阅读说明：本技术 乙二醇锑的制备方法及根据该制备方法制备的乙二醇锑 (Method for preparing ethylene glycol antimony and ethylene glycol antimony prepared according to method ) 是由 璩洁荷 雍万雄 戴泽青 俞晓鲲 康国培 葛盛才 于 2020-06-08 设计创作，主要内容包括：本发明提供一种乙二醇锑的制备方法及根据该制备方法制备的乙二醇锑,乙二醇锑的制备方法包括：步骤一、溶解,将质量分数不高于99%的三氧化二锑用PH值为7～8的弱碱性溶液溶解,静置。步骤二、吸附,将至少一种碱性金属氧化物粉末和至少一种碱性金属氢氧化物粉末制成丸粒,将丸粒放入反应柱中,将步骤一中制得的三氧化二锑碱性水溶液通过反应柱吸附,得到纯净的碱性三氧化二锑溶液。经过两步处理后得到碱性三氧化二锑溶液可用于制备乙二醇锑,该乙二醇锑制备方法具有成本低、工艺简单和产品品质好的优点。(The invention provides a preparation method of ethylene glycol antimony and the ethylene glycol antimony prepared by the preparation method, wherein the preparation method of the ethylene glycol antimony comprises the following steps: dissolving, namely dissolving antimony trioxide with the mass fraction not higher than 99% by using a weak alkaline solution with the pH value of 7-8, and standing. And step two, adsorption, namely preparing at least one alkaline metal oxide powder and at least one alkaline metal hydroxide powder into pills, putting the pills into a reaction column, and adsorbing the antimony trioxide alkaline aqueous solution prepared in the step one through the reaction column to obtain a pure alkaline antimony trioxide solution. The alkaline antimony trioxide solution obtained after the two-step treatment can be used for preparing ethylene glycol antimony, and the preparation method of the ethylene glycol antimony has the advantages of low cost, simple process and good product quality.)

1. The preparation method of the ethylene glycol antimony comprises the following steps: dissolving, namely dissolving antimony trioxide with the mass fraction not higher than 99% by using a weak alkaline solution with the pH value of 7-8, and standing;

step two, adsorption, namely preparing at least one alkaline metal oxide powder and at least one alkaline metal hydroxide powder into pills, putting the pills into a reaction column, and adsorbing the antimony trioxide alkaline solution prepared in the step one through the reaction column to obtain a pure alkaline antimony trioxide solution;

step three, reacting, namely reacting the alkaline antimony trioxide solution obtained in the step two with excessive glycol to obtain a mixture containing glycol antimony;

and step four, purifying, namely centrifugally separating the mixture containing the ethylene glycol antimony, washing the lower layer of ethylene glycol antimony solid, and then drying in vacuum to obtain the ethylene glycol antimony powder.

2. The method for preparing ethylene glycol antimony according to claim 1, wherein the mass fraction of antimony trioxide in the first step is 75-98%.

3. The method for preparing ethylene glycol antimony according to claim 1, wherein the weak alkaline solution with a pH value of 7-8 in the first step is a mixed aqueous solution of triethanolamine and polyacrylamide with a mass fraction of 0.2% -15%, wherein the mass ratio of triethanolamine to polyacrylamide is 1 (1-1.5).

4. The method for preparing ethylene glycol antimony according to claim 1, wherein in the second step, two basic metal oxides and one basic metal hydroxide are made into pellets, the basic metal oxides are nano zinc oxide and nano cerium oxide, the basic metal hydroxide is nano magnesium hydroxide, and the mass ratio of the nano zinc oxide to the nano cerium oxide to the nano magnesium hydroxide is (1-1.5): (1-2).

5. The method for preparing ethylene glycol antimony according to claim 4, wherein in the second step, the powder granulator is used to press the alkali metal oxide and the alkali metal hydroxide into pellets with the diameter of 0.5 cm-1 cm, the pellets are placed into the reaction column, and the adsorption time of the antimony trioxide alkaline aqueous solution passing through the reaction column is 40 min-2 h.

6. The method for preparing the ethylene glycol antimony according to claim 1, wherein the mass of the ethylene glycol added in the third step is 5-10 times that of the antimony trioxide in the first step, and the mixture containing the ethylene glycol antimony is obtained after the ethylene glycol is added in the third step and reacts for 3-4 hours at 170-190 ℃ in an inert atmosphere.

7. The method for preparing the ethylene glycol antimony according to claim 1, wherein the ethylene glycol antimony solid in the fourth step is washed with the monohydric alcohol containing 1-6 carbon atoms for three times, and the monohydric alcohol is used in the first two times.

8. The method for producing ethylene glycol antimony according to claim 7, wherein the monohydric alcohol is methanol or ethanol.

9. The method for producing ethylene glycol antimony according to claim 1, wherein the degree of vacuum at the time of vacuum drying is 0.095 to 0.1MPa, and the temperature is 55 to 60 ℃.

10. Ethylene glycol antimony prepared according to the method of preparing ethylene glycol antimony of claims 1-9.

Technical Field

The invention relates to a preparation method of ethylene glycol antimony and the ethylene glycol antimony prepared according to the preparation method.

Background

The catalyst for synthesizing the PET (polyethylene terephthalate) material mainly comprises antimony catalysts such as antimony trioxide, antimony acetate, ethylene glycol antimony and the like, wherein the ethylene glycol antimony has the highest catalytic activity and is a soluble antimony catalyst with the highest antimony content; meanwhile, the ethylene glycol antimony can also reduce the probability of broken filaments and floating filaments in the spinning processing process of the PET downstream process, and improve the high-quality product rate of spinning. The ethylene glycol antimony is a product obtained by dehydrating high-purity antimony trioxide and excessive ethylene glycol, filtering and removing impurities, has lower effective antimony content than the antimony trioxide, and increases the dosage of the ethylene glycol antimony during catalytic use; antimony ethylene glycol is more expensive than antimony trioxide, resulting in an increase in the cost of PET materials, which is a major obstacle affecting the use of antimony ethylene glycol in PET synthesis.

The patent with publication number CN 103044200A and title of the invention is a preparation method of ethylene glycol antimony, which comprises reacting antimony trioxide with ethylene glycol under heating and reduced pressure, decolorizing, crystallizing and centrifuging to obtain ethylene glycol antimony. The method adopts high-purity antimony trioxide reaction, and has high cost. The patent with publication number CN101074186A and title of the invention is a preparation method of crystalline ethylene glycol antimony, which comprises subjecting antimony trioxide and ethylene glycol to esterification dehydration under heating and pressure reduction conditions, adding activated carbon and heavy metal inhibitor, decolorizing, crystallizing and centrifuging to obtain ethylene glycol antimony, and using heavy metal inhibitor to solve the problem of high content of heavy metal impurities, but the cost is also increased correspondingly.

In order to solve the problems of high preparation cost and large raw material consumption of the existing ethylene glycol antimony which adopts high-purity antimony trioxide, a method for preparing the ethylene glycol antimony by treating the low-purity antimony trioxide to remove impurities is developed, and the cost is reduced to meet the market demand.

Disclosure of Invention

The invention aims to provide a method for preparing ethylene glycol antimony by using low-purity antimony trioxide aiming at the defects of the prior art, and the technical scheme is as follows:

a method for preparing ethylene glycol antimony comprises the following steps: dissolving, namely dissolving antimony trioxide with the mass fraction not higher than 99% by using a weak alkaline solution with the pH value of 7-8, and standing. The standing time is preferably not less than 24h, so that impurities are ionized and can fully form a complex with the alkali liquor.

And step two, adsorption, namely mixing at least one alkaline metal oxide powder and at least one alkaline metal hydroxide powder to prepare pills, putting the pills into a reaction column, and adsorbing the antimony trioxide alkaline solution prepared in the step one through the reaction column to obtain a pure alkaline antimony trioxide solution. Before two kinds of powder are selected to prepare the pill for adsorption, the powder needs to be uniformly mixed.

And step three, reacting, namely reacting the alkaline antimony trioxide solution with excessive glycol to obtain a mixture containing glycol antimony.

And step four, purifying, namely centrifugally separating the mixture containing the ethylene glycol antimony, washing the lower layer of ethylene glycol antimony solid, and then drying in vacuum to obtain the ethylene glycol antimony powder.

The antimony trioxide used in the invention is low in purity and gray in color, and the impurities in the antimony trioxide mainly contain metal impurities such as lead, arsenic, iron and the like. And (3) the alkalescent solution with the pH value of 7-8 added in the step one can form a complex with the metal impurities in the antimony trioxide, so that the metal impurities are ionized, and subsequent adsorption is facilitated. And step two, adsorbing metal ion impurities by using an adsorbent under a weakly alkaline condition to reduce the metal impurities in antimony trioxide, wherein the adsorbent can be selected from adsorbents with electrode potentials larger than three metal ions of lead, arsenic and iron in an alkaline solution with the pH value of 7-8, such as: magnesium, zinc, cerium, and the like. According to the technical scheme, metal impurities in the antimony trioxide with low purity are removed through the first step and the second step, then the reaction is carried out, the antimony trioxide with low purity can be used as a raw material, and the production cost of the ethylene glycol antimony is reduced.

The price of the antimony trioxide raw material with the mass fraction higher than 98 percent is not greatly different from that of the common high-purity antimony trioxide with the mass fraction of 99.5 percent, and the antimony trioxide with the mass fraction lower than 75 percent has more adsorbents for impurity removal and higher cost. As a further improvement of the technical scheme, the mass fraction of the antimony trioxide in the step one is 75-98%.

As a further improvement of the technical scheme, in the step I, the weak alkaline solution is a mixed aqueous solution of triethanolamine and polyacrylamide with the mass fraction of 0.2-15%, wherein the mass ratio of the triethanolamine to the polyacrylamide is 1 (1-1.5).

As a further improvement of the technical scheme, in the second step, two alkaline metal oxides and one alkaline metal hydroxide are prepared into pills, wherein the two alkaline metal oxides are respectively nano zinc oxide and nano cerium oxide, and the alkaline metal hydroxide is nano magnesium hydroxide. The mass ratio of the nano zinc oxide to the nano cerium oxide to the nano magnesium hydroxide is (1-1.5) to (1-1.5): (1-2). The nano zinc oxide is also called nano zinc oxide, the nano cerium oxide is also called nano cerium oxide, and the nano magnesium hydroxide is also called nano magnesium hydroxide. The three are all nano materials, and as the particle size of the nano materials is reduced, the surface atomic number occupies a large proportion, the adsorption capacity is enhanced, and the chemical activity is increased.

As a further improvement of the technical scheme, in the second step, a powder granulator is used for pressing the alkaline metal oxide and the alkaline metal hydroxide into pills with the diameter of 0.5 cm-1 cm, the pills are placed into a reaction column, and the adsorption time of the antimony trioxide alkaline aqueous solution passing through the reaction column is 40 min-2 h.

As a further improvement of the technical scheme, the mass of the ethylene glycol added in the third step is 5-10 times of that of the antimony trioxide in the first step, and after the ethylene glycol is added in the third step, the mixture containing the ethylene glycol and antimony is obtained after the reaction for 3-4 hours in an inert atmosphere at 170-190 ℃. The yield of the product is improved by increasing the dosage of the glycol, and when the dosage of the glycol is excessive, the generated glycol antimony is partially dissolved in the glycol, so that the yield of the glycol antimony is reduced. The reaction temperature is raised, the esterification speed is accelerated, water in the reaction process is favorably moved out of a reaction system, the reaction is carried out in the direction favorable for generating the ethylene glycol antimony, and the product yield is continuously improved. However, excessive temperature may promote side reactions to produce antimony organic compounds in a single valence state. Meanwhile, the over-high temperature causes large loss of the ethylene glycol and is unfavorable for the reaction.

As a further improvement of the technical scheme, in the fourth step, the ethylene glycol antimony solid is washed for three times by using monohydric alcohol with the carbon atom number of 1-6, and the same monohydric alcohol is used in the first two times of washing. Because the ethylene glycol antimony is partially dissolved in the ethylene glycol, the loss of ethylene glycol antimony can be reduced by washing the ethylene glycol with the same batch of monohydric alcohol in the first two washes.

As a further improvement of the technical scheme, the monohydric alcohol is methanol or ethanol.

As a further improvement of the technical scheme, the vacuum degree during vacuum drying is (0.095-0.1) MPa, and the temperature is 55-60 ℃.

Ethylene glycol antimony prepared according to the technical scheme.

Compared with the prior art, the invention has prominent substantive characteristics and remarkable progress, and the invention has the following beneficial effects:

1. the invention does not need to use high-purity antimony trioxide with the mass fraction of 99.5% as the raw material, thereby saving the cost.

2. The invention does not need the step of active carbon adsorption, thereby simplifying the process flow.

3. The invention improves the content of antimony in the product, wherein the content of antimony is more than 56 wt%.

4. The product yield of the invention is higher, the antimony yield of the ethylene glycol antimony prepared by antimony trioxide raw materials with the weight percent of more than 75 percent is more than 80 percent, the ethylene glycol antimony is separated out and stuck on the cup wall and a centrifuge tube to cause partial loss due to the limitation of objective conditions, and the antimony yield in the embodiment is smaller than the actual antimony yield.

5. The invention improves the quality of the product ethylene glycol antimony, and the hue value is more excellent: the value a of the ethylene glycol antimony is more than or equal to-0.4, the value b is less than or equal to 1.2, and the value L is more than or equal to 97. Among them, commercially available ethylene glycol antimony: the value of a is more than or equal to 3 and less than or equal to 0.9, the value of b is more than or equal to 2.4 and less than or equal to 6, and the value of L is more than or equal to 90 and less than or equal to 94.

6. The dissolving time of the ethylene glycol powder prepared by the invention is 20-30 minutes at 15-20 ℃, so that the use cost of users is greatly reduced. The dissolving temperature of the glycol antimony sold in the market is 100 ℃, the dissolving time is 150 minutes, the dissolving temperature of the invention is 15-20% of the product sold in the market, and the dissolving time is 13-20% of the product sold in the market.

7. The ethylene glycol antimony prepared by the invention has less metal impurities, the contents of lead ions, arsenic ions and iron ions are not more than 3ppm, and the content of each impurity metal ion in the ethylene glycol antimony sold in the market is about 100 ppm.

Detailed Description

The technical solution of the present invention is further described in detail by the following embodiments.

The data of the ethylene glycol antimony prepared in each example are determined by the following methods or instruments: the mass fraction of antimony in the ethylene glycol antimony is titrated by adopting a potassium bromate standard titration method, the content of metal ions is measured by using an atomic absorption tester, and the hue value a, the hue value b and the hue value L are measured by using a color difference meter.