A method for preparing high-purity nano yellow tungstic acid

Abstract

The present invention belongs to the technical field of tungsten smelting, and specifically relates to a method for preparing high-purity nano yellow tungstic acid, wherein a tungstate solution is prepared for use; hydrochloric acid is prepared for use, and the volume of the hydrochloric acid is 1.2 to 2.0 times the volume of the tungstate solution; the prepared tungstate solution is quickly added to the prepared hydrochloric acid, and then stirred; and high-purity nano yellow tungstic acid is obtained after filtration. By accurately controlling the addition sequence and addition speed of the raw materials, not only can the purity of the obtained product reach the high-purity standard, the purity of the high-purity nano yellow tungstic acid is ≥99.9%, and stable nano yellow tungstic acid can be prepared, and the industrialization prospect is broad.

Description

Technical Field

[0001] The invention belongs to the technical field of tungsten smelting, and specifically relates to a method for preparing high-purity nano yellow tungstic acid. Background Art

[0002] Tungstic acid is an inorganic acid composed of three chemical elements: transition metal tungsten, non-metallic oxygen and hydrogen. It is a compound composed of positive monovalent hydrogen ions and negative divalent tungstate ions. It is an important raw material for the production of tungsten oxide and tungstate. Its color is different depending on the ratio of tungsten trioxide to water. There are two types: yellow and white. According to the different colors, they are named yellow tungstic acid and white tungstic acid, which are slightly different in physical and chemical properties and production processes. The appearance of yellow tungstic acid is light yellow crystals or powder, with a melting point of about 1473℃ and a density of about 5.5g / cm 3 It is insoluble in water and phosphoric acid solution, but soluble in alkaline solution (such as ammonia water) and concentrated hydrochloric acid. It can stably exist at room temperature and pressure, but its thermal stability is poor. It is easy to generate tungsten trioxide and water when heated. In the existing technology, the production of yellow tungstic acid is often mixed with white tungstic acid, and high-purity nano yellow tungstic acid cannot be stably prepared, which affects the application of yellow tungstic acid. Summary of the invention

[0003] In order to solve the problems existing in the prior art, the main purpose of the present invention is to propose a method for preparing high-purity nano yellow tungstic acid. By accurately controlling the addition sequence and addition speed of the raw materials, not only the purity of the obtained product can reach the high-purity standard, but also stable nano yellow tungstic acid can be prepared, and the industrialization prospect is broad.

[0004] To solve the above technical problems, according to one aspect of the present invention, the present invention provides the following technical solutions:

[0005] A method for preparing high-purity nano yellow tungstic acid, wherein the purity of the high-purity nano yellow tungstic acid is ≥99.9%, comprising the following steps:

[0006] S1. Take tungstate solution for later use;

[0007] S2. Prepare hydrochloric acid for use, wherein the volume of the hydrochloric acid is 1.2 to 2.0 times the volume of the tungstate solution;

[0008] S3. The reserved tungstate solution is quickly added to the reserved hydrochloric acid and then stirred;

[0009] S4. After filtration, high-purity nano yellow tungstic acid is obtained.

[0010] As a preferred embodiment of the method for preparing high-purity nano yellow tungstic acid described in the present invention, wherein: in the step S1, the tungstate solution is a solution with a concentration C of 50 to 300 g / L in terms of tungsten trioxide.

[0011] As a preferred embodiment of the method for preparing high-purity nano tungstic acid according to the present invention, wherein: in the step S2, the concentration H of the hydrochloric acid is adjusted according to the concentration C of the tungstate solution.

[0012] As a preferred embodiment of the method for preparing high-purity nano tungstic acid according to the present invention, wherein: when the tungstate solution is a solution with a concentration C of 50 g / L ≤ C ≤ 100 g / L in terms of tungsten trioxide, the hydrochloric acid concentration H is 2.8 mol / L < H ≤ 4.2 mol / L.

[0013] As a preferred embodiment of the method for preparing high-purity nano tungstic acid according to the present invention, wherein: when the tungstate solution is a solution with a concentration C of 100 g / L < C ≤ 150 g / L in terms of tungsten trioxide, the hydrochloric acid concentration H is 4.2 mol / L < H ≤ 5.5 mol / L.

[0014] As a preferred embodiment of the method for preparing high-purity nano tungstic acid according to the present invention, wherein: when the tungstate solution is a solution with a concentration C of 150 g / L < C ≤ 200 g / L in terms of tungsten trioxide, the hydrochloric acid concentration H is 5.5 mol / L < H ≤ 6.6 mol / L.

[0015] As a preferred embodiment of the method for preparing high-purity nano tungstic acid according to the present invention, wherein: when the tungstate solution is a solution with a concentration C of 200 g / L < C ≤ 250 g / L in terms of tungsten trioxide, the hydrochloric acid concentration H is 6.6 mol / L < H ≤ 8.4 mol / L.

[0016] As a preferred embodiment of the method for preparing high-purity nano tungstic acid according to the present invention, wherein: when the tungstate solution is a solution with a concentration C of 250 g / L < C ≤ 350 g / L in terms of tungsten trioxide, the hydrochloric acid concentration H > 8.4 mol / L.

[0017] As a preferred embodiment of the method for preparing high-purity nano tungstic acid according to the present invention, wherein: in the step S2, the stirring time is 0.5 - 1.0 h.

[0018] A high-purity nano tungstic acid is prepared by the above method for preparing high-purity nano tungstic acid.

[0019] As a preferred embodiment of the high-purity nano tungstic acid according to the present invention, wherein: the purity of the high-purity nano tungstic acid is ≥ 99.9%.

[0020] The beneficial effects of the present invention are as follows:

[0021] The present invention proposes a method for preparing high-purity nano yellow tungstic acid, which comprises the following steps: taking a tungstate solution for standby; taking hydrochloric acid for standby, wherein the volume of the hydrochloric acid is 1.2 to 2.0 times the volume of the tungstate solution; rapidly adding the standby tungstate solution into the standby hydrochloric acid, and then stirring; filtering to obtain high-purity nano yellow tungstic acid. By precisely controlling the order and speed of adding the raw materials, not only can the purity of the obtained product reach the high-purity standard, the purity of the high-purity nano yellow tungstic acid is ≥99.9%, but also stable nano yellow tungstic acid can be prepared, and the industrialization prospect is broad. DETAILED DESCRIPTION

[0022] The following will be described clearly and completely in conjunction with the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0023] The main purpose of the present invention is to provide a method for preparing high-purity nano yellow tungstic acid. By accurately controlling the order and speed of adding raw materials, not only can the purity of the obtained product reach the high-purity standard, but also stable nano yellow tungstic acid can be prepared, and the industrialization prospect is broad.

[0024] According to one aspect of the present invention, the present invention provides the following technical solution:

[0025] A method for preparing high-purity nano yellow tungstic acid, wherein the purity of the high-purity nano yellow tungstic acid is ≥99.9%, comprising the following steps:

[0026] S1. Take tungstate solution for later use;

[0027] S2. Prepare hydrochloric acid for use, wherein the volume of the hydrochloric acid is 1.2 to 2.0 times the volume of the tungstate solution;

[0028] S3. The reserved tungstate solution is quickly added to the reserved hydrochloric acid and then stirred;

[0029] S4. After filtration, high-purity nano yellow tungstic acid is obtained.

[0030] Preferably, in step S1, the tungstate solution is a solution with a concentration C of 50 to 300 g / L in terms of tungsten trioxide. Specifically, in terms of tungsten trioxide, the concentration C can be, for example but not limited to, any one of 50 g / L, 100 g / L, 150 g / L, 200 g / L, 250 g / L, 300 g / L or a range between any two thereof. In a system where the tungstate is only ammonium tungstate, the ammonium tungstate is stored in an alkali to ensure stability except when the temperature rises suddenly, and the concentration of the alkali is 2 mol / L.

[0031] Preferably, in the step S2, the volume of the hydrochloric acid is 1.2 to 2.0 times the volume of the tungstate solution; specifically, the volume of the hydrochloric acid can be, for example but not limited to, any one of 1.2 times, 1.3 times, 1.4 times, 1.5 times, 1.6 times, 1.7 times, 1.8 times, 1.9 times, 2.0 times the volume of the tungstate solution or the range between any two of them;

[0032] Preferably, in the step S2, the concentration H of the hydrochloric acid is adjusted according to the concentration C of the tungstate solution:

[0033] When the tungstate solution is a solution with a concentration C of 50 g / L ≤ C ≤ 100 g / L in terms of tungsten trioxide, the hydrochloric acid concentration H is 2.8 mol / L < H ≤ 4.2 mol / L;

[0034] When the tungstate solution is a solution with a concentration C of 100 g / L < C ≤ 150 g / L in terms of tungsten trioxide, the hydrochloric acid concentration H is 4.2 mol / L < H ≤ 5.5 mol / L;

[0035] When the tungstate solution is a solution with a concentration C of 150 g / L < C ≤ 200 g / L in terms of tungsten trioxide, the hydrochloric acid concentration H is 5.5 mol / L < H ≤ 6.6 mol / L;

[0036] When the tungstate solution is a solution with a concentration C of 200 g / L < C ≤ 250 g / L in terms of tungsten trioxide, the hydrochloric acid concentration H is 6.6 mol / L < H ≤ 8.4 mol / L;

[0037] When the tungstate solution is a solution with a concentration C of 250 g / L < C ≤ 350 g / L in terms of tungsten trioxide, the hydrochloric acid concentration H > 8.4 mol / L.

[0038] Preferably, in the step S2, the stirring time is 0.5 to 1.0 h. During the stirring process, the remaining metatungstic acid is converted into yellow tungstic acid; specifically, the stirring time can be, for example but not limited to, any one of 0.5 h, 0.75 h, 1.0 h or the range between any two of them.

[0039] Preferably, in the step S3, the reserved tungstate solution is quickly added to the reserved hydrochloric acid, and then stirred; if the container capacity is sufficient and the input amount is sufficient, it can be required to be added within 10 s. Generally speaking, the tungstate solution should be added within 1 min. Specifically, the time for adding the reserved tungstate solution to the reserved hydrochloric acid can be, for example but not limited to, any one of 60 s, 50 s, 40 s, 30 s, 20 s, 10 s, 5 s, etc. or the range between any two of them.

[0040] A high-purity nano yellow tungstic acid is prepared by the above method for preparing high-purity nano yellow tungstic acid.

[0041] As a preferred embodiment of the high-purity nano tungsten yellow acid of the present invention, wherein: the purity of the high-purity nano tungsten yellow acid is ≥ 99.9%.

[0042] The technical solution of the present invention will be further described below in conjunction with specific embodiments.

[0043] Example 1

[0044] A method for preparing high-purity nano tungsten yellow acid includes the following steps:

[0045] S1. Take a tungstate solution with a concentration C of 250 g / L in terms of tungsten trioxide for standby;

[0046] S2. In terms of tungsten trioxide, when the concentration C of the tungstate solution is in the range of 200 g / L < C ≤ 250 g / L, the hydrochloric acid concentration H should be 6.6 mol / L < H ≤ 8.4 mol / L. In this example, 7 mol / L hydrochloric acid is taken for standby, and the volume of the hydrochloric acid is 2.0 times the volume of the tungstate solution;

[0047] S3. Add the standby tungstate solution with a concentration C of 250 g / L into the standby 7 mol / L hydrochloric acid within 10 s, and then stir for 1 h;

[0048] S4. After filtration, high-purity nano tungsten yellow acid is obtained, and the purity of the high-purity nano tungsten yellow acid is 99.94%.

[0049] Example 2

[0050] A method for preparing high-purity nano tungsten yellow acid includes the following steps:

[0051] S1. Take a tungstate solution with a concentration C of 50 g / L in terms of tungsten trioxide for standby;

[0052] S2. In terms of tungsten trioxide, when the concentration C of the tungstate solution is in the range of 50 g / L ≤ C ≤ 100 g / L, the hydrochloric acid concentration H should be 2.8 mol / L < H ≤ 4.2 mol / L. In this example, 3 mol / L hydrochloric acid is taken for standby, and the volume of the hydrochloric acid is 1.2 times the volume of the tungstate solution;

[0053] S3. Add the standby tungstate solution with a concentration C of 50 g / L into the standby 3 mol / L hydrochloric acid within 5 s, and then stir for 0.5 h;

[0054] S4. After filtration, high-purity nano tungsten yellow acid is obtained, and the purity of the high-purity nano tungsten yellow acid is 99.91%.

[0055] Example 3

[0056] A method for preparing high-purity nano tungsten yellow acid includes the following steps:

[0057] S1. Take a tungstate solution with a concentration C of 120 g / L in terms of tungsten trioxide for later use;

[0058] S2. In terms of tungsten trioxide, the concentration C of the tungstate solution is in the range of 100g / L≤C≤150g / L, and the concentration H of hydrochloric acid should be 4.2mol / L<H≤5.5mol / L. In this embodiment, 5mol / L hydrochloric acid is used as standby, and the volume of the hydrochloric acid is 1.5 times the volume of the tungstate solution;

[0059] S3. The reserved concentration C of 120g / L tungstate solution was added to the reserved 5mol / L hydrochloric acid within 20s, and then stirred for 0.75h;

[0060] S4. After filtering, high-purity nano yellow tungstic acid is obtained, and the purity of the high-purity nano yellow tungstic acid is 99.92%.

[0061] Example 4

[0062] A method for preparing high-purity nano yellow tungstic acid comprises the following steps:

[0063] S1. Take a tungstate solution with a concentration C of 180 g / L in terms of tungsten trioxide for later use;

[0064] S2. In terms of tungsten trioxide, the concentration C of the tungstate solution is in the range of 150g / L≤C≤200g / L, and the concentration H of hydrochloric acid should be 5.5mol / L<H≤6.6mol / L. In this embodiment, 6mol / L hydrochloric acid is used as standby, and the volume of the hydrochloric acid is 1.5 times the volume of the tungstate solution;

[0065] S3. The reserved concentration C of 180g / L tungstate solution was added to the reserved 6mol / L hydrochloric acid within 60s, and then stirred for 1h;

[0066] S4. After filtering, high-purity nano yellow tungstic acid is obtained, and the purity of the high-purity nano yellow tungstic acid is 99.91%.

[0067] Example 5

[0068] A method for preparing high-purity nano yellow tungstic acid comprises the following steps:

[0069] S1. Take a tungstate solution with a concentration C of 280 g / L in terms of tungsten trioxide for later use;

[0070] S2. In terms of tungsten trioxide, the concentration C of the tungstate solution is in the range of 250g / L≤C≤350g / L, and the hydrochloric acid concentration H should be>8.4mol / L. In this embodiment, 9mol / L hydrochloric acid is used as standby, and the volume of the hydrochloric acid is 2.0 times the volume of the tungstate solution;

[0071] S3. The reserved concentration C of 280g / L tungstate solution was added to the reserved 9mol / L hydrochloric acid within 30s, and then stirred for 1h;

[0072] S4. After filtering, high-purity nano yellow tungstic acid is obtained, and the purity of the high-purity nano yellow tungstic acid is 99.93%.

[0073] Comparative Example 1

[0074] A method for preparing tungstic acid comprises the following steps:

[0075] S1. Take a tungstate solution with a concentration C of 250 g / L in terms of tungsten trioxide for later use;

[0076] S2. Take 6 mol / L hydrochloric acid for use, the volume of the hydrochloric acid being 2.0 times the volume of the tungstate solution;

[0077] S3. The reserved concentration C of 250g / L tungstate solution was added to the reserved 6mol / L hydrochloric acid for 10s, and then stirred for 1h;

[0078] S4. After filtration, yellow tungstic acid is obtained, and white tungstic acid is also present.

[0079] Comparative Example 2

[0080] A method for preparing tungstic acid comprises the following steps:

[0081] S1. Take a tungstate solution with a concentration C of 250 g / L in terms of tungsten trioxide for later use;

[0082] S2. Take 7 mol / L hydrochloric acid for use, the volume of the hydrochloric acid being 2.0 times the volume of the tungstate solution;

[0083] S3. The reserved concentration C of 250g / L tungstate solution was placed in a separatory funnel, added dropwise to the reserved 7mol / L hydrochloric acid, the addition time was 2h, and then stirred for 1h;

[0084] S4. After filtration, yellow tungstic acid is obtained, and white tungstic acid is also present.

[0085] Comparative Example 3

[0086] A method for preparing tungstic acid comprises the following steps:

[0087] S1. Take a tungstate solution with a concentration C of 250 g / L in terms of tungsten trioxide for later use;

[0088] S2. Take 7 mol / L hydrochloric acid for use, the volume of the hydrochloric acid being 2.0 times the volume of the tungstate solution;

[0089] S3. The reserved 7mol / L hydrochloric acid was placed in a separatory funnel and added dropwise to the reserved concentration C of 250g / L tungstate solution for 2h, and then stirred for 1h;

[0090] S4. After filtering, white tungstic acid is obtained, and yellow tungstic acid is also present.

[0091] Comparative Example 4

[0092] A method for preparing tungstic acid comprises the following steps:

[0093] S1. Take a tungstate solution with a concentration of 250g / L in terms of tungsten trioxide for later use;

[0094] S2. Take 7 mol / L hydrochloric acid for use, the volume of the hydrochloric acid being 2.0 times the volume of the tungstate solution;

[0095] S3. Add the reserved 7 mol / L hydrochloric acid to the reserved 250 g / L tungstate solution within 10 s, and stir for 1 h;

[0096] S4. After filtration, yellow tungstic acid is obtained, and white tungstic acid is also present.

[0097] The present invention prepares a tungstate solution for use; prepares hydrochloric acid for use, wherein the volume of the hydrochloric acid is 1.2 to 2.0 times the volume of the tungstate solution; quickly adds the prepared tungstate solution into the prepared hydrochloric acid, and then stirs; and obtains high-purity nano yellow tungstic acid after filtration. By precisely controlling the order and speed of adding the raw material screen, not only can the purity of the obtained product reach the high-purity standard, the purity of the high-purity nano yellow tungstic acid is ≥99.9%, but also stable nano yellow tungstic acid can be prepared, and the industrialization prospect is broad.

[0098] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A method for preparing high-purity nano yellow tungstic acid, characterized in that: The purity of the high-purity nano tungstic acid is ≥ 99.9%, and the method includes the following steps: S1. Prepare a tungstate solution for use. The tungstate solution is a solution with a concentration C of 50 - 300 g / L in terms of tungsten trioxide. S2. Prepare hydrochloric acid for use. The volume of the hydrochloric acid is 1.2 - 2.0 times the volume of the tungstate solution. The concentration H of the hydrochloric acid is adjusted according to the concentration C of the tungstate solution: When the tungstate solution is a solution with a concentration C of 50 g / L ≤ C ≤ 100 g / L in terms of tungsten trioxide, the hydrochloric acid concentration H is 2.8 mol / L < H ≤ 4.2 mol / L; When the tungstate solution is a solution with a concentration C of 100 g / L < C ≤ 150 g / L in terms of tungsten trioxide, the hydrochloric acid concentration H is 4.2 mol / L < H ≤ 5.5 mol / L; When the tungstate solution is a solution with a concentration C of 150 g / L < C ≤ 200 g / L in terms of tungsten trioxide, the hydrochloric acid concentration H is 5.5 mol / L < H ≤ 6.6 mol / L; When the tungstate solution is a solution with a concentration C of 200 g / L < C ≤ 250 g / L in terms of tungsten trioxide, the hydrochloric acid concentration H is 6.6 mol / L < H ≤ 8.4 mol / L; When the tungstate solution is a solution with a concentration C of 250 g / L < C ≤ 350 g / L in terms of tungsten trioxide, the hydrochloric acid concentration H > 8.4 mol / L; S3. Add the prepared tungstate solution into the prepared hydrochloric acid within 1 min, and then stir. The stirring time is 0.5 - 1.0 h. S4. After filtration, high-purity nano tungstic acid is obtained.