Method for preparing soluble vanadate phase with high vanadium enrichment rate through cooling-roasting coordinated regulation and control of vanadium slag

Abstract

The invention discloses a method for preparing a soluble vanadate phase with a high vanadium enrichment rate through vanadium slag cooling-roasting coordinated regulation and control, and belongs to the technical field of resource circulation valuable metal separation and extraction. According to the method, the industrial vanadium slag is placed in a tubular furnace, the temperature is increased to be higher than 1600 DEG C, high-temperature vanadium slag obtained by smelting vanadium titano-magnetite in a blast furnace or high-temperature vanadium slag obtained by smelting vanadium-containing molten iron in a converter is simulated, the temperature is reduced to 1000-1600 DEG C, heat preservation is conducted, the content of V2O3 in a spinel phase in the vanadium slag is reduced, and separation of an olivine phase and an alloy phase is inhibited; carrying out solid phase treatment by adopting water quenching to obtain water-quenched slag; and drying and crushing the water-quenched slag, mixing the crushed water-quenched slag with calcium oxide, and carrying out oxidizing roasting to obtain a soluble vanadate phase. According to the method, guidance can be provided for cooling and roasting of the vanadium extraction secondary resource vanadium slag, the roasted vanadium slag is more beneficial to follow-up vanadium extraction treatment, and the vanadium extraction efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of resource recycling and valuable metal separation and extraction technology, specifically relating to a method for preparing a soluble vanadate phase with high vanadium enrichment by synergistic regulation of vanadium slag cooling-roasting. Background Technology

[0002] Vanadium is widely used in metallurgy, energy, chemical industry, aerospace and other fields due to its positive effects on mechanical properties, corrosion resistance and catalytic properties. Vanadium is abundant in natural mineral resources, mainly including vanadium-titanium magnetite, vanadium mica, and vanadium-lead ore. However, most vanadium is extracted from secondary resources such as coal shale, vanadium-containing slag, and used catalysts. Among these, vanadium-containing slag, due to its high vanadium content, is the main secondary resource for vanadium extraction. Currently, vanadium-containing slag produced during blast furnace ironmaking and electric arc furnace steelmaking is the main resource for vanadium extraction, accounting for more than 40% of vanadium-containing products. The mainstream processing technology for vanadium slag is currently roasting-assisted leaching, including sodium roasting-water leaching, calcium roasting-acid leaching, salt-free roasting-alkali leaching, magnesium roasting-acid leaching, and manganese roasting-acid leaching. Industrially, sodium roasting-water leaching and calcium roasting-acid leaching are mainly used to extract vanadium from vanadium-containing slag.

[0003] The main phases of vanadium slag include spinel, olivine, liquid phase, and alloy phase. Vanadium mainly exists in the liquid phase and vanadium spinel, where its structure is destroyed during roasting, forming soluble vanadates. Subsequent processes such as leaching, precipitation, and calcination yield vanadium-containing products. Compared to the liquid phase, due to the ultra-stability of vanadium spinel, the efficiency of its transformation into soluble vanadates during roasting becomes a key factor in evaluating the vanadium extraction efficiency of vanadium slag during roasting.

[0004] The existing technology for controlling vanadium slag mainly involves introducing different amounts of calcium oxide for roasting, followed by cooling under different conditions to promote the formation of soluble vanadates from vanadium and other metal oxides such as calcium oxide. This method firstly requires consuming more calcium oxide, and secondly, it has extremely strict cooling regimes for the cooling process of the roasted product, with a long cooling time and high technical requirements. In addition, this method inevitably leaves free calcium oxide residues, which affect the vanadium extraction efficiency in the subsequent acid leaching process. Summary of the Invention

[0005] To address the problems of low vanadium extraction efficiency and complex processes in existing technologies for vanadium slag, the present invention aims to provide a method for preparing a soluble vanadate phase with high vanadium enrichment by synergistic regulation of vanadium slag cooling and roasting. This method regulates the cooling process of vanadium slag to directionally control its phase composition and components, and, combined with further regulation in the subsequent calcification and roasting process, achieves the enrichment of V2O5 in the soluble vanadate phase, thereby improving the vanadium extraction efficiency of subsequent leaching.

[0006] To achieve the above-mentioned technical objectives, this invention provides a method for preparing a soluble vanadate phase with high vanadium enrichment by synergistic control of vanadium slag cooling and roasting. The method involves placing industrial vanadium slag in a tubular furnace and heating it to above 1600°C to simulate the high-temperature vanadium slag obtained by smelting vanadium-titanium magnetite in a blast furnace or the high-temperature vanadium slag obtained by smelting vanadium-containing molten iron in a converter. The slag is then cooled to 1000-1600°C and held at this temperature to reduce the V2O3 content in the spinel phase and inhibit the precipitation of olivine and alloy phases. Subsequently, water quenching is used to solidify the phase, yielding water-quenched slag. This water-quenched slag is then dried, crushed, mixed with calcium oxide, and subjected to oxidative roasting to obtain the final product.

[0007] This invention proposes a novel process for preparing soluble vanadate phases with high vanadium enrichment through a synergistic control of vanadium slag cooling and roasting. The key lies in the dual effects of cooling phase control and roasting control, thereby regulating the distribution of vanadium in different phases within the vanadium slag. Specifically, the inventors discovered that using different cooling regimes during the cooling process yields vanadium slags with varying phase compositions and distributions. In the process of this invention, the cooling process aims to minimize the formation of a stable spinel phase from V₂O₃ and suppress the precipitation of other phases to maintain the reactivity of the vanadium slag, effectively improving the efficiency of subsequent roasting. Pre-heating with controlled rate is beneficial for accurate phase control in vanadium slag, and the temperature range of the holding temperature has a significant impact on the phase composition of vanadium slag. At 1600℃ water quenching, only spinel and liquid phases exist, exhibiting high reactivity. Olivine begins to precipitate at 1400℃, reducing reactivity, and because the olivine phase does not fully grow, it will continue to grow during subsequent roasting, consuming energy. At 1200℃ water quenching, alloy, olivine, liquid, and spinel phases coexist in the slag, further reducing reactivity. Within the temperature range selected in this invention, as the temperature decreases, the V2O3 content in the spinel phase decreases, and is lower than the V2O3 content in the spinel phase of the original industrial vanadium slag. At this point, water quenching can fix the desired vanadium slag phase, preventing further changes. Subsequent roasting with calcium oxide can further form Fe2O3 solid solution, SiO2 solid solution, Fe2TiO5, and vanadate, achieving V2O5 enrichment in the soluble vanadate phase. The insulation temperature is further preferred to be 1200~1600℃, and even more preferred to be 1400~1600℃.

[0008] As a preferred embodiment, the heat preservation time is 30-90 minutes. Within the heat preservation time selected in this invention, the uniform distribution of each component in the vanadium slag can be ensured, while simultaneously promoting the full transformation of each phase.

[0009] The industrial vanadium slag used in this invention contains olivine, liquid phase, alloy phase and spinel phase simultaneously.

[0010] As a preferred embodiment, the heating rate and the cooling rate are both 5~10℃ / min.

[0011] As a preferred embodiment, the phases of the water-quenched slag include spinel, olivine, liquid phase, and alloy phase.

[0012] As a preferred option, the amount of calcium oxide added is determined based on the V₂O₃ content in the vanadium slag, with a CaO to V₂O₃ mass ratio of 0.5 to 0.7. The CaO includes the original CaO present in the vanadium slag.

[0013] As a preferred embodiment, when cooling to a temperature greater than 1400℃ and less than or equal to 1600℃ for holding, the oxidation roasting conditions are: temperature 850~900℃, holding time 30~120min, and atmosphere of nitrogen and oxygen mixture; when cooling to a temperature of 1000~1400℃ for holding, the oxidation roasting conditions are: temperature 850~900℃, holding time 60~120min, and atmosphere of nitrogen and oxygen mixture. The oxidation roasting process converts vanadium into soluble vanadate. If the roasting time is too short or the temperature is too low, the final product will contain spinel, olivine, and free CaO residues, indicating incomplete roasting and affecting subsequent vanadium extraction. Within the scope of this invention, appropriately extending the time and increasing the temperature is beneficial for increasing the V2O5 content and reducing the impurity content in the soluble vanadate phase. A further preferred time is 100~120min. Furthermore, the applicable heat preservation time varies depending on the temperature. When using a higher temperature, the heat preservation time can achieve a better control effect even with a shorter time.

[0014] As a preferred embodiment, the water-quenched slag must be added to the tubular furnace after it has been heated to a preset roasting temperature before oxidative roasting. This method allows for precise control of the roasting time.

[0015] As a preferred embodiment, the sample is immediately removed and air-cooled to room temperature at the end of the oxidation roasting holding time. Air cooling in this invention allows the sample to cool down rapidly after the roasting holding time, preventing the furnace temperature from further affecting the phase composition.

[0016] As a preferred embodiment, the soluble vanadate phase contains more than 54 wt% V2O5 and less than 12 wt% impurities.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) This invention proposes a novel process for preparing soluble vanadate phases with high vanadium enrichment by synergistic regulation of vanadium slag cooling-roasting. By synergistic effect of cooling phase regulation and roasting regulation, the distribution of vanadium in different phases is regulated, thereby achieving the enrichment of vanadium in soluble vanadate phases and improving the vanadium extraction efficiency of subsequent leaching.

[0019] (2) The present invention reduces the V2O3 content in the spinel phase of vanadium slag and inhibits the precipitation of olivine phase and alloy phase by temperature control and cooling system. At the same time, it combines water quenching cooling to solidify the phase, which is beneficial to maintain the reactivity of vanadium slag and the enrichment of vanadium in the subsequent calcination roasting process.

[0020] (3) The present invention adopts the method of first cooling and regulating the phase in the vanadium slag and then calcining and roasting to convert it into acid-soluble vanadate. At the same time, the amount of calcium oxide added is controlled to avoid the presence of free calcium oxide after roasting, which will not affect the vanadium extraction efficiency in the subsequent vanadium slag leaching process. Attached Figure Description

[0021] Figure 1 This is a comparison diagram of the physical composition of the water-quenched slag obtained at different temperatures and the original slag in Example 1.

[0022] Figure 2 This is a comparison diagram of the morphology of the water-quenched slag obtained at different temperatures and the original slag in Example 1.

[0023] Figure 3 The morphology and phase composition of the 1600℃ water-quenched slag in Example 2 after calcination at 900℃ for 30 minutes are shown.

[0024] Figure 4 The morphology and phase composition of the 1600℃ water-quenched slag in Example 3 after calcination at 900℃ for 120 min are shown.

[0025] Figure 5 The morphology and phase composition of the 1400℃ water-quenched slag in Example 4 after calcination at 900℃ for 120 min are shown.

[0026] Figure 6 The morphology and phase composition of the 1200℃ water-quenched slag in Example 5 after calcination at 900℃ for 120 min are shown.

[0027] Figure 7 The morphology and phase composition of the slag quenched at 1400℃ in Comparative Example 1 after being roasted at 900℃ for 30 minutes are shown.

[0028] Figure 8 The morphology and phase composition of the 1200℃ water-quenched slag in Comparative Example 2 after calcination at 900℃ for 30 minutes are shown.

[0029] Figure 9 The morphology and phase composition of the raw residue in Comparative Example 3 after calcination at 900℃ for 30 min are shown.

[0030] Figure 10 The morphology and phase composition of the slag quenched at 1600℃ in Comparative Example 4 after being roasted at 800℃ for 120 minutes are shown.

[0031] Figure 11 The morphology and phase composition of the slag quenched at 1400℃ in Comparative Example 5 after being roasted at 800℃ for 120 min are shown.

[0032] Figure 12 The morphology and phase composition of the 1200℃ water-quenched slag in Comparative Example 6 after calcination at 800℃ for 120 min are shown.

[0033] Figure 13 The morphology and phase composition of the raw residue in Comparative Example 7 after calcination at 800℃ for 120 min are shown.

[0034] Figure 14 The morphology and phase composition of the raw residue in Comparative Example 8 after calcination at 900℃ for 120 min are shown. Detailed Implementation

[0035] The following specific embodiments are intended to further illustrate the content of this invention, rather than to limit the scope of protection of the claims. Unless otherwise specified, all pharmaceutical agents used are commercially available conventional products.

[0036] Example 1

[0037] This embodiment provides an experiment to investigate the temperature during the cooling process of vanadium slag, specifically:

[0038] S1: Load industrial vanadium slag into a platinum crucible and place it in the isothermal zone of a vertical tube furnace that can be quenched; introduce argon gas at a flow rate of 400 ml / min; set the tube furnace to heat to a temperature greater than 1600℃ at a heating rate of 10℃ / min, and then cool to 1600℃, 1400℃ and 1200℃ respectively at a cooling rate of 10℃ / min, and hold at the corresponding temperatures for 60 min; the argon gas should be introduced for no less than 30 min before the heating begins;

[0039] S2: After the heat preservation is completed, the sample is rapidly quenched (water quenched) to obtain vanadium slag with four different phase compositions (including the original vanadium slag that has not been cooled and regulated).

[0040] The slags after water quenching were dried and named 1600℃ water-quenched slag, 1400℃ water-quenched slag, and 1200℃ water-quenched slag, respectively. XRD phase and SEM-EPMA morphology and composition analyses were performed on the three types of water-quenched slags and industrial vanadium slag (referred to as raw slag). The XRD results of the four types of slags are as follows: Figure 1 As shown, the microstructure is as follows Figure 2 As shown.

[0041] As shown in the figure, in the slag quenched at 1600℃, only spinel and liquid phase exist, exhibiting high reactivity. Olivine begins to precipitate at 1400℃, with decreasing reactivity. When the water quenching temperature drops to 1200℃, the morphology and phase composition of the quenched slag are similar to the original slag, further reducing reactivity. The composition of the spinel phase in the four types of slags is listed in Table 1. It can be seen that as the water quenching temperature decreases, the V2O3 content in the spinel phase decreases, and is lower than that in the original slag. This is beneficial for vanadium enrichment during subsequent roasting. Therefore, during the cooling process of vanadium slag, controlling the phase composition and maintaining high reactivity through temperature-controlled cooling combined with water quenching can improve the subsequent roasting efficiency.

[0042]

[0043] Example 2

[0044] This embodiment provides a method for preparing a soluble vanadate phase with high vanadium enrichment by oxidative roasting of slag quenched at 1600℃. Specifically:

[0045] S1: Place CaO and V2O3 in an agate grinding bowl at a mass ratio of 0.6 (including the original CaO in the vanadium slag) and grind them thoroughly to make them evenly mixed;

[0046] S2: Place the obtained mixture sample in an MgO crucible. After heating the tube furnace used for calcination to the set temperature, introduce a mixture of N2 (80%) and O2 (20%) gas. Once the gas stabilizes, place the MgO crucible containing the mixture sample to be calcined into the constant temperature zone of the tube furnace for heat preservation. The oxidation calcination temperature is 900℃, and the holding time is 30 minutes.

[0047] S3: After the heat preservation is completed, immediately remove the MgO crucible and air cool it to room temperature.

[0048] After cooling, the samples were subjected to XRD phase analysis and SEM-EPMA morphology and quantitative phase composition analysis. The results of SEM morphology analysis and XRD phase analysis are as follows: Figure 3 As shown, after the 1600℃ water-quenched slag is oxidized and roasted at 900℃ for 30 minutes, there are no original spinel, olivine, liquid phase, alloy phase and free CaO residues. Instead, Fe2O3 solid solution, SiO2 solid solution, Fe2TiO5 and vanadate are generated, and the roasting reaction is complete.

[0049] The quantitative analysis results of vanadate composition are listed in Table 2. It can be seen that under these calcination conditions, the V2O5 content in vanadate is 54.806 wt%, and the impurity content is 9.203 wt% (the sum of Fe2O3, Cr2O3, TiO2, Al2O3 and SiO2).

[0050]

[0051] Example 3

[0052] The other conditions in this embodiment are the same as in embodiment 2, except that the oxidation calcination time is 120 min.

[0053] XRD phase analysis and SEM-EPMA morphology and quantitative phase composition analysis of the calcined samples were performed. The results of SEM morphology analysis and XRD phase analysis are shown below. Figure 4 As shown, after the 1600℃ water-quenched slag is calcined at 900℃ for 120 min, there are no original spinel, olivine, liquid phase, alloy phase and free CaO residues. Instead, Fe2O3 solid solution, SiO2 solid solution, Fe2TiO5 and vanadate are generated, and the calcination reaction is complete.

[0054] The quantitative analysis results of the vanadate composition are shown in Table 2. It can be seen that under this calcination condition, the V2O5 content in the vanadate is 55.534 wt%, and the impurity content is 8.909 wt%.

[0055] Example 4

[0056] The other conditions in this embodiment are the same as in embodiment 3, except that the 1600℃ water-quenched slag is replaced with an equal amount of 1400℃ water-quenched slag.

[0057] XRD phase analysis and SEM-EPMA morphology and quantitative phase composition analysis of the calcined samples were performed. The results of SEM morphology analysis and XRD phase analysis are shown below. Figure 5 As shown, after the 1400℃ water-quenched slag is oxidized and roasted at 900℃ for 120 min, there are no original spinel, olivine, liquid phase, alloy phase and free CaO residues. Instead, Fe2O3 solid solution, SiO2 solid solution, Fe2TiO5 and vanadate are generated, and the roasting reaction is complete.

[0058] The quantitative analysis results of the vanadate composition are listed in Table 2. It can be seen that under these calcination conditions, the V2O5 content in the vanadate is 54.736 wt%, and the impurity content is 9.764 wt%.

[0059] Example 5

[0060] The other conditions in this embodiment are the same as in embodiment 3, except that the 1600℃ water-quenched slag is replaced with an equal amount of 1200℃ water-quenched slag.

[0061] XRD phase analysis and SEM-EPMA morphology and quantitative phase composition analysis of the calcined samples were performed. The results of SEM morphology analysis and XRD phase analysis are shown below. Figure 6As shown, after the 1200℃ water-quenched slag is oxidized and roasted at 900℃ for 120 min, there are no original spinel, olivine, liquid phase, alloy phase and free CaO residues. Instead, Fe2O3 solid solution, SiO2 solid solution, Fe2TiO5 and vanadate are generated, and the roasting reaction is complete.

[0062] The quantitative analysis results of the vanadate composition are listed in Table 2. It can be seen that under these calcination conditions, the V2O5 content in the vanadate is 54.194 wt%, and the impurity content is 11.238 wt%.

[0063] Comparative Example 1

[0064] The conditions for this comparative example were the same as in Example 4, except that the oxidative calcination time was 30 min. XRD phase analysis and SEM morphology analysis of the calcined samples were performed. The results of the SEM morphology analysis and XRD phase analysis are shown below. Figure 7 As shown, after the 1400℃ water-quenched slag was oxidized and roasted at 900℃ for 30 minutes, there were still original spinel, olivine and free CaO residues, indicating that the roasting reaction was incomplete.

[0065] Comparative Example 2

[0066] The conditions for this comparative example were the same as in Example 5, except that the oxidative calcination time was 30 min. XRD phase analysis and SEM morphology analysis of the calcined samples were performed. The results of the SEM morphology analysis and XRD phase analysis are as follows: Figure 8 As shown, it can be seen that after the 1200℃ water-quenched slag is oxidized and roasted at 900℃ for 30 minutes, there are still original olivine and free CaO residues, indicating that the roasting reaction is incomplete.

[0067] Comparative Example 3

[0068] The conditions for this comparative example were the same as in Example 2, except that the 1600℃ water-quenched slag was replaced with an equal amount of the original slag. XRD phase analysis and SEM morphology analysis of the calcined samples were performed. The results of the SEM morphology analysis and XRD phase analysis are as follows: Figure 9 As shown, after the original slag was oxidized and roasted at 900℃ for 30 minutes, there were still original olivine and free CaO residues, indicating that the roasting reaction was incomplete.

[0069] Comparative Example 4

[0070] The conditions for this comparative example were the same as in Example 3, except that the oxidative calcination temperature was 800℃. XRD phase analysis and SEM morphology analysis of the calcined samples were performed. The results of the SEM morphology analysis and XRD phase analysis are shown below. Figure 10 As shown, after the 1600℃ water-quenched slag is roasted at 800℃ for 120 minutes, there are still original spinel, liquid phase and free CaO residues, indicating that the roasting reaction is incomplete.

[0071] Comparative Example 5

[0072] The conditions for this comparative example were the same as in Example 4, except that the oxidative calcination temperature was 800℃. XRD phase analysis and SEM morphology analysis of the calcined samples were performed. The results of the SEM morphology analysis and XRD phase analysis are shown below. Figure 11 As shown, after the 1400℃ water-quenched slag was roasted at 800℃ for 120 minutes, there were still original spinel, olivine and free CaO residues, indicating that the roasting reaction was incomplete.

[0073] Comparative Example 6

[0074] The conditions for this comparative example were the same as in Example 5, except that the oxidative calcination temperature was 800℃. XRD phase analysis and SEM morphology analysis of the calcined samples were performed. The results of the SEM morphology analysis and XRD phase analysis are shown below. Figure 12 As shown, after the 1200℃ water-quenched slag was roasted at 800℃ for 120 minutes, there were still original spinel, olivine and free CaO residues, indicating that the roasting reaction was incomplete.

[0075] Comparative Example 7

[0076] The conditions for this comparative example were the same as those for Comparative Example 6, except that the 1200℃ water-quenched slag was replaced with an equal amount of the original slag. XRD phase analysis and SEM morphology analysis of the calcined samples were performed. The results of the SEM morphology analysis and XRD phase analysis are as follows: Figure 13 As shown, after the raw residue was roasted at 800℃ for 120 minutes, there were still original olivine and free CaO residues, indicating that the roasting reaction was incomplete.

[0077] Comparative Example 8

[0078] The conditions for this comparative example were the same as in Example 3, except that the 1600℃ water-quenched slag was replaced with an equal amount of the original slag. XRD phase analysis and SEM-EPMA morphology and quantitative phase composition analysis of the calcined samples were performed. The results of SEM morphology analysis and XRD phase analysis are shown below. Figure 14 As shown, after the original slag was oxidized and roasted at 900℃ for 120 min, there were no original spinel, olivine, liquid phase, alloy phase and free CaO residues. Fe2O3 solid solution, SiO2 solid solution, Fe2TiO5 and vanadate were generated, and the roasting reaction was completed.

[0079] The quantitative analysis results of the vanadate composition are listed in Table 2. It can be seen that under these calcination conditions, the V2O5 content in the vanadate is 49.192 wt%, and the impurity content is 18.145 wt%.

[0080] Based on the results of Examples 2-5 and Comparative Example 8, it can be seen that as the water quenching temperature decreases, the V2O5 content in the soluble vanadate phase after oxidative roasting decreases, but is still higher than that after oxidative roasting of the original slag. Conversely, as the water quenching temperature decreases, the impurity content in the soluble vanadate phase after oxidative roasting increases, but is still lower than that after oxidative roasting of the original slag. Therefore, direct water quenching after phase regulation at 1600℃, followed by drying and oxidative roasting, yields the best results. Comparing the V2O5 and impurity content in the soluble vanadate phase obtained after oxidative roasting of the slag quenched at 1600℃ for 30 min and 120 min at 900℃, it can be seen that appropriately extending the roasting time within the scope of this invention improves the oxidative roasting effect to a certain extent.

[0081] The above description is only a preferred embodiment of the present invention and does not limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing a soluble vanadate phase with high vanadium enrichment by synergistic control of vanadium slag cooling-calcination, characterized in that: Industrial vanadium slag is placed in a tubular furnace and heated to above 1600℃ to simulate the high-temperature vanadium slag obtained by smelting vanadium-titanium magnetite in a blast furnace or the high-temperature vanadium slag obtained by smelting vanadium-containing molten iron in a converter. The slag is then cooled to 1000~1600℃ and held at that temperature to reduce the V2O3 content in the spinel phase and inhibit the precipitation of olivine and alloy phases. Subsequently, water quenching is used to solidify the phase, resulting in water-quenched slag. The water-quenched slag is then dried, crushed, mixed with calcium oxide, and subjected to oxidative roasting to obtain the final product.

2. The method for preparing a soluble vanadate phase with high vanadium enrichment by synergistic control of vanadium slag cooling-roasting according to claim 1, characterized in that: The heat preservation time is 30~90 minutes.

3. The method for preparing a soluble vanadate phase with high vanadium enrichment by synergistic control of vanadium slag cooling-roasting according to claim 1 or 2, characterized in that: The heating rate and cooling rate are both 5~10℃ / min.

4. The method for preparing a soluble vanadate phase with high vanadium enrichment by synergistic control of vanadium slag cooling-roasting according to claim 3, characterized in that: The phases of the industrial vanadium slag include spinel, olivine, liquid phase, and alloy phase.

5. The method for preparing a soluble vanadate phase with high vanadium enrichment by synergistic control of vanadium slag cooling-calcination according to claim 1, characterized in that: The amount of calcium oxide added is determined based on the V2O3 content in the vanadium slag, and the mass ratio of CaO to V2O3 is 0.5~0.

7.

6. The method for preparing a soluble vanadate phase with high vanadium enrichment by synergistic control of vanadium slag cooling-roasting according to claim 5, characterized in that: When the temperature is cooled to a temperature greater than 1400℃ and less than or equal to 1600℃ and then held at that temperature, the oxidation calcination conditions are: temperature of 850~900℃, holding time of 30~120min, and atmosphere of nitrogen and oxygen mixture. When the temperature is cooled to 1000~1400℃ and held for heating, the oxidation calcination conditions are: temperature of 850~900℃, holding time of 60~120min, and atmosphere of nitrogen and oxygen mixture.

7. The method for preparing a soluble vanadate phase with high vanadium enrichment by synergistic control of vanadium slag cooling-roasting according to claim 6, characterized in that: Before the water-quenched slag is oxidized and roasted, it must be placed into the tubular furnace after it has been heated to the preset roasting temperature.

8. The method for preparing a soluble vanadate phase with high vanadium enrichment by synergistic control of vanadium slag cooling-roasting according to claim 7, characterized in that: When the oxidative roasting and heat preservation time ends, immediately remove the product and air-cool it to room temperature.

9. The method for preparing a soluble vanadate phase with high vanadium enrichment by synergistic control of vanadium slag cooling-calcination according to claim 1, characterized in that: The soluble vanadate phase contains more than 54 wt% V2O5 and less than 12 wt% impurities.

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