realizes selective separation of rhenium and impurity ions in a rhenium-containing solution and synchronous enrichment of rhenium by coupling electric field forced interphase migration with organic reagent selective extraction of rhenium.

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

[0036] It should be noted that the organic reagent 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 reagent includes an extractant and a diluent.

[0039] In the method of the present invention, under the action of the electric field, the anode undergoes oxygen evolution or chlorine evolution reaction, and anions need to be supplemented in the organic phase chamber to maintain the electrical neutrality of the anode liquid. The organic reagent saturated with rhenium in the organic phase chamber releases ReO4 - , and migrate to the anode chamber under the action of the electric field; while the anions in the rhenium-containing solution need to migrate from the cathode chamber to the organic phase chamber to maintain the electrical neutrality of the organic reagent, because the organic reagent in the organic chamber only selectively reacts with ReO4 - Therefore, the ReO4 in the rhenium solution in the cathode chamber - Under the action of the electric field, it continuously migrates from the cathode chamber to the organic phase chamber. - Migrate to the organic phase chamber continuously, and the organic reagent in the organic phase chamber needs to release ReO4 - To maintain the electrical neutrality of the anode region, thus forcing the ReO4 in the organic phase - Continue to migrate toward the anode chamber and accumulate in the anode chamber. When the entire system reaches dynamic stability, under the continuous driving of the electric field, ReO4 - It is continuously and 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 the synchronous separation and enrichment of rhenium and strengthening the separation and enrichment process.

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

[0041] Preferably, the extractant is at least one of TBP (tributyl phosphate), N235 (trialkyl tertiary amine), TOPO (trioctyl phosphine oxide), N263 (trioctyl methyl ammonium chloride), sec-octanol, isoamyl alcohol and cyclohexanone.

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

[0043] In a 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 the present invention must satisfy the requirement that perrhenate has a high solubility therein, that is, the perrhenate formed by perrhenate and supporting electrolyte cations has a high solubility; in addition, in order to avoid the generation of corrosive gases such as chlorine during the electrolysis process as much as possible, the selected supporting electrolyte should be a chlorine-free salt.

[0046] In a 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, 2 mol / L. If the concentration is too low, the conductivity of the supporting electrolyte is poor; if the concentration is too high, it is not economical and increases the difficulty of subsequent treatment.

[0047] In a specific embodiment, in step (1), the rhenium-containing solution is at least one of a leachate obtained from wet smelting of rhenium-containing molybdenum concentrate, a smoke leaching solution obtained from pyrometallurgy of rhenium-containing molybdenum concentrate, and a waste acid obtained from pyrometallurgy of rhenium-containing copper concentrate.

[0048] Specifically, the pH of the rhenium-containing solution is 0.1-14, 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 a specific embodiment, in step (1), the current density in the electric field is 1-30 mA / cm 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 make the perrhenate ions in the rhenium solution in the cathode chamber migrate in a directional manner to the organic phase chamber and the anode chamber, it is necessary to apply a voltage between the cathode and the anode to provide an electric field. At the same time, a certain current density must be controlled to avoid the problem of reduced rhenium separation effect due to low migration rate caused by too low current density or excessive current density causing a large amount of impurity ions to migrate.

[0051] It should be noted that in order to stably and continuously realize the electrochemical separation and enrichment of rhenium in the present invention, the cathode and anode selected need to be corrosion-resistant and stable electrodes with low hydrogen or oxygen evolution overpotential.

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

[0053] It should be noted that in order to prevent the organic reagent from being dissolved due to direct contact with the rhenium-containing solution or supporting electrolyte and reduce the amount of organic reagent, a diaphragm is required to divide the electrolytic cell into a cathode chamber, an organic phase chamber and an anode chamber. At the same time, because the organic phase chamber has an organic reagent that selectively extracts rhenium, the diaphragm used does not need to have special ion selectivity.

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

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

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

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

[0058] Specifically, the evaporation concentration is such that the rhenium concentration is greater than 10 g / L.

[0059] In a specific embodiment, the precipitant is a soluble potassium salt or ammonium salt. Preferably, the precipitant is at least one of 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 precipitation, the rhenium-rich solution in the anode chamber needs to be evaporated and concentrated, and then a precipitant is added to precipitate rhenium, and the precipitant needs to form a perrhenate with lower solubility with the perrhenate ion.

[0061] In the method of the present invention, the enrichment multiple 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, 60 times, and the separation coefficient of rhenium and molybdenum is ≥60, for example, 60, 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400 00, the separation factor 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 is further explained below in conjunction with specific embodiments. The raw materials used in the present invention are all commercially available raw materials.

[0063] Example 1

[0064] A method for separating and enriching rhenium from a rhenium-containing solution in this embodiment, wherein the rhenium-containing solution is a smoke leaching liquid obtained from pyrometallurgical smelting of rhenium-containing molybdenum concentrate, comprises the following steps:

[0065] (1) Two modified asbestos porous diaphragms were used to divide the electrolytic cell into a cathode chamber, an organic phase chamber and an anode chamber, 500 mL of smoke leaching liquid (pH 0.1, specific composition as shown in Table 1) obtained by pyrometallurgical smelting of rhenium-containing molybdenum concentrate was added to the cathode chamber, 500 mL of 1 mol / L sodium sulfate solution was added to the anode chamber as a supporting electrolyte, and TBP, an extractant previously saturated with rhenium in pure ammonium rhenate solution, was added to the organic phase chamber, wherein sulfonated kerosene was used as a diluent, and the volume fraction of TBP was 90%;

[0066] Insert graphite anode and graphite cathode into the cathode chamber and anode chamber respectively, and then control the current density to 1mA / cm by external power supply. 2 Electrochemical separation and enrichment of rhenium are performed, and under the action of the electric field, the perrhenate in the rhenium-containing solution in the cathode chamber undergoes directional migration and is 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 (rhenium extraction rate is 99.98%), a new rhenium-containing solution is replaced to continue electrochemical separation and enrichment, and 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, then add potassium chloride as a precipitant to precipitate rhenium, thereby obtaining 1.51 g of potassium perrhenate product.

[0069] In step (2), after the first power-on, that is, after 3.5 hours of electrolysis, the ion concentrations in the cathode chamber and the anode chamber are sampled and analyzed, wherein the concentrations of rhenium, molybdenum, and sulfur in the rhenium solution in the cathode chamber are 0.1 mg / L, 3647 mg / L, and 3572 mg / L, respectively, and 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, molybdenum, and sulfur are 89.79 and 595.14, respectively, reflecting a good separation effect.

[0070] Table 1 Main components of the leaching liquid from the pyrometallurgical smoke of rhenium-containing molybdenum concentrate

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

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

[0073] The curves of rhenium concentration in the cathode chamber and the anode chamber changing with electrolysis time are shown in Figure 2 As shown in the figure, in the process of electrochemical separation and enrichment of rhenium, as the electrolysis time increases, the rhenium concentration in the rhenium-containing solution in the cathode chamber gradually decreases, while the rhenium concentration in the supporting electrolyte in the anode chamber continues to rise. After 15 hours of electrolysis, the rhenium concentration in the supporting electrolyte in the anode chamber reaches 2120 mg / L; in addition, the results in the figure show that continuous enrichment of rhenium can be achieved by replacing a new rhenium-containing solution.

[0074] Example 2

[0075] A method for separating and enriching rhenium from a rhenium-containing solution in this embodiment, wherein the rhenium-containing solution is a leachate obtained by hydrometallurgical smelting of rhenium-containing molybdenum concentrate, comprises the following steps:

[0076] (1) A polytetrafluoroethylene porous diaphragm and a polyvinyl chloride porous diaphragm are respectively used to divide the electrolytic cell into a cathode chamber, an organic phase chamber and an anode chamber, 1500 mL of a leaching solution (pH 14, specific composition as shown in Table 2) obtained by hydrometallurgy of rhenium-containing molybdenum concentrate is added to the cathode chamber, 1500 mL of a 2 mol / L sodium bisulfate solution is added to the anode chamber as a supporting electrolyte, and an extractant N235 which has been saturated with rhenium in a pure sodium rhenate solution is added to the organic phase chamber, wherein kerosene is used as a diluent and the volume fraction of N235 is 2.5%;

[0077] A titanium anode and a platinum cathode were inserted into the cathode chamber and the anode chamber, respectively, and then the current density was controlled to 30 mA / cm by an external power supply. 2 Electrochemical separation and enrichment of rhenium are performed, and under the action of the electric field, the perrhenate in the rhenium-containing solution in the cathode chamber undergoes directional migration and is 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 (rhenium extraction rate is 99.55%), a new rhenium-containing solution is replaced to continue electrochemical separation and enrichment, and 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, then add potassium sulfate as a precipitant to precipitate rhenium, thereby obtaining 2.61 g of potassium perrhenate product.

[0080] In step (2), after the first power-on, that is, after 2 hours of electrolysis, the ion concentrations in the cathode chamber and the anode chamber are sampled and analyzed, wherein the concentrations of rhenium, molybdenum, and sulfur in the rhenium solution in the cathode chamber are 0.1 mg / L, 26549 mg / L, and 18556 mg / L, respectively, and 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 of rhenium, molybdenum, and sulfur are 1310 and 3051, respectively, reflecting a good separation effect.

[0081] Table 2 Main components of the leachate from the hydrometallurgical smelting of rhenium-containing 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 the analysis step (3) are: Re: 1.29 g / L, Mo: 1.39 g / L, S: 0.36 g / L. Compared with the rhenium concentration in the raw material (22 mg / L), the rhenium concentration in the rhenium-rich solution reaches 1290 mg / L, and the rhenium enrichment multiple reaches 58.6 times.

[0084] Example 3

[0085] A method for separating and enriching rhenium from a rhenium-containing solution in this embodiment, wherein the rhenium-containing solution is a waste acid solution obtained by pyrometallurgical smelting of rhenium-containing copper concentrate, comprises the following steps:

[0086] (1) A polyvinylidene fluoride homogeneous membrane and a polyvinyl chloride semi-homogeneous membrane are respectively used to divide the electrolytic cell into a cathode chamber, an organic phase chamber and an anode chamber, 2000 mL of a waste acid solution (pH 1.25, specific composition is shown in Table 3) obtained by pyrometallurgical smelting of rhenium-containing copper concentrate is added to the cathode chamber, 2000 mL of a 1.5 mol / L sodium hydroxide solution is added to the anode chamber as a supporting electrolyte, and TOPO and 2-octanol, extractants that have been saturated with rhenium in pure ammonium rhenate solution in advance, are added to the organic phase chamber, wherein sulfonated kerosene is used as a diluent, and the volume fractions of TOPO and 2-octanol are 50% and 20%, respectively;

[0087] Insert a platinum anode and a stainless steel cathode into the cathode chamber and anode chamber respectively, and then control the current density to 10mA / cm by an external power supply. 2 Electrochemical separation and enrichment of rhenium are performed, and under the action of the electric field, the perrhenate in the rhenium-containing solution in the cathode chamber undergoes directional migration and is 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 (rhenium extraction rate is 99.95%), a new rhenium-containing solution is replaced to continue electrochemical separation and enrichment, and 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, then add potassium sulfate as a precipitant to precipitate rhenium, thereby obtaining 4.20 g of potassium perrhenate product.

[0090] Table 3 Main components of waste acid solution obtained from pyrometallurgical smelting of rhenium-containing 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), and the separation coefficients of rhenium from molybdenum and sulfur were calculated to be 184 and 410, respectively, reflecting a good separation effect of rhenium from 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 multiple of rhenium reached 7.2 times.

[0093] Example 4

[0094] A method for separating and enriching rhenium from a rhenium-containing solution in this embodiment, wherein the rhenium-containing solution is a smoke leaching liquid obtained from pyrometallurgical smelting of rhenium-containing molybdenum concentrate, comprises the following steps:

[0095] (1) A polysulfone homogeneous membrane and a polyvinylidene fluoride homogeneous membrane are respectively used to divide the electrolytic cell into a cathode chamber, an organic phase chamber and an anode chamber, 5 L of smoke leaching liquid (pH 0.1, specific composition as shown in Table 1) obtained by pyrometallurgical smelting of rhenium-containing molybdenum concentrate is added to the cathode chamber, 5 L of 1.5 mol / L sodium nitrate solution is added to the anode chamber as a supporting electrolyte, and an extractant N263, which is pre-saturated with pure ammonium rhenate solution to extract rhenium, is added to the organic phase chamber, wherein sulfonated kerosene is used as a diluent, and the volume fraction of N263 is 30%;

[0096] Insert a titanium anode and a copper cathode into the cathode chamber and anode chamber respectively, and then control the current density to 15 mA / cm by an external power supply. 2 Electrochemical separation and enrichment of rhenium are performed, and under the action of the electric field, the perrhenate in the rhenium-containing solution in the cathode chamber undergoes directional migration and is enriched in the supporting electrolyte in the anode chamber;

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

[0098] (3) Repeat step (2) until 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, then add a precipitant ammonium chloride to precipitate rhenium, thereby obtaining 13.33 g of ammonium perrhenate product.

[0099] By analyzing the composition of the main impurity ions in the rhenium-rich solution in step (3) (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, showing a good separation effect. 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 multiple 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 embodiment 1, except that in step (1), the organic reagent in the organic phase chamber is isoamyl alcohol, which is an extractant used to saturate extract rhenium in pure ammonium rhenate solution, and the diluent is kerosene, the volume fraction of isoamyl alcohol is 50%, and the current density is 5 mA / cm 2 Electrochemical separation and enrichment of rhenium was carried out under the condition of

[0102] After electrochemical separation and enrichment, the rhenium concentration in the rhenium-poor solution in the cathode chamber was 0.1 mg / L (rhenium extraction rate was 99.98%), and 500 mL of 2.35 g / L rhenium-rich solution was obtained in the anode chamber. The 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 perrhenate;

[0103] The main impurity ion concentrations in the rhenium-rich solution in the analysis step (3) are Mo 0.26 g / L and S 0.041 g / L. The calculated separation coefficients of rhenium from molybdenum and sulfur are 66.9 and 411.8, respectively, reflecting a good separation effect. In addition, compared with the rhenium concentration in the rhenium-containing solution (498 mg / L), the rhenium concentration in the rhenium-rich solution reaches 2350 mg / L, and the rhenium enrichment multiple reaches 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 embodiment 1, except that in step (1), the organic reagent in the organic phase chamber is cyclohexanone, an extractant that has been saturated with rhenium in pure ammonium rhenate solution, and the diluent is sulfonated kerosene, with a volume fraction of cyclohexanone of 60%; at a current density of 8 mA / cm 2 Electrochemical separation and enrichment of rhenium was carried out under the condition of

[0106] After electrochemical separation and enrichment, the rhenium concentration in the rhenium-lean solution in the cathode chamber is 0.05 mg / L (the extraction rate of rhenium is 99.99%), and 500 mL of 2.86 g / L rhenium-rich solution is obtained in the anode chamber. The solution is concentrated to 32.59 g / L by evaporation, and potassium chloride is added to precipitate rhenium to obtain 1.92 g of potassium perrhenate; the main impurity ion concentrations in the rhenium-rich solution are analyzed to be Mo 0.19 g / L and S 0.025 g / L, and the separation coefficients of rhenium, molybdenum and sulfur are calculated to be 111.5 and 821.9, respectively, reflecting good separation effects of rhenium-molybdenum and rhenium-sulfur; in addition, compared with the rhenium concentration in the rhenium-containing solution (498 mg / L), the rhenium concentration in the rhenium-rich solution reaches 2860 mg / L, and the enrichment multiple of rhenium reaches 5.7 times.

[0107] Example 7

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

[0109] After electrochemical separation and enrichment, the ion concentrations in the rhenium-depleted solution and the rhenium-rich solution were separated, and the separation coefficient and enrichment multiple 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] It can be seen from Table 4 that at different pH values, the electrochemical separation and enrichment method of rhenium provided by the present invention has good separation and enrichment effects, indicating that the method has a wide range of adaptability 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 by a 2 mol / L sodium sulfate solution.

[0115] After 3.5 hours of electrolysis, the ion concentrations in the cathode chamber and the anode chamber were analyzed. The concentrations of rhenium, molybdenum, and sulfur in the rhenium solution in the cathode chamber were 20 mg / L, 24454 mg / L, and 17648 mg / L, respectively, and 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 when an organic extraction system with selective extraction effect on rhenium is not added to the organic phase chamber, the effective separation of rhenium and impurity ions and the enrichment of rhenium cannot be achieved simply by relying on electric field drive.

[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 / cm 2 Electrochemical separation and enrichment of rhenium.

[0119] After 2 hours of electrolysis, the ion concentrations in the cathode chamber and the anode chamber were analyzed. The concentrations of rhenium, molybdenum and sulfur in the rhenium solution in the cathode chamber were 50 mg / L, 2463 mg / L and 3426 mg / L, respectively, and 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 reduced compared with those in Example 1.

[0120] The results show that in the process of electrochemical separation and enrichment of rhenium, it is necessary to control the appropriate current density for electrolysis to obtain better separation effect.

[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 in step (1), the volume fraction of TBP is 2%.

[0123] After electrolysis for 3.5 hours, the ion concentrations in the cathode chamber and the anode chamber were analyzed. The concentrations of rhenium, molybdenum and sulfur in the rhenium solution in the cathode chamber were 30 mg / L, 1763 mg / L and 3526 mg / L, respectively, and 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 reduced compared with those in Example 1.

[0124] The results show that a good separation effect can be achieved only when the volume fraction of the extractant is within the range of the present invention.

[0125] Comparative Example 4

[0126] A 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 preliminarily subjected to saturated extraction of rhenium in an ammonium rhenate solution, that is, only an organic reagent is added as the extractant TBP, wherein sulfonated kerosene is used as a diluent, and the volume fraction of TBP is 90%.

[0127] Since the organic extractant that has not been pre-saturated with rhenium has very poor conductivity and the voltage of the electrolysis process is very high, the electrolysis cannot be carried out effectively, thereby failing to achieve the separation of rhenium and impurity elements.

[0128] A comprehensive comparison of Example 1, Example 2, Comparative Example 1 and Comparative Example 2 shows that the good separation and enrichment effect achieved by the method for separating and enriching rhenium from a rhenium-containing solution provided by the present invention is achieved by coupling appropriate electric field drive and organic reagent extraction.

[0129] The above description is only a preferred specific implementation manner 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 any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A method for separating and enriching rhenium from a rhenium-containing solution, characterized in that: The steps include: (1) Add a rhenium-containing solution to the cathode chamber and a supporting electrolyte to the anode chamber. Under the action of the electric field, ReO4 - Directional migration occurs from the cathode chamber through the organic phase chamber into the supporting electrolyte in the anode chamber, and the organic phase chamber is added with an organic reagent for saturated extraction of rhenium; (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 replaced to continue electrochemical enrichment; (3) Repeat step (2) until the rhenium concentration in the anode chamber is greater than 1 g / L, then stop electrolysis and obtain a rhenium-rich solution at the anode.

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

3. A 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. A 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-octanol, isoamyl alcohol and cyclohexanone, and the diluent is kerosene or 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 method for separating and enriching rhenium from a rhenium-containing solution according to any one of claims 1 to 5, characterized in that: Step (3) also includes taking out the rhenium-rich solution, evaporating and concentrating it, and then adding a precipitant to obtain a perrhenate.

7. A method for separating and enriching rhenium from a rhenium-containing solution according to claim 6, characterized in that: The rhenium concentration was evaporated to a concentration of >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 ammonium salt.

9. A method for separating and enriching rhenium from a rhenium-containing solution according to any one of claims 1 to 5, characterized in that: The rhenium-containing solution is at least one of a leachate obtained from wet smelting of rhenium-containing molybdenum concentrate, a smoke leaching solution obtained from pyrometallurgy of rhenium-containing molybdenum concentrate, and a waste acid obtained from pyrometallurgy of rhenium-containing copper concentrate.

10. A 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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