Method for extracting vanadium from vanadium slag calcified clinker by acid leaching and purifying solution

Abstract

The invention relates to the field of hydrometallurgy, and discloses a vanadium slag calcified clinker acid leaching vanadium extraction and solution purification method which comprises the following steps: S1, carrying out first acid leaching on calcified vanadium extraction clinker, and adding an impurity removal agent in the later stage of first leaching to remove impurities P and Pb; s2, after the first-time leaching is finished, filtering and washing are conducted, and a first-time leaching solution, a first-time washing solution and first-time vanadium extraction tailings are obtained; s3, secondary acid leaching is conducted on the primary vanadium extraction tailings, filtering and washing are conducted after secondary leaching is completed, and secondary leaching liquid, secondary washing liquid and secondary vanadium extraction tailings are obtained; and S4, the primary leaching solution is used for subsequent vanadium precipitation, the primary washing solution serves as mother liquor of first-time acid leaching in the step S1, the secondary leaching solution is used for washing after first-time leaching in the step S2 is finished, and the secondary washing solution serves as mother liquor of second-time acid leaching in the step S3. The method is shorter in process, simple in process and small in vanadium loss, and the leaching yield of the calcified clinker is increased.

Description

Technical Field

[0001] The invention relates to the field of hydrometallurgy, and in particular to a method for acid leaching vanadium from calcified vanadium slag clinker and purifying a solution. Background Art

[0002] The vanadium steelmaking process of vanadium-titanium magnetite is to first obtain vanadium-containing molten iron through blast furnace or electric furnace ironmaking, and then blow oxygen into the converter to oxidize and enrich the vanadium in the molten iron into the slag to obtain vanadium slag as the main raw material for vanadium extraction. At present, the industrialization technology of vanadium slag extraction mainly includes sodium roasting-water leaching, calcium roasting-acid leaching and sub-molten salt vanadium chromium co-extraction process. Among them, the vanadium slag calcium roasting-acid leaching vanadium extraction process has good promotion and application prospects due to the advantages of low cost of calcium salt additives, simple wastewater treatment, and less waste by-products.

[0003] In the acid leaching process of calcified clinker, in order to obtain a stable high-concentration pentavalent vanadium solution and avoid vanadium hydrolysis, the acid leaching pH is usually controlled at 2.5~3.5 in industry. At the same time, the total vanadium (TV) content in the calcified vanadium extraction tailings is 1.0%~2.0%. In order to further reduce the TV content of the tailings and improve the leaching yield, deep vanadium extraction from calcified clinker of vanadium slag has become a research hotspot.

[0004] In the prior art, the relevant literature on deep vanadium extraction from vanadium slag calcified clinker is as follows: Patent CN 107475518 B discloses a method for graded leaching of vanadium: by adjusting the pH of the vanadium-containing leaching slurry in sequence, graded leaching is performed in sequence, including primary leaching of 10≤pH<13, secondary leaching of 7≤pH<10, tertiary leaching of 6≤pH<7, quaternary leaching of 4≤pH<5, fifth leaching of 2.5≤pH<3; sixth leaching of 1.5≤pH<2.5, and seventh leaching of 1.0≤pH<1.5. This method creatively provides a vanadium graded entry and exit method based on the existence form and color of V5+ in leachates of different pH values, produces different leaching products, significantly improves the vanadium leaching rate, and the graded cumulative leaching rate can reach more than 96%.

[0005] Patent CN 109338103 B discloses a method for extracting vanadium by countercurrent acid leaching of calcified roasted clinker, comprising the following steps: a. mixing clinker with a first-stage filtrate or / and a second-stage leachate, adding sulfuric acid for leaching, controlling the pH of the first-stage leaching process system to be 2.8-3.5, separating the solid and the liquid to obtain a first-stage leachate and a solid; washing to obtain a first-stage filtrate and a solid; b. leaching the solid with a third-stage leachate or / and a third-stage filtrate, controlling the pH of the second-stage leaching endpoint system to be 1.8-3.5, separating the solid and the liquid to obtain a second-stage leachate and a solid; c. leaching the solid, controlling the pH of the third-stage leaching endpoint system to be 1.4-2.2, separating the solid and the liquid to obtain a third-stage leachate and a solid; washing to obtain a third-stage filtrate and vanadium extraction tailings. The method has the advantages of high vanadium extraction rate and low cost.

[0006] Patent CN 118186234 A uses a leaching solution to perform a primary leaching of vanadium slag calcified clinker in a high-pressure ultrasonic tank, and solid-liquid separation is performed to obtain a first solid residue and a first separated liquid; the first solid residue is subjected to a secondary leaching using a leaching solution in a high-pressure ultrasonic tank, and a second separated liquid is obtained after solid-liquid separation; finally, the first separated liquid and the second separated liquid are mixed to obtain a vanadium-containing filtrate. This method can significantly shorten the acid leaching time while ensuring a high leaching rate.

[0007] The above patents use multi-stage leaching, multiple countercurrent acid leaching or high-pressure acid leaching methods to improve the leaching yield of vanadium in vanadium slag calcified clinker, but the process is complicated and the cost is high, making it difficult to expand its application. At the same time, it is not difficult to find from the above method that lowering the leaching pH value can achieve deep leaching of vanadium. However, when leaching is carried out at a lower pH value, the impurity content in the leachate is high, especially P and Pb. Due to the continuous circulation of the solution, the primary leachate used for vanadium precipitation cannot be used for subsequent normal vanadium precipitation. Usually, the P concentration in the primary leachate can reach 0.1~0.3g / L, and the Pb concentration can reach ~0.02g / L. Therefore, the removal of impurities P and Pb in acidic vanadium solution has become the primary focus of consideration. Regarding the removal of P from acid leaching vanadium solution, there are related patent documents on the use of iron salts (CN 103966437 B, CN109355515 B), zirconium salts (CN 104894374 B) or microemulsion extraction dephosphorization (CN 108754187 A), but there are problems such as large vanadium loss, high cost, or complicated operation, while there are few reports on the removal of the impurity Pb.

[0008] Therefore, there is still room for improvement in the existing deep vanadium extraction process of calcified clinker. Summary of the invention

[0009] In view of this, an object of the embodiments of the present invention is to provide a method for acid leaching of vanadium from calcified vanadium slag clinker and purification of the solution.

[0010] Based on the above purpose, the embodiment of the present invention provides a method for acid leaching vanadium from calcified clinker of vanadium slag and purifying the solution, comprising: S1, performing the first acid leaching on the calcified vanadium extraction clinker, and adding an impurity remover in the late stage of the first leaching to remove impurities P and Pb; S2, filtering and washing after the first leaching is completed to obtain a primary leaching solution, a primary washing solution and a primary vanadium extraction tailings; S3, subjecting the primary vanadium extraction tailings to a second acid leaching, and filtering and washing after the second leaching to obtain a secondary leaching solution, a secondary washing solution and a secondary vanadium extraction tailings; S4, the primary leaching liquid is pumped into the qualified liquid tank for subsequent vanadium precipitation, the primary washing liquid is used as the mother liquor for the first acid leaching in S1, the secondary leaching liquid is used for washing after the first leaching in S2, and the second washing liquid is used as the mother liquor for the second acid leaching in S3.

[0011] According to one embodiment of the present invention, in step S1, the pH value of the first acid leaching is 2.5-3.5, the liquid-solid ratio is 2.0-6.0:1 mL / g, the temperature is 25-50°C, and the time is 60-120 min.

[0012] According to one embodiment of the present invention, in step S1, the impurity remover is iron sulfide, and the amount of the impurity remover added is 0.05% to 0.25% of the mass of the calcified clinker.

[0013] According to one embodiment of the present invention, in step S1, the late period of the first acid leaching is 10 to 30 minutes before the end of the first leaching.

[0014] According to one embodiment of the present invention, in step S2, the liquid-to-solid ratio of washing after the first leaching is 2.0-6.0:1 mL / g.

[0015] According to one embodiment of the present invention, in step S3, the pH value of the second acid leaching is 0.8-1.8, the liquid-solid ratio is 1.5-4.0:1 mL / g, the temperature is 25-40°C, and the time is 10-40 min.

[0016] According to one embodiment of the present invention, in step S3, the liquid-to-solid ratio of washing after the second leaching is 1.5-4.0:1 mL / g.

[0017] According to one embodiment of the present invention, in step S1, the main components of the calcified vanadium-extracting clinker are, by mass percentage, TV 7.0%~11.0%, TFe 20.0%~35.0%, SiO2 9.0%~15.0%, Al2O3 1.0%~4.0%, CaO 5.0%~12.0%, MgO 2.0%~4.0%, TiO2 8.0%~12.0%, Mn 3.0%~7.0%, P 0.02~0.07%, and Pb 0.02~0.04%.

[0018] According to one embodiment of the present invention, in step S3, the TV content in the secondary vanadium extraction tailings is ≤0.5%, and the leaching rate is ≥95.0%.

[0019] According to one embodiment of the present invention, in step S3, natural water is used for washing after the second leaching is completed.

[0020] The present invention has at least the following beneficial technical effects: The invention uses roasted clinker obtained by the vanadium slag calcification vanadium extraction process as raw material, adopts two acid leaching methods, cooperates with the impurity removal process, realizes the simultaneous removal of impurities phosphorus and lead in the acid leaching solution, can make the TV content in the tailings after the two acid leaching vanadium extraction less than or equal to 0.5%, and the leaching rate is greater than or equal to 95.0%, and avoids the problem of impurity enrichment in the primary leaching solution caused by the recycling of the solution in the leaching process. While improving the leaching vanadium yield, purified leaching vanadium liquid is obtained, the process flow is short, the operation is simple, the control is easy, and the vanadium loss is small, wherein the amount of impurity remover used is small, and there is no acid-base adjustment process in the reaction process, the investment cost is low, and it is easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] 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.

[0022] Figure 1 This is a flow chart of an embodiment of a method for deep extraction of vanadium from calcified clinker provided by the present invention. DETAILED DESCRIPTION

[0023] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.

[0024] The terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions; the terms "first", "second", etc. in the specification and claims of the present invention or the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order. "Multiple" means two or more, unless otherwise clearly and specifically defined.

[0025] In addition, reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0026] like Figure 1 The present invention provides a method for acid leaching vanadium from vanadium slag calcified clinker and purifying the solution, comprising the following steps: S1, performing the first acid leaching on the calcified vanadium extraction clinker, and adding an impurity remover in the late stage of the first leaching to remove impurities P and Pb; S2, filtering and washing after the first leaching is completed to obtain a primary leaching solution, a primary washing solution and a primary vanadium extraction tailings; S3, subjecting the primary vanadium extraction tailings to a second acid leaching, and filtering and washing after the second leaching to obtain a secondary leaching solution, a secondary washing solution and a secondary vanadium extraction tailings; S4, the primary leaching liquid is pumped into the qualified liquid tank for subsequent vanadium precipitation, the primary washing liquid is used as the mother liquor for the first acid leaching in S1, the secondary leaching liquid is used for washing after the first leaching in S2, and the second washing liquid is used as the mother liquor for the second acid leaching in S3.

[0027] In some embodiments, first, the calcified clinker is subjected to the first acid leaching and an impurity remover is added in the later stage of leaching to remove impurities P and Pb, and after filtering and washing, a primary leachate, a primary washing liquid and a primary vanadium extraction tailings are obtained. Secondly, the primary vanadium extraction tailings are subjected to the second acid leaching, and after filtering and washing, a secondary leachate, a secondary washing liquid and a secondary vanadium extraction tailings are obtained. Among them, the primary leachate is used for subsequent vanadium precipitation, the primary washing liquid is used as the mother liquor of the first acid leaching, the secondary leachate is used for washing the primary vanadium extraction tailings, and the secondary washing liquid is used as the mother liquor of the second acid leaching, so as to realize solution circulation and vanadium enrichment.

[0028] The double acid leaching process involved in the present invention has simple process and strong operability, and adopts chemical precipitation method to realize effective separation of impurities P and Pb in the secondary leaching solution, which can realize deep vanadium extraction from vanadium slag calcified clinker and realize high-efficiency recovery of vanadium resources.

[0029] In some embodiments, in step S1, the pH value of the first acid leaching is 2.5-3.5, the liquid-to-solid ratio is 2.0-6.0:1 (mL / g), the temperature is 25-50°C, and the time is 60-120 min. Among them, the first washing liquid is used as the first acid leaching mother liquid, and the liquid-to-solid ratio of the first acid leaching is preferably 2.5-3.5:1 (mL / g), the temperature of the first acid leaching is preferably 40-50°C, and the time of the first acid leaching is preferably 70-90 min.

[0030] In some embodiments, in step S1, the impurity remover is iron sulfide, and the amount of the impurity remover added is 0.05% to 0.25% of the mass of the calcified clinker, preferably 0.10% to 0.15%.

[0031] In some embodiments, in step S1, the late stage of the first acid leaching is 10 to 30 minutes before the end of the first leaching, preferably 15 to 25 minutes.

[0032] In some embodiments, in step S2, the liquid-to-solid ratio of washing after the first leaching is 2.0-6.0:1 (mL / g). The secondary leaching solution in step S3 is first used for washing, and the portion of the secondary leaching solution that does not meet the liquid-to-solid ratio of 2.0-6.0:1 (mL / g) is supplemented with tap water.

[0033] In some embodiments, in step S3, the pH value of the second acid leaching is 0.8-1.8, the liquid-solid ratio is 1.5-4.0:1 (mL / g), the temperature is 25-40°C, and the time is 10-40 min. Among them, the pH value of the second acid leaching is preferably 1.0-1.2, the liquid-solid ratio of the second acid leaching is preferably 2.0-3.0:1 (mL / g), the temperature of the second acid leaching is preferably 30°C, and the time of the second acid leaching is preferably 15-30 min.

[0034] In some embodiments, in step S3, the liquid-to-solid ratio of washing after the second leaching is 1.5-4.0:1 (mL / g).

[0035] In some embodiments, in step S1, the main components of the calcified vanadium-extracting clinker are, by mass percentage, TV 7.0%~11.0%, TFe 20.0%~35.0%, SiO2 9.0%~15.0%, Al2O3 1.0%~4.0%, CaO 5.0%~12.0%, MgO 2.0%~4.0%, TiO2 8.0%~12.0%, Mn 3.0%~7.0%, P 0.02~0.07%, and Pb 0.02~0.04%.

[0036] In some embodiments, in step S3, the TV content in the secondary vanadium extraction tailings is ≤0.5%, and the leaching rate is ≥95.0%.

[0037] In some embodiments, in step S3, natural water is used for washing after the second leaching is completed.

[0038] In some embodiments, the method can be implemented in the following manner in production: first, a washing liquid is added to a leaching tank, stirring is started, and vanadium slag calcified clinker is added according to a set liquid-solid ratio of 2.0-6.0:1 (mL / g) to implement the first acid leaching, and the pH value is in the range of 2.5-3.5 and the temperature is 25-50°C for 60-120min. An impurity remover is added 10-30min before the end of the leaching, and the amount of the impurity remover is 0.05%-0.25% of the mass of the clinker. After the leaching is completed, filtering and washing are performed, and the primary leachate is pumped into a qualified liquid tank for subsequent vanadium precipitation process. The washing of the primary vanadium extraction tailings The washing liquid-to-solid ratio is the same as that of the primary acid leaching, both of which are 2.0~6.0:1 (mL / g), and the secondary leaching liquid is used for washing first, and the insufficient part is supplemented with tap water; secondly, the primary vanadium extraction tailings enter the secondary leaching tank via a belt, and the secondary washing liquid with a liquid-to-solid ratio of 1.5~4.0:1 (mL / g) is pre-added in the secondary leaching tank and stirring is turned on. The leaching is carried out for 10~40 minutes at a constant pH value of 0.8~1.8 at 25~40°C. After the leaching is completed, it is filtered and washed. The washing liquid-to-solid ratio is the same as that of the secondary acid leaching, and tap water of 1.5~4.0:1 (mL / g) is used for washing.

[0039] In some embodiments, the impurity remover is iron sulfide (FeS), and in the leaching and impurity removal process of step S1, S 2- Can react with Pb in solution 2+ The reaction generates PbS, which is a poorly soluble precipitate with a Ksp value of 9.3×10 -28 ; At the same time, Fe 2+ VO2 + Oxidized to Fe 3+ , Fe 3+ With PO4 in solution 3- The reaction generates FePO4, which is a poorly soluble precipitate with a Ksp value of 1.3×10 -22 During the whole impurity removal process, due to the low dosage of impurity remover, only a small amount of VO2 + Restored to VO 2+ , no vanadium precipitation reaction occurs, and the vanadium loss is small. The main reactions involved in the whole process are as follows:

[0040] The invention uses roasted clinker obtained by the vanadium slag calcification vanadium extraction process as a raw material, adopts a chemical precipitation method to effectively separate the impurities P and Pb in the secondary leaching solution, has a simple process and is easy to operate; the amount of impurity remover used is small, and the reaction process does not have an acid-base adjustment process, the investment cost is low, and it is easy to implement; in the impurity removal process, the vanadium in the solution does not participate in the precipitation reaction, and the vanadium loss is small; the TV content in the tailings after the two acid leaching vanadium extractions is less than or equal to 0.5%, and the leaching rate is greater than or equal to 95.0%, and the problem of impurity enrichment in the primary leaching solution caused by the recycling of the solution in the leaching process is avoided, and the leaching yield of the calcified clinker is improved, and a purified leached vanadium solution is obtained.

[0041] The present invention is further explained below in conjunction with specific embodiments and comparative examples.

[0042] In the following comparative examples and embodiments, the main components of the vanadium slag calcified clinker used are TV: 8.68%, TFe: 31.20%, SiO2: 9.87%, Al2O3: 2.35%, CaO: 6.56%, MgO: 2.12%, TiO2: 9.08%, Mn: 5.32%, P: 0.055%, and Pb: 0.031%.

[0043] In order to use the primary washing liquid as the mother liquor in the primary leaching process in the embodiment, the secondary leaching liquid is used for washing in the primary washing process, and the secondary washing liquid is used as the mother liquor in the secondary leaching process, the above-mentioned calcified clinker is first used to carry out three rounds of two acid leaching tests, wherein 2 kg of calcified clinker is used in each round to obtain more circulating solution. The first round of this test: the pH value of the primary acid leaching is 3.0, tap water is added at a liquid-solid ratio of 3.0:1 (mL / g), the temperature is 50°C, and the time is 90min, and then filtering and washing are carried out, and the washing adopts 3.0:1 (mL / g) tap water to obtain the primary leaching liquid and the primary washing liquid; the pH value of the secondary acid leaching is 1.2, tap water is added at a liquid-solid ratio of 2.0:1 (mL / g), the temperature is 30°C, and the time is 15min, and then filtering and washing are carried out, and the washing adopts 2.0:1 (mL / g) tap water to obtain the secondary leaching liquid and the secondary washing liquid. The parameters of the two acid leaching tests in the second and third rounds were the same as those in the first round. The difference was that the first acid leaching process in the second and third rounds used the first washing liquid of the previous round as the mother liquor, the first tailings washing process used the second leaching liquid of the previous round, and the second acid leaching process used the second washing liquid of the previous round as the mother liquor, and the insufficient part was made up of tap water.

[0044] The main components of the primary leachate, primary washing liquid, secondary leachate and secondary washing liquid obtained from three rounds of two acid leaching tests are shown in Table 1. At the same time, the primary leachate components in Table 1 can also be used as a comparative example. It can be seen that without the solution circulation process of impurity removal, the concentrations of P and Pb in the primary leachate are relatively high, which will affect the subsequent vanadium precipitation operation.

[0045] Table 1 Main components of the solutions obtained from three rounds of experiments / g·L -1

[0046] Example 1 First, take 200g of the above-mentioned calcified clinker, add 1200mL of the primary washing liquid in Table 1 according to a liquid-solid ratio of 6.0:1 (mL / g), leaching for 60min at a constant pH value of 2.5 at a temperature of 25°C, and add 0.5g of iron sulfide (i.e., 0.25% of the mass of the calcified clinker) after leaching for 40min. After leaching, filter and wash, and wash with 1200mL of the secondary leaching liquid in Table 1 at a liquid-solid ratio of 6.0:1 (mL / g) to obtain a primary leaching liquid, a primary washing liquid and a primary tailings; perform secondary acid leaching on the primary tailings, add 800mL of the secondary washing liquid in Table 1 at a liquid-solid ratio of 4.0:1 (mL / g), and leaching for 40min at a constant pH value of 0.8 at a temperature of 25°C. After leaching, filter and wash, and wash with 800mL of tap water at a liquid-solid ratio of 4.0:1 (mL / g) to obtain a secondary leaching liquid, a secondary washing liquid and a secondary tailings. After testing, the TV content of the secondary tailings was 0.46% and the leaching rate was 95.45%; the TV content in the primary leachate was 22.37g / L, and the P and Pb concentrations were 0.013g / L and 0.001g / L respectively.

[0047] Example 2 First, 500 g of the above-mentioned calcified clinker was taken, 1750 mL of the primary washing solution in Table 1 was added according to a liquid-solid ratio of 3.5:1 (mL / g), and the mixture was leached for 90 min at a constant pH value of 3.0 at a temperature of 40°C, and 0.5 g of iron sulfide (i.e., 0.10% of the mass of the calcified clinker) was added after leaching for 60 min. After leaching, the mixture was filtered and washed. During washing, 1750 mL of the secondary leaching solution in Table 1 was used according to a liquid-solid ratio of 3.5:1 (mL / g) to obtain a primary leaching solution, a primary washing solution and a primary tailings. The primary tailings were subjected to secondary acid leaching, 1000 mL of the secondary washing solution in Table 1 was added according to a liquid-solid ratio of 2.0:1 (mL / g), and the mixture was leached for 30 min at a constant pH value of 1.8 at a temperature of 30°C. After leaching, the mixture was filtered and washed. During washing, 1000 mL of tap water was used according to a liquid-solid ratio of 2.0:1 (mL / g) to obtain a secondary leaching solution, a secondary washing solution and a secondary tailings. After testing, the TV content of the secondary tailings was 0.48%, and the leaching rate was 95.18%; the TV content in the primary leachate was 21.98g / L, and the P and Pb concentrations were 0.009g / L and 0.002g / L respectively.

[0048] Example 3 First, 800 g of the above calcified clinker was taken, 1600 mL of the primary washing solution in Table 1 was added according to a liquid-to-solid ratio of 2.0:1 (mL / g), and the mixture was leached for 120 min at a constant pH value of 3.5 at a temperature of 50°C, and 0.4 g of iron sulfide (i.e., 0.05% of the mass of the calcified clinker) was added after leaching for 110 min. After leaching, the mixture was filtered and washed. During washing, 1600 mL of the secondary leaching solution in Table 1 was used according to a liquid-to-solid ratio of 2.0:1 (mL / g). The first tailings were subjected to secondary acid leaching, and 1200 mL of the secondary washing solution in Table 1 was added at a liquid-solid ratio of 1.5:1 (mL / g), and the leaching was carried out for 10 min at a constant pH value of 1.5 at a temperature of 40°C. After the leaching, the leaching was filtered and washed. During the washing, 1200 mL of tap water was used at a liquid-solid ratio of 1.5:1 (mL / g), and the secondary leaching solution, secondary washing solution and secondary tailings were obtained. According to the test, the TV content of the secondary tailings was 0.42%, and the leaching rate was 96.01%; the TV content in the first leaching solution was 22.65 g / L, and the concentrations of P and Pb were 0.011 g / L and 0.001 g / L, respectively.

[0049] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of implementation of the present invention. If the present invention is modified or replaced by equivalents without departing from the spirit and scope of the present invention, it should be included in the protection scope of the claims of the present invention.

[0050] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the embodiments of the present invention as described above, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.

Claims

1. A method for acid leaching vanadium from calcified vanadium slag clinker and solution purification, characterized in that: include: S1, performing the first acid leaching on the calcified vanadium extraction clinker, and adding an impurity remover in the late stage of the first leaching to remove impurities P and Pb; S2, filtering and washing after the first leaching is completed to obtain a primary leaching solution, a primary washing solution and a primary vanadium extraction tailings; S3, subjecting the primary vanadium extraction tailings to a second acid leaching, and filtering and washing after the second leaching to obtain a secondary leaching solution, a secondary washing solution and a secondary vanadium extraction tailings; S4, the primary leaching liquid is pumped into the qualified liquid tank for subsequent vanadium precipitation, the primary washing liquid is used as the mother liquor for the first acid leaching in S1, the secondary leaching liquid is used for washing after the first leaching in S2, and the second washing liquid is used as the mother liquor for the second acid leaching in S3.

2. The method according to claim 1, characterized in that In step S1, the pH value of the first acid leaching is 2.5-3.5, the liquid-solid ratio is 2.0-6.0:1 mL / g, the temperature is 25-50°C, and the time is 60-120 min.

3. The method according to claim 1, characterized in that In step S1, the impurity remover is iron sulfide, and the amount of the impurity remover added is 0.05% to 0.25% of the mass of the calcified clinker.

4. The method according to claim 1, characterized in that: In step S1, the late stage of the first acid leaching is 10 to 30 minutes before the end of the first leaching.

5. The method according to claim 1, characterized in that In step S2, the liquid-to-solid ratio of washing after the first leaching is 2.0-6.0:1 mL / g.

6. The method according to claim 1, characterized in that In step S3, the pH value of the second acid leaching is 0.8-1.8, the liquid-solid ratio is 1.5-4.0:1 mL / g, the temperature is 25-40°C, and the time is 10-40 min.

7. The method according to claim 1, characterized in that In step S3, the liquid-to-solid ratio of washing after the second leaching is 1.5-4.0:1 mL / g.

8. The method according to claim 1, characterized in that In step S1, the main components of the calcified vanadium-extracting clinker are, by mass percentage, TV 7.0%-11.0%, TFe 20.0%-35.0%, SiO2 9.0%-15.0%, Al2O3 1.0%-4.0%, CaO 5.0%-12.0%, MgO 2.0%-4.0%, TiO2 8.0%-12.0%, Mn 3.0%-7.0%, P 0.02-0.07%, and Pb 0.02-0.04%.

9. The method according to claim 1, characterized in that: In step S3, the TV content in the secondary vanadium extraction tailings is ≤0.5%, and the leaching rate is ≥95.0%.

10. The method according to claim 1, characterized in that In step S3, natural water is used for washing after the second leaching is completed.

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