Method for separating vanadium, iron and phosphorus in acidic vanadium-containing solution by using ion exchange method

Abstract

The invention relates to a method for separating vanadium, iron and phosphorus in an acidic vanadium-containing solution by using an ion exchange method. According to the technical scheme, the method comprises the following steps: enabling an acidic vanadium-containing solution to flow into an ion exchange column at a flow rate of 1-1.5 BV / h until resin filled in the ion exchange column is adsorbed to be saturated, so as to obtain loaded resin and adsorption residual liquid; the pH value of the acidic vanadium-containing solution is 0-2.5. Enabling 5-10BV deionized water to reversely flow through the loaded resin in the ion exchange column at the flow rate of 2-5BV / h to obtain resin to be desorbed and washing wastewater; then, a desorption agent of 0.2-0.5 BV reversely flows through the resin to be desorbed in the ion exchange column at the flow rate of 0.2-0.5 BV / h for desorption, and desorbed resin and vanadium-rich liquid are obtained. The method has the characteristics of wide pH application range, good vanadium and iron phosphorus separation effect and low medicament consumption.

Description

Technical Field

[0001] The present invention belongs to the technical field of separation of vanadium, iron and phosphorus from vanadium-containing solution, and specifically relates to a method for separating vanadium, iron and phosphorus from an acidic vanadium-containing solution by using an ion exchange method. Background Art

[0002] When ion exchange resin is used to adsorb vanadium ions in acidic vanadium-containing solution, it has the advantages of being cheap, having high adsorption saturation capacity and being simple to operate. Among them, macroporous anion exchange resin has a good adsorption effect on vanadium in acidic vanadium-containing solution with a pH value of 2 to 3. The initial pH value of the acidic vanadium-containing solution obtained by leaching vanadium shale is about 0. If a good adsorption effect is to be obtained, the pH value of the solution needs to be adjusted to 2 to 3 to adapt to the optimal adsorption pH value of the macroporous anion exchange resin. The acidic vanadium-containing solution contains a variety of impurity ions, among which the ions that have a greater impact on the adsorption of vanadium are mainly iron ions and phosphate ions. Iron ions are easily competitively adsorbed with vanadium in acidic vanadium-containing solution, affecting the adsorption rate of vanadium. Phosphate ions have a great influence on the preparation process of vanadium products. Excessive phosphorus content will cause the purity of vanadium products to be substandard. Therefore, how to separate vanadium, phosphorus and iron from acidic vanadium-containing solution is a concern of technicians in this field.

[0003] The patented technology of "A method for extracting vanadium by ion exchange from high-iron and low-vanadium solution" (CN114959308B) adds a neutralizing agent to the acidic vanadium-containing solution for neutralization, adjusts the pH value of the acidic vanadium-containing solution to 1.8-1.9, and then uses an ion exchange process to extract vanadium. This technology is only applicable to acidic vanadium-containing solutions with a pH value of 1.8-1.9, and the pH application range is narrow. This technology requires a large amount of alkali to adjust the pH value of the solution to 1.8-1.9, and the consumption of reagents is large; and this method simultaneously adsorbs iron and vanadium ions, and cannot achieve the simultaneous separation of vanadium and iron, and the separation effect of vanadium and iron is poor.

[0004] The patented technology of "A method for treating stone coal acid leaching solution" (CN108754191B) first cools and crystallizes the acidic vanadium-containing solution, obtains alum and separated liquid after solid-liquid separation, then adsorbs the separated liquid, separates and recovers molybdenum and uranium, purifies and recovers iron precipitate, and then uses ion exchange to enrich vanadium, then purifies phosphorus, silicon, and arsenic ions, and finally precipitates vanadium to obtain ammonium vanadate products. This method uses adsorption and crystallization methods to separate and recover multiple valuable metal components. Although it has the advantages of high vanadium recovery rate, high vanadium purity and low process cost, it cannot separate vanadium, iron and phosphorus in the acidic vanadium-containing solution in one step in the adsorption process. It needs to be combined with crystallization to remove iron and phosphorus. The separation effect of vanadium, iron and phosphorus is poor during the adsorption process.

[0005] The patented technology of "A method for purifying and enriching vanadium from a vanadium-containing solution" (CN 110241306 B) uses a chelating resin to adsorb an acidic vanadium-containing solution, uses sodium hydroxide to desorb the adsorbed vanadium in stages, and uses oxalic acid to regenerate the desorbed chelating resin. However, the pH application range of this technology is narrow. The pH value of the acidic vanadium-containing solution needs to be adjusted to 1.4-2.6, and then the chelating resin is used for adsorption. This process consumes a large amount of alkali and a large amount of reagents.

[0006] In summary, the prior art has the following defects: the method for separating vanadium from iron and phosphorus in an acidic vanadium-containing solution has a narrow pH applicable range, a large amount of reagent consumption, and a poor separation effect of vanadium from iron and phosphorus. Summary of the invention

[0007] The present invention aims to overcome the defects of the prior art and aims to provide a method for separating vanadium from iron and phosphorus in an acidic vanadium-containing solution by ion exchange. The method has a wide pH applicable range, low reagent consumption and good separation effect of vanadium, iron and phosphorus.

[0008] To achieve the above object, the technical solution adopted by the present invention is:

[0009] Step 1: Resin adsorption

[0010] The filling resin is placed in the ion exchange column at a ratio of 1:2-3 of the volume of the filling resin to the volume of the ion exchange column, and then the acidic vanadium-containing solution is flowed into the ion exchange column at a flow rate of 1-1.5 BV / h until the resin filled in the ion exchange column is saturated with adsorption, thereby obtaining loaded resin and adsorption residual liquid.

[0011] Step 2: Resin desorption

[0012] First, 5-10 BV of deionized water is countercurrently passed through the loaded resin in the ion exchange column at a flow rate of 2-5 BV / h to obtain the resin to be desorbed and washing wastewater; then 0.2-0.5 BV of sulfuric acid is countercurrently passed through the resin to be desorbed in the ion exchange column at a flow rate of 0.2-0.5 BV / h to desorb and obtain the desorbed resin and vanadium-rich liquid.

[0013] The filling resin is a resin used for adsorbing vanadium in an acidic vanadium-containing solution. The preparation method of the resin is as follows: a macroporous anion exchange resin and phytic acid are mixed at a solid-liquid ratio of 1: (15-30) kg / L to obtain a mixture I; the mixture I is stirred for the first time at a temperature of 30-90° C., and the solid-liquid separation is performed to obtain a resin to be treated and a pre-treated liquid; the resin to be treated and oxalic acid are mixed at a solid-liquid ratio of 1: (18-32) kg / L to obtain a mixture II; the mixture II is stirred for the second time at a temperature of 40-80° C., and the solid-liquid separation is performed to obtain a treated resin and a modified residual liquid; the treated resin is allowed to stand to obtain a resin used for adsorbing vanadium in an acidic vanadium-containing solution.

[0014] The pH of the acidic vanadium-containing solution is 0-2.5.

[0015] The concentration of the sulfuric acid is 2-5 mol / L.

[0016] The functional group of the macroporous anion exchange resin is [-N(CH3)3OH].

[0017] The concentration of the phytic acid is 0.03-0.13 mol / L.

[0018] The concentration of the oxalic acid is 0.1-0.5 mol / L.

[0019] The stirring time of the first stirring is 20 to 40 hours, and the rotation speed of the first stirring is 100 to 300 r / min.

[0020] The stirring time of the second stirring is 20 to 36 hours, and the rotation speed of the second stirring is 100 to 300 r / min.

[0021] The standing time is 24 to 36 hours.

[0022] Due to the adoption of the above technical solution, the present invention has the following positive effects compared with the prior art:

[0023] 1. The existing method for separating vanadium from iron and phosphorus in an acidic vanadium-containing solution is only applicable to an acidic environment with a pH value of 0.5-2.0, while the "resin for adsorbing vanadium in an acidic vanadium-containing solution" filled in the ion exchange column of the present invention can extract vanadium from an acidic vanadium-containing solution with a pH value of 0-2.5, so the pH adaptability range of the present invention is wider.

[0024] In the present invention, when the pH value is 0-1, the vanadium in the acidic vanadium-containing solution is mainly in the form of VO2 +The phosphorus-containing group in the resin used for adsorbing vanadium in acidic vanadium-containing solution exchanges cations with the vanadium in the acidic vanadium-containing solution; when the pH value is 1-2, the vanadium in the acidic vanadium-containing solution is mainly in the form of VO2 + There are many forms such as polyvanadate anions, VO2 + The vanadium in the form of polyvanadate anions exchanges cations with phosphorus-containing groups, and the vanadium in the form of polyvanadate anions exchanges anions with nitrogen-containing groups; when the pH value is 2 to 2.5, the vanadium in the acidic vanadium-containing solution mainly exists in the form of polyvanadate anions, and the adopted "resin for adsorbing vanadium in the acidic vanadium-containing solution" exchanges anions with vanadium through nitrogen-containing groups, so the pH adaptability range of the present invention is wide.

[0025] 2. The present invention uses an ion exchange column and a "resin for adsorbing vanadium in an acidic vanadium-containing solution" filled in the ion exchange column to adsorb the acidic vanadium-containing solution. By adjusting the flow rate of the acidic vanadium-containing solution through the ion exchange column and the volume of the "resin for adsorbing vanadium in an acidic vanadium-containing solution" filled in the ion exchange column, and then by adjusting the concentration of sulfuric acid, the flow rate of sulfuric acid through the ion exchange column, etc., the resin has the characteristics of large saturated adsorption capacity and high vanadium adsorption rate, and effectively realizes the efficient separation of vanadium from iron and phosphorus. In addition, since the iron in the acidic vanadium-containing solution exists in the form of cations and phosphorus exists in the form of phosphates, the method of the present invention has low affinity with iron and phosphates in the form of cations, and has low affinity with VO2 + The affinity with polyvanadate anion is high, so the adsorption rate of vanadium is high, the adsorption rate of iron and phosphorus is low, and the separation effect of vanadium, iron and phosphorus is good. After testing: the adsorption rate of vanadium is >99%, the adsorption rate of iron is <25%, and the adsorption rate of phosphorus is <20%. Through desorption: the desorption rate of vanadium is >99%, the iron content in vanadium-rich liquid is <1g / L, and the phosphorus content is <0.2g / L, and the separation effect of vanadium, iron and phosphorus is good.

[0026] 3. Since the present invention is applicable to an acidic environment with a pH value of 0.5-2.0 and has the advantage of a wide applicable pH range, the present invention does not need to use alkaline agents to adjust the pH of the acidic vanadium-containing solution. Compared with other methods that use ion exchange processes to separate vanadium from iron and phosphorus in acidic vanadium-containing solutions, the present invention reduces the process of using alkaline agents such as sodium hydroxide and calcium hydroxide to adjust the pH, and the agent consumption is small.

[0027] Therefore, the present invention has the characteristics of wide pH applicable range, low reagent consumption and good separation effect of vanadium, iron and phosphorus. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with specific implementation modes, but is not intended to limit the protection scope thereof.

[0029] A method for separating vanadium from iron and phosphorus in an acidic vanadium-containing solution by ion exchange. The method described in this specific embodiment is:

[0030] Step 1: Resin adsorption

[0031] The filling resin is placed in the ion exchange column at a ratio of 1:2-3 of the volume of the filling resin to the volume of the ion exchange column, and then the acidic vanadium-containing solution is flowed into the ion exchange column at a flow rate of 1-1.5 BV / h until the resin filled in the ion exchange column is saturated with adsorption, thereby obtaining loaded resin and adsorption residual liquid.

[0032] Step 2: Resin desorption

[0033] First, 5-10 BV of deionized water is countercurrently passed through the loaded resin in the ion exchange column at a flow rate of 2-5 BV / h to obtain the resin to be desorbed and washing wastewater; then 0.2-0.5 BV of sulfuric acid is countercurrently passed through the resin to be desorbed in the ion exchange column at a flow rate of 0.2-0.5 BV / h to desorb and obtain the desorbed resin and vanadium-rich liquid.

[0034] The filling resin is a resin used for adsorbing vanadium in an acidic vanadium-containing solution. The preparation method of the resin is as follows: a macroporous anion exchange resin and phytic acid are mixed at a solid-liquid ratio of 1: (15-30) kg / L to obtain a mixture I; the mixture I is stirred for the first time at a temperature of 30-90° C., and the solid-liquid separation is performed to obtain a resin to be treated and a pre-treated liquid; the resin to be treated and oxalic acid are mixed at a solid-liquid ratio of 1: (18-32) kg / L to obtain a mixture II; the mixture II is stirred for the second time at a temperature of 40-80° C., and the solid-liquid separation is performed to obtain a treated resin and a modified residual liquid; the treated resin is allowed to stand to obtain a resin used for adsorbing vanadium in an acidic vanadium-containing solution.

[0035] The pH of the acidic vanadium-containing solution is 0-2.5.

[0036] The concentration of the sulfuric acid is 2-5 mol / L.

[0037] The functional group of the macroporous anion exchange resin is [-N(CH3)3OH].

[0038] The concentration of the phytic acid is 0.03-0.13 mol / L.

[0039] The concentration of the oxalic acid is 0.1-0.5 mol / L.

[0040] The stirring time of the first stirring is 20 to 40 hours, and the rotation speed of the first stirring is 100 to 300 r / min.

[0041] The stirring time of the second stirring is 20 to 36 hours, and the rotation speed of the second stirring is 100 to 300 r / min.

[0042] The standing time is 24 to 36 hours.

[0043] In this specific implementation mode:

[0044] The functional group of the macroporous anion exchange resin is [-N(CH3)3OH].

[0045] This will not be described in detail in the embodiments.

[0046] Example 1

[0047] A method for separating vanadium from iron and phosphorus in an acidic vanadium-containing solution by ion exchange. The method described in this embodiment is carried out according to the following steps:

[0048] Step 1: Resin adsorption

[0049] The filling resin is placed in the ion exchange column at a ratio of 1:3 of the volume of the filling resin to the volume of the ion exchange column, and then the acidic vanadium-containing solution is flowed into the ion exchange column at a flow rate of 1 BV / h until the resin filled in the ion exchange column is saturated with adsorption, thereby obtaining loaded resin and adsorption residual liquid.

[0050] Step 2: Resin desorption

[0051] First, 5BV of deionized water is countercurrently passed through the loaded resin in the ion exchange column at a flow rate of 2BV / h to obtain the resin to be desorbed and washing wastewater; then 0.2BV of sulfuric acid is countercurrently passed through the resin to be desorbed in the ion exchange column at a flow rate of 0.2BV / h to desorb and obtain the desorbed resin and vanadium-rich liquid.

[0052] The filling resin is a resin used for adsorbing vanadium in an acidic vanadium-containing solution. The preparation method of the resin is as follows: a macroporous anion exchange resin and phytic acid are mixed at a solid-liquid ratio of 1:15 kg / L to obtain a mixture I; the mixture I is stirred for the first time at a temperature of 30°C, and the solid-liquid separation is performed to obtain a resin to be treated and a pre-treated liquid; the resin to be treated and oxalic acid are mixed at a solid-liquid ratio of 1:18 kg / L to obtain a mixture II; the mixture II is stirred for the second time at a temperature of 40°C, and the solid-liquid separation is performed to obtain a treated resin and a modified residual liquid; the treated resin is allowed to stand to obtain a resin used for adsorbing vanadium in an acidic vanadium-containing solution.

[0053] The pH of the acidic vanadium-containing solution is 0.

[0054] The concentration of the sulfuric acid is 2 mol / L.

[0055] The concentration of the phytic acid is 0.13 mol / L.

[0056] The concentration of the oxalic acid is 0.5 mol / L.

[0057] The stirring time of the first stirring is 20 hours, and the rotation speed of the first stirring is 100 r / min.

[0058] The stirring time of the second stirring is 20 hours, and the rotation speed of the second stirring is 100 r / min.

[0059] The standing time is 24h.

[0060] In this embodiment, the V concentration in the acidic vanadium-containing solution is 1.5 g / L; the Fe concentration is 6.5 g / L, and the P concentration is 1.2 g / L. The separation effect of vanadium from iron and phosphorus is shown in Table 1:

[0061] Table 1 Separation effect of vanadium, iron and phosphorus

[0062]

[0063] Example 2

[0064] A method for separating vanadium from iron and phosphorus in an acidic vanadium-containing solution by ion exchange. The method described in this embodiment is carried out according to the following steps:

[0065] Step 1: Resin adsorption

[0066] The filling resin is placed in the ion exchange column at a ratio of 1:2.6 of the volume of the filling resin to the volume of the ion exchange column, and then the acidic vanadium-containing solution is flowed into the ion exchange column at a flow rate of 1.2 BV / h until the resin filled in the ion exchange column is saturated with adsorption, thereby obtaining loaded resin and adsorption residual liquid.

[0067] Step 2: Resin desorption

[0068] First, 6.65BV of deionized water is countercurrently passed through the loaded resin in the ion exchange column at a flow rate of 3BV / h to obtain the resin to be desorbed and washing wastewater; then 0.3BV of sulfuric acid is countercurrently passed through the resin to be desorbed in the ion exchange column at a flow rate of 0.3BV / h to desorb and obtain the desorbed resin and vanadium-rich liquid.

[0069] The filling resin is a resin used for adsorbing vanadium in an acidic vanadium-containing solution. The preparation method of the resin is as follows: a macroporous anion exchange resin is mixed with phytic acid at a solid-liquid ratio of 1:20 kg / L to obtain a mixture I; the mixture I is stirred for the first time at a temperature of 50°C, and the solid-liquid separation is performed to obtain a resin to be treated and a pre-treated liquid; the resin to be treated and oxalic acid are mixed at a solid-liquid ratio of 1:23 kg / L to obtain a mixture II; the mixture II is stirred for the second time at a temperature of 55°C, and the solid-liquid separation is performed to obtain a treated resin and a modified residual liquid; the treated resin is allowed to stand to obtain a resin used for adsorbing vanadium in an acidic vanadium-containing solution.

[0070] The pH of the acidic vanadium-containing solution is 0.8.

[0071] The concentration of the sulfuric acid is 3 mol / L.

[0072] The concentration of the phytic acid is 0.1 mol / L.

[0073] The concentration of the oxalic acid is 0.35 mol / L.

[0074] The stirring time of the first stirring is 25 hours, and the rotation speed of the first stirring is 165 r / min.

[0075] The stirring time of the second stirring is 25 hours, and the rotation speed of the second stirring is 165 r / min.

[0076] The standing time is 28 hours.

[0077] In this embodiment, the V concentration in the acidic vanadium-containing solution is 1.5 g / L; the Fe concentration is 6.5 g / L, and the P concentration is 1.2 g / L. The separation effect of vanadium from iron and phosphorus is shown in Table 1:

[0078] Table 1 Separation effect of vanadium, iron and phosphorus

[0079]

[0080] Example 3

[0081] A method for separating vanadium from iron and phosphorus in an acidic vanadium-containing solution by ion exchange. The method described in this embodiment is carried out according to the following steps:

[0082] Step 1: Resin adsorption

[0083] The filling resin is placed in the ion exchange column at a ratio of 1:2.3 of the volume of the filling resin to the volume of the ion exchange column, and then the acidic vanadium-containing solution is flowed into the ion exchange column at a flow rate of 1.35 BV / h until the resin filled in the ion exchange column is saturated with adsorption, thereby obtaining a loaded resin and adsorption residual liquid.

[0084] Step 2: Resin desorption

[0085] First, 8.30 BV of deionized water is countercurrently passed through the loaded resin in the ion exchange column at a flow rate of 4 BV / h to obtain the resin to be desorbed and washing wastewater; then 0.4 BV of sulfuric acid is countercurrently passed through the resin to be desorbed in the ion exchange column at a flow rate of 0.4 BV / h to desorb, and the desorbed resin and vanadium-rich liquid are obtained.

[0086] The filling resin is a resin used for adsorbing vanadium in an acidic vanadium-containing solution. The preparation method of the resin is as follows: a macroporous anion exchange resin and phytic acid are mixed at a solid-liquid ratio of 1:25 kg / L to obtain a mixture I; the mixture I is stirred for the first time at a temperature of 70°C, and the solid-liquid is separated to obtain a resin to be treated and a pre-treated liquid; the resin to be treated and oxalic acid are mixed at a solid-liquid ratio of 1:28 kg / L to obtain a mixture II; the mixture II is stirred for the second time at a temperature of 68°C, and the solid-liquid is separated to obtain a treated resin and a modified residual liquid; the treated resin is allowed to stand to obtain a resin used for adsorbing vanadium in an acidic vanadium-containing solution.

[0087] The pH of the acidic vanadium-containing solution is 1.65.

[0088] The concentration of the sulfuric acid is 4 mol / L.

[0089] The concentration of the phytic acid is 0.06 mol / L.

[0090] The concentration of the oxalic acid is 0.25 mol / L.

[0091] The stirring time of the first stirring is 30 hours, and the rotation speed of the first stirring is 230 r / min.

[0092] The stirring time of the second stirring is 30 hours, and the rotation speed of the second stirring is 230 r / min.

[0093] The standing time is 32h.

[0094] In this embodiment, the V concentration in the acidic vanadium-containing solution is 1.5 g / L; the Fe concentration is 6.5 g / L, and the P concentration is 1.2 g / L. The separation effect of vanadium from iron and phosphorus is shown in Table 1:

[0095] Table 1 Separation effect of vanadium, iron and phosphorus

[0096]

[0097] Example 4

[0098] A method for separating vanadium from iron and phosphorus in an acidic vanadium-containing solution by ion exchange. The method described in this embodiment is carried out according to the following steps:

[0099] Step 1: Resin adsorption

[0100] The filling resin is placed in the ion exchange column at a ratio of 1:2 of the volume of the filling resin to the volume of the ion exchange column, and then the acidic vanadium-containing solution is flowed into the ion exchange column at a flow rate of 1.5 BV / h until the resin filled in the ion exchange column is saturated with adsorption, thereby obtaining loaded resin and adsorption residual liquid.

[0101] Step 2: Resin desorption

[0102] First, 10BV of deionized water is countercurrently passed through the loaded resin in the ion exchange column at a flow rate of 5BV / h to obtain the resin to be desorbed and washing wastewater; then 0.5BV of sulfuric acid is countercurrently passed through the resin to be desorbed in the ion exchange column at a flow rate of 0.5BV / h to desorb and obtain the desorbed resin and vanadium-rich liquid.

[0103] The filling resin is a resin used for adsorbing vanadium in an acidic vanadium-containing solution. The preparation method of the resin is as follows: a macroporous anion exchange resin and phytic acid are mixed at a solid-liquid ratio of 1:30 kg / L to obtain a mixture I; the mixture I is stirred for the first time at a temperature of 90°C, and the solid-liquid is separated to obtain a resin to be treated and a pre-treated liquid; the resin to be treated and oxalic acid are mixed at a solid-liquid ratio of 1:32 kg / L to obtain a mixture II; the mixture II is stirred for the second time at a temperature of 80°C, and the solid-liquid is separated to obtain a treated resin and a modified residual liquid; the treated resin is allowed to stand to obtain a resin used for adsorbing vanadium in an acidic vanadium-containing solution.

[0104] The pH of the acidic vanadium-containing solution is 2.5.

[0105] The concentration of the sulfuric acid is 5 mol / L.

[0106] The concentration of the phytic acid is 0.03 mol / L.

[0107] The concentration of the oxalic acid is 0.1 mol / L.

[0108] The stirring time of the first stirring is 40 hours, and the rotation speed of the first stirring is 300 r / min.

[0109] The stirring time of the second stirring is 36 hours, and the rotation speed of the second stirring is 300 r / min.

[0110] The standing time is 36 hours.

[0111] In this embodiment, the V concentration in the acidic vanadium-containing solution is 1.5 g / L; the Fe concentration is 6.5 g / L, and the P concentration is 1.2 g / L. The separation effect of vanadium from iron and phosphorus is shown in Table 1:

[0112] Table 1 Separation effect of vanadium, iron and phosphorus

[0113]

[0114] Compared with the prior art, this specific implementation has the following positive effects:

[0115] 1. The existing method of separating vanadium from iron and phosphorus in an acidic vanadium-containing solution is only applicable to an acidic environment with a pH value of 0.5-2.0, while the "resin for adsorbing vanadium in an acidic vanadium-containing solution" filled in the ion exchange column of this specific embodiment can extract vanadium from an acidic vanadium-containing solution with a pH value of 0 to 2.5, so the pH adaptability range of this specific embodiment is wider.

[0116] In this specific embodiment: when the pH value is 0-1, the vanadium in the acidic vanadium-containing solution is mainly in the form of VO2 + The phosphorus-containing group in the resin used for adsorbing vanadium in acidic vanadium-containing solution exchanges cations with the vanadium in the acidic vanadium-containing solution; when the pH value is 1-2, the vanadium in the acidic vanadium-containing solution is mainly in the form of VO2 + There are many forms such as polyvanadate anions, VO2 + The vanadium in the form of polyvanadate anions exchanges cations with phosphorus-containing groups, and the vanadium in the form of polyvanadate anions exchanges anions with nitrogen-containing groups; when the pH value is 2 to 2.5, the vanadium in the acidic vanadium-containing solution mainly exists in the form of polyvanadate anions, and the "resin for adsorbing vanadium in the acidic vanadium-containing solution" used exchanges anions with vanadium through nitrogen-containing groups, so the pH adaptability range of this specific embodiment is wide.

[0117] 2. This specific implementation method uses an ion exchange column and a "resin for adsorbing vanadium in an acidic vanadium-containing solution" filled in the ion exchange column to adsorb the acidic vanadium-containing solution. By adjusting the flow rate of the acidic vanadium-containing solution through the ion exchange column and the volume of the "resin for adsorbing vanadium in an acidic vanadium-containing solution" filled in the ion exchange column, and then adjusting the concentration of sulfuric acid, the flow rate of sulfuric acid through the ion exchange column, etc., the resin has the characteristics of large saturated adsorption capacity and high vanadium adsorption rate, and effectively realizes the efficient separation of vanadium from iron and phosphorus. In addition, since the iron in the acidic vanadium-containing solution exists in the form of cations and phosphorus exists in the form of phosphates, the method described in this specific implementation method has low affinity with iron and phosphates in the form of cations, and has low affinity with VO2 +The affinity with polyvanadate anion is high, so the adsorption rate of vanadium is high, the adsorption rate of iron and phosphorus is low, and the separation effect of vanadium, iron and phosphorus is good. After testing: the adsorption rate of vanadium is >99%, the adsorption rate of iron is <25%, and the adsorption rate of phosphorus is <20%. Through desorption: the desorption rate of vanadium is >99%, the iron content in vanadium-rich liquid is <1g / L, and the phosphorus content is <0.2g / L, and the separation effect of vanadium, iron and phosphorus is good.

[0118] 3. Since this specific implementation is applicable to an acidic environment with a pH value of 0.5-2.0 and has the advantage of a wide pH application range, this specific implementation does not require the use of alkaline agents to adjust the pH of the acidic vanadium-containing solution. Compared with other methods that use ion exchange processes to separate vanadium from iron and phosphorus in acidic vanadium-containing solutions, this method reduces the process of using alkaline agents such as sodium hydroxide and calcium hydroxide to adjust the pH, and the agent consumption is small.

[0119] Therefore, this specific implementation has the characteristics of wide pH applicable range, low reagent consumption, and good separation effect of vanadium, iron and phosphorus.

Claims

1. A method for separating vanadium from iron and phosphorus in an acidic vanadium-containing solution by ion exchange, characterized in that: The method for separating vanadium from iron and phosphorus is carried out according to the following steps: Step 1: Resin adsorption The filling resin is placed in the ion exchange column at a ratio of 1:2-3 of the volume of the filling resin to the volume of the ion exchange column, and then the acidic vanadium-containing solution is flowed into the ion exchange column at a flow rate of 1-1.5 BV / h until the filling resin in the ion exchange column is saturated with adsorption, thereby obtaining a loaded resin and an adsorption residual liquid; Step 2: Resin desorption First, 5-10 BV of deionized water is countercurrently passed through the loaded resin in the ion exchange column at a flow rate of 2-5 BV / h to obtain the resin to be desorbed and washing wastewater; then 0.2-0.5 BV of sulfuric acid is countercurrently passed through the resin to be desorbed in the ion exchange column at a flow rate of 0.2-0.5 BV / h to desorb and obtain the desorbed resin and vanadium-rich liquid.

2. The method for separating vanadium from iron and phosphorus in an acidic vanadium-containing solution by ion exchange according to claim 1, characterized in that: The filling resin is a resin used for adsorbing vanadium in an acidic vanadium-containing solution. The preparation method of the resin is as follows: a macroporous anion exchange resin and phytic acid are mixed at a solid-liquid ratio of 1: (15-30) kg / L to obtain a mixture I; the mixture I is stirred for the first time at a temperature of 30-90° C., and the solid-liquid separation is performed to obtain a resin to be treated and a pre-treated liquid; the resin to be treated and oxalic acid are mixed at a solid-liquid ratio of 1: (18-32) kg / L to obtain a mixture II; the mixture II is stirred for the second time at a temperature of 40-80° C., and the solid-liquid separation is performed to obtain a treated resin and a modified residual liquid; the treated resin is allowed to stand to obtain a resin used for adsorbing vanadium in an acidic vanadium-containing solution.

3. The method for separating vanadium from iron and phosphorus in an acidic vanadium-containing solution by ion exchange according to claim 1, characterized in that: Features The pH of the acidic vanadium-containing solution is 0-2.

5.

4. The method for separating vanadium from iron and phosphorus in an acidic vanadium-containing solution by ion exchange according to claim 1, characterized in that: Features The concentration of the sulfuric acid is 2-5 mol / L.

5. The method for separating vanadium from iron and phosphorus in an acidic vanadium-containing solution by ion exchange according to claim 2, characterized in that: The functional group of the macroporous anion exchange resin is [-N(CH3)3OH].

6. The method for separating vanadium from iron and phosphorus in an acidic vanadium-containing solution by ion exchange according to claim 2, characterized in that: The concentration of the phytic acid is 0.03-0.13 mol / L.

7. The method for separating vanadium from iron and phosphorus in an acidic vanadium-containing solution by ion exchange according to claim 2, characterized in that: The concentration of the oxalic acid is 0.1-0.5 mol / L.

8. The method for separating vanadium from iron and phosphorus in an acidic vanadium-containing solution by ion exchange according to claim 2, characterized in that: The stirring time of the first stirring is 20 to 40 hours, and the rotation speed of the first stirring is 100 to 300 r / min.

9. The method for separating vanadium from iron and phosphorus in an acidic vanadium-containing solution by ion exchange according to claim 2, characterized in that: The stirring time of the second stirring is 20 to 36 hours, and the rotation speed of the second stirring is 100 to 300 r / min.

10. The method for separating vanadium from iron and phosphorus in an acidic vanadium-containing solution by ion exchange according to claim 2, characterized in that: The standing time is 24 to 36 hours.

Images