Process for deeply separating tungsten and vanadium in molybdate solution

Abstract

The invention provides a process for deeply separating tungsten and vanadium in a molybdate solution, which comprises the following steps: (1) adjusting the pH value of the molybdate solution containing tungsten and vanadium to 7.0-8.0 and the specific gravity to 1.05-1.22, and filtering to obtain a pre-exchange solution; (2) adsorbing the pre-exchange solution through strong-alkalinity macroporous anion exchange resin, stopping adsorption when the concentration of vanadium discharged from a column is greater than a set value, and washing with industrial water until the concentration of molybdenum discharged from the column is lower than 50mg / L; (3) adding a vanadium resolving agent, resolving to obtain a vanadium-containing solution, washing with water, and stopping washing when the pH is greater than 3 to obtain tungsten to be resolved; and (4) feeding a tungsten resolving agent, and resolving to obtain a tungsten-containing solution. According to the method, tungsten and vanadium in the molybdate solution are enriched through an ion exchange method, molybdenum enters the after-exchange solution, the tungsten and the vanadium are separated through step-by-step analysis, the vanadium is analyzed through a mixed solution of hydrochloric acid and hydrogen peroxide, then the tungsten is analyzed through a liquid alkali solution with a certain concentration, and therefore deep separation of the molybdenum, the tungsten and the vanadium is achieved, and the yield of the molybdenum, the yield of the tungsten and the yield of the vanadium are all larger than 99%.

Description

Technical Field

[0001] The invention belongs to the technical field of molybdenum, tungsten and vanadium separation, and relates to a process for deeply separating tungsten and vanadium in a molybdate solution. Background Art

[0002] Molybdenum is an important strategic resource, widely used in industry, and is known as the "teeth of industry". With the continuous mining of raw ore, molybdenum resources are becoming increasingly depleted. Separating tungsten and vanadium from molybdate solutions containing tungsten and vanadium can not only purify molybdenum, but also make comprehensive use of valuable metal resources.

[0003] The separation of tungsten and vanadium from molybdate mainly adopts precipitation method, extraction method and ion exchange method.

[0004] Precipitation method: Calcium chloride, ammonium chloride and ferric chloride are currently mainly used to precipitate vanadium. After vanadium precipitation with ammonium chloride, the mother liquor needs to be deaminated, and the precipitation rate of vanadium is about 98.5%, the precipitation rate of molybdenum is about 47.5%, and the precipitation rate of tungsten is about 50.3%; vanadium precipitation with ferric chloride and calcium chloride, the precipitation rate of vanadium is about 99.5%, the precipitation rate of molybdenum and the precipitation rate of tungsten are 67.1% and 75.2% respectively; the precipitation method cannot achieve the deep separation of molybdenum, tungsten and vanadium, and the loss of molybdenum is too large.

[0005] Extraction method: The cost of the extractant is high, the loss is large, the on-site environment is poor, and the separation of molybdenum, tungsten and vanadium is not complete.

[0006] Ion exchange method: It has been reported that the ion exchange method can only enrich tungsten and vanadium in molybdate solution, but there is no report on the method of deep separation of tungsten and vanadium by ion exchange. Summary of the invention

[0007] In view of the above problems, the purpose of the present invention is to provide a process for deep separation of tungsten and vanadium in molybdate solution. Through adsorption, the molybdenum in the molybdate solution enters the post-delivery liquid, thereby realizing the deep separation of tungsten and vanadium. Through step-by-step analysis, the deep separation of tungsten and vanadium is realized.

[0008] The technical solution adopted by the present invention is:

[0009] A process for deep separation of tungsten and vanadium in molybdate solution, comprising:

[0010] (1) adjusting the pH of the molybdate solution containing tungsten and vanadium to 7.0-8.0 and the specific gravity to 1.05-1.22, and filtering to obtain a pre-delivery solution;

[0011] (2) The pre-handling liquid is adsorbed by a macroporous strong alkaline anion exchange resin. When the vanadium concentration out of the column is greater than the set value, the adsorption is stopped and industrial water is used for washing until the molybdenum concentration out of the column is less than 50 mg / L;

[0012] (3) adding a vanadium analytical agent to analyze to obtain a vanadium-containing solution, washing with water until the pH value is greater than 3, and then washing is stopped to analyze tungsten;

[0013] (4) Add a tungsten analyzing agent to obtain a tungsten-containing solution.

[0014] Preferably, in step (1), the tungsten-vanadium-containing molybdate solution contains 10-100 g / L Mo, 0.1-100 g / L W, 0.1-30 g / L V, and a pH of 1-14; more preferably 40-100 g / L Mo, 1-30 g / L W, 0.1-30 g / L V, and a pH of 5-12.

[0015] Preferably, in step (1), the pH of the molybdate solution containing tungsten and vanadium is adjusted to 7.0-8.0 using an inorganic acid or base.

[0016] Preferably, in step (2), the adsorption linear velocity is 0.5 to 3 m / s, more preferably 1.0 to 2.0 m / s.

[0017] Preferably, in step (2), the adsorption endpoint is when the column outlet vanadium concentration is greater than 10 mg / L.

[0018] Preferably, in step (3), the vanadium desorbing agent is a mixed solution of hydrochloric acid with a mass volume concentration of 60 to 100 g / L and hydrogen peroxide with a mass percentage concentration of 4% to 10%.

[0019] Preferably, in step (3), the linear speed of vanadium desorption is 1 to 2 m / s.

[0020] Preferably, in step (3), the linear speed of water washing is 2 to 3 m / s.

[0021] Preferably, in step (4), the tungsten analyzing agent is a sodium hydroxide solution with a mass volume concentration of 100 to 160 g / L.

[0022] Preferably, in step (4), the linear speed of analyzing tungsten is 1 to 2 m / s.

[0023] The beneficial effects of the present invention are:

[0024] The molybdate solution containing tungsten and vanadium is separated from molybdenum and enriched with tungsten and vanadium by ion exchange adsorption. The step-by-step analysis is adopted, firstly the vanadium is analyzed with a mixed solution of hydrochloric acid and hydrogen peroxide, and then the tungsten is analyzed with a liquid alkali solution, so as to achieve the deep separation of tungsten and vanadium. After the removal of tungsten and vanadium, the tungsten concentration and vanadium concentration in the molybdate solution are both lower than 10 mg / L, the tungsten concentration and molybdenum concentration in the obtained vanadium solution are both lower than 50 mg / L, the molybdenum concentration in the tungsten-containing solution is lower than 50 mg / L, and the vanadium concentration is lower than 100 mg / L; the recovery rates of tungsten and vanadium are both greater than 99%. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0026] In order to explain the present invention more clearly, the present invention is further described in detail below in conjunction with embodiments and with reference to the accompanying drawings. It should be understood by those skilled in the art that the content described below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention.

[0027] Example

[0028] The raw material is a sodium molybdate solution containing tungsten and vanadium. The pre-handling liquid Mo: 45.2g / l, W: 8.8g / L, V: 4.8g / L, pH: 9-10. The deep separation of molybdenum, tungsten and vanadium in the sodium molybdate solution is achieved by the following method.

[0029] Combination Figure 1 , the method of the present invention mainly comprises the following steps:

[0030] Pretreatment: By adjusting the pH value of the sodium molybdate solution containing tungsten and vanadium, the optimal conditions for enriching tungsten and vanadium with the ion exchange resin are achieved. Under this condition, the affinity of tungstate ions and vanadate ions with the resin exceeds that of molybdate ions. Molybdate ions compete with tungstate ions and vanadate ions for adsorption, and are not adsorbed by the ion exchange resin and enter the post-exchange liquid, thereby achieving the separation of molybdenum from tungsten and vanadium. Add inorganic acid (including but not limited to sulfuric acid, hydrochloric acid, nitric acid, etc., hydrochloric acid is used in this embodiment) to adjust the pH to about 7.5 (7.0-8.0), the specific gravity of the sodium molybdate mixed solution is 1.05-1.22, and the specific gravity of the solution is less than the wet true specific gravity of the resin. The ion exchange resin will not float up to cause a short circuit between the ions in the solution and the resin, which is conducive to the occurrence of adsorption behavior.

[0031] Adsorption: The pre-handover liquid is adsorbed by a macroporous strongly basic anion exchange resin (D231 resin is used in this embodiment), and the adsorption linear velocity is 1.5 m / s. Through experimental determination, the solution flow rate is lower than the adsorption rate of the ionic group at this linear velocity, which is conducive to the combination of the ionic group and the resin; if the vanadium in the molybdate solution is to be deeply removed, the lower the vanadium concentration in the post-handover liquid solution, the higher the impurity removal rate of molybdenum, and the affinity of the resin for the ionic group is molybdenum> tungsten> vanadium, so the vanadium concentration in the column solution is used as the adsorption end point judgment, and the adsorption end point judgment standard is: the column vanadium concentration is greater than 10 mg / l. After adsorption saturation, it is washed with industrial water, and the washing qualified standard is: the column molybdenum is less than 50 mg / L.

[0032] Vanadium desorbent: a mixed solution of 75g / L hydrochloric acid and 5% hydrogen peroxide (when preparing, add 27L of 30% concentrated hydrochloric acid and 27.5% hydrogen peroxide to every 100L of water). 2 O 22.2L), stirring and mixing to form a vanadium desorbent, the mixed desorbent can desorb vanadate ions from the ion exchange resin into the solution, while tungstate remains on the ion exchange resin, thereby achieving deep separation of vanadium and tungsten. A mixed solution of hydrochloric acid mass volume concentration of 60-100g / L and hydrogen peroxide mass percentage concentration of 4%-10% can be used as the vanadium desorbent of the present application.

[0033] Analysis of vanadium: Add vanadium analyzer, the analysis line speed is 1.5m / s, and the vanadium-containing solution (V 29.5g / L, W 25.6mg / L) is obtained.

[0034] Analysis and water washing: After the vanadium is analyzed, water is added for washing at a line speed of 3m / s until the pH is greater than 3 and the washing is stopped until the tungsten is analyzed.

[0035] Tungsten analytical agent: Sodium hydroxide solution with a concentration of 150g / L, 100-160g / L strong alkaline solution can desorb tungstate ions from ion exchange resin.

[0036] Tungsten analysis: Add tungsten analyzer, analyze at a linear speed of 1.5m / s, and obtain sodium tungstate solution (W 46.1g / L, V 33.50mg / L).

[0037] Ion exchange resin can be recycled through adsorption-desorption.

[0038] The sodium molybdate solution containing tungsten and vanadium is separated from molybdenum and enriched with tungsten and vanadium by ion exchange adsorption. The solution is analyzed step by step, first using a mixed solution of hydrochloric acid and hydrogen peroxide to analyze vanadium, and then using a liquid alkali solution to analyze tungsten. Among them, 99.5% of the molybdenum in the pre-delivery liquid enters the post-delivery liquid, and the recovery rate of vanadium desorbed is 99.2%, and the recovery rate of tungsten desorbed is 99.6%, thereby achieving deep separation of molybdenum, tungsten and vanadium.

[0039] It can be understood that, based on the inventive concept of the present application, the raw material, in addition to the sodium molybdate solution in the embodiment, can also be other molybdate solutions containing tungsten and vanadium (preferably composed of Mo10-100g / L, W 0.1-100g / L, V 0.1-30g / L, pH 1-14; more preferably Mo40-100g / L, W 1-30g / L, V0.1-30g / L, pH 5-12).

[0040] Obviously, the above embodiments of the present invention are merely examples to more clearly illustrate the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A process for deep separation of tungsten and vanadium in molybdate solution, comprising: (1) adjusting the pH of the molybdate solution containing tungsten and vanadium to 7.0-8.0 and the specific gravity to 1.05-1.22, and filtering to obtain a pre-delivery solution; (2) The pre-handling liquid is adsorbed by a macroporous strong alkaline anion exchange resin. When the vanadium concentration out of the column is greater than the set value, the adsorption is stopped and industrial water is used for washing until the molybdenum concentration out of the column is less than 50 mg / L; (3) adding a vanadium analytical agent to analyze and obtain a vanadium-containing solution, washing with water until the pH value is greater than 3 and then stopping the washing. Tungsten to be analyzed; (4) Add a tungsten analyzing agent to obtain a tungsten-containing solution.

2. A process for deep separation of tungsten and vanadium in molybdate solution according to claim 1, characterized in that: The molybdate solution containing tungsten and vanadium contains 10-100 g / L Mo, 0.1-100 g / L W, 0.1-30 g / L V, and has a pH of 1-14.

3. The process for deep separation of tungsten and vanadium in molybdate solution according to claim 1, characterized in that: In step (1), the pH of the molybdate solution containing tungsten and vanadium is adjusted to 7.0-8.0 using an inorganic acid or base.

4. The process for deep separation of tungsten and vanadium in molybdate solution according to claim 1, characterized in that: In step (2), the adsorption linear velocity is 0.5 to 3 m / s.

5. The process for deep separation of tungsten and vanadium in molybdate solution according to claim 1, characterized in that: In step (2), the adsorption endpoint is when the vanadium concentration at the outlet of the column is greater than 10 mg / L.

6. The process for deep separation of tungsten and vanadium in molybdate solution according to claim 1, characterized in that: In step (3), the vanadium analytical agent is a mixed solution of hydrochloric acid with a mass volume concentration of 60-100 g / L and hydrogen peroxide with a mass percentage concentration of 4%-10%.

7. A process for deep separation of tungsten and vanadium in molybdate solution according to claim 1 or 6, characterized in that: In step (3), the linear velocity of vanadium extraction is 1 to 2 m / s.

8. The process for deep separation of tungsten and vanadium in molybdate solution according to claim 1, characterized in that: In step (3), the linear speed of water washing is 2 to 3 m / s.

9. The process for deep separation of tungsten and vanadium in molybdate solution according to claim 1, characterized in that: In step (4), the tungsten analyzing agent is a sodium hydroxide solution with a mass volume concentration of 100 to 160 g / L.

10. A process for deep separation of tungsten and vanadium in molybdate solution according to claim 1 or 9, characterized in that: In step (4), the linear speed of analyzing tungsten is 1 to 2 m / s.

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