Method for synergistically extracting gallium and scandium by coupling titanium white waste acid with vanadium extraction converter sludge

Abstract

The invention relates to the technical field of hydrometallurgy production, and particularly discloses a method for synergistically extracting gallium and scandium by coupling titanium white waste acid with vanadium extraction converter sludge, which comprises the following steps: mixing titanium white waste acid and vanadium extraction converter sludge in proportion, stirring and leaching to obtain a leaching solution; adding an extraction agent and a diluent into the leaching solution for extraction, and washing to obtain a gallium and scandium loaded organic phase; a first stripping agent is added into the loaded organic phase of gallium and scandium for stripping treatment, and a gallium stripping solution and a loaded organic phase of scandium are obtained; sequentially carrying out alkali precipitation, alkali dissolution and electrolytic treatment on the gallium reverse extraction solution to obtain crude gallium; a second stripping agent is added into the scandium-loaded organic phase for stripping treatment, and a scandium precipitation solution and an organic phase solution are obtained; and the scandium precipitation solution is filtered, washed and subjected to acid dissolution, and a scandium-containing solution is obtained. According to the method, the titanium white waste acid is effectively recycled, rare and precious metals in the vanadium extraction converter sludge are efficiently and synergistically extracted, and the method has a relatively good popularization prospect.

Description

Technical Field

[0001] The invention relates to the technical field of hydrometallurgical production, and in particular to a method for synergistically extracting gallium and scandium by coupling titanium dioxide waste acid with vanadium extraction converter sludge. Background Art

[0002] During the sulfuric acid process for titanium dioxide production, a solution containing approximately 20% sulfuric acid is produced, often referred to in the industry as waste acid or 20 acid. For every ton of titanium dioxide produced, an estimated 6-8 tons of waste acid are generated. Patents such as CN110983044B, CN112429780B, and CN112458294B demonstrate that extracting scandium from titanium dioxide waste acid is a mature technology currently in industrial production. Vanadium converter sludge, a waste product generated during the smelting of vanadium-titanium magnetite, is not effectively utilized.

[0003] Extracting scandium from spent titanium dioxide acid does not effectively utilize the acid concentration of the spent titanium dioxide acid, and recovering gallium from vanadium converter sludge requires a large amount of acid to disrupt the solid phase lattice structure. The cost of extracting precious metals is generally concentrated in the acid hydrolysis and solvent extraction processes. If scandium and gallium can be extracted synergistically, the cost of extracting a single element would be significantly reduced. Therefore, research on the simultaneous recovery of scandium and gallium from spent titanium dioxide acid coupled with vanadium converter sludge is particularly important.

[0004] Based on this, the existing technology still needs to be improved. Summary of the Invention

[0005] To solve the above technical problems, an embodiment of the present invention proposes a method for synergistically extracting gallium and scandium by coupling titanium dioxide waste acid with vanadium extraction converter sludge, so as to solve the technical problem in the prior art that titanium dioxide waste acid and vanadium extraction converter sludge are not effectively utilized.

[0006] To solve the above technical problems, some embodiments of the present invention disclose a method for synergistically extracting gallium and scandium by coupling titanium dioxide waste acid with vanadium extraction converter sludge, comprising: Step 1: mixing titanium dioxide waste acid and vanadium extraction converter sludge in proportion, stirring and leaching to obtain a leaching solution; Step 2: adding an extractant and a diluent to the leaching solution for extraction and subsequent washing to obtain a gallium and scandium loaded organic phase; Step 3: adding a first stripping agent to the gallium and scandium loaded organic phase for stripping to obtain a gallium stripping solution and a scandium loaded organic phase; The gallium stripping solution is sequentially subjected to alkaline precipitation, alkaline dissolution and electrolysis to obtain crude gallium; Step 4: adding a second stripping agent to the scandium-loaded organic phase for stripping treatment to obtain a scandium precipitation solution and an organic phase solution; filtering, washing, and acid-dissolving the scandium precipitation solution to obtain a scandium-containing solution.

[0007] In some embodiments, the above method further comprises: Step 5: subjecting the scandium-containing solution to a precipitation reaction-filtration-washing-drying process to obtain scandium oxalate, which is then calcined to obtain scandium oxide.

[0008] In some embodiments, in step 1 of the above method, the amount of the titanium dioxide waste acid and the vanadium extraction converter sludge added is 3 mL-10 mL of titanium dioxide waste acid per 1 g of vanadium extraction converter sludge; and the reaction temperature is 25°C~80°C.

[0009] In some embodiments, in step 2 of the above method, the extractant is one or a mixture of two or more of P204, P507, TBP, Cyanex272, Cyanex925, and TRPO; The diluent is one or a mixture of two or more of sulfonated kerosene, aviation kerosene, xylene, cyclohexane, and n-heptane; During extraction, the concentration of the extractant is 5 vol.%-40 vol.%, and the corresponding diluent concentration is 95 vol.%-60 vol.%; the relative O / A ratio of the back extraction treatment is 1: (1~5).

[0010] In some embodiments, in step 3 of the above method, before adding the first stripping agent, the gallium and scandium loaded organic phase is washed, and the washing agent is pure water and / or a dilute acid solution.

[0011] In some embodiments, in step 3 of the above method, the first stripping agent is one or a mixture of two or more of sulfuric acid, hydrochloric acid, and nitric acid; The phase ratio O / A of the stripping treatment is 1:1-1:5.

[0012] In some embodiments, in step 3 of the above method, when the gallium stripping solution is sequentially subjected to alkaline precipitation, alkaline dissolution and electrolysis, the alkali is one or a mixture of two or more of sodium hydroxide, potassium hydroxide, calcium hydroxide, etc.

[0013] In some embodiments, in step 4 of the above method, the second stripping agent is one or a mixture of two or more of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, etc.; The phase ratio O / A of the stripping treatment is 1:1-1:5.

[0014] In some embodiments, in step 4 of the above method, the acid used for the acid dissolution is one or a mixture of two or more of hydrochloric acid, nitric acid, and sulfuric acid.

[0015] In some embodiments, in step 5 of the above method, the calcination temperature is 650-950° C., and the calcination time is 1-6 hours.

[0016] By adopting the above technical solution, the present invention has at least the following beneficial effects: The present invention provides a method for the synergistic extraction of gallium and scandium from vanadium-extracting converter sludge by coupling titanium dioxide waste acid with vanadium-extracting converter sludge. The method utilizes titanium dioxide waste acid to treat vanadium-extracting converter sludge and utilizes titanium dioxide waste acid to destroy the lattice structure of the solid phase in the vanadium-extracting converter sludge, thereby achieving the synergistic recovery of scandium and gallium resources in the vanadium-extracting converter sludge, significantly reducing the extraction cost of a single element, and realizing the effective reuse of titanium dioxide waste acid while enabling the efficient synergistic extraction of rare and precious metals in the vanadium-extracting converter sludge. The method has good promotion prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0018] Figure 1 A process flow chart of a method for synergistically extracting gallium and scandium using titanium dioxide waste acid coupled with vanadium extraction converter sludge disclosed in some embodiments of the present invention; Figure 2 This is a diagram of the crude gallium product obtained in Example 1 of the present invention; Figure 3 This is a picture of the scandium oxide product obtained in Example 1 of the present invention. DETAILED DESCRIPTION

[0019] The following embodiments of the present disclosure are further described in detail with reference to the accompanying drawings and examples. The detailed description of the following examples and the accompanying drawings are intended to illustrate the principles of the present disclosure, but are not intended to limit the scope of the present disclosure. The present disclosure can be implemented in many different forms and is not limited to the specific embodiments disclosed herein, but rather includes all technical solutions within the scope of the claims.

[0020] The present disclosure provides these embodiments in order to make this disclosure thorough and complete, and to fully convey the scope of the present disclosure to those skilled in the art. It should be noted that: unless otherwise specifically stated, the relative arrangement of parts and steps, the composition of materials, numerical expressions and numerical values ​​set forth in these embodiments should be interpreted as merely exemplary, and not as limiting.

[0021] It should be noted that, in the description of this disclosure, unless otherwise specified, "plurality" means greater than or equal to two; terms such as "upper," "lower," "left," "right," "inner," and "outer" indicating directions or positional relationships are intended solely to facilitate and simplify the description of this disclosure, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on this disclosure. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0022] In addition, the terms "first," "second," and similar terms used in this disclosure do not denote any order, quantity, or importance, but are merely used to distinguish different parts. "Perpendicular" does not mean perpendicular in the strict sense, but rather means within the tolerance range. "Parallel" does not mean parallel in the strict sense, but rather means within the tolerance range. "Include" or "comprising" and similar terms mean that the elements preceding the term include the elements listed after the term, and do not exclude the possibility of also including other elements.

[0023] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of the above terms in this disclosure depending on the specific circumstances. When a specific device is described as being located between a first device and a second device, there may or may not be an intervening device between the specific device and the first or second device.

[0024] All terms used in this disclosure have the same meaning as understood by one of ordinary skill in the art to which this disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in, for example, common dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an idealized or highly formal sense, unless explicitly defined as such herein.

[0025] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0026] like Figure 1 As shown, some embodiments of the present invention disclose a method for synergistically extracting gallium and scandium by coupling titanium dioxide waste acid with vanadium extraction converter sludge, comprising: Step 1: Titanium dioxide waste acid and vanadium-extracting converter sludge are mixed in proportion and stirred for leaching, and the titanium dioxide waste acid is used to destroy the lattice structure of the solid phase in the vanadium-extracting converter sludge at a predetermined temperature to obtain a leaching solution containing Fe, Ga and Sc; The amount of the titanium dioxide waste acid and the vanadium-extracting converter sludge added is 3 mL to 10 mL of titanium dioxide waste acid per 1 g of vanadium-extracting converter sludge; and the reaction temperature is preferably 25° C. to 80° C.

[0027] Step 2: adding an extractant and a diluent to the leaching solution for extraction and subsequent washing to obtain a gallium and scandium loaded organic phase, so that gallium and scandium elements are separated from the vanadium converter sludge, providing a prerequisite for their synergistic extraction; The extractant may be one or a mixture of two or more of P204 (di(2-ethylhexyl) phosphate), P507 (2-ethylhexyl mono-2-ethylhexyl phosphate), TBP (tributyl phosphate), Cyanex272 (di(2,4,4-trimethylpentyl)phosphinic acid), Cyanex925 (branched trialkylphosphine oxide), and TRPO (trialkylphosphine oxide); The diluent may be one or a mixture of two or more of sulfonated kerosene, aviation kerosene, xylene, cyclohexane, and n-heptane; During extraction, the concentration of the extractant is 5 vol.%-40 vol.%, and the corresponding diluent concentration is 95 vol.%-60 vol.%; the O / A ratio in the stripping treatment is preferably 1: (1-5).

[0028] Step 3: adding a first stripping agent to the gallium and scandium loaded organic phase for stripping to obtain a gallium stripping solution and a scandium loaded organic phase; Preferably, before adding the first stripping agent, the gallium and scandium loaded organic phase is washed, and the washing agent is pure water and / or a dilute acid solution.

[0029] The first stripping agent can be one of sulfuric acid, hydrochloric acid, and nitric acid, or a mixture of two or more thereof, and the O / A ratio for stripping treatment is 1:1-1:5.

[0030] When the gallium stripping solution is subjected to alkaline precipitation, alkaline dissolution and electrolysis treatment in sequence, the alkali can be one of sodium hydroxide, potassium hydroxide, calcium hydroxide, etc., or a mixture of two or more thereof.

[0031] Then, the gallium stripping solution is sequentially subjected to alkaline precipitation, alkaline dissolution and electrolysis treatment to obtain crude gallium.

[0032] Step 4: adding a second stripping agent to the scandium-loaded organic phase for stripping treatment to obtain a scandium precipitation solution and an organic phase solution; filtering, washing, and acid-dissolving the scandium precipitation solution to obtain a scandium-containing solution.

[0033] The second stripping agent may be one or a mixture of two or more selected from the group consisting of sodium hydroxide, potassium hydroxide, sodium carbonate, and sodium bicarbonate; the O / A ratio in the stripping treatment may be 1:1-1:5; and the acid used in the acid dissolution may be one or a mixture of two or more selected from the group consisting of hydrochloric acid, nitric acid, and sulfuric acid.

[0034] This embodiment utilizes titanium dioxide waste acid to treat vanadium-extracting converter sludge, and utilizes titanium dioxide waste acid to destroy the lattice structure of the solid phase in the vanadium-extracting converter sludge, thereby realizing the coordinated recovery of scandium resources and gallium resources in the vanadium-extracting converter sludge, significantly reducing the extraction cost of a single element, and realizing the effective reuse of titanium dioxide waste acid, while enabling the efficient coordinated extraction of precious metals in the vanadium-extracting converter sludge, and has good promotion prospects.

[0035] The method for synergistically extracting gallium and scandium using titanium dioxide waste acid coupled with vanadium extraction converter sludge disclosed in some embodiments of the present invention, based on the above-described embodiment, further includes step five: subjecting the scandium-containing solution to a precipitation reaction, filtration, washing, and drying process to obtain scandium oxalate, which is then calcined to obtain scandium oxide. The calcination temperature is preferably 650-950°C, and the calcination time is preferably 1-6 hours.

[0036] Example 1 Weigh 50g of vanadium-extracting sludge and place it in a beaker with a magnetic stirrer, add 150mL of titanium dioxide waste acid, set the water bath temperature to 50℃, seal the beaker and place it in the water bath for 60 minutes of stirring. After the reaction is completed, filter it and you can get a gallium leaching rate of 70%. At this time, the concentrations of gallium and scandium in the solution are 80 mg / L and 20 mg / L, respectively. In terms of volume percentage, 5%P204+5%TBP+90% sulfonated kerosene is used as the organic extractant. When O / A is 1 / 2 and the extraction time is 4min, the extraction rates of gallium and scandium are 85.3% and 89.8%, respectively. Use 0.5wt.% dilute sulfuric acid to rinse the metal-loaded organic phase to remove Fe. 2+The purpose of the experiment is to use a 10wt.% hydrochloric acid solution to strip the organic phase loaded with scandium and gallium. The process parameters are O / A 1 / 1, stripping time 5 min, gallium stripping rate 94.6%, scandium loss rate 0.25%, and 20 wt.% NaOH solution to strip the organic phase loaded with scandium. The process parameters are O / A 1 / 1, stripping time 5 min, scandium stripping rate 96.8%. Saturated sodium hydroxide solution was used to adjust the pH of the stripping gallium solution to 4.5 to obtain a gallium hydroxide sample. The gallium hydroxide sample was dissolved in 10wt.% NaOH solution to obtain a gallium solution to be electrolyzed. SUS316L was used as the anode and cathode electrode plates, and the current density was 2000 A / m 2 , the electrolysis time is 3h, and the crude gallium product can be obtained, such as Figure 2 As shown. The stripping solution containing scandium precipitate is filtered and dissolved in 2.5 mol / L hydrochloric acid solution to obtain scandium chloride solution. The pH of the solution is adjusted to about 1.5. Oxalic acid is added at 90 ° C and stirred for 30 minutes. After the solution cools to room temperature, it is filtered to obtain scandium oxalate precipitate. The scandium oxalate is placed in a muffle furnace for calcination at a temperature of 850 ° C and a calcination time of 60 minutes to obtain a scandium oxide product, as shown. Figure 3 shown.

[0037] Example 2 50g of vanadium-extraction converter sludge was weighed and placed in a beaker with a magnetic stirrer. 150mL of titanium dioxide waste acid was added, and the water bath temperature was set to 70°C. The beaker was sealed and placed in the water bath, stirring for 120 minutes. After the reaction, filtration was performed, revealing a gallium leaching yield of 90%. At this point, the concentrations of gallium and scandium in the solution were measured to be 102 mg / L and 20 mg / L, respectively. Using 10% P204, 5% TBP, and 85% sulfonated kerosene as the organic extractant, at an O / A ratio of 1 / 2 and an extraction time of 6 minutes, the extraction yields of gallium and scandium were 94.2% and 97.4%, respectively. A 10 wt.% hydrochloric acid solution was used to strip the organic phase loaded with scandium and gallium. The process parameters were O / A of 1 / 2, stripping time of 5 min, gallium stripping efficiency of 98.3%, and scandium loss rate of 0.27%. A 20 wt.% NaOH solution was used to strip the organic phase loaded with scandium. The process parameters were O / A of 1 / 2, stripping time of 5 min, and scandium stripping efficiency of 98.5%. A saturated sodium hydroxide solution was used to adjust the pH of the stripped gallium solution to 4.5 to obtain a gallium hydroxide sample. A 10 wt.% NaOH solution was used to dissolve the gallium hydroxide sample to obtain a gallium solution to be electrolyzed. SUS316L was used as the anode and cathode electrode plates, and the current density was 2500 A / m 2The electrolysis time is 3 hours to obtain a crude gallium product. The stripping solution containing the scandium precipitate is filtered and dissolved in 2.5 mol / L hydrochloric acid to obtain a scandium chloride solution. The pH of the solution is adjusted to approximately 1.5. Oxalic acid is added at 90°C and stirred for 30 minutes. After the solution cools to room temperature, it is filtered to obtain a scandium oxalate precipitate. The scandium oxalate is calcined in a muffle furnace at 850°C for 60 minutes to obtain a scandium oxide product.

[0038] Example 3 Weigh 50g of vanadium-extracting converter sludge and place it in a beaker with a magnetic stirrer, add 200mL of titanium dioxide waste acid, set the water bath temperature to 50℃, seal the beaker and place it in the water bath to stir for 60 minutes. After the reaction is completed, filter it and you can get a gallium leaching rate of 82%. At this time, the concentrations of gallium and scandium in the solution are 70.28 mg / L and 20mg / L, respectively. In terms of volume percentage, 15% P204+5% TBP+80% sulfonated kerosene is used as the organic extractant. When O / A is 1 / 2 and the extraction time is 4min, the extraction rates of gallium and scandium are 98.6% and 99.3%, respectively. Use 0.5wt.% dilute sulfuric acid to rinse the metal-loaded organic phase to remove Fe. 2+ The purpose of the experiment is to use a 5wt.% hydrochloric acid solution to strip the organic phase loaded with scandium and gallium. The process parameters are O / A of 1 / 2, stripping time of 5 min, gallium stripping rate of 85.6%, and scandium loss rate of 0.15%. A 10 wt.% NaOH solution is used to strip the organic phase loaded with scandium. The process parameters are O / A of 1 / 2, stripping time of 5 min, and scandium stripping rate of 88.5%. A saturated sodium hydroxide solution is used to adjust the pH of the stripping gallium solution to 4.5 to obtain a gallium hydroxide sample. A 10wt.% NaOH solution is used to dissolve the gallium hydroxide sample to obtain a gallium solution to be electrolyzed. SUS316L is used as the anode and cathode electrode plates, and the current density is 2750 A / m 2 The electrolysis time is 3 hours to obtain a crude gallium product. The stripping solution containing the scandium precipitate is filtered and dissolved in 2.5 mol / L hydrochloric acid to obtain a scandium chloride solution. The pH of the solution is adjusted to approximately 1.5. Oxalic acid is added at 90°C and stirred for 30 minutes. After the solution cools to room temperature, it is filtered to obtain a scandium oxalate precipitate. The scandium oxalate is calcined in a muffle furnace at 850°C for 60 minutes to obtain a scandium oxide product.

[0039] Example 4 Weigh 50g of vanadium-extracting converter sludge and place it in a beaker with a magnetic stirrer, add 300mL of titanium dioxide waste acid, set the water bath temperature to 50℃, seal the beaker and place it in the water bath to stir for 120 minutes. After the reaction is completed, filter it and you can get a gallium leaching rate of 98.6%. At this time, the concentrations of gallium and scandium in the solution are 56.33 mg / L and 20mg / L, respectively. In terms of volume percentage, 15%P204+5%TBP+80% sulfonated kerosene is used as the organic extractant. When O / A is 1 / 2 and the extraction time is 4min, the extraction rates of gallium and scandium are 95.6% and 97.8%, respectively. Use 0.5wt.% dilute sulfuric acid to rinse the metal-loaded organic phase to remove Fe. 2+ The purpose of the experiment is to use a 5wt.% hydrochloric acid solution to strip the organic phase loaded with scandium and gallium. The process parameters are O / A of 1 / 2, stripping time of 5 min, gallium stripping rate of 85.6%, and scandium loss rate of 0.15%. A 15 wt.% NaOH solution is used to strip the organic phase loaded with scandium. The process parameters are O / A of 1 / 2, stripping time of 5 min, and scandium stripping rate of 93.4%. A saturated sodium hydroxide solution is used to adjust the pH of the stripping gallium solution to 4.5 to obtain a gallium hydroxide sample. A 10wt.% NaOH solution is used to dissolve the gallium hydroxide sample to obtain a gallium solution to be electrolyzed. SUS316L is used as the anode and cathode electrode plates, and the current density is 2750 A / m 2 The electrolysis time is 3 hours to obtain a crude gallium product. The stripping solution containing the scandium precipitate is filtered and dissolved in 2.5 mol / L hydrochloric acid to obtain a scandium chloride solution. The pH of the solution is adjusted to approximately 1.5. Oxalic acid is added at 90°C and stirred for 30 minutes. After the solution cools to room temperature, it is filtered to obtain a scandium oxalate precipitate. The scandium oxalate is calcined in a muffle furnace at 850°C for 60 minutes to obtain a scandium oxide product.

[0040] Example 5 Weigh 50g of vanadium-extracting converter sludge and place it in a beaker with a magnetic stirrer, add 500mL of titanium dioxide waste acid, set the water bath temperature to 80℃, seal the beaker and place it in the water bath to stir for 1 minute. After the reaction is completed, filter it and you can get a gallium leaching rate of 99.6%. At this time, the concentrations of gallium and scandium in the solution are 43.89mg / L and 20mg / L respectively. In terms of volume percentage, 10% P507 + 5% Cyanex272 + 2% Cyanex925 + 3% TRPO + 30% aviation kerosene + 30% xylene + 20% cyclohexane are used as organic extractants. When O / A is 1 / 5 and the extraction time is 3 minutes, the extraction rates of gallium and scandium are 86.8% and 88.5% respectively. Use 0.5wt.% dilute sulfuric acid to rinse the metal-loaded organic phase to remove Fe. 2+ The purpose of the experiment is to use a 5wt.% hydrochloric acid solution to strip the organic phase loaded with scandium and gallium. The process parameters are O / A of 1:1, stripping time of 5 min, gallium stripping rate of 87%, and scandium loss rate of 0.21%. A 15 wt.% NaOH solution is used to strip the organic phase loaded with scandium. The process parameters are O / A of 1:1, stripping time of 5 min, and scandium stripping rate of 90.26%. A saturated sodium hydroxide solution is used to adjust the pH of the stripping gallium solution to 4.5 to obtain a gallium hydroxide sample. A 10wt.% NaOH solution is used to dissolve the gallium hydroxide sample to obtain a gallium solution to be electrolyzed. SUS316L is used as the anode and cathode electrode plates, and the current density is 2750 A / m 2 The electrolysis time is 3 hours to obtain a crude gallium product. The stripping solution containing the scandium precipitate is filtered and dissolved in 2.5 mol / L hydrochloric acid to obtain a scandium chloride solution. The pH of the solution is adjusted to approximately 1.5. Oxalic acid is added at 90°C and stirred for 30 minutes. After the solution cools to room temperature, it is filtered to obtain a scandium oxalate precipitate. The scandium oxalate is calcined in a muffle furnace at 650°C for 360 minutes to obtain a scandium oxide product.

[0041] Example 6 Weigh 50g of vanadium-extracting converter sludge and place it in a beaker with a magnetic stirrer, add 150mL of titanium dioxide waste acid, set the water bath temperature to 25℃, seal the beaker and place it in the water bath to stir for reaction for min. After the reaction is completed, filter it and the gallium leaching rate can be obtained to be 78%. At this time, the concentrations of gallium and scandium in the solution are 90.65mg / L and 20mg / L respectively. In terms of volume percentage, 5% Cyanex272+7% Cyanex925+8% TRPO+30% sulfonated kerosene+20% xylene+30% n-heptane are used as organic extractants. When O / A is 1 / 1 and the extraction time is 4min, the extraction rates of gallium and scandium are 84.6% and 86.3% respectively. Use 0.5wt.% dilute sulfuric acid to rinse the metal-loaded organic phase to remove Fe. 2+ The purpose of the experiment is to use a 5wt.% hydrochloric acid solution to strip the organic phase loaded with scandium and gallium. The process parameters are O / A of 1:5, stripping time of 5min, gallium stripping rate of 90.85%, and scandium loss rate of 0.18%. A 15wt.% NaOH solution is used to strip the organic phase loaded with scandium. The process parameters are O / A of 1:5, stripping time of 5min, and scandium stripping rate of 93.63%. A saturated sodium hydroxide solution is used to adjust the pH of the stripping gallium solution to 4.5 to obtain a gallium hydroxide sample. A 10wt.% NaOH solution is used to dissolve the gallium hydroxide sample to obtain a gallium solution to be electrolyzed. SUS316L is used as the anode and cathode electrode plates, and the current density is 2750 A / m 2 The electrolysis time is 3 hours to obtain a crude gallium product. The stripping solution containing the scandium precipitate is filtered and dissolved in 2.5 mol / L hydrochloric acid to obtain a scandium chloride solution. The pH of the solution is adjusted to approximately 1.5. Oxalic acid is added at 90°C and stirred for 30 minutes. After the solution cools to room temperature, it is filtered to obtain a scandium oxalate precipitate. The scandium oxalate is calcined in a muffle furnace at 950°C for 120 minutes to obtain a scandium oxide product.

[0042] Thus far, various embodiments of the present disclosure have been described in detail. To avoid obscuring the concept of the present disclosure, some details known in the art have not been described. Based on the above description, those skilled in the art can fully understand how to implement the technical solutions disclosed herein.

[0043] Although some specific embodiments of the present disclosure have been described in detail through examples, those skilled in the art will understand that the above examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Those skilled in the art will understand that the above embodiments may be modified or some technical features may be replaced with equivalents without departing from the scope and spirit of the present disclosure. In particular, as long as there are no structural conflicts, the various technical features mentioned in the various embodiments may be combined in any manner.

Claims

1. A method for synergistically extracting gallium and scandium by coupling titanium dioxide waste acid with vanadium extraction converter sludge, characterized in that: include: Step 1: mixing titanium dioxide waste acid and vanadium extraction converter sludge in proportion, stirring and leaching to obtain a leaching solution; Step 2: adding an extractant and a diluent to the leaching solution for extraction and subsequent washing to obtain a gallium and scandium loaded organic phase; Step 3: adding a first stripping agent to the gallium and scandium loaded organic phase for stripping to obtain a gallium stripping solution and a scandium loaded organic phase; The gallium stripping solution is sequentially subjected to alkaline precipitation, alkaline dissolution and electrolysis to obtain crude gallium; Step 4: adding a second stripping agent to the scandium-loaded organic phase for stripping to obtain a scandium precipitation solution and an organic phase solution; The scandium precipitation solution is filtered, washed, and acid-dissolved to obtain a scandium-containing solution.

2. The method for synergistically extracting gallium and scandium by coupling titanium dioxide waste acid with vanadium extraction converter sludge according to claim 1, characterized in that: Also includes: Step 5: subjecting the scandium-containing solution to a precipitation reaction-filtration-washing-drying process to obtain scandium oxalate, which is then calcined to obtain scandium oxide.

3. The method for synergistically extracting gallium and scandium by coupling titanium dioxide waste acid with vanadium extraction converter sludge according to claim 1, characterized in that: In step 1, the amount of the titanium dioxide waste acid and the vanadium extraction converter sludge added is 3 mL-10 mL of titanium dioxide waste acid per 1 g of vanadium extraction converter sludge; and the reaction temperature is 25° C. to 80° C.

4. The method for synergistically extracting gallium and scandium by coupling titanium dioxide waste acid with vanadium extraction converter sludge according to claim 1, characterized in that: In step 2, the extractant is one or a mixture of two or more of P204, P507, TBP, Cyanex272, Cyanex925, and TRPO; The diluent is one or a mixture of two or more of sulfonated kerosene, aviation kerosene, xylene, cyclohexane, and n-heptane; During extraction, the concentration of the extractant is 5 vol.%-40 vol.%, and the corresponding diluent concentration is 95 vol.%-60 vol.%; the relative O / A ratio of the back extraction treatment is 1: (1~5).

5. The method for synergistically extracting gallium and scandium by coupling titanium dioxide waste acid with vanadium extraction converter sludge according to claim 1, characterized in that: In step three, before adding the first stripping agent, the gallium and scandium loaded organic phase is washed, and the washing agent is pure water and / or a dilute acid solution.

6. The method for synergistically extracting gallium and scandium by coupling titanium dioxide waste acid with vanadium extraction converter sludge according to claim 1, characterized in that: In step 3, the first stripping agent is one or a mixture of two or more of sulfuric acid, hydrochloric acid, and nitric acid; The phase ratio O / A of the stripping treatment is 1:1-1:

5.

7. The method for synergistically extracting gallium and scandium by coupling titanium dioxide waste acid with vanadium extraction converter sludge according to claim 1, characterized in that: In step 3, when the gallium stripping solution is subjected to alkaline precipitation, alkaline dissolution and electrolysis treatment in sequence, the alkali is one or a mixture of two or more of sodium hydroxide, potassium hydroxide, calcium hydroxide and the like.

8. The method for synergistically extracting gallium and scandium by coupling titanium dioxide waste acid with vanadium extraction converter sludge according to claim 1, characterized in that: In step 4, the second stripping agent is one or a mixture of two or more of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, etc.; The phase ratio O / A of the stripping treatment is 1:1-1:

5.

9. The method for synergistically extracting gallium and scandium by coupling titanium dioxide waste acid with vanadium extraction converter sludge according to claim 1, characterized in that: In step 4, the acid used for the acid dissolution is one or a mixture of two or more of hydrochloric acid, nitric acid, and sulfuric acid.

10. The method for synergistically extracting gallium and scandium by coupling titanium dioxide waste acid with vanadium extraction converter sludge according to claim 2, characterized in that: In step 5, the calcination temperature is 650-950° C., and the calcination time is 1-6 hours.

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