A method for green conversion of tartaric acid decomposition residue of scheelite and efficient recovery of tartaric acid and tungsten

Abstract

The present invention belongs to the field of green smelting and comprehensive utilization of secondary resources of tungsten, and specifically relates to a method for green conversion of tartaric acid decomposition residue of scheelite to efficiently recover tartaric acid and tungsten. The method first prepares the tartaric acid decomposition residue of scheelite into a slurry, then adds sulfuric acid for room-temperature green conversion, converting calcium tartrate into calcium sulfate while releasing tartaric acid. The released tartaric acid and the tungsten remaining in the decomposition residue undergo secondary dissolution, followed by filtration and washing to achieve solid-liquid separation. The resulting solid is calcium sulfate, which can be used to prepare building materials. The concentrated material is filtered and subjected to resin adsorption to recover tungsten, resulting in a sodium tungstate solution that is returned to the main tungsten smelting process. The residual solution from the resin adsorption is then re-prepared as a leaching agent for scheelite, thereby achieving the recycling of tartaric acid. The method achieves green conversion of tartaric acid decomposition residue of scheelite while efficiently recovering tartaric acid and tungsten, providing a new method for green resource utilization of tartaric acid decomposition residue of scheelite.

Description

Technical Field

[0001] The present invention belongs to the field of green smelting and comprehensive utilization of secondary resources of tungsten, and particularly relates to a method for green conversion of tartaric acid decomposition slag of scheelite and efficient recovery of tartaric acid and tungsten. Background Art

[0002] As a pillar material of the modern industrial system, tungsten plays an irreplaceable role in key areas such as electronic component manufacturing, precision chemical synthesis, and medical equipment production.

[0003] While the most widely used high-temperature alkaline autoclave process can extract tungsten, its inherent drawbacks include: high temperature and high pressure operating conditions lead to accelerated equipment corrosion and increased energy consumption, while the resulting alkaline leaching residue is difficult to recycle. To overcome the bottlenecks of this traditional process, a new technique, tartaric acid room-temperature decomposition, has been developed. By introducing tartaric acid into an acidic medium, it has successfully achieved room-temperature dissociation of the tungsten-calcium chemical bond in scheelite. However, this process faces two technical obstacles in its industrialization: first, tartaric acid combines with calcium ions during the reaction to form a stable calcium tartrate solid phase, resulting in unintended consumption of the active reagent; second, 0.3% to 1.0% of WO3 remains in the final decomposition residue, which is not effectively extracted.

[0004] Direct landfill disposal of tartaric acid decomposition residue from scheelite not only wastes tungsten-containing resources and organic reagents, but also poses potential ecological risks, such as the slow decomposition of calcium tartaric acid in the natural environment, which could alter the physical and chemical properties of the soil. Existing decomposition residue recovery technologies have significant shortcomings: strong acid leaching, requiring high-concentration corrosive acid, exacerbates equipment wear; high-temperature roasting, while recovering tungsten, irreversibly damages the tartaric acid molecular structure, hindering its recycling pathway; and bioleaching, limited by the poor environmental adaptability of microorganisms, has yet to overcome the technical and economic bottlenecks of industrial application.

[0005] Solving the technical challenges of green recycling tartaric acid decomposition slag from scheelite will directly improve the overall economic efficiency and environmental friendliness of the tartaric acid decomposition process. Therefore, establishing an efficient, low-carbon technology system for resource utilization of decomposition slag has become an urgent need to promote the clean transformation of the tungsten metallurgical industry. Summary of the Invention

[0006] In order to solve the problems of green conversion of tartaric acid decomposition slag of scheelite and efficient recovery and utilization of tartaric acid and tungsten in the slag, the present invention provides a method for green conversion of tartaric acid decomposition slag of scheelite and efficient recovery of tartaric acid and tungsten.

[0007] The embodiment of the present invention provides a method for green conversion of tartaric acid decomposition residue of scheelite and efficient recovery of tartaric acid and tungsten, comprising the following steps:

[0008] S1. Preparing slurry: placing tartaric acid decomposition residue of scheelite in a reactor, adding tap water and stirring to prepare slurry;

[0009] S2, room temperature green conversion: gradually add sulfuric acid to the slurry obtained in step S1 and stir, the conversion temperature is 20°C to 35°C, after the conversion is completed, the converted slurry is obtained and enter the next step;

[0010] S3, Filtration and Washing: After step S2 is completed, the converted slurry is filtered, and the obtained concentrated conversion material is collected for standby use. The converted slag is washed twice again. The residual liquid of the first washing is collected and used for the next slurry preparation. The residual liquid of the second washing is collected and partly used as the first washing water for the next filtration step, and partly collected for treatment;

[0011] S4, resin adsorption recovery of tungsten: The conversion concentrate obtained in step S3 is subjected to dynamic adsorption using a simulated exchange column. The residual liquid containing tartaric acid after adsorption is collected and sent to the next step. The tungstate solution obtained by desorption on the loaded resin is collected and returned to the main tungsten smelting process;

[0012] S5. Secondary preparation and recycling: The tartaric acid adsorption residual liquid obtained in step S4 is placed in a dissolver and stirred, and then a sample is taken to analyze the concentration of tartaric acid and calculate the amount of solid tartaric acid to be added, and a secondary dissolution preparation is performed. The prepared tartaric acid solution is returned to the decomposition link of the scheelite.

[0013] As a preference in some embodiments of the present invention, in step S1, the liquid-to-solid ratio of tap water to tartaric acid decomposition slag of scheelite is 4:1 mL / g to 10:1 mL / g.

[0014] As preferred in some embodiments of the present invention, in step S2, the conversion time is 3 h to 6 h, and the stirring speed is 60 r / min to 120 r / min.

[0015] As preferred in some embodiments of the present invention, in step S2, when the concentration of sulfate in the supernatant of the slurry is ≥0.5 mol / L, the conversion is completed and the addition of sulfuric acid is stopped.

[0016] As a preference in some embodiments of the present invention, in step S3, the amount of tap water used for the first washing is 4 to 10 times the weight of the original tartaric acid decomposition residue of the scheelite, and the amount of tap water used for the second washing is 4 to 10 times the weight of the original tartaric acid decomposition residue of the scheelite.

[0017] As a preference in some embodiments of the present invention, in step S4, the simulated exchange column is filled with D318 resin, and the ratio of the diameter of the simulated exchange column to the height of the resin layer is 1:6 to 1:12.

[0018] As a preference in some embodiments of the present invention, in step S4, when WO3 in the adsorption residual solution is ≥ 0.01 g / L, the adsorption is stopped.

[0019] As a preference in some embodiments of the present invention, in step S4, the desorbent is NaOH solution or dilute ammonia solution, the concentration of which is controlled to be 80 g / L to 100 g / L, and sodium tungstate solution or ammonium tungstate solution is obtained by desorption.

[0020] As a preference in some embodiments of the present invention, in step S5, stirring is performed for 10 min to 30 min, and the stirring speed is controlled to be 60 r / min to 120 r / min.

[0021] As a preference in some embodiments of the present invention, in step S5, the concentration of the tartaric acid prepared by secondary dissolution is controlled to be 120 g / L to 180 g / L.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. Environmentally friendly and efficient resource recycling: Through a room-temperature sulfuric acid conversion reaction, calcium tartrate in the tartaric acid decomposition residue of scheelite is converted into calcium sulfate (a harmless byproduct that can be directly used in building materials production). This simultaneously releases tartaric acid and secondary dissolves residual tungsten, achieving efficient recovery of both tartaric acid and tungsten. The entire process involves no high temperature, high pressure, or hazardous reagents, significantly reducing waste emissions and alleviating the environmental burden.

[0024] 2. Economic efficiency and resource recycling: The staged washing residual liquid reuse technology is adopted, and the washing water and adsorption residual liquid are used in the slurry preparation, filtration and scheelite decomposition stages respectively, realizing the recycling of tartaric acid and significantly reducing the consumption of fresh reagents. The resin adsorption method accurately recovers tungsten, and after desorption, sodium tungstate or ammonium tungstate solution is directly obtained, which can be returned to the main smelting process, reducing production costs and improving the comprehensive utilization rate of resources.

[0025] 3. Process Simplification and Industrial Compatibility: Based on room-temperature reaction conditions and conventional equipment, the process is simple and energy-efficient, avoiding complex, energy-intensive processes. The secondary dissolution of tungsten from the conversion slag is highly efficient, and the conversion rate of calcium tartrate is near complete. This not only solves the conversion and disposal issues of tartaric acid decomposition slag from scheelite, but also allows for the recovery of tartaric acid and residual tungsten from the decomposition slag, achieving efficient resource utilization of tartaric acid decomposition slag from scheelite. The technology is stable and easily scalable, providing an efficient and sustainable solution for green scheelite smelting. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific implementation of the present invention or the technical solutions in the prior art, the drawings required for describing the specific implementation or the prior art will be briefly introduced below. Obviously, the drawings described below are only one implementation of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 This is a schematic diagram of the process flow of an embodiment of the present application;

[0028] Figure 2 This is an EDS analysis result diagram of tartaric acid decomposition residue of scheelite in the embodiment of the present application;

[0029] Figure 3 This is the EDS analysis result of the conversion slag of Example 1 of the present application;

[0030] Figure 4 This is the EDS analysis result of the conversion slag of Example 2 of the present application;

[0031] Figure 5 This is the EDS analysis result of the conversion slag in Example 3 of the present application. DETAILED DESCRIPTION

[0032] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the technical solutions in the specific implementation methods of the present invention are clearly and completely described below to further illustrate the present invention. Obviously, the specific implementation methods described are only part of the implementation methods of the present invention, rather than all styles.

[0033] The embodiments of the present application provide a method for green conversion of tartaric acid decomposition residue of scheelite and efficient recovery of tartaric acid and tungsten, thereby solving the problems of wasteful landfill and difficult recycling of tartaric acid decomposition residue of scheelite in the prior art. By constructing a collaborative recovery system of slurry preparation-normal temperature conversion-filtration separation-resin adsorption-circulation, the tartaric acid decomposition residue of scheelite is converted at normal temperature to achieve a phase transition of calcium tartrate to calcium sulfate and release bound tartaric acid, and a tungstate solution for reuse in the main process can be obtained through desorption.

[0034] The technical solution in the embodiment of the present application is to solve the above-mentioned recycling difficulties, and the overall idea is as follows:

[0035] like Figure 1 As shown in the figure, the decomposition slag is first prepared into slurry and then introduced into sulfuric acid for room temperature conversion. The core reaction is: C4H4CaO 6(s) +2H2O (aq) +H2SO 4(aq) →CaSO4·2H2O (s) +C4H6O 6(aq) , achieving the physical transformation of calcium tartrate to calcium sulfate and releasing bound tartaric acid. At the same time, the residual calcium tungstate (CaWO4) reacts with free tartaric acid for a secondary reaction: CaWO 4(s) +2C4H6O 6(aq) + 4H2O = C4H4CaO6·4H2O (S)+H2WO4(C4H6O6), the newly generated calcium tartrate can further react with sulfuric acid to achieve deep tungsten leaching. Efficient solid-liquid separation is achieved through graded filtration and washing. The converted liquid is selectively adsorbed by D318 resin, and desorption yields a tungstate solution that can be directly reused in the main process. The adsorption residue, rich in tartaric acid, is returned to the initial decomposition process after concentration control, forming a complete material recycling system.

[0036] In order to better understand the above technical solution, the above technical solution is described in detail below with specific implementation methods.

[0037] Source of raw materials: tartaric acid decomposition residue of scheelite, which is a mixture of multiple batches of washing residues produced by the decomposition of scheelite by tartaric acid at room temperature. After low-temperature drying and ball milling, the residue is prepared into a dry powder sample for standby use. The sample is tested by weight method. The WO3 content in the decomposition residue is 0.91%. The decomposition residue was characterized by EDS. The results are shown in the figure. Figure 2 .Depend on Figure 2 It can be seen that the distribution contents of O, C, Ca, W, Cl, S and Na elements in the decomposition slag are 59.83%, 22.38%, 16.74%, 0.97%, 0.07%, 0% and 0%, respectively.

[0038] Example 1: This example is a method for green conversion of tartaric acid decomposition residue of scheelite and efficient recovery of tartaric acid and tungsten. The specific steps are as follows:

[0039] S1. Prepare slurry: Weigh 200 g of the tartaric acid decomposition residue of scheelite, place it in a 2000 ml glass beaker, add tap water at a liquid-solid ratio of 5:1 mL / g, and stir to prepare slurry;

[0040] S2. Room-temperature green conversion: Sulfuric acid is gradually added to the slurry obtained in step S1. The conversion time is controlled to 6 hours, the stirring speed is 60 r / min, and the conversion temperature is room temperature (25°C, using a water bath to maintain temperature balance). At the end of the conversion process, the concentration of sulfate in the supernatant of the conversion slurry is 0.67 mol / L. The conversion is completed and the converted slurry is obtained, and the next step is entered;

[0041] S3, filtration and washing: After step S2 is completed, the room temperature green conversion slurry is filtered and washed. First, the conversion slurry is filtered. After the filtration is completed, the obtained conversion concentrate is collected for use (after testing, the volume of the conversion concentrate is 945 ml, the WO3 concentration is 1.85 g / L, and the tartaric acid concentration is 113.90 g / L). The conversion slag is washed twice again. In the first washing, the amount of tap water used is 5 times the weight of the original tartaric acid decomposition slag of the scheelite. The first washing residue is collected and used for the next preparation of the slurry. In the second washing, the amount of tap water used is 5 times the weight of the original tartaric acid decomposition slag of the scheelite. The second washing residue is collected, part of which is used as the first washing water for the next filtration step, and part is collected for treatment. The final conversion slag was dried at 105°C for 6 hours, and then weighed to 166.20 g. The WO3 analysis showed that it was 0.05%. The conversion slag was characterized by EDS, and the results are shown in the table. Figure 3 .Depend on Figure 3 The content of O, Ca, S, C, W, Cl, and Na in the conversion slag is 49.08%, 29.09%, 21.66%, 0.11%, 0.04%, 0.02%, and 0%, respectively. Compared with the element distribution in the tartaric acid decomposition slag of scheelite, the C content decreases from 22.38% to 0.11%, and the W content decreases from 0.97% to 0.04%. The secondary dissolution rate of WO3 based on the slag is 95.43%, and the calcium tartrate conversion rate is 99.59% based on the C content in the slag before and after conversion (calculation formula: WO3 secondary dissolution rate = (1-(0.05% × 166.20 ÷ 0.91% ÷ 200)) × 100%; tartaric acid conversion rate = (1-(0.11% × 166.20 ÷ 22.38% ÷ 200)) × 100%).

[0042] S4. Tungsten recovery by resin adsorption: The conversion concentrate obtained in step S3 is subjected to dynamic adsorption using a simulated exchange column (column specifications: φ2cm × 70cm). The adsorption column is filled with D318 resin, and the ratio of the simulated column diameter to the resin layer height is 1:6. When adsorption is complete, the volume of the adsorbed residual liquid is 936ml, and adsorption is stopped. The adsorption residual liquid containing tartaric acid is collected and transferred to the next step. The loaded resin is desorbed using a dilute ammonia solution with a concentration controlled at 100g / L. The ammonium tungstate solution obtained by desorption (tested to have a WO3 concentration of 92.36g / L) is collected and returned to the main tungsten smelting process.

[0043] S5. Secondary preparation and recycling: The adsorption residual liquid containing tartaric acid obtained in step S3 is placed in a dissolver and stirred for 30 minutes at a stirring speed of 120 r / min. The amount of solid tartaric acid to be added is calculated based on the concentration of tartaric acid (tested, WO3 is 0.001 g / L and the tartaric acid concentration is 111.61 g / L). In this embodiment, 49.97 g of solid tartaric acid is required based on a concentration of 165.0 g / L. Secondary dissolution and preparation are then carried out. After the preparation is completed, the final tartaric acid concentration is 164.12 g / L. The prepared tartaric acid solution is returned to the decomposition step of the scheelite.

[0044] Example 2: This example is a method for green conversion of tartaric acid decomposition residue of scheelite and efficient recovery of tartaric acid and tungsten. The specific steps are as follows:

[0045] S1. Prepare slurry: Weigh 200 g of the tartaric acid decomposition residue of scheelite, place it in a 2000 ml glass beaker, add tap water at a liquid-solid ratio of 6:1 mL / g, and stir to prepare slurry;

[0046] S2. Room-temperature green conversion: Sulfuric acid is gradually added to the slurry obtained in step S1. The conversion time is controlled to 6 hours, the stirring speed is 80 r / min, and the conversion temperature is room temperature (25°C, using a water bath to maintain temperature balance). At the end of the conversion process, the concentration of sulfate in the supernatant of the conversion slurry is 0.58 mol / L. After the conversion is completed, a conversion slurry is obtained and the process proceeds to the next step.

[0047] S3, filtration and washing: After step S2 is completed, the room temperature green conversion slurry is filtered and washed. First, the conversion slurry is filtered. After the filtration is completed, the obtained conversion concentrate is collected for use (after testing, the volume of the conversion concentrate is 1145 ml, the WO3 concentration is 1.56 g / L, and the tartaric acid concentration is 94.12 g / L), and then washed twice. In the first washing, the amount of tap water used is 6 times the weight of the original tartaric acid decomposition slag of the scheelite. The first washing residue is collected and used for the next preparation of the slurry. In the second washing, the amount of tap water used is 6 times the weight of the original tartaric acid decomposition slag of the scheelite. The second washing residue is collected, part of which is used as the first washing water for the next filtration step, and part is collected for treatment. The final conversion slag was dried at 105°C for 6 hours, and then weighed to 167.30 g. The WO3 analysis showed that it was 0.01%. The conversion slag was characterized by EDS, and the results are shown in the table. Figure 4 .Depend on Figure 4The content of O, Ca, S, C, W, Cl, and Na in the conversion slag is 49.49%, 29.27%, 21.08%, 0.16%, 0%, 0%, and 0%, respectively. Compared with the element distribution in the tartaric acid decomposition slag of scheelite, the C content decreases from 22.38% to 0.16%, and the W content decreases from 0.97% to 0.01%. The secondary dissolution rate of WO3 based on the slag is 99.08%, and the calcium tartrate conversion rate, calculated based on the C content in the slag before and after conversion, is 99.40% (calculation formula: WO3 secondary dissolution rate = (1-(0.01% × 167.30 ÷ 0.91% ÷ 200)) × 100%; tartaric acid conversion rate = (1-(0.16% × 167.30 ÷ 22.38% ÷ 200)) × 100%).

[0048] S4: Resin adsorption to recover tungsten. The conversion concentrate obtained in step S3 is subjected to dynamic adsorption using a simulated exchange column (column dimensions: φ2cm x 70cm). The column is packed with D318 resin, with a ratio of 1:6 between the column diameter and the resin layer height. Upon completion of adsorption, the residual adsorption liquid volume is 1147ml. The tartaric acid-containing residual adsorption liquid is collected and transferred to the next step. The loaded resin is desorbed using NaOH solution at a controlled concentration of 80g / L. The resulting sodium tungstate solution (tested to have a WO3 concentration of 85.45g / L) is collected and returned to the main tungsten smelting process.

[0049] S5. Secondary preparation and recycling: The tartaric acid-containing adsorption residual liquid obtained in step S4 is placed in a dissolver and stirred for 25 minutes at a stirring speed of 100 r / min. The amount of solid tartaric acid to be added is calculated based on the concentration of tartaric acid (tested, WO3 is 0.001 g / L, and the tartaric acid concentration is 94.48 g / L). In this embodiment, 46.48 g of solid tartaric acid is required to be added based on a concentration of 135.0 g / L. Secondary dissolution and preparation are then carried out. After the preparation is completed, the final tartaric acid concentration is 135.31 g / L. The prepared tartaric acid solution is returned to the decomposition step of the scheelite.

[0050] Example 3: This example is a method for green conversion of tartaric acid decomposition residue of scheelite and efficient recovery of tartaric acid and tungsten. The specific steps are as follows:

[0051] S1. Prepare slurry: Weigh 200 g of the tartaric acid decomposition residue of scheelite, place it in a 2000 ml glass beaker, add tap water at a liquid-solid ratio of 4:1 mL / g, and stir to prepare slurry;

[0052] S2. Room-temperature green conversion: Sulfuric acid is gradually added to the slurry obtained in step S1. The conversion time is controlled to 5 hours, the stirring speed is 100 r / min, and the conversion temperature is room temperature (25°C, using a water bath to maintain temperature balance). At the end of the conversion process, the concentration of sulfate in the supernatant of the conversion slurry is 0.75 mol / L. After the conversion is completed, a conversion slurry is obtained and the process proceeds to the next step.

[0053] S3, filtration and washing: After step S2 is completed, the room temperature green conversion slurry is filtered and washed. First, the conversion slurry is filtered. After the filtration is completed, the obtained conversion concentrate is collected for use (after testing, the volume of the conversion concentrate is 755 ml, the WO3 concentration is 2.36 g / L, and the tartaric acid concentration is 142.74 g / L), and then washed twice. In the first washing, the amount of tap water used is 4 times the weight of the original tartaric acid decomposition slag of the scheelite. The first washing residue is collected and used for the next preparation of the slurry. In the second washing, the amount of tap water used is 4 times the weight of the original tartaric acid decomposition slag of the scheelite. The second washing residue is collected, part of which is used as the first washing water for the next filtration step, and part is collected for treatment. The final conversion slag was dried at 105°C for 6 hours, and then weighed to 168.46 g. The WO3 analysis showed that it was 0.03%. The conversion slag was characterized by EDS, and the results are shown in the table. Figure 5 .Depend on Figure 5 The content of O, Ca, S, C, W, Cl, and Na in the conversion slag is 48.67%, 29.49%, 21.30%, 0.54%, 0%, 0%, and 0%, respectively. Compared with the element distribution in the decomposition slag, the content of C decreases from 22.38% to 0.54%, and the content of W decreases from 0.97% to 0.03%. The secondary dissolution rate of WO3 based on the slag is 97.22%, and the conversion rate of calcium tartaric acid is 97.97% based on the C content in the slag before and after conversion (calculation formula: secondary dissolution rate of WO3 = (1-(0.03% × 168.46 ÷ 0.91% ÷ 200)) × 100%; conversion rate of tartaric acid = (1-(0.54% × 168.46 ÷ 22.38% ÷ 200)) × 100%).

[0054] S4, Resin Adsorption Recovery of Tungsten: The conversion concentrate obtained in step S3 is subjected to dynamic adsorption using a simulated exchange column (column dimensions: φ2cm x 70cm). The column is packed with D318 resin, with a ratio of 1:6 between the column diameter and the resin layer height. Upon completion of adsorption, the residual adsorption liquid volume is 746ml. The tartaric acid-containing residual adsorption liquid is collected and transferred to the next step. The loaded resin undergoes desorption using a NaOH solution at a controlled concentration of 100g / L. The resulting sodium tungstate solution (tested to have a WO3 concentration of 96.71g / L) is collected and returned to the main tungsten smelting process.

[0055] S5. Secondary preparation and recycling: The tartaric acid-containing adsorption residual liquid obtained in step S4 is placed in a dissolver and stirred for 20 minutes at a stirring speed of 80 r / min. The amount of solid tartaric acid to be added is calculated based on the concentration of tartaric acid (tested, WO3 is 0.001 g / L, and the tartaric acid concentration is 139.36 g / L). In this embodiment, 4.21 g of solid tartaric acid is required based on a concentration of 145.0 g / L. Secondary dissolution and preparation are then carried out. After the preparation is completed, the final tartaric acid concentration is 144.89 g / L. The prepared tartaric acid solution is returned to the decomposition step of the scheelite.

[0056] The above describes the main technical features and basic principles of the present invention and the related advantages. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments and that the present invention can be implemented in other specific forms without departing from the concept or essential characteristics of the present invention. Therefore, from all perspectives, the above-mentioned specific embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the foregoing description, and it is intended that all changes that come within the meaning and range of equivalents of the claims be included within the present invention.

[0057] In addition, it should be understood that although this specification is described according to various implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation method can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A method for green conversion of tartaric acid decomposition residue of scheelite and efficient recovery of tartaric acid and tungsten, characterized in that: The steps include: S1. Preparing slurry: placing tartaric acid decomposition residue of scheelite in a reactor, adding tap water and stirring to prepare slurry; S2, room temperature green conversion: gradually add sulfuric acid to the slurry obtained in step S1 and stir, the conversion temperature is 20°C to 35°C, after the conversion is completed, the converted slurry is obtained and enter the next step; S3, Filtration and Washing: After step S2 is completed, the converted slurry is filtered, and the obtained concentrated conversion material is collected for standby use. The converted slag is washed twice again. The residual liquid of the first washing is collected and used for the next slurry preparation. The residual liquid of the second washing is collected and partly used as the first washing water for the next filtration step, and partly collected for treatment; S4, resin adsorption recovery of tungsten: The conversion concentrate obtained in step S3 is subjected to dynamic adsorption using a simulated exchange column. The residual liquid containing tartaric acid after adsorption is collected and sent to the next step. The tungstate solution obtained by desorption on the loaded resin is collected and returned to the main tungsten smelting process; S5, secondary preparation and recycling: the tartaric acid adsorption residual liquid obtained in step S4 is placed in a dissolver and stirred, and then a sample is taken to analyze the concentration of tartaric acid and calculate the amount of solid tartaric acid to be added, and a secondary dissolution preparation is performed. The prepared tartaric acid solution is returned to the decomposition stage of the scheelite; In step S2, the conversion time is 3 h to 6 h, and the stirring speed is 60 r / min to 120 r / min; when the concentration of sulfate ions in the supernatant of the slurry is ≥0.5 mol / L, the conversion is completed and the addition of sulfuric acid is stopped.

2. The method for green conversion and efficient recovery of tartaric acid and tungsten from tartaric acid decomposition residue of scheelite according to claim 1 is characterized in that: In step S1, the liquid-to-solid ratio of tap water to tartaric acid decomposition residue of scheelite is 4:1 mL / g to 10:1 mL / g.

3. The method for green conversion and efficient recovery of tartaric acid and tungsten from tartaric acid decomposition residue of scheelite according to claim 1 is characterized in that: In step S3, the amount of tap water used for the first washing is 4 to 10 times the weight of the original tartaric acid decomposition residue of scheelite, and the amount of tap water used for the second washing is 4 to 10 times the weight of the original tartaric acid decomposition residue of scheelite.

4. The method for green conversion and efficient recovery of tartaric acid and tungsten from tartaric acid decomposition residue of scheelite according to claim 1 is characterized in that: In step S4, the simulated exchange column is filled with D318 resin, and the ratio of the diameter of the simulated exchange column to the height of the resin layer is 1:6 to 1:

12.

5. The method for green conversion and efficient recovery of tartaric acid and tungsten from tartaric acid decomposition residue of scheelite according to claim 1 is characterized in that: In step S4, when WO3 in the adsorption residual solution is ≥ 0.01 g / L, the adsorption is stopped.

6. The method for green conversion and efficient recovery of tartaric acid and tungsten from tartaric acid decomposition residue of scheelite according to claim 1 is characterized in that: In step S4, the desorbent is NaOH solution or dilute ammonia solution, the concentration of which is controlled to be 80 g / L to 100 g / L, and sodium tungstate solution or ammonium tungstate solution is obtained by desorption.

7. The method for green conversion and efficient recovery of tartaric acid and tungsten from tartaric acid decomposition residue of scheelite according to claim 1 is characterized in that: In step S5, stirring is performed for 10 min to 30 min, and the stirring speed is controlled to be 60 r / min to 120 r / min.

8. The method for green conversion and efficient recovery of tartaric acid and tungsten from tartaric acid decomposition residue of scheelite according to claim 1 is characterized in that: In step S5, the concentration of the tartaric acid prepared by the secondary dissolution is controlled to be 120 g / L to 180 g / L.

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