Method for improving roasting conversion rate of high-calcium vanadium slag

Abstract

The invention relates to the technical field of metallurgy, and provides a method for improving the roasting conversion rate of high-calcium vanadium slag, which comprises the following steps: mixing a high-calcium vanadium slag sample with a ferrous sulfide compound to obtain a mixture; carrying out oxidizing roasting on the mixture at 120-300 DEG C for 20-60 minutes, heating to 850-950 DEG C, continuing oxidizing roasting for 30-60 minutes, cooling, and grinding the roasted product to obtain a roasted material; and a sample of the roasted material is taken to be subjected to acid leaching treatment, vanadium-containing leachate and residues are obtained, and the vanadium dissolution rate in the roasted material is calculated. According to the scheme, after the high-calcium vanadium slag and the sulfate are mixed, high-temperature oxidizing roasting is directly carried out, the calcium element is converted into a calcium sulfate phase, the influence of calcium on the vanadium extraction process is greatly avoided, and the roasting conversion rate of the high-calcium vanadium slag is increased.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgy, and in particular to a method for improving the roasting conversion rate of high-calcium-vanadium slag. Background Art

[0002] Vanadium is an important microalloying element widely used in metallurgy, chemical industry, aerospace and other fields. It can improve the strength, toughness and ductility of steel. For example, vanadium-titanium magnetite is treated at high temperature in a blast furnace or electric furnace to obtain vanadium-containing molten iron, which is then selectively oxidized from the molten iron to obtain vanadium slag, which is used as a raw material for vanadium extraction. As the quality requirements for steel become higher and higher, the sulfur content and phosphorus content in the steel grade are required to be very low. For example, some steel grades require the phosphorus content to be below 0.005%. By adding lime to the vanadium-containing molten iron, the phosphorus element can be effectively removed to achieve vanadium extraction and pre-dephosphorization. However, the calcium content in the vanadium slag obtained in this way increases irreversibly, even reaching 10%, which is difficult to meet the existing requirements for steel grades.

[0003] The existing vanadium slag vanadium extraction mainly adopts the sodium vanadium extraction method and the calcium vanadium extraction method. In the process of sodium vanadium extraction, CaO easily reacts with V2O5 to form water-insoluble calcium vanadate (CaO•V2O5) or calcium-containing vanadium bronze (CaV 12 O 30 ), seriously affecting the vanadium roasting conversion rate in the vanadium extraction process. In the process of vanadium extraction by calcification, the calcium content is relatively high, resulting in the production of more calcium sulfate during wet acid leaching, which in turn makes the leached slurry viscous and makes it difficult to stir and transport the slurry. At the same time, during the high-temperature roasting process, excessive calcium combines with titanium and iron in the vanadium slag to form a vanadium-containing phase that is solid-dissolved with vanadate and difficult to dissolve in acid, which also seriously affects the vanadium roasting conversion rate in the vanadium extraction process. Based on this, the existing technology is in urgent need of improvement. Summary of the invention

[0004] In view of this, the existing technology is to decalcify the high calcium vanadium slag to obtain low calcium vanadium slag, and then extract vanadium. In this process, other water-insoluble calcium vanadate (CaO•V2O5) or calcium-containing vanadium bronze (CaV 12 O 30 ), or produces more calcium sulfate, which makes the leaching slurry viscous, and the slurry stirring and transportation are difficult, which seriously affects the vanadium roasting conversion rate of the vanadium extraction process. The present disclosure provides a method for improving the roasting conversion rate of high-calcium vanadium slag.

[0005] According to a first aspect of the present invention, there is provided a method for improving the roasting conversion rate of high calcium vanadium slag, comprising: Step a, mixing a high calcium vanadium slag sample with a sulfide iron compound to obtain a mixture; Step b, oxidatively roasting the mixture at 120-300° C. for 20-60 minutes, then heating to 850-950° C. for further oxidative roasting for 30-60 minutes, and grinding the roasted product after cooling to obtain a roasted material; Step c, taking a sample of the roasted material and subjecting it to acid leaching treatment to obtain a vanadium-containing leaching solution and a residue to calculate the vanadium dissolution rate in the roasted material.

[0006] In some embodiments, the mass ratio of CaO to V2O5 in the high calcium-vanadium slag sample is greater than or equal to 0.75.

[0007] In some embodiments, the high calcium vanadium slag sample can pass through an 80 mesh sieve.

[0008] In some embodiments, step a comprises: The high calcium vanadium slag sample is mixed with the sulfide iron compound, and the water content during the mixing process is controlled to account for 0-30% of the mass of the high calcium vanadium slag sample to obtain a mixture.

[0009] In some embodiments, step a comprises: The high calcium vanadium slag sample is mixed with a ferrosulfide compound, and the molar ratio of sulfur element in the ferrosulfide compound to calcium element in the high calcium vanadium slag sample is controlled to be 0.4-0.9:1.

[0010] In some embodiments, the iron sulfide compound is one or more of FeSO4, Fe2(SO4)3, FeS2, and FeS.

[0011] In some embodiments, step b comprises: The mixed material is oxidatively roasted at 300° C. for 30 minutes, then heated to 900° C. for further oxidative roasting for 30 minutes, and after cooling, the roasted product is ground into powder to obtain a roasted material.

[0012] In some embodiments, step c comprises: Step c1, taking a sample of the roasted material and subjecting it to acid leaching treatment under acid leaching conditions; Step c2, performing solid-liquid separation on the product obtained by acid leaching to obtain a residue and a vanadium-containing leaching solution, detecting the vanadium content in the residue, and calculating the vanadium dissolution rate in the roasting material.

[0013] In some embodiments, step c1 comprises: A sample of the calcined material was taken and subjected to acid leaching treatment under the conditions of pH 1, liquid-solid ratio of 50 ml:1 g, and temperature of 50°C.

[0014] In some embodiments, the step c1 further comprises: A sample of the calcined material was taken and subjected to acid leaching for 30 minutes under the acid leaching conditions of pH 1, liquid-solid ratio of 50 ml:1 g, and temperature of 50°C.

[0015] The above method for improving the roasting conversion rate of high calcium vanadium slag is as follows: a high calcium vanadium slag sample and a sulfide iron compound are mixed to obtain a mixture, and the mixture is oxidatively roasted at 120-300°C for 20-60 minutes, then the temperature is raised to 850-950°C for further oxidative roasting for 30-60 minutes, and the roasted product is finely ground after cooling to obtain a roasted material, and a roasted material sample is taken for acid leaching to obtain a vanadium-containing leaching solution and a residue to calculate the vanadium dissolution rate in the roasted material. The present invention provides a simple method for improving the roasting conversion rate of high calcium vanadium slag, after mixing the high calcium vanadium slag with sulfate, the sulfide iron compound is mixed with the high calcium slag to react, so that the calcium in the converter high calcium slag generates a calcium sulfate phase with higher stability, and in the high temperature oxidative roasting process, the vanadium-containing perovskite phase is decomposed, the influence of calcium on the vanadium extraction process is greatly avoided, and the roasting conversion rate of vanadium is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0017] Figure 1 A flow chart of a method for improving the roasting conversion rate of high-calcium-vanadium slag provided in one embodiment of the present invention. DETAILED DESCRIPTION

[0018] The following is a further detailed description of the embodiments of the present disclosure in conjunction with the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to exemplarily illustrate the principles of the present disclosure, but cannot be used 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 includes all technical solutions that fall within the scope of the claims.

[0019] The present disclosure provides these embodiments to make the present disclosure thorough and complete, and to fully express 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 the parts and steps, the composition of the materials, the numerical expressions and the numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary, and not as limiting.

[0020] It should be noted that, in the description of the present disclosure, unless otherwise specified, the meaning of "multiple" is greater than or equal to two; the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present disclosure. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0021] In addition, the words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. The words "include" or "comprise" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements.

[0022] It should also be noted that in the description of the present disclosure, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present disclosure can be understood according to 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 intermediate device between the specific device and the first device or the second device.

[0023] All terms used in the present disclosure have the same meanings as those understood by those of ordinary skill in the art to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, for example, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined as such herein.

[0024] 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.

[0025] It should be understood that the embodiments of the present invention shown in the exemplary embodiments are only illustrative. Although only a few embodiments are described in detail in the present invention, it is easy for those skilled in the art to appreciate that multiple modifications are feasible without actually departing from the teaching of the subject matter of the present invention. Accordingly, all such modifications should be included within the scope of the present invention. Without departing from the gist of the present invention, other replacements, modifications, changes and deletions may be made to the design, operating conditions and parameters of the following exemplary embodiments.

[0026] Please refer to Figure 1 , Figure 1 The flowchart of a method for improving the roasting conversion rate of high calcium vanadium slag provided by one embodiment of the present invention is shown. A method for improving the roasting conversion rate of high calcium vanadium slag comprises: Step a, mixing a high calcium vanadium slag sample with a sulfide iron compound to obtain a mixture; Step b, oxidatively roasting the mixture at 120-300° C. for 20-60 minutes, then heating to 850-950° C. for further oxidative roasting for 30-60 minutes, and grinding the roasted product after cooling to obtain a roasted material; Step c, taking a sample of the roasted material for acid leaching to obtain a vanadium-containing leaching solution and residue to calculate the vanadium dissolution rate in the roasted material.

[0027] The above method for improving the roasting conversion rate of high calcium vanadium slag is as follows: a high calcium vanadium slag sample and a sulfide iron compound are mixed to obtain a mixture, and the mixture is oxidatively roasted at 120-300°C for 20-60 minutes, and then the temperature is raised to 850-950°C for further oxidative roasting for 30-60 minutes, and after cooling, the roasting product is finely ground to obtain a roasting material, and a roasting material sample is taken for acid leaching to obtain a vanadium-containing leaching liquid and a residue, and the dissolution rate of vanadium in the roasting material is calculated. After the high calcium vanadium slag is mixed with sulfate, the sulfide iron compound is mixed with the high calcium slag to react, so that the calcium in the converter high calcium slag generates a calcium sulfate phase with higher stability, and the vanadium-containing perovskite phase is decomposed during the high temperature oxidative roasting process, thereby greatly avoiding the influence of calcium on the vanadium extraction process and improving the roasting conversion rate of vanadium.

[0028] According to several embodiments of the present invention, the mass ratio of CaO to V2O5 in the high calcium vanadium slag sample is greater than or equal to 0.75. The high calcium vanadium slag sample contains perovskite, etc., and the mass ratio of CaO to V2O5 is greater than or equal to 0.75, indicating that the calcium content in the high calcium vanadium slag sample is relatively high, that is, the high calcium vanadium slag is guaranteed to ensure the effective applicability of the method of the present application.

[0029] According to some embodiments of the present invention, the high calcium vanadium slag sample can pass through an 80 mesh sieve. The high calcium vanadium slag sample can pass through an 80 mesh sieve, which ensures that the particle size of the high calcium vanadium slag sample is small enough, which is conducive to more uniform mixing of the subsequent high calcium vanadium slag sample and the sulfide iron compound.

[0030] According to several embodiments of the present invention, step a includes: mixing a high-calcium vanadium slag sample with a sulfide iron compound, and controlling the water content during the mixing process to account for 0-30% of the mass of the high-calcium vanadium slag sample to obtain a mixture, which is conducive to the mixing reaction of the high-calcium vanadium slag sample and the sulfide iron compound to be converted into calcium sulfate, so that the calcium in the high-calcium vanadium slag sample generates a calcium sulfate phase with higher stability.

[0031] According to several embodiments of the present invention, step a includes: mixing a high-calcium vanadium slag sample with a ferrosulfide compound, and controlling the molar ratio of sulfur in the ferrosulfide compound to calcium in the high-calcium vanadium slag sample to be 0.4 to 0.9: 1. A suitable molar ratio of sulfur to calcium can promote a specific chemical reaction between the ferrosulfide compound and the substances in the high-calcium vanadium slag, which is conducive to the formation of a calcium sulfate phase with higher stability by calcium, thereby improving the recovery rate and purity of vanadium.

[0032] According to some embodiments of the present invention, the ferrous sulfide compound is one or more of FeSO4, Fe2(SO4)3, FeS2, and FeS. A variety of ferrous sulfide compounds are provided as additives for use, and can be flexibly selected according to actual use requirements, which is conducive to improving the flexibility of the method.

[0033] According to some embodiments of the present invention, step b includes: oxidatively roasting the mixture at 300°C for 30 minutes, then heating it to 900°C and continuing oxidatively roasting for 30 minutes, and grinding the roasted product after cooling to obtain a roasted material. During the high-temperature oxidative roasting process, the vanadium-containing perovskite phase is decomposed, the effect of calcium on the vanadium extraction process is greatly reduced, and the roasting conversion rate of vanadium is improved.

[0034] According to several embodiments of the present invention, step c includes: step c1, taking a sample of the roasted material and performing acid leaching treatment under acid leaching conditions; step c2, performing solid-liquid separation on the product obtained by the acid leaching treatment to obtain a residue and a vanadium-containing leaching solution, detecting the vanadium content in the residue, and calculating the vanadium dissolution rate in the roasted material. The roasted material is subjected to acid leaching treatment under specific acid leaching conditions, followed by solid-liquid separation to obtain a residue and a vanadium leaching solution, so as to achieve a more accurate characterization of the vanadium roasting conversion rate in the subsequent step.

[0035] According to some embodiments of the present invention, step c1 includes: taking a sample of the roasted material and performing an acid leaching treatment under the acid leaching conditions of pH 1, liquid-solid ratio of 50 ml: 1 g, and temperature of 50° C. Controlling the pH value, solid-liquid ratio, and temperature can ensure that the acid solution fully surrounds the solid particles, increase the reaction interface area, and improve the mass transfer efficiency.

[0036] According to some embodiments of the present invention, step c1 further comprises: taking a sample of the roasted material and acid leaching it for 30 minutes under acid leaching conditions of pH 1, liquid-solid ratio of 50 ml:1 g, and temperature of 50° C. Controlling the acid leaching of the roasted material in the acid solution for a period of time is conducive to ensuring that the acid leaching of the roasted material is more sufficient, and is conducive to more accurate characterization of the vanadium roasting conversion rate.

[0037] In order to further understand the method for improving the roasting conversion rate of high calcium vanadium slag provided by the present invention, it is further described in detail in the following specific examples.

[0038] Example 1 Take 100g of high-calcium vanadium slag sample, of which the CaO content is 13.85%, the V content is 8.10%, the TiO2 content is 9.89%, and the mass ratio of CaO to V2O5 is 0.75. This high-calcium vanadium slag sample can pass through an 80-mesh sieve.

[0039] A certain mass of ferrosulfide compound is mixed and evenly mixed with the above-mentioned high calcium vanadium slag sample, and the molar ratio of sulfur element in the ferrosulfide compound to calcium element in the high calcium vanadium slag sample is controlled to be 0.4-0.9:1. In this embodiment 1, 33g of FeSO4·7H2O is taken, mixed evenly with the above-mentioned 100g of high calcium vanadium slag, and 3ml of water is added to soak it, and the water content in the mixing process is controlled to account for 0-30% of the mass of the high calcium vanadium slag sample to obtain a mixture.

[0040] The mixture was oxidatively roasted at 300°C for 20 minutes, and then heated to 950°C for 60 minutes. After roasting, it was cooled to room temperature and the roasted product was ground to obtain a roasted material. The V content in the roasted material was detected to be 6.98%.

[0041] Take 10g sample of the above calcined material, and carry out acid leaching treatment for 30 minutes under acidic conditions of liquid-solid ratio of 50ml:1g, temperature of 50℃ and pH of 1, then carry out solid-liquid separation treatment to obtain residue and vanadium-containing leaching solution, the vanadium content in the residue is detected to be 0.43%, and the vanadium dissolution rate is calculated according to the weight of calcined material, the vanadium content in the calcined material and the weight of residue and the vanadium content in the residue, vanadium dissolution rate (%) = [(calcined material weight*vanadium content in calcined material-residue weight*vanadium content in residue) / (calcined material weight*vanadium content in calcined material)]*100%, and the calculated vanadium dissolution rate is 95.28%.

[0042] Example 2 Take 100g of high-calcium vanadium slag sample, of which the CaO content is 25.38%, the V content is 5.85%, the TiO2 content is 7.78%, and the mass ratio of CaO to V2O5 is 2.43. This high-calcium vanadium slag sample can pass through an 80-mesh sieve.

[0043] A certain mass of ferrosulfide compound is mixed and evenly mixed with the above-mentioned high calcium vanadium slag sample, and the molar ratio of sulfur element in the ferrosulfide compound to calcium element in the high calcium vanadium slag sample is controlled to be 0.4-0.9:1. In this embodiment 1, 22g of FeSO4·7H2O is taken and evenly mixed with the above-mentioned 100g of high calcium vanadium slag, and 10ml of water is added to soak it, and the water content in the mixing process is controlled to account for 0-30% of the mass of the high calcium vanadium slag sample to obtain a mixture.

[0044] The mixture was oxidatively roasted at 120°C for 60 minutes, then heated to 850°C for 30 minutes. After roasting, it was cooled to room temperature and the roasted product was ground to obtain a roasted material. The V content in the roasted material was detected to be 4.43%.

[0045] Take 10g sample of the above calcined material, and carry out acid leaching treatment for 30 minutes under acidic conditions of liquid-solid ratio of 50ml:1g, temperature of 50℃ and pH of 1, then carry out solid-liquid separation treatment to obtain residue and vanadium-containing leaching solution, the vanadium content in the residue is detected to be 0.43%, and the vanadium dissolution rate is calculated according to the weight of the calcined material, the vanadium content in the calcined material, the weight of the residue and the vanadium content in the residue, vanadium dissolution rate (%) = [(calcined material weight*vanadium content in the calcined material-residue weight*vanadium content in the residue) / (calcined material weight*vanadium content in the calcined material)]*100%, and the calculated vanadium dissolution rate is 94.10%.

[0046] Comparative Example 1 Take 100g of high-calcium vanadium slag sample, which includes perovskite, etc., among which the CaO content is 13.85%, the V content is 8.10%, the TiO2 content is 9.89%, and the mass ratio of CaO to V2O5 is 0.75. This high-calcium vanadium slag sample can pass through an 80-mesh sieve.

[0047] The high calcium vanadium slag sample was oxidatively roasted at 950°C for 20 minutes and then cooled to room temperature. The roasted product was ground to obtain a roasted material. The V content in the roasted material was detected to be 7.63%.

[0048] Take 10g sample of the above calcined material, and carry out acid leaching treatment for 30 minutes under acidic conditions of liquid-solid ratio of 50ml:1g, temperature of 50℃ and pH of 1, then carry out solid-liquid separation treatment to obtain residue and vanadium-containing leaching solution, the vanadium content in the residue is detected to be 0.87%, and the vanadium dissolution rate is calculated according to the weight of the calcined material, the vanadium content in the calcined material, the weight of the residue and the vanadium content in the residue, vanadium dissolution rate (%) = [(calcined material weight*vanadium content in the calcined material-residue weight*vanadium content in the residue) / (calcined material weight*vanadium content in the calcined material)]*100%, and the calculated vanadium dissolution rate is 91.05%.

[0049] Comparative Example 2 Take 100g of high-calcium vanadium slag sample, which includes perovskite, etc., among which the CaO content is 25.38%, the V content is 5.85%, the TiO2 content is 7.78%, and the mass ratio of CaO to V2O5 is 2.43. This high-calcium vanadium slag sample can pass through an 80-mesh sieve.

[0050] The high calcium vanadium slag sample was oxidatively roasted at 850°C for 30 minutes and then cooled to room temperature. The roasted product was ground to obtain a roasted material. The V content in the roasted material was detected to be 5.83%.

[0051] Take 10g sample of the above calcined material, and carry out acid leaching treatment for 30 minutes under acidic conditions of liquid-solid ratio of 50ml:1g, temperature of 50℃ and pH of 1, then carry out solid-liquid separation treatment to obtain residue and vanadium-containing leaching solution, the vanadium content in the residue is detected to be 0.95%, and the vanadium dissolution rate is calculated according to the weight of the calcined material, the vanadium content in the calcined material, the weight of the residue and the vanadium content in the residue, vanadium dissolution rate (%) = [(calcined material weight*vanadium content in the calcined material-residue weight*vanadium content in the residue) / (calcined material weight*vanadium content in the calcined material)]*100%, and the calculated vanadium dissolution rate is 84.22%.

[0052] The above examples 1 and 2 are processes for extracting vanadium from high calcium vanadium slag samples based on the method for improving the roasting conversion rate of high calcium vanadium slag provided by the present application, and comparative examples 1 and 2 are processes for extracting vanadium from high calcium vanadium slag samples based on the method of the prior art. By comparing the above examples 1 and comparative example 1, it can be seen that, on the basis of ensuring that the high calcium vanadium slag samples are the same, compared with comparative example 1, and compared with comparative example 2, the vanadium content in the detected residue is less, and the vanadium dissolution rate in the vanadium-containing leaching solution is higher. Based on the method for improving the roasting conversion rate of high calcium vanadium slag provided by the present application, examples 1 and 2 are obtained by mixing a high calcium vanadium slag sample and a sulfide iron compound, and soaking them with water to obtain a mixture, and the mixture is oxidatively roasted at 120-300°C for 20-60 minutes, then heated to 850-950°C and continued to oxidatively roast for 30-60 minutes, and after cooling, the roasted product is finely ground to obtain a roasted material, and a roasted material sample is taken for acid leaching. By mixing ferrosulfide compounds with high-calcium slag, the calcium in the converter high-calcium slag is converted into a calcium sulfate phase with higher stability. During the high-temperature oxidation roasting process, the vanadium-containing perovskite phase is decomposed, which greatly avoids the influence of calcium on the vanadium extraction process and improves the roasting conversion rate of vanadium.

[0053] So far, various embodiments of the present disclosure have been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0054] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict.

Claims

1. A method for improving the roasting conversion rate of high calcium vanadium slag, characterized in that: include: Step a, mixing a high calcium vanadium slag sample with a ferrosulfide compound to obtain a mixture; Step b, oxidatively roasting the mixture at 120-300° C. for 20-60 minutes, then heating to 850-950° C. for further oxidative roasting for 30-60 minutes, and grinding the roasted product after cooling to obtain a roasted material; Step c, taking a sample of the roasted material and subjecting it to acid leaching treatment to obtain a vanadium-containing leaching solution and a residue to calculate the vanadium dissolution rate in the roasted material.

2. The method for improving the roasting conversion rate of high calcium vanadium slag according to claim 1, characterized in that: The mass ratio of CaO to V2O5 in the high calcium vanadium slag sample is greater than or equal to 0.

75.

3. The method for improving the roasting conversion rate of high calcium vanadium slag according to claim 2, characterized in that: The high calcium vanadium slag sample can pass through an 80-mesh sieve.

4. The method for improving the roasting conversion rate of high calcium vanadium slag according to claim 1, characterized in that: The step a comprises: The high calcium vanadium slag sample is mixed with the sulfide iron compound, and the water content during the mixing process is controlled to account for 0-30% of the mass of the high calcium vanadium slag sample to obtain a mixture.

5. The method for improving the roasting conversion rate of high calcium vanadium slag according to claim 1, characterized in that: The step a comprises: The high calcium vanadium slag sample is mixed with a ferrosulfide compound, and the molar ratio of sulfur element in the ferrosulfide compound to calcium element in the high calcium vanadium slag sample is controlled to be 0.4-0.9:

1.

6. The method for improving the roasting conversion rate of high calcium vanadium slag according to claim 1, characterized in that: The ferrous sulfide compound is one or more of FeSO4, Fe2(SO4)3, FeS2, and FeS.

7. The method for improving the roasting conversion rate of high calcium vanadium slag according to claim 1, characterized in that: The step b comprises: The mixed material is oxidatively roasted at 300° C. for 30 minutes, then heated to 900° C. for further oxidative roasting for 30 minutes, and after cooling, the roasted product is ground into powder to obtain a roasted material.

8. The method for improving the roasting conversion rate of high calcium vanadium slag according to claim 1, characterized in that: The step c comprises: Step c1, taking a sample of the roasted material and subjecting it to acid leaching treatment under acid leaching conditions; Step c2, performing solid-liquid separation on the product obtained by acid leaching to obtain a residue and a vanadium-containing leaching solution, detecting the vanadium content in the residue to calculate the vanadium dissolution rate in the roasting material.

9. The method for improving the roasting conversion rate of high calcium vanadium slag according to claim 8, characterized in that: The step c1 comprises: A sample of the calcined material was taken and subjected to acid leaching treatment under the conditions of pH 1, liquid-solid ratio of 50 ml:1 g, and temperature of 50°C.

10. The method for improving the roasting conversion rate of high calcium vanadium slag according to claim 9, characterized in that: The step c1 further comprises: A sample of the calcined material was taken and subjected to acid leaching for 30 minutes under the acid leaching conditions of pH 1, liquid-solid ratio of 50 ml:1 g, and temperature of 50°C.

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