阅读说明：本技术 一种高纯偏磷酸钡及其制备方法 (High-purity barium metaphosphate and preparation method thereof ) 是由 梁启波 万洋 曾开文 于 2021-11-18 设计创作，主要内容包括：本发明属于无机磷化工技术领域,具体涉及一种高纯偏磷酸钡及其制备方法。本发明的高纯偏磷酸钡的制备方法,包括：(1)在反应器中加入磷酸溶液作为底液,并加热；(2)另取磷酸溶液,使其与碳酸钡按比例缓慢加入到所述反应器中,加热,搅拌,反应结束后经固液分离得到固体和滤液；(3)将所述滤液加到所述反应器中作为底液循环利用,将所述固体烘干,然后经灼烧至恒重后进行水洗；(4)再次烘干,得到高纯偏磷酸钡。本发明的高纯偏磷酸钡的制备方法工艺流程简单、设备投资小、经济环保,符合绿色化学理念。(The invention belongs to the technical field of inorganic phosphorus chemical industry, and particularly relates to high-purity barium metaphosphate and a preparation method thereof. The preparation method of the high-purity barium metaphosphate comprises the following steps: (1) adding phosphoric acid solution as base solution into a reactor, and heating; (2) slowly adding phosphoric acid solution and barium carbonate into the reactor according to a certain proportion, heating, stirring, and carrying out solid-liquid separation after the reaction is finished to obtain solid and filtrate; (3) adding the filtrate into the reactor to be used as a base solution for recycling, drying the solid, then burning to constant weight, and washing with water; (4) and drying again to obtain the high-purity barium metaphosphate. The preparation method of the high-purity barium metaphosphate has the advantages of simple process flow, small equipment investment, economy and environmental protection, and accords with the green chemical concept.)

1. A preparation method of high-purity barium metaphosphate is characterized by comprising the following steps:

(1) adding phosphoric acid solution as base solution into a reactor, and heating;

(2) slowly adding phosphoric acid solution and barium carbonate into the reactor according to a certain proportion, heating, stirring, and carrying out solid-liquid separation after the reaction is finished to obtain solid and filtrate;

(3) adding the filtrate into the reactor to be used as a base solution for recycling, drying the solid, burning to constant weight, and then washing with water;

(4) and drying again to obtain the high-purity barium metaphosphate.

2. The method for preparing high-purity barium metaphosphate according to claim 1, wherein the concentration of said phosphoric acid solution is 6-10mol/L, and the temperature for heating is 50-90 ℃.

3. The method for preparing high-purity barium metaphosphate according to claim 1, wherein in the step (2), the molar ratio of phosphoric acid to barium carbonate in the phosphoric acid solution is (1.5-3): 1.

4. The method for preparing high-purity barium metaphosphate of claim 1, wherein said drying temperature is 80-150 ℃, and said burning temperature is 500-800 ℃.

5. The method for preparing high-purity barium metaphosphate according to claim 1, wherein said filtrate has an acidity value of 3.0 to 5.0 mol/L.

6. The method for preparing high-purity barium metaphosphate according to claim 1, wherein said filtrate is recycled as reaction base solution, and phosphoric acid solution participating in the reaction is added simultaneously with the base solution in a volume ratio of (45-50): 100.

7. The method for producing high-purity barium metaphosphate according to any one of claims 1 to 2 and 4, wherein said barium carbonate may be replaced with barium hydroxide.

8. The method for preparing high-purity barium metaphosphate according to claim 7, wherein when said filtrate is recycled as a reaction base solution, said filtrate has an acidity value of 2.8-4.5 mol/L.

9. The method for preparing high-purity barium metaphosphate according to claim 7, wherein in the step (2), the molar ratio of phosphoric acid to barium hydroxide in the phosphoric acid solution is (1.8-3): 1.

10. A high-purity barium metaphosphate which is produced by the production method for a high-purity barium metaphosphate according to any one of claims 1 to 9.

Technical Field

The invention belongs to the technical field of inorganic phosphorus chemical industry, and particularly relates to high-purity barium metaphosphate and a preparation method thereof.

Background

Metaphosphate is the most stable phosphate among dibasic phosphates, and is a basic raw material for the production of phosphate glass. The high-purity metaphosphate has excellent light transmittance, so that the metaphosphate can be used as an important raw material of laser glass in a high-power laser, and also can be used as an important raw material of some advanced optical devices such as camera lenses, high-definition cameras, smart phone lenses and mobile phone panel substrates. The transition metals of Fe, Co, Ni and the like can cause strong absorption of metaphosphate glass in the near ultraviolet to infrared regions, and the optical performance of the glass is influenced. Therefore, the preparation of high purity metaphosphate raw material becomes the key to the manufacture of high performance laser glass.

Currently, there are three main methods for preparing barium metaphosphate: (1) calcining the mixture of barium hydrogen phosphate and barium carbonate at high temperature for 15 hours to prepare barium metaphosphate; (2) reacting barium peroxide with phosphoric acid to generate barium phosphate precipitate, and heating the barium phosphate to convert the barium phosphate into barium metaphosphate; (3) the method comprises the following steps of performing synthetic reaction on barium hydroxide and phosphoric acid, specifically, firstly, adsorbing contents of iron, copper, nickel, manganese and cobalt in a barium hydroxide solution by using activated carbon to prepare refined barium hydroxide, transferring the refined barium hydroxide into another container, adding high-grade phosphoric acid while stirring to obtain a barium hydrogen phosphate precipitate, and performing centrifugal spray drying and condensation to synthesize the barium metaphosphate.

The former two barium metaphosphate preparation methods have high production cost, unstable yield and product quality and complex production process, so the method is not suitable for large-scale popularization and application. The third method for preparing barium metaphosphate has the advantages of simple production process and low impurity content of the product compared with the first two methods, but the method adopts a centrifugal spray drying tower in the process of converting barium hydrogen phosphate into barium metaphosphate, which undoubtedly increases the production cost. Moreover, in the third method, the waste liquid is not effectively recycled, which is not only uneconomical but also environmentally unfriendly.

Disclosure of Invention

The invention aims to provide high-purity barium metaphosphate and a preparation method thereof aiming at the defects of the prior art.

Specifically, the preparation method of the high-purity barium metaphosphate comprises the following steps:

(1) adding phosphoric acid solution as base solution into a reactor, and heating;

(2) slowly adding phosphoric acid solution and barium carbonate into the reactor according to a certain proportion, heating, stirring, and carrying out solid-liquid separation after the reaction is finished to obtain solid and filtrate;

(3) adding the filtrate into the reactor to be used as a base solution for recycling, drying the solid, then burning to constant weight, and washing with water;

(4) and drying again to obtain the high-purity barium metaphosphate.

In the preparation method of the high-purity barium metaphosphate, the concentration of the phosphoric acid solution is 6-10mol/L, preferably 7-9 mol/L; the heating temperature is 50-90 deg.C, preferably 70-90 deg.C.

In the above-mentioned method for producing high-purity barium metaphosphate, in the step (2), the molar ratio of phosphoric acid to barium carbonate in the phosphoric acid solution is (1.5-3):1, preferably (2.0-2.2): 1.

In the preparation method of the high-purity barium metaphosphate, the drying temperature is 80-150 ℃, preferably 80-120 ℃; the burning temperature is 500-800 ℃, preferably 550-650 ℃.

According to the preparation method of the high-purity barium metaphosphate, the acidity value of the filtrate is 3.0-5.0 mol/L.

According to the preparation method of the high-purity barium metaphosphate, when the filtrate is circularly used as the reaction base solution, the volume ratio of the phosphoric acid solution participating in the reaction to the base solution is (45-50): 100.

According to the preparation method of the high-purity barium metaphosphate, the barium carbonate can be replaced by barium hydroxide.

According to the preparation method of the high-purity barium metaphosphate, when the filtrate is circularly used as the reaction base solution, the acidity value of the filtrate is 2.8-4.5 mol/L.

In the method for preparing high-purity barium metaphosphate, the molar ratio of phosphoric acid to barium hydroxide in the phosphoric acid solution is (1.8-3):1, preferably (2.0-2.2): 1.

In another aspect, the invention provides high-purity barium metaphosphate, which is prepared by the preparation method of the high-purity barium metaphosphate.

The technical scheme of the invention has the following beneficial effects:

(1) the preparation method of the high-purity barium metaphosphate has the advantages of simple process flow, small equipment investment, economy and environmental protection, and accords with the green chemical concept;

(2) the purity of the high-purity barium metaphosphate prepared by the method is up to 99.9 percent by weight, and the requirement of downstream production is met;

(3) the invention provides a novel preparation method of high-purity barium metaphosphate, which adds a new choice for manufacturers producing high-purity barium metaphosphate.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention.

FIG. 1 is a process route for synthesizing high-purity barium metaphosphate in accordance with the present invention.

Detailed Description

The present invention will be described in detail with reference to the following embodiments in order to fully understand the objects, features and effects of the invention. The process of the present invention employs conventional methods or apparatus in the art, except as described below. The following noun terms have meanings commonly understood by those skilled in the art unless otherwise specified.

The terms "the," "said," "an," and "an" as used herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. In addition, all ranges disclosed herein are inclusive of the endpoints and independently combinable.

Specifically, the preparation method of the high-purity barium metaphosphate comprises the following steps:

(1) adding phosphoric acid solution as base solution into a reactor, and heating;

(2) slowly adding phosphoric acid solution and barium carbonate into the reactor according to a certain proportion, heating, stirring, and carrying out solid-liquid separation after the reaction is finished to obtain solid and filtrate;

(3) adding the filtrate into the reactor to be used as a base solution for recycling, drying the solid, then burning to constant weight, and washing with water;

(4) and drying again to obtain the high-purity barium metaphosphate.

The preparation method of the high-purity barium metaphosphate has the advantages of simple process flow, small equipment investment, economy and environmental protection, and accords with the green chemical concept. Practice proves that the invention can obtain barium metaphosphate with purity of 99.9 wt%, and meet the downstream production requirement.

In some preferred embodiments, the method for preparing high-purity barium metaphosphate according to the present invention comprises:

(1) phosphoric acid solution was added as a base solution to the reactor and heated.

In a specific embodiment, the phosphoric acid solution is obtained by diluting concentrated phosphoric acid (85%, AR, 14.6mol/L) with water. Wherein the concentration of the phosphoric acid solution is 6-10mol/L, preferably 7-9 mol/L.

Wherein the heating temperature is 50-90 ℃, preferably 70-90 ℃.

(2) And slowly adding phosphoric acid solution and barium carbonate into the reactor according to a certain proportion, heating, stirring, and carrying out solid-liquid separation after the reaction is finished to obtain solid and filtrate.

Wherein the barium carbonate is high-purity barium carbonate.

Wherein, the phosphoric acid solution taken in addition has the same solubility as the phosphoric acid solution used as the base solution, and is obtained by adding water to concentrated phosphoric acid (85%, AR, 14.6mol/L) and diluting the concentrated phosphoric acid to 6-10mol/L, preferably 7-9 mol/L.

Optionally, the phosphoric acid solution as the base solution accounts for 30-45%, preferably 35-40% of the total volume of the phosphoric acid solution.

Preferably, in the step (2), the molar ratio of the barium carbonate to the phosphoric acid in the phosphoric acid solution is 1: (1.5-3), preferably 1: (2.0-2.2:.

Wherein the heating temperature is 50-90 ℃, preferably 70-90 ℃.

Wherein, after the addition is finished, the reaction is finished after the continuous stirring for 0.5 to 3 hours, preferably 0.5 to 2 hours.

Optionally, the solid-liquid separation is performed by a centrifugal separation method.

(3) And adding the filtrate into the reactor to be used as a base solution for recycling, drying the solid, then burning to constant weight, and washing with water.

Preferably, the acidity value of the filtrate is 3.0-5.0 mol/L.

And recycling the reaction filtrate as a reaction base solution, adding the reaction base solution into a reaction container, and adding concentrated phosphoric acid and high-purity barium carbonate for reaction, wherein the steps are the same as the above. Wherein, when the molar ratio of the phosphoric acid to the barium carbonate is (1.5-3):1, preferably (2.0-2.2):1, the barium metaphosphate meeting the requirement can be prepared.

Wherein, after the filtrate is circulated for many times, when the acidity value is lower than 3.5mol/L, a proper amount of concentrated phosphoric acid is added, and the filtrate can be continuously recycled after the acidity value is adjusted to be 3.0-5.0 mol/L.

More preferably, the solid is dried at 80-150 deg.C (preferably 80-120 deg.C), and then is placed into a high temperature furnace to be burned to constant weight, the burning temperature is 500-. Then, the burned sample was measured according to the following ratio of 1: (1-5) (preferably 1 (1-3)) washing 1-3 times (preferably 1-2 times) in the feed-water ratio.

Wherein, when the filtrate is circularly used as reaction base liquid, the volume ratio of the phosphoric acid solution participating in the reaction to the base liquid is about 45-50mL:100 mL.

(4) And drying again to obtain the high-purity barium metaphosphate.

Preferably, the drying temperature is 80-150 ℃, preferably 80-120 ℃.

The purity of the pure barium metaphosphate is up to 99.9 wt% through detection.

In some embodiments of the present invention, barium hydroxide may be used in place of barium carbonate to react with the phosphoric acid solution to produce high purity barium metaphosphate. Except the acidity value of the filtrate, the other reaction steps are the same as those in the synthesis using barium carbonate, and the specific steps are as follows:

(1) adding phosphoric acid solution as base solution into a reactor, and heating;

(2) slowly adding phosphoric acid solution and barium hydroxide into the reactor according to a certain proportion, heating, stirring, and carrying out solid-liquid separation after the reaction is finished to obtain solid and filtrate;

optionally, the barium hydroxide is barium hydroxide monohydrate.

(3) Adding the filtrate into the reactor to be used as a base solution for recycling, drying the solid, then burning to constant weight, and washing with water;

wherein, when the filtrate is recycled as the reaction base solution, the acidity value is 2.8-4.5mol/L, and the phosphoric acid solution and the barium hydroxide are added according to the molar ratio of (1.8-3) to 1, preferably (2.0-2.2) to 1.

When the acidity value of the filtrate is lower than 2.8mol/L after circulation for many times, the filtrate can be evaporated and concentrated to the acidity value of 2.8-4.5mol/L, and the reaction is continued.

(4) And drying again to obtain the high-purity barium metaphosphate.

In another aspect, the invention provides high-purity barium metaphosphate, which is prepared by the preparation method of the high-purity barium metaphosphate.

The purity of the high-purity barium metaphosphate of the invention is up to 99.9 percent by weight, and meets the requirements of downstream production.

Examples

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention. Experimental procedures without specifying specific conditions in the following examples were carried out according to conventional methods and conditions. The starting materials used in the following examples are all conventionally commercially available.

Example 1

3420mL of concentrated phosphoric acid (85%, 14.6mol/L and 1.2ppm of Fe) is added to 6000mL (the solution concentration is 8.32mol/L), the reaction vessel is placed in a 80 ℃ constant-temperature water bath kettle, 2400mL (40%) of phosphoric acid solution is added into the reaction vessel in advance, 3600mL of the residual phosphoric acid solution is added by a constant-flow pump when the temperature of the phosphoric acid solution in the reaction vessel is increased to 80 ℃, 3000g of high-purity barium carbonate is added for synthetic reaction, the molar ratio of the added phosphoric acid to the barium carbonate is 29.9:15.20, the residual phosphoric acid solution and the barium carbonate are added at the same time at the speed of about 120mL:100g, stirring is started at the same time for 500r/min, the reaction is continued for 1h after the addition is finished, centrifugal separation is carried out, 4380g of crystallized wet weight is obtained, 4320mL of filtrate, and the acidity is 4.15 mol/L.

Drying the crystal at 100 ℃, and then burning the crystal in a high-temperature furnace at 600 ℃ for 5 h. And then washing the burned sample for 1 time: the ratio of material to water is 1:2, the washing temperature is 60 ℃, the washing time is 1h, and the materials are dried for 2h at the temperature of 100 ℃ after being washed with water.

Example 2

4300mL of filtrate obtained in the reaction of the example 1 is recovered (the concentration of phosphoric acid is 2.96mol/L, the acidity is 4.15mol/L), the filtrate is used as a reaction base solution to be added into a reaction vessel, the reaction vessel is placed in a constant-temperature water bath kettle at 85 ℃, after the temperature of the solution in the reaction vessel rises to 85 ℃, 2070mL of concentrated phosphoric acid (85%, AR) is added by a constant-flow pump at one time, 3000g of high-purity barium carbonate is added for synthetic reaction, the materials are added at the same time at the speed of about 69mL:100g, stirring is started at the same time for 500r/min, the reaction is continued for 1.5h after the materials are added, and centrifugal separation is carried out to obtain 5500g of wet weight of crystals, 4600mL of filtrate and 4.02mol/L of acidity.

Drying the crystal at 100 ℃, and then burning the crystal in a high-temperature furnace at 580 ℃ for 6 h. And then washing the burned sample for 1 time: the ratio of material to water is 1:2, the washing temperature is 60 ℃, the washing time is 1h, and the materials are dried for 2h at the temperature of 100 ℃ after being washed with water.

Example 3

Concentrated phosphoric acid (85%, Fe content 1.2ppm)0.56m³Diluting with water to volume of 1m³To a concentration of about 10.7mol/L, a phosphoric acid solution of 0.4m was previously added to the reaction vessel³Heating the reaction bottom solution, adding the residual phosphoric acid solution of 0.6m while heating the phosphoric acid solution in the reaction container to 80 DEG C³Simultaneously adding 0.5t of high-purity barium carbonate for synthetic reaction, feeding at the speed of about 120L:100kg, simultaneously starting stirring for 500r/min, continuously reacting for 1h after the feeding is finished, and performing centrifugal separation to obtain 0.73t of wet weight of crystals and 0.41m of filtrate³The acidity is 4.12 mol/L.

Drying the crystal at 110 ℃, and then burning the crystal for 4 hours in a high-temperature furnace at 620 ℃. And then washing the burned sample for 1 time: the ratio of material to water is 1:2, the washing temperature is 60 ℃, the washing time is 1h, and the materials are dried for 2h at the temperature of 110 ℃ after being washed with water.

Example 4

3420mL of concentrated phosphoric acid (85%, 14.6mol/L and 1.2ppm of Fe) is added to 6000mL (the solution concentration is 8.32mol/L), the reaction vessel is placed in a 80 ℃ constant-temperature water bath kettle, 2400mL (40%) of phosphoric acid solution is added into the reaction vessel in advance, 3600mL of residual phosphoric acid solution is added by a constant-flow pump when the temperature of the phosphoric acid solution in the reaction vessel is raised to 80 ℃, 2850g of barium hydroxide monohydrate is added at the same time for synthetic reaction, and the added phosphoric acid: barium hydroxide monohydrate (29.9 mol:15.04 mol) is added at the speed of about 126mL:100g, stirring is started for 500r/min, the reaction is continued for 1h after the addition is finished, and centrifugal separation is carried out to obtain 4374g of crystal wet weight, 4600mL of filtrate and 3.82mol/L of acidity.

Drying the crystal at 100 ℃, and then burning the crystal in a high-temperature furnace at 600 ℃ for 5 h. And then washing the burned sample for 1 time: the ratio of material to water is 1:2, the washing temperature is 60 ℃, the washing time is 1h, and the materials are dried for 2h at the temperature of 100 ℃ after being washed with water.

Example 5

4600mL of filtrate (the concentration of phosphoric acid is 2.72mol/L and the acidity is 3.82mol/L) reacted in the example 4 is recovered, the filtrate is added into a reaction vessel as reaction base liquid, the reaction vessel is placed in a constant-temperature water bath kettle at 85 ℃, after the temperature of the solution in the reaction vessel is raised to 85 ℃, 2070mL of concentrated phosphoric acid (85 percent, AR) is added by a constant flow pump at one side, 2820g of barium hydroxide monohydrate is added for synthesis reaction, the materials are simultaneously added at the speed of about 73mL:100g, stirring is started at 500r/min, the reaction is continuously carried out for 1.5h after the materials are added, and centrifugal separation is carried out to obtain 5420g of wet weight of crystals, 4850mL of filtrate and the acidity is 3.75 mol/L.

Drying the crystal at 100 ℃, and then burning the crystal in a high-temperature furnace at 580 ℃ for 6 h. And then washing the burned sample for 1 time: the ratio of material to water is 1:2, the washing temperature is 60 ℃, the washing time is 1h, and the materials are dried for 2h at the temperature of 100 ℃ after being washed with water.

Physical and chemical property test

The purity of the barium metaphosphate products prepared in examples 1 to 5 is measured, the measuring method is conventional in the field, the invention is not specifically limited herein, and the measuring results are as follows:

TABLE 1 data relating to barium metaphosphate prepared in examples 1-5

Name (R)	Content/%	K/ppm	Na/ppm	Ca/ppm	Mg/ppm	Fe/ppm	Sr/ppm
								Example 1	99.77	5.7	45.5	47.4	3.0	3.0	111.8
Example 2	99.79	6.3	44.3	47.7	3.4	3.3	131.9
								Example 3	99.80	5.0	42.7	43.8	2.8	2.9	104.3
Example 4	99.91	9.0	42.5	59.2	3.3	3.5	123.5
								Example 5	99.88	8.2	44.5	58.7	2.8	3.1	113.4

From the results shown in table 1, it can be seen that the barium metaphosphate prepared by the present invention has a purity of 99.7 wt% or more, even as high as 99.9 wt%, and has a low impurity content, which meets the downstream production requirements.

The present invention has been disclosed in the foregoing in terms of preferred embodiments, but it will be understood by those skilled in the art that these embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of the present invention. It should be noted that all changes and substitutions that are equivalent to these embodiments are deemed to be within the scope of the claims of the present invention. Therefore, the protection scope of the present invention should be subject to the scope defined in the claims.