Method for separating molybdenum and rhenium from molybdenum smelting waste acid by using resin

Abstract

The invention relates to the technical field of non-ferrous metal hydrometallurgy, in particular to a method for separating molybdenum and rhenium from molybdenum smelting waste acid by using resin, which comprises the following steps: adding a phosphorus source into the molybdenum smelting waste acid, and then adjusting the acidity to an acid environment in which the hydrogen ion concentration is greater than or equal to 1mol / L; molybdenum and rhenium in the molybdenum smelting waste acid with the acidity adjusted are separated through weak-base anion exchange resin, and a rhenium product with the lower molybdenum impurity content is obtained. According to the method, the phosphorus source is added into the molybdenum smelting waste acid, so that phosphate ions are hydrolyzed from the phosphorus source, molybdenum can be effectively prevented from being adsorbed by the alkalescent anion exchange resin, the selectivity of the anion exchange resin to rhenium is greatly improved, and the rhenium recovery rate and the molybdenum-rhenium separation effect are improved; the problems that in the prior art, ion exchange resin is difficult to adapt to molybdenum-rhenium separation under the high molybdenum concentration, the rhenium recovery rate is low, the rhenium-molybdenum separation effect is poor, and a high-molybdenum-concentration solution cannot be treated are solved.

Description

Technical Field

[0001] This invention relates to the field of hydrometallurgical technology for non-ferrous metals, and more particularly to a method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin. Background Technology

[0002] Rhenium, a rare dispersed metal with a high melting point, wear resistance, corrosion resistance, and stable mechanical properties, is mainly found in molybdenite and copper-rhenium sulfide ores. One of its main refining methods involves obtaining a rhenium-containing leachate through leaching, and then recovering rhenium from the leachate using ion exchange. However, the existing ion exchange method for purifying rhenium still has the following drawbacks:

[0003] On the one hand, existing ion exchange resins generally have limited adsorption capacity and are only suitable for low acid concentrations (pH>1). On the other hand, since molybdenum is a common associated element of rhenium, and rhenium and molybdenum have similar chemical properties, co-adsorption occurs during the separation of molybdenum and rhenium and the enrichment of rhenium. Especially when the hydrogen ion concentration is high (hydrogen ion concentration ≥1mol / L), molybdenum complex ions easily compete with rhenium for adsorption sites, resulting in a decrease in rhenium adsorption efficiency, a more complex subsequent separation process, a longer process flow, and a limitation on the overall recovery rate of rhenium and the separation effect of rhenium and molybdenum. Summary of the Invention

[0004] Based on the above analysis, the present invention aims to provide a method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin, which solves at least one of the problems existing in the prior art, such as the difficulty of ion exchange resins to adapt to the separation of molybdenum and rhenium under high acidity, low rhenium recovery rate, poor separation effect of rhenium and molybdenum, and inability to handle high molybdenum concentration solutions.

[0005] The objective of this invention is mainly achieved through the following technical solutions:

[0006] A method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin includes:

[0007] Add a phosphorus source to the waste acid from molybdenum smelting and adjust the acidity to an acidic environment;

[0008] Molybdenum and rhenium were separated from waste acid from molybdenum smelting after the acidity was adjusted by using a weakly basic anion exchange resin, resulting in a rhenium product with less molybdenum impurities.

[0009] Preferably, the phosphorus source is one or a combination of phosphoric acid, phosphate, and phosphorus-containing oxides; the phosphate ions obtained by hydrolysis of the phosphorus source can effectively inhibit the adsorption of molybdenum by the weakly basic anion exchange resin.

[0010] Preferably, the phosphate ions are one or more of hydrogen phosphate and dihydrogen phosphate.

[0011] Preferably, the concentration of phosphate ions in the waste acid from molybdenum smelting is 0.5 mol / L to 1.5 mol / L.

[0012] Preferably, the hydrogen ion concentration in the waste acid from molybdenum smelting is ≥1 mol / L after adjusting the acidity.

[0013] Preferably, the weakly basic anion exchange resin is a weakly basic anion exchange resin containing amine groups.

[0014] Preferably, the weakly basic anion exchange resin containing amine groups can be any one of commercially available weakly basic anion exchange resins such as RCX-5143, D301, D314, or D315.

[0015] Preferably, the method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin includes:

[0016] S1: Adjust the acidity of the molybdenum-rhenium feed solution and add a phosphorus source to obtain an acidic phosphorus-containing molybdenum-rhenium solution;

[0017] S2: The acidic phosphorus-containing molybdenum-rhenium solution obtained in step S1 is statically adsorbed using a weakly basic anion exchange resin to obtain a rhenium-rich weakly basic anion exchange resin phase and a molybdenum-rich acidic tail liquid.

[0018] S3: The rhenium-rich weakly basic anion exchange resin phase was subjected to analytical treatment to obtain a rhenium-rich eluent.

[0019] S4: The weakly basic anion exchange resin after analysis is recycled for adsorption of the acidic phosphorus-containing molybdenum-rhenium solution in step S2.

[0020] Preferably, the molybdenum-rhenium mass concentration ratio in the waste acid from molybdenum smelting in step S1 is 0.001 to 30:1.

[0021] An application of a weakly basic anion exchange resin containing amine groups includes: using the weakly basic anion exchange resin containing amine groups to separate and purify rhenium from waste acid from molybdenum smelting.

[0022] An ammonium perrhenate product is prepared by further evaporating and crystallizing the rhenium-rich eluent prepared by the above-mentioned method of separating molybdenum and rhenium from waste acid in molybdenum smelting using resin, to obtain ammonium perrhenate crystals, wherein the molybdenum content is less than 8 mg / kg.

[0023] Specifically, the molybdenum concentration in the waste acid from molybdenum smelting is ≤5g / L, and the rhenium mass concentration is ≥2mg / L.

[0024] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0025] (1) This invention uses a weakly basic anion exchange resin as the exchange resin. Due to the relatively weak basicity of its functional groups, its adsorption capacity for weakly acidic anions is relatively weak. For some difficult-to-hydrolyze anions, such as perrhenate ions (ReO4), it is less effective. - The weakly basic resin exhibits better selectivity, improving the recovery rate of rhenium and the separation effect of molybdenum and rhenium compared with existing technologies.

[0026] (2) By adding a phosphorus source to the waste acid from molybdenum smelting, the phosphorus source hydrolyzes to release phosphate ions, which can effectively inhibit the adsorption of molybdenum by weakly basic anion exchange resin, greatly improve the selectivity of the anion exchange resin for rhenium, and improve the recovery rate of rhenium and the separation effect of molybdenum and rhenium.

[0027] (3) By controlling the concentration of hydrogen ions in the waste acid from molybdenum smelting, this invention can not only inhibit the formation of heteropolyacid anions by molybdenum complexing with phosphate, thus avoiding competition with rhenium for adsorption, but also facilitate the protonation of the amino functional groups of the weakly basic anion exchange resin, transforming it into a positively charged ammonium salt.

[0028] (4) This invention utilizes a weakly basic anion exchange resin as an adsorbent and introduces phosphoric acid into an acidic solution containing rhenium and molybdenum, solving the problem of rhenium-molybdenum separation in high-acid-concentration solutions and significantly improving the adsorption rate and selectivity of rhenium. It effectively addresses the problems of traditional adsorption methods, such as the difficulty of ion exchange resins adapting to high-acid-concentration molybdenum-rhenium separation and their inability to handle high-molybdenum-concentration solutions. Under specific process conditions, the weakly basic anion exchange resin exhibits an adsorption rate of ≥95% for rhenium, reaching as high as 95.2%–98.5%, preferably 97%–98.5%, and an adsorption rate of ≤3% for molybdenum. After 10 cycles, the weakly basic anion exchange resin achieves an adsorption rate of ≥97% for rhenium and an adsorption rate of ≤3% for molybdenum. The molybdenum content in the perrhenate product is ≤8 mg / kg, preferably ≤6 mg / kg.

[0029] (5) This invention uses a weakly basic anion exchange resin as an adsorbent, introduces phosphoric acid into an acidic solution containing rhenium and molybdenum, and uses ammonia water as an eluent, which simplifies the process flow, improves the selective extraction of rhenium, reduces the co-adsorption phenomenon of molybdenum and rhenium, thereby simplifying the subsequent separation and purification steps, shortening the process flow, and improving the overall recovery rate of rhenium resources.

[0030] Other features and advantages of the 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 the invention may be realized and obtained from the embodiments described and the accompanying drawings. Attached Figure Description

[0031] Figure 1 This is a process flow diagram of one embodiment of the present invention. Detailed Implementation

[0032] 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 present invention.

[0033] On one hand, this invention discloses a method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin, comprising:

[0034] Add a phosphorus source to the waste acid from molybdenum smelting and adjust the acidity to an acidic environment;

[0035] Molybdenum and rhenium were separated from waste acid from molybdenum smelting after the acidity was adjusted by using a weakly basic anion exchange resin, resulting in a rhenium product with less molybdenum impurities.

[0036] It should be noted that rhenium exists in a stable anionic state in an acidic environment, thus enabling it to bind with weakly basic anion exchange resins. These resins, however, require protonation to acquire a positive charge, thereby adsorbing anions. Due to the relatively weak basicity of their functional groups, their adsorption capacity for weakly acidic anions is relatively weak. However, for some poorly hydrolyzed anions, such as perrhenate ions (ReO4), they can still adsorb these anions. - Weakly basic resins exhibit better selectivity.

[0037] Compared with existing technologies, this invention uses a weakly basic anion exchange resin as the exchange resin. Because its functional groups are relatively weakly basic, its adsorption capacity for weakly acidic anions is relatively weak. For some difficult-to-hydrolyze anions, such as perrhenate ions (ReO4), it is less effective. - The weakly basic resin exhibits better selectivity, improving the recovery rate of rhenium and the separation effect of molybdenum and rhenium compared with existing technologies.

[0038] The applicant's research found that after introducing a phosphorus source into the waste acid from molybdenum smelting, the phosphorus source hydrolyzes to release phosphate ions, which have a stronger binding and adsorption capacity with weakly basic anion exchange resin than the complexed anions of molybdenum, thus effectively inhibiting the adsorption of molybdenum by the ion exchange resin.

[0039] This is because: on the one hand, rhenium has a high oxidation state and tends to form stable oxyacid anions under acidic conditions. Therefore, rhenium mainly exists as high-rhenate anions (ReO4) under acidic conditions. - Molybdenum exists in the form of a complex anion, such as MoO2(SO4)2, under acidic conditions. 2- However, the binding and adsorption capacity of molybdenum complex anions to weakly basic anion exchange resins is not as strong as that of phosphate ions. Therefore, phosphate ions can effectively inhibit the adsorption of molybdenum by ion exchange resins.

[0040] On the other hand, in an acidic medium with an introduced phosphorus source, the weakly basic anion exchange resin is fully protonated and adsorbs H2PO4. - This forms a phosphorus-type weakly basic anion exchange resin. This type of resin is effective against perrhenate ions (ReO4). - The molybdenum acyl cation exhibits good exchange adsorption performance. However, the behavior of molybdenum in this system is different. This is because the waste acid from molybdenum smelting contains strong acid anions such as sulfate, chloride, and nitrate, while molybdenum acyl cations (MoO2) exhibit good exchange adsorption performance. 2+ It readily forms anionic complexes with sulfate, chloride, and nitrate ions (e.g., MoO2(SO4)2). 2- In a sulfuric acid medium without the introduction of phosphoric acid, these anionic complexes can be adsorbed by protonated resins. However, in the presence of phosphoric acid, the phosphorus adsorbed by the resin has a strong complexation with molybdenum itself, which can destroy MoO2(SO4)2. 2- The complexation of molybdenum with molybdenum leads to its existence as molybdate cations in MoO2. 2+ Rhenium cannot be adsorbed by the resin. Therefore, the introduction of phosphate and sulfate ions changed the adsorption mechanism of the resin and the occurrence form of molybdenum, selectively promoting the adsorption of rhenium and inhibiting the adsorption of molybdenum, ultimately improving the rhenium-molybdenum separation effect.

[0041] Compared with existing technologies, this invention adds a phosphorus source to the waste acid from molybdenum smelting. On the one hand, the phosphorus source hydrolyzes to release phosphate ions, which can effectively inhibit the adsorption of molybdenum by weakly basic anion exchange resin. On the other hand, phosphoric acid changes the adsorption mechanism of the resin and the occurrence form of molybdenum, selectively promoting the adsorption of rhenium and inhibiting the adsorption of molybdenum. This greatly improves the selectivity of the anion exchange resin for rhenium, thereby improving the rhenium recovery rate and the molybdenum-rhenium separation effect.

[0042] Specifically, the phosphorus source is one or a combination of phosphoric acid, phosphate, and phosphorus-containing oxides; the phosphate ions obtained by hydrolysis of the phosphorus source can be one or more of hydrogen phosphate and dihydrogen phosphate; the phosphate ions can form anions by complexing with molybdenum, such as MoO2(SO4)22- and MoO2(NO3)3-. - and MoO2Cl3 - It competes for binding sites on the anion exchange resin, thereby effectively inhibiting the adsorption of molybdenum.

[0043] Specifically, the concentration of phosphate ions obtained from the hydrolysis of phosphorus source in the waste acid of molybdenum smelting is 0.5 mol / L to 1.5 mol / L. Calculated by phosphorus atoms, the concentration of phosphate ions in the waste acid of molybdenum smelting is 0.5 mol / L, 0.6 mol / L, 0.7 mol / L, 0.8 mol / L, 0.9 mol / L, 1.0 mol / L, 1.1 mol / L, 1.2 mol / L, 1.3 mol / L, 1.4 mol / L, or 1.5 mol / L.

[0044] Preferably, the concentration of phosphate ions in the waste acid from molybdenum smelting is 0.5 mol / L to 1.0 mol / L.

[0045] Preferably, the hydrogen ion concentration in the waste acid from molybdenum smelting is ≥1 mol / L after adjusting the acidity.

[0046] It should be noted that a higher hydrogen ion concentration can inhibit the formation of heteropolyacid anions by molybdenum and phosphate complexes, thus preventing them from competing with rhenium for adsorption and facilitating the separation of molybdenum and rhenium. Simultaneously, a higher hydrogen ion concentration ensures that the weakly basic anion exchange resin is fully protonated and adsorbs H₂PO₄. - This forms a phosphorus-type weakly basic anion exchange resin that selectively adsorbs rhenium.

[0047] More preferably, the hydrogen ion concentration in the molybdenum smelting waste acid after adjusting the acidity is 1 mol / L to 3 mol / L, which can be 1.0 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, 2.0 mol / L, 2.1 mol / L, 2.2 mol / L, 2.3 mol / L, 2.4 mol / L, 2.5 mol / L, 2.6 mol / L, 2.7 mol / L, 2.8 mol / L, 2.9 mol / L, or 3.0 mol / L.

[0048] More preferably, the hydrogen ion concentration in the waste acid from molybdenum smelting is 1.5 mol / L to 3 mol / L after adjusting the acidity.

[0049] Compared with existing technologies, this invention, by controlling the hydrogen ion concentration in the waste acid from molybdenum smelting, not only inhibits the formation of heteropolyacid anions from molybdenum complexing with phosphate, thus avoiding competition with rhenium for adsorption, but also facilitates the full protonation and adsorption of H2PO4 by the weakly basic anion exchange resin. - This forms a phosphorus-type weakly basic anion exchange resin, improving rhenium recovery and molybdenum-rhenium separation efficiency.

[0050] Specifically, the weakly basic anion exchange resin is a weakly basic anion exchange resin containing amine groups.

[0051] Preferably, the weakly basic anion exchange resin containing amine groups is any one of RCX-5143, D301, D314 or D315.

[0052] The applicant's research found that the functional groups of weakly basic anion exchange resins are usually amine groups (-NH2, -NHR, -NR2). These groups only undergo protonation under acidic conditions to become positively charged, thereby adsorbing anions. Due to the weak basicity of their functional groups, their adsorption capacity for weakly acidic anions is relatively weak. However, for some difficult-to-hydrolyze anions, such as perrhenate ions (ReO4), the adsorption capacity is relatively strong. - Weakly basic resins exhibit better selectivity.

[0053] Specifically, methods for separating molybdenum and rhenium from waste acid in molybdenum smelting using resins include:

[0054] S1: Adjust the acidity of the molybdenum-rhenium feed solution and add a phosphorus source to obtain an acidic phosphorus-containing molybdenum-rhenium solution;

[0055] S2: The acidic phosphorus-containing molybdenum-rhenium solution obtained in step S1 is statically adsorbed using a weakly basic anion exchange resin to obtain a rhenium-rich weakly basic anion exchange resin phase and a molybdenum-rich acidic tail liquid.

[0056] S3: The rhenium-rich weakly basic anion exchange resin phase was subjected to analytical treatment to obtain a rhenium-rich eluent.

[0057] S4: The weakly basic anion exchange resin after analysis is recycled for adsorption of the acidic phosphorus-containing molybdenum-rhenium solution in step S2.

[0058] Specifically, the raw material liquid for molybdenum and rhenium in step S1 can be obtained by filtering out impurities from waste acid from molybdenum smelting.

[0059] Specifically, in step S1, the molybdenum-rhenium mass concentration ratio in the molybdenum smelting waste acid is 0.001:1 to 30:1, and can be 0.001:1, 0.002:1, 0.006:1, 0.008:1, 0.01:1, 0.02:1, 0.06:1, 0.08:1, 0.1:1, 0.2:1, 0.5:1, 0.8:1, 1:1, 1.5:1, 2:1, etc. 2.6:1, 3:1, 3.6:1, 5:1, 7:1, 8:1, 9:1, 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 20:1, 21:1, 22:1, 23:1, 24:1, 25:1, 26:1, 27:1, 28:1, 29:1, or 30:1.

[0060] It should be noted that the higher the molybdenum-rhenium mass concentration ratio, the stronger the interference of molybdenum on rhenium, and the greater the difficulty in achieving high rhenium recovery and good molybdenum-rhenium separation.

[0061] Specifically, in step S1, the concentration of molybdenum in the waste acid from molybdenum smelting is greater than 0.001 mg / L, and can further be greater than 500 mg / L, or even reach 5000 mg / L; the concentration of rhenium is >2 mg / L.

[0062] Compared with existing technologies, this invention uses a weakly basic anion exchange resin as an adsorbent and introduces phosphoric acid into an acidic solution containing rhenium and molybdenum, which solves the problem of rhenium-molybdenum separation in high molybdenum concentration solutions and significantly improves the adsorption rate and selectivity of rhenium. It effectively solves the problems of ion exchange resins in traditional adsorption methods being unable to adapt to the separation of molybdenum and rhenium under high molybdenum concentrations and being unable to handle high molybdenum concentration solutions.

[0063] Specifically, in step S2, the liquid-to-solid ratio (ml / g) of the waste liquid volume to the dry resin during the static adsorption process is 100 / 1 to 1 / 10, and can be 100 / 1, 90 / 1, 80 / 1, 70 / 1, 60 / 1, 50 / 1, 40 / 1, 30 / 1, 25 / 1, 10 / 1, 8 / 1, 6 / 1, 4 / 1, 2 / 1, 1 / 1, 1 / 2, 1 / 5, 1 / 8 or 1 / 10, preferably 100 / 1 to 25 / 1.

[0064] It should be noted that the liquid-to-solid ratio (mL / g) of the waste liquid to the resin directly affects the adsorption efficiency. A higher liquid-to-solid ratio (i.e., less resin) means fewer active sites available for adsorption per unit volume of solution, and vice versa.

[0065] Specifically, the adsorption temperature in step S2 is 10℃~50℃, which can be 10℃, 20℃, 30℃, 40℃ or 50℃, preferably 20℃~30℃.

[0066] It should be noted that the effect of adsorption temperature is dual: increasing the temperature can enhance the diffusion of solute molecules, thereby accelerating the adsorption rate; however, temperature can also affect the adsorption equilibrium constant, and excessively high temperatures may even damage the resin structure and reduce adsorption performance.

[0067] Specifically, the adsorption time in step S2 is 10 min to 240 min, and can be 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, 110 min, 120 min, 130 min, 140 min, 150 min, 160 min, 170 min, 180 min, 190 min, 200 min, 210 min, 220 min, 230 min or 240 min, preferably 90 min to 180 min.

[0068] It should be noted that adsorption time is also crucial. In the initial stage of adsorption, the resin has not yet reached adsorption saturation, and the adsorption amount increases with time. After adsorption equilibrium is reached, the effect of extending the adsorption time on the adsorption amount becomes negligible. The above-mentioned liquid-solid ratio, adsorption temperature, and time ensure sufficient and efficient adsorption of perrhenate ions.

[0069] Preferably, the weakly basic anion exchange resin described in step S2 needs to undergo pretreatment, including:

[0070] S201: A certain amount of resin is placed in deionized water to fully swell, and repeatedly washed to remove suspended impurities on the surface of the resin particles.

[0071] S202: Wash the resin three times in sequence with 5% NaOH or ammonia solution and 5% HCl, sulfuric acid or nitric acid solution, and then wash with deionized water until neutral.

[0072] It should be noted that the pretreatment process for weakly basic resins aims to maximize their exchange performance. Pretreatment involves soaking in NaOH solution to dissolve organic impurities inside and on the surface of the resin, and to fully expand the resin skeleton, thereby exposing more active amine functional groups. This is followed by treatment with HCl solution to remove inorganic impurities, neutralize residual alkali, and protonate the amine matrix, placing it in an exchangeable, active state. The NaOH and HCl treatments are repeated three times, alternating, to ensure thorough removal of stubborn contaminants deep within and on the surface of the resin, guaranteeing its internal and external cleanliness. Finally, the resin is repeatedly rinsed with deionized water until the effluent is neutral to prevent residual acid or alkali from interfering with the pH environment of subsequent experiments or industrial processes.

[0073] Specifically, in step S3, the liquid-to-solid ratio (ml / g) of the waste liquid volume to the dry resin during the analysis process is 10 / 1 to 2 / 1, which can be 10 / 1, 9 / 1, 8 / 1, 7 / 1, 6 / 1, 5 / 1, 4 / 1, 3 / 1 or 2 / 1, preferably 10 / 1 to 7 / 1.

[0074] It should be noted that a high liquid-to-solid ratio (i.e., a large amount of eluent) results in a large contact area between the eluent and the resin, which is beneficial for eluent removal; while a low liquid-to-solid ratio prevents the eluent from fully contacting all adsorption sites, leading to incomplete eluent removal.

[0075] Specifically, the analysis temperature in step S3 is 10℃~50℃, which can be 10℃, 20℃, 30℃, 40℃ or 50℃, preferably 20℃~30℃.

[0076] It should be noted that increasing the temperature enhances the thermal motion of molecules, promotes the desorption of perrhenate ions from the resin, and accelerates the desorption rate; however, excessively high temperatures may damage the resin structure, reduce its service life and adsorption performance.

[0077] Specifically, the parsing time in step S3 is 10 min to 180 min, which can be 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, 110 min, 120 min, 130 min, 140 min, 150 min, 160 min, 170 min, or 180 min, preferably 90 min to 150 min.

[0078] It should be noted that if the desorption time is too short, the desorption will be insufficient, resulting in a low desorption rate, which will affect resin regeneration and subsequent adsorption. As the desorption time is extended, the desorption rate gradually increases until it reaches equilibrium. After that, further extending the desorption time will not significantly increase the desorption rate. The liquid-solid ratio, desorption temperature, and desorption time described above can achieve sufficient desorption of perrhenate and effective resin regeneration.

[0079] Compared with existing technologies, this invention utilizes a weakly basic anion exchange resin as an adsorbent, introduces phosphoric acid into an acidic solution containing rhenium and molybdenum, and uses ammonia as an eluent. This simplifies the process flow, improves the selective extraction of rhenium, reduces the co-adsorption of molybdenum and rhenium, thereby simplifying subsequent separation and purification steps, shortening the process flow, and improving the overall recovery rate of rhenium resources.

[0080] It should be noted that although the steps involved in this invention, such as acid adjustment, phosphorus introduction, anion adsorption of rhenium, rhenium desorption, and resin cyclic adsorption, have been verified in static adsorption mode, these principles are also applicable to dynamic resin adsorption processes.

[0081] On the other hand, the present invention discloses an application of a weakly basic anion exchange resin containing amine groups, wherein the weakly basic anion exchange resin containing amine groups is used to separate and purify rhenium from waste acid from molybdenum smelting with a molybdenum concentration ≤5g / L and a rhenium mass concentration ≥2mg / L.

[0082] Specifically, the weakly basic anion exchange resin is a weakly basic anion exchange resin containing amine groups.

[0083] Preferably, the weakly basic anion exchange resin containing amine groups is any one of commercially available weakly basic anion exchange resins such as RCX-5143, D301, D314, or D315.

[0084] It should be noted that the functional groups of weakly basic anion exchange resins are usually amine groups (-NH2, -NHR, -NR2). These groups only undergo protonation under acidic conditions to become positively charged, thereby adsorbing anions. Due to the relatively weak basicity of their functional groups, their adsorption capacity for weakly acidic anions is relatively weak. However, for some difficult-to-hydrolyze anions, such as perrhenate ions (ReO4), they can adsorb these anions. -Weakly basic resins exhibit better selectivity.

[0085] Thirdly, the present invention also discloses an ammonium perrhenate product, wherein the rhenium-rich eluent prepared by the above-mentioned method of separating molybdenum and rhenium from waste acid of molybdenum smelting using resin is further evaporated and crystallized to obtain ammonium perrhenate crystals, wherein the molybdenum content is less than 8 mg / kg.

[0086] To further illustrate the technical solution of the present invention, the following embodiments and comparative examples are provided:

[0087] Example 1

[0088] On one hand, this embodiment discloses a method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin, comprising the following steps:

[0089] S1: After filtering out impurities from the waste acid from molybdenum smelting, the acidity of the resulting filtrate is adjusted and phosphoric acid is added to obtain a high-acidity molybdenum-rhenium solution containing phosphorus.

[0090] The molybdenum smelting waste acid is the waste acid that flows out of the spray tower after the flue gas generated during the oxidative roasting of molybdenum concentrate has been sprayed and dust removed. The concentration of molybdenum in the waste acid is 1000 mg / L, the concentration of rhenium is 50 mg / L, the acidity is adjusted to a hydrogen ion concentration of 2 mol / L, and phosphoric acid concentration of 1 mol / L is introduced.

[0091] S2: The highly acidic phosphorus-containing molybdenum-rhenium solution obtained in step S1 is contacted with a weakly basic anion exchange resin for static adsorption to obtain a rhenium-loaded resin and a molybdenum-containing acidic tail liquid.

[0092] In this study, D301 was used as the ion exchange resin. During static adsorption, the volume ratio of waste acid to dry resin (ml / g) was 50 / 1, the adsorption temperature was 25℃, and the adsorption time was 180 min. Under these conditions, the adsorption rate of rhenium reached 97.3%, while the adsorption rate of molybdenum was 1.3%. The adsorption rate α was calculated using the following formula: α(%) = (1-C / C0) × 100%, where C0 is the initial concentration of the target substance in the solution before adsorption (mg / L), and C is the concentration of the target substance in the solution after adsorption equilibrium (mg / L).

[0093] S3: The rhenium-loaded resin is desorbed using a specific desorption solution to obtain a rhenium-rich desorption solution.

[0094] The eluent used was 1 mol / L ammonia water, the liquid-to-solid ratio (ml / g, eluent / resin) during the resin eluent process was 10 / 1, the eluent temperature was 25℃, and the eluent time was 100 min. Under these conditions, the rhenium eluent efficiency was 99.1%.

[0095] The resolution β is calculated using the following formula: β(%)={C1×V1 / [(C0-C)×V0]}×100%, where C0 is the initial concentration of the target substance in the solution before adsorption (mg / L); C is the concentration of the target substance in the solution after adsorption equilibrium (mg / L); V0 is the volume of the adsorption treatment solution (L); C1 is the concentration of the target substance in the solution after desorption (mg / L); and V1 is the volume of the desorption solution (L).

[0096] S4: The resin obtained after analysis in S3 is directly used for the cyclic adsorption of the highly acidic phosphorus-containing molybdenum-rhenium solution described in S2.

[0097] The adsorption operating conditions are the same as in step S2. Under these conditions, after 10 cycles, the adsorption rate of rhenium is as high as 97.1%, while the adsorption rate of molybdenum is only 2.1%, achieving a good cycle effect.

[0098] On the other hand, this embodiment also discloses the application of a weakly basic anion exchange resin containing amine groups for separating and purifying rhenium from a molybdenum-rhenium solution with a molybdenum concentration of 1000 mg / L and a rhenium concentration of 50 mg / L.

[0099] Thirdly, this embodiment also discloses an ammonium perrhenate product, which is obtained by further evaporating and crystallizing the rhenium-rich eluent prepared by the above-mentioned method of separating molybdenum and rhenium from waste acid of molybdenum smelting using resin, wherein the molybdenum content is about 4.32 mg / kg.

[0100] Example 2

[0101] On one hand, this embodiment discloses a method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin, comprising the following steps:

[0102] S1: After filtering out impurities from the waste acid from molybdenum smelting, the acidity of the resulting filtrate is adjusted and phosphoric acid is added to obtain a high-acidity molybdenum-rhenium solution containing phosphorus.

[0103] The aforementioned waste acid from molybdenum smelting is the waste acid that flows out of the spray tower after the flue gas generated during the oxidative roasting of molybdenum concentrate has been sprayed and dust removed. The concentration of molybdenum in the waste acid is 5000 mg / L, the concentration of rhenium is 10 mg / L, the concentration of hydrogen ions is adjusted to 2 mol / L, and the concentration of phosphorus is introduced to 1 mol / L.

[0104] S2: The highly acidic phosphorus-containing molybdenum-rhenium solution obtained in step S1 is contacted with a weakly basic anion exchange resin for static adsorption to obtain a rhenium-loaded resin and a molybdenum-containing acidic tail liquid.

[0105] RCX-5143 was used as the ion exchange resin. During static adsorption, the liquid-to-solid ratio (ml / g) of the waste acid to the dry resin was 50 / 1, the adsorption temperature was 25℃, and the adsorption time was 60 min. Under these conditions, the adsorption rate of rhenium reached 95.5%, while the adsorption rate of molybdenum was 2.7%.

[0106] S3: The rhenium-loaded resin is desorbed using a specific desorption solution to obtain a rhenium-rich desorption solution.

[0107] The eluent used was 1 mol / L ammonia water, the liquid-to-solid ratio (ml / g, eluent / resin) during the resin eluent process was 10 / 1, the eluent temperature was 25℃, and the eluent time was 100 min. Under these conditions, the rhenium eluent efficiency was 98.5%.

[0108] S4: The resin obtained from the analysis in step S3 is directly used for the cyclic adsorption of the highly acidic phosphorus-containing molybdenum-rhenium solution described in S2.

[0109] The adsorption operating conditions are the same as in step S2. Under these conditions, after 10 cycles, the adsorption rate of rhenium is as high as 95.4%, while the adsorption rate of molybdenum is only 2.8%, achieving a good cycle effect.

[0110] On the other hand, this embodiment also discloses the application of a weakly basic anion exchange resin containing amine groups for separating and purifying rhenium from a molybdenum-rhenium solution with a molybdenum concentration of 1000 mg / L and a rhenium concentration of 50 mg / L.

[0111] Thirdly, this embodiment also discloses an ammonium perrhenate product, which is obtained by further evaporating and crystallizing the rhenium-rich eluent prepared by the above-mentioned method of separating molybdenum and rhenium from waste acid of molybdenum smelting using resin, wherein the molybdenum content is about 3.9 mg / kg.

[0112] Example 3

[0113] On one hand, this embodiment discloses a method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin, comprising the following steps:

[0114] S1: After filtering out impurities from the waste acid from molybdenum smelting, the acidity of the resulting filtrate is adjusted and phosphoric acid is added to obtain a high-acidity molybdenum-rhenium solution containing phosphorus.

[0115] The aforementioned waste acid from molybdenum smelting is the waste acid that flows out of the spray tower after the flue gas generated during the oxidative roasting of molybdenum concentrate has been sprayed and dust removed. The concentration of molybdenum in the waste acid is 900 mg / L, the concentration of rhenium is 40 mg / L, the concentration of hydrogen ions is adjusted to 1.5 mol / L, and the concentration of phosphorus is introduced at 0.8 mol / L.

[0116] S2: The highly acidic phosphorus-containing molybdenum-rhenium solution obtained in step S1 is contacted with a weakly basic anion exchange resin for static adsorption to obtain a rhenium-loaded resin and a molybdenum-containing acidic tail liquid.

[0117] RCX-5143 was used as the ion exchange resin. During static adsorption, the liquid-to-solid ratio (ml / g) of the waste acid to the dry resin was 50 / 1, the adsorption temperature was 25℃, and the adsorption time was 60 min. Under these conditions, the adsorption rate of rhenium reached 96.3%, while the adsorption rate of molybdenum was 1.6%.

[0118] S3: The rhenium-loaded resin is desorbed using a specific desorption solution to obtain a rhenium-rich desorption solution.

[0119] The eluent used was 0.8 mol / L ammonia water, the liquid-to-solid ratio (ml / g, eluent / resin) during the resin eluent process was 10 / 1, the eluent temperature was 25℃, and the eluent time was 100 min. Under these conditions, the rhenium eluent efficiency was 99.4%.

[0120] S4: The resin obtained from the analysis in step S3 is directly used for the cyclic adsorption of the highly acidic phosphorus-containing molybdenum-rhenium solution in step S2.

[0121] The adsorption operating conditions are the same as in step S2. Under these conditions, after 10 cycles, the adsorption rate of rhenium is as high as 97.1%, while the adsorption rate of molybdenum is only 1.2%, achieving a good cycle effect.

[0122] On the other hand, this embodiment also discloses the application of a weakly basic anion exchange resin containing amine groups for separating and purifying rhenium from a molybdenum-rhenium solution with a molybdenum concentration of 900 mg / L and a rhenium concentration of 40 mg / L.

[0123] Thirdly, this embodiment also discloses an ammonium perrhenate product, which is obtained by further evaporating and crystallizing the rhenium-rich eluent prepared by the above-mentioned method of separating molybdenum and rhenium from waste acid of molybdenum smelting using resin, wherein the molybdenum content is about 5.4 mg / kg.

[0124] Example 4

[0125] This embodiment discloses a method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin. The difference from Example 1 is that in step S1, a phosphoric acid concentration of 0.5 mol / L is introduced, while the other conditions remain the same as in Example 1. The adsorption rate of rhenium is 95.2%, while the adsorption rate of molybdenum is 1.9%. Compared to Example 1, the adsorption rate of rhenium is slightly lower.

[0126] The rhenium-rich eluent prepared by the above method of separating molybdenum and rhenium from waste acid in molybdenum smelting using resin was further evaporated and crystallized to obtain ammonium perrhenate crystals, in which the molybdenum content was about 4.1 mg / kg.

[0127] Example 5

[0128] This embodiment discloses a method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin. The difference from Example 1 is that the eluent in step S3 is 0.5 mol / L ammonia water, while the other conditions are the same as in Example 1. The adsorption rate of rhenium is 95.9%, while the adsorption rate of molybdenum is 2.1%. The rhenium eluent during the eluent removal process is 87.4%, which is lower than that in Example 1.

[0129] The rhenium-rich eluent prepared by the above method of separating molybdenum and rhenium from waste acid in molybdenum smelting using resin was further evaporated and crystallized to obtain ammonium perrhenate crystals, in which the molybdenum content was about 7.2 mg / kg.

[0130] Example 6

[0131] This embodiment discloses a method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin. The difference from Embodiment 1 is that the concentration of molybdenum in the waste acid is 5 mg / L and the concentration of rhenium is 5000 mg / L.

[0132] The rhenium-rich eluent prepared by the above method of separating molybdenum and rhenium from waste acid in molybdenum smelting using resin was further evaporated and crystallized to obtain ammonium perrhenate crystals, in which the molybdenum content was about 0.5 mg / kg.

[0133] Comparative Example 1

[0134] This comparative example discloses a method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin. The difference from Example 1 is that in step S1, the acidity of the waste acid in molybdenum smelting is adjusted to a hydrogen ion concentration of 0.5 mol / L, while the other conditions remain the same as in Example 1. The adsorption rate of rhenium is increased to 98.5%, while the adsorption rate of molybdenum is 14%. Compared to Example 2, the adsorption rate of rhenium is slightly improved, but the adsorption rate of molybdenum is significantly improved.

[0135] The rhenium-rich eluent prepared by the above method of separating molybdenum and rhenium from waste acid in molybdenum smelting using resin was further evaporated and crystallized to obtain ammonium perrhenate crystals, in which the molybdenum content was about 36.2 mg / kg.

[0136] Comparative Example 2

[0137] This comparative example discloses a method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin. The difference from Example 1 is that no phosphorus source was added in step S1, while the remaining conditions were the same as in Example 1. The adsorption rate of rhenium was 97.9%, while the adsorption rate of molybdenum was 43.3%. Compared to Example 2, the adsorption rate of rhenium was slightly improved, but the adsorption rate of molybdenum was significantly improved.

[0138] The rhenium-rich eluent prepared by the above method of separating molybdenum and rhenium from waste acid in molybdenum smelting using resin was further evaporated and crystallized to obtain ammonium perrhenate crystals, in which the molybdenum content was about 153.2 mg / kg.

[0139] Comparative Example 3

[0140] This comparative example discloses a method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin. The difference from Example 1 is that in step S3, sodium hydroxide of the same concentration is used instead of ammonia as the eluent, while the other conditions remain the same as in Example 1. The adsorption rate of rhenium is 98.8%, while the adsorption rate of molybdenum is 2.1%. Compared to Example 2, the adsorption rate of rhenium does not change significantly. The use of sodium hydroxide introduces sodium impurities, which requires an additional sodium removal step for the subsequent preparation of high-purity rhenium products, increasing the complexity of the process and hindering industrial production.

[0141] Comparative Example 4

[0142] This comparative example discloses a method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin. The difference between this comparative example and Example 1 is that a strongly basic anion exchange resin D201 is used instead of anion exchange resin D301; otherwise, the methods are the same as in Example 1. Under these conditions, the adsorption rate of rhenium is 94.6%, while the adsorption rate of molybdenum is 43.7%. Compared to Example 1, the adsorption rate of molybdenum shows a significant upward trend, which is unfavorable for the separation of rhenium and molybdenum.

[0143] The rhenium-rich eluent prepared by the above method of separating molybdenum and rhenium from waste acid in molybdenum smelting using resin was further evaporated and crystallized to obtain ammonium perrhenate crystals, in which the molybdenum content was about 152.2 mg / kg.

[0144] The results show:

[0145] In Examples 1-6, the weakly basic anion exchange resin exhibits an adsorption rate of ≥95% for rhenium under defined process conditions, reaching as high as 95.2% to 98.5%, preferably 97% to 98.5%, and an adsorption rate of ≤3% for molybdenum. After 10 cycles, the weakly basic anion exchange resin exhibits an adsorption rate of ≥97% for rhenium and an adsorption rate of ≤3% for molybdenum. The molybdenum content in the perrhenate product is ≤8 mg / kg, preferably ≤6 mg / kg.

[0146] Comparing Example 1 with Comparative Examples 1 and 2, it can be seen that the absence of any phosphorus source or the low acidity in the waste acid from molybdenum smelting leads to a significant increase in the adsorption rate of molybdenum and a significant decrease in the separation effect of molybdenum and rhenium.

[0147] Comparing Example 1 and Comparative Example 4, it is evident that replacing anion exchange resin D301 with a strongly basic anion exchange resin D201 significantly increases the molybdenum adsorption rate and noticeably reduces the molybdenum-rhenium separation efficiency. This indicates that the strongly basic anion exchange resin D201 has poor selectivity for rhenium in a strongly acidic environment. Furthermore, for further removal of molybdenum from the eluent perrhenate solution, the above method can be repeated: adjusting the eluent solution back to acidity and introducing a phosphorus source for re-adsorption and eluent removal, thus achieving a deeper removal of molybdenum from the eluent solution.

[0148] 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 method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin, characterized in that, include: Add a phosphorus source to the waste acid from molybdenum smelting and adjust the acidity to an acidic environment with a hydrogen ion concentration ≥1mol / L; Molybdenum and rhenium were separated from the waste acid of molybdenum smelting after the acidity was adjusted using a weakly basic anion exchange resin.

2. The method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin according to claim 1, characterized in that, The phosphorus source is one or a combination of phosphoric acid, phosphate, and phosphorus-containing oxides; the phosphate ions obtained by hydrolyzing the phosphorus source inhibit the adsorption of molybdenum by the weakly basic anion exchange resin.

3. The method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin according to claim 2, characterized in that, The phosphate ions are one or more of hydrogen phosphate and dihydrogen phosphate.

4. The method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin according to claim 3, characterized in that, The concentration of the phosphate ions in the waste acid from molybdenum smelting is 0.5 mol / L to 1.5 mol / L.

5. The method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin according to claim 4, characterized in that, The weakly basic anion exchange resin is a weakly basic anion exchange resin containing amine groups.

6. The method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin according to claim 5, characterized in that, The weakly basic anion exchange resin containing amine groups is a commercially available weakly basic anion exchange resin.

7. The method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin according to any one of claims 1-6, characterized in that, The method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin includes: S1: Adjust the acidity of waste acid from molybdenum smelting and add a phosphorus source to obtain an acidic molybdenum-rhenium solution containing phosphorus; S2: The acidic phosphorus-containing molybdenum-rhenium solution obtained in step S1 is statically adsorbed using a weakly basic anion exchange resin to obtain a rhenium-rich weakly basic anion exchange resin phase and a molybdenum-rich acidic tail liquid. S3: The rhenium-rich weakly basic anion exchange resin phase was subjected to analytical treatment to obtain a rhenium-rich eluent. S4: The weakly basic anion exchange resin after analysis is recycled for adsorption of the acidic phosphorus-containing molybdenum-rhenium solution in step S2.

8. The method for separating molybdenum and rhenium from waste acid in molybdenum smelting using resin according to claim 7, characterized in that, In step S1, the molybdenum-rhenium mass concentration ratio in the waste acid from molybdenum smelting is 0.001:1 to 500:

1.

9. An application of a weakly basic anion exchange resin containing amine groups, characterized in that, include: A weakly basic anion exchange resin containing amine groups was used to separate and purify rhenium from waste acid in molybdenum smelting.

10. An ammonium perrhenate product, characterized in that, The rhenium-rich eluent prepared by the method of separating molybdenum and rhenium from waste acid in molybdenum smelting using resin as described in any one of claims 1-8 is further evaporated and crystallized to obtain ammonium perrhenate crystals, wherein the molybdenum content is less than 8 mg / kg.

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