Preparation method of high-purity antimony trioxide powder

Abstract

The application discloses a preparation method of high-purity antimony trioxide and belongs to the technical field of powder processing. Compared with the existing traditional wet process, the preparation method of the antimony trioxide has the advantages that molten antimony salt is used as raw material, the raw material is first converted into an oxide state through a distribution hydrolysis-ammonolysis step, the accumulation and internal encapsulation of impurities in the raw material are inhibited, the generated ammonium chloride in the reaction stage does not further stay on the product, after further ripening and calcination, the prepared antimony trioxide powder has a purity of 99.999% and high grain integrity; the process has a small amount of introduced reagent, the waste liquid generated by the process has low treatment difficulty, and therefore, the overall process has high cost performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of powder processing, in particular to a preparation method of high-purity antimony trioxide powder. BACKGROUND

[0002] Antimony trioxide is widely used in various fields such as plastics, fabrics, semiconductors, etc. due to its excellent flame retardancy, processability, and special color-changing effect (different colors in normal temperature and heated state). At the same time, based on the use requirements of some high-end application fields, the purity requirements of the existing supplied antimony trioxide powder are also gradually increasing.

[0003] Currently, the common preparation processes of antimony trioxide powder are fire method and wet method. The fire method is to directly calcine the screened antimony ore to obtain antimony trioxide powder. Although this process is simple to operate and has low requirements for processing hardware, the product prepared can be maintained within 95-98%, but the requirements for antimony ore are extremely strict, and the impurity content needs to be guaranteed within a very small range, otherwise the product quality cannot be guaranteed. The wet method is to use leaching to oxidize antimony element and separate impurities from raw materials such as metallic antimony, oxygen-containing antimony, and antimony salt, and then reduce to obtain antimony trioxide powder. This process has low requirements for raw materials, and the product quality can be guaranteed, but it uses more reagents, and the process waste liquid needs to be specially recovered, which is high in cost. SUMMARY

[0004] Based on the defects of the prior art, the purpose of the present application is to provide a preparation method of high-purity antimony trioxide, which uses antimony salt for wet preparation as raw material, has low requirements for preparation raw materials, and is converted into antimony trioxide powder through the processes of melt hydrolysis, ammonolysis, curing, and calcination. The reagent addition amount is controllable, and the powder purity can reach 99.999%.

[0005] In order to achieve the above purpose, the technical scheme adopted by the present application is as follows:

[0006] A preparation method of antimony trioxide powder, comprising the following steps:

[0007] (1) heating the antimony trichloride to be processed to a molten state, and dividing it into several equal-mass portions of antimony trichloride;

[0008] (2) mixing and hydrolyzing one portion of the molten antimony trichloride with water, separating the solid from the obtained mixture and washing it;

[0009] (3) Put the product washed in step (2) into water, then pass in ammonia water and carry out ammonolysis reaction, when the pH of the obtained mixture is 7-8, remove supernatant and wash; the concentration of the ammonia water is 25-30%, the ratio of the mass of one portion of molten antimony trichloride to the volume of ammonia water is 1g:(0.4-0.5)mL;

[0010] (4) Add one portion of molten antimony trichloride to the product washed in step (3), then carry out corresponding treatment to the obtained mixture according to the method of step (2) and step (3);

[0011] (5) Repeat the method of step (4) for 2 times or more until the portioned antimony trichloride in step (1) is used up;

[0012] (6) Remove supernatant of the product obtained in step (5) and heat to boiling for 1-1.5h, separate the solid, wash, dry to obtain the crude antimony trioxide;

[0013] (7) Keep the crude antimony trioxide at 350-450℃ for 3.5-4.5h in vacuum environment to obtain the antimony trioxide powder;

[0014] In step (4) and step (5), the volume of ammonia water in the ammonolysis reaction is increased by 10-25% of the volume of ammonia water used in step (3) for each portion of molten antimony trichloride added.

[0015] In the traditional wet method for preparing antimony trioxide powder, excessive chemicals (such as complexing agents, transformation agents, etc.) are generally introduced to ensure full use of raw materials and complete reaction, but these chemicals are difficult to recover and cost a lot, and the prepared product still contains some impurities and has low purity, incomplete crystal structure and small particle size. In the technical scheme of the present application, when antimony trichloride is used as raw material and treated by stepwise repeated batch addition and hydrolysis and ammonolysis, it can be fully converted into antimony trioxide without additional introduction of chemicals, and the soluble impurities accumulated in the raw material can be fully removed in the process, the probability of impurity wrapping is low, and the ammonium chloride generated in the ammonolysis process does not adhere to the product, the chlorine ion content is low, which ensures the high purity of the crude product, and after further aging and calcination, the purity of the obtained antimony trioxide powder is higher (5N grade) and the crystal grains are more complete. On the other hand, since the process does not involve special treatment devices or steps, the reagent cleaning is easy, so the overall process has high cost performance.

[0016] Preferably, the temperature of the hydrolysis reaction in step (2) is 60-70℃, and the reaction time is 0.5-1h;

[0017] Preferably, the temperature of the ammonolysis reaction in step (3) is 60-70°C, and the reaction time is 0.5-1 h.

[0018] When the molten antimony trichloride is contacted with water and the hydrolysis reaction is carried out at the above temperature, high activity of the reaction can be ensured without introducing additional complexing agents and the like, and the following reaction occurs:

[0019] SbCl3+ H2O → SbOCl + 2HCl

[0020] 4SbOCl + H2O → Sb2O3 · 2SbOCl + 2HCl

[0021] Subsequently, under mixing with ammonia water of a specific concentration, the diantimony oxychloride of the hydrolysis reaction is further converted into diantimony trioxide containing certain impurities and ammonium chloride:

[0022] Sb2O3 · 2SbOCl + 2NH3 · H2O → 2Sb2O3 + 2NH4Cl + H2O

[0023] Since the reaction produces ammonium chloride which does not remain in the interior of the reaction device due to the repeated processing steps in batches, the content of chlorine ions in the product is lower, and the reaction does not produce excess by-products or unreacted substances under the above conditions, and the treatment of the reaction waste liquid is difficult.

[0024] More preferably, the mass of the antimony trichloride to the volume of water in the hydrolysis reaction in step (2) is 1 g: (7-9) mL.

[0025] Under the above reaction conditions, the molten antimony trichloride can be fully contacted and reacted with water, and the reaction will not be too violent due to a large amount of heat exchange.

[0026] Preferably, the separated solid in step (6) is washed with water until the conductivity is ≤2 μs / cm.

[0027] After the previous distribution hydrolysis-ammonolysis treatment and aging treatment, most of the soluble impurities are transferred to the outside of the product, so that the separated solid product only needs to be further washed with water until the above lower limit of conductivity, so that the soluble impurities in the product can be basically removed.

[0028] Preferably, the vacuum degree in the vacuum environment in step (7) is ≤-0.1 MPa.

[0029] The application has the beneficial effect that the application provides a preparation method of high-purity antimony trioxide, compared with the existing traditional wet process, the method takes molten antimony salt as raw material, first converts the raw material into oxide state through the distribution hydrolysis-ammonolysis step, while inhibiting the accumulation and internal wrapping of impurities in the raw material, and the generated ammonium chloride in the reaction stage will not further stay attached to the product, after further ripening and calcination, the prepared antimony trioxide powder has a purity of up to 99.999% and high grain integrity; the process has a small amount of introduced reagent, and the waste liquid generated by the process has low treatment difficulty, so the overall process has high cost performance. DETAILED DESCRIPTION

[0030] In order to better illustrate the purpose, technical scheme and advantages of the application, the application will be further described below in combination with specific examples and comparative examples, the purpose of which is to understand the content of the application in detail, rather than to limit the application. All other examples obtained by those of ordinary skill in the art without creative labor fall within the protection scope of the application. The reagents, raw materials and instruments designed for the experiments of the application and comparative examples are all common ordinary reagents, raw materials and instruments unless otherwise specified.

[0031] Example 1

[0032] An embodiment of the preparation method of antimony trioxide powder according to the application, the preparation method comprises the following steps:

[0033] (1) heat 1 kg of antimony trichloride to be processed to a molten state, and divide it into 5 equal parts of antimony trichloride;

[0034] (2) mix one part of the molten antimony trichloride with 1600 mL of water and heat to 60℃ for hydrolysis reaction for 0.5 h, separate the solid from the obtained mixture and wash;

[0035] (3) place the washed product of step (2) into 800 mL of water, then pass in 85 mL (concentration 28%) of ammonia water and heat to 60℃ for ammonolysis reaction for 0.5 h, when the pH of the obtained mixture is 7, remove the supernatant and wash;

[0036] (4) additionally add one part of molten antimony trichloride to the washed product of step (3), mix with 1600 mL of water and heat to 60℃ for hydrolysis reaction for 0.5 h, separate the solid from the obtained mixture and wash;

[0037] (5) place the washed product of step (4) into 800 mL of water, then pass in 105 mL (concentration 28%) of ammonia water and heat to 60℃ for ammonolysis reaction for 0.5 h, when the pH of the obtained mixture is 7, remove the supernatant and wash;

[0038] (6) In the product after washing in step (5), one portion of molten antimony trichloride is additionally added, mixed with 1600 mL of water and heated to 60°C to perform hydrolysis reaction for 0.5 h, and the obtained mixture is separated to obtain solid and washed;

[0039] (7) The product after washing in step (6) is placed into 800 mL of water, then 125 mL (concentration 28%) of ammonia water is introduced and heated to 60°C to perform ammonolysis reaction for 0.5 h, and when the pH of the obtained mixture is 7, the supernatant is removed and washed;

[0040] (8) In the product after washing in step (7), one portion of molten antimony trichloride is additionally added, mixed with 1600 mL of water and heated to 60°C to perform hydrolysis reaction for 0.5 h, and the obtained mixture is separated to obtain solid and washed;

[0041] (9) The product after washing in step (8) is placed into 800 mL of water, then 145 mL (concentration 28%) of ammonia water is introduced and heated to 60°C to perform ammonolysis reaction for 0.5 h, and when the pH of the obtained mixture is 7, the supernatant is removed and washed;

[0042] (10) In the product after washing in step (9), one portion of molten antimony trichloride is additionally added, mixed with 1600 mL of water and heated to 60°C to perform hydrolysis reaction for 0.5 h, and the obtained mixture is separated to obtain solid and washed;

[0043] (11) The product after washing in step (10) is placed into 800 mL of water, then 165 mL (concentration 28%) of ammonia water is introduced and heated to 60°C to perform ammonolysis reaction for 0.5 h, and when the pH of the obtained mixture is 7, the supernatant is removed and washed;

[0044] (12) The product obtained in step (11) is removed supernatant and heated to boiling for 1 h, the solid is separated, washed with water until the conductivity is lower than 0.2 μs / cm, and dried at 100°C to obtain the crude antimony trioxide;

[0045] (13) The crude antimony trioxide is placed in a calcining furnace under vacuum of -0.1 MPa at 400°C for 4 h to obtain the antimony trioxide powder.

[0046] Example 2

[0047] One embodiment of the preparation method of the antimony trioxide powder according to the present application, the preparation method comprises the following steps:

[0048] (1) 1 kg of antimony trichloride to be processed is heated to a molten state, and divided into 5 portions of equal mass of antimony trichloride;

[0049] (2) One portion of molten antimony trichloride was mixed with 1600 mL of water and heated to 60°C for hydrolysis reaction for 1 hour, and the resulting mixture was separated to remove the solid and washed;

[0050] (3) The washed product of step (2) was placed in 800 mL of water, followed by the introduction of 85 mL (concentration 28%) of aqueous ammonia and heating to 60°C for ammonolysis reaction for 1 hour, and when the pH of the resulting mixture was 7, the supernatant was removed and washed;

[0051] (4) One portion of molten antimony trichloride was additionally added to the washed product of step (3), mixed with 1600 mL of water and heated to 60°C for hydrolysis reaction for 1 hour, and the resulting mixture was separated to remove the solid and washed;

[0052] (5) The washed product of step (4) was placed in 800 mL of water, followed by the introduction of 105 mL (concentration 28%) of aqueous ammonia and heating to 60°C for ammonolysis reaction for 1 hour, and when the pH of the resulting mixture was 7, the supernatant was removed and washed;

[0053] (6) One portion of molten antimony trichloride was additionally added to the washed product of step (5), mixed with 1600 mL of water and heated to 60°C for hydrolysis reaction for 1 hour, and the resulting mixture was separated to remove the solid and washed;

[0054] (7) The washed product of step (6) was placed in 800 mL of water, followed by the introduction of 125 mL (concentration 28%) of aqueous ammonia and heating to 60°C for ammonolysis reaction for 1 hour, and when the pH of the resulting mixture was 7, the supernatant was removed and washed;

[0055] (8) One portion of molten antimony trichloride was additionally added to the washed product of step (7), mixed with 1600 mL of water and heated to 60°C for hydrolysis reaction for 1 hour, and the resulting mixture was separated to remove the solid and washed;

[0056] (9) The washed product of step (8) was placed in 800 mL of water, followed by the introduction of 145 mL (concentration 28%) of aqueous ammonia and heating to 60°C for ammonolysis reaction for 1 hour, and when the pH of the resulting mixture was 7, the supernatant was removed and washed;

[0057] (10) One portion of molten antimony trichloride was additionally added to the washed product of step (9), mixed with 1600 mL of water and heated to 60°C for hydrolysis reaction for 1 hour, and the resulting mixture was separated to remove the solid and washed;

[0058] (11) The washed product of step (10) was placed in 800 mL of water, followed by the introduction of 165 mL (concentration 28%) of aqueous ammonia and heating to 60°C for ammonolysis reaction for 1 hour, and when the pH of the resulting mixture was 7, the supernatant was removed and washed;

[0059] (12) remove supernatant of the product obtained in step (11) and heat to boiling for 1 h, separate the solid, wash with water until the conductivity is less than 0.2 μs / cm, dry at 100 ℃ to obtain the crude antimony trioxide;

[0060] (13) calcine the crude antimony trioxide in a calcining furnace at -0.1 MPa vacuum at 400 ℃ for 4 h to obtain the antimony trioxide powder.

[0061] Example 3

[0062] One embodiment of the preparation method of the antimony trioxide powder according to the present application, the preparation method comprises the following steps:

[0063] (1) heat 2 kg of antimony trichloride to be processed to a molten state, and divide the antimony trichloride into 5 equal parts;

[0064] (2) mix one part of the molten antimony trichloride with 1600 mL of water and heat to 60 ℃ to perform a hydrolysis reaction for 1 h, separate the solid from the obtained mixture and wash;

[0065] (3) place the washed product of step (2) into 800 mL of water, then pass in 170 mL (concentration 28%) of ammonia water and heat to 60 ℃ to perform an ammonolysis reaction for 1 h, when the pH of the obtained mixture is 7, remove the supernatant and wash;

[0066] (4) additionally add one part of the molten antimony trichloride to the washed product of step (3), mix with 1600 mL of water and heat to 60 ℃ to perform a hydrolysis reaction for 1 h, separate the solid from the obtained mixture and wash;

[0067] (5) place the washed product of step (4) into 800 mL of water, then pass in 190 mL (concentration 28%) of ammonia water and heat to 60 ℃ to perform an ammonolysis reaction for 1 h, when the pH of the obtained mixture is 7, remove the supernatant and wash;

[0068] (6) additionally add one part of the molten antimony trichloride to the washed product of step (5), mix with 1600 mL of water and heat to 60 ℃ to perform a hydrolysis reaction for 1 h, separate the solid from the obtained mixture and wash;

[0069] (7) place the washed product of step (6) into 800 mL of water, then pass in 210 mL (concentration 28%) of ammonia water and heat to 60 ℃ to perform an ammonolysis reaction for 1 h, when the pH of the obtained mixture is 7, remove the supernatant and wash;

[0070] (8) Add one portion of molten antimony trichloride to the product after washing in step (7), mix with 1600 mL of water and heat to 60°C to perform hydrolysis reaction for 1 h, separate the solid from the mixture and wash;

[0071] (9) Put the product after washing in step (8) into 800 mL of water, then pass 230 mL (concentration 28%) of ammonia water and heat to 60°C to perform ammonolysis reaction for 1 h, when the pH of the obtained mixture is 7, remove the supernatant and wash;

[0072] (10) Add one portion of molten antimony trichloride to the product after washing in step (9), mix with 1600 mL of water and heat to 60°C to perform hydrolysis reaction for 1 h, separate the solid from the mixture and wash;

[0073] (11) Put the product after washing in step (10) into 800 mL of water, then pass 250 mL (concentration 28%) of ammonia water and heat to 60°C to perform ammonolysis reaction for 1 h, when the pH of the obtained mixture is 7, remove the supernatant and wash;

[0074] (12) Remove the supernatant from the product obtained in step (11) and heat to boiling for 1 h, separate the solid, wash with water until the conductivity is less than 0.2 μs / cm, and dry at 100°C to obtain the crude antimony trioxide;

[0075] (13) Put the crude antimony trioxide in a calcining furnace under vacuum at -0.1 MPa and heat to 400°C for 4 h to obtain the antimony trioxide powder.

[0076] Comparative Example 1

[0077] A preparation method of an antimony trioxide powder, the preparation method comprising the following steps:

[0078] (1) Heat 1 kg of antimony trichloride to be processed to a molten state;

[0079] (2) Mix the molten antimony trichloride with 1600 mL of water and heat to 60°C to perform hydrolysis reaction for 0.5 h, separate the solid from the mixture and wash;

[0080] (3) Put the product after washing in step (2) into 800 mL of water, then pass 200 mL (concentration 28%) of ammonia water and heat to 60°C to perform ammonolysis reaction for 1 h, when the pH of the obtained mixture is 7, remove the supernatant and wash;

[0081] (4) Remove the supernatant from the product obtained in step (3) and heat to boiling for 1 h, separate the solid, wash with water until the conductivity is less than 0.2 μs / cm, and dry at 100°C to obtain the crude antimony trioxide;

[0082] (5) the crude antimony trioxide is kept in a calcining furnace at 400 DEG C for 4 h under vacuum at -0.1 MPa to obtain the antimony trioxide powder.

[0083] Comparative Example 2

[0084] A preparation method of antimony trioxide powder, the preparation method comprising the following steps:

[0085] (1) 1 kg of antimony trichloride to be processed is heated to a molten state and divided into two equal parts of antimony trichloride;

[0086] (2) one part of the molten antimony trichloride is mixed with 1600 mL of water and heated to 60 DEG C for hydrolysis reaction for 0.5 h, and the obtained mixture is separated into solid and washed;

[0087] (3) the washed product of step (2) is put into 800 mL of water, then 85 mL (concentration 28%) of ammonia water is introduced and heated to 60 DEG C for ammonolysis reaction for 0.5 h, when the pH of the obtained mixture is 7, the supernatant is removed and washed;

[0088] (4) one part of the molten antimony trichloride is additionally added to the washed product of step (3), mixed with 1600 mL of water and heated to 60 DEG C for hydrolysis reaction for 0.5 h, and the obtained mixture is separated into solid and washed;

[0089] (5) the washed product of step (4) is put into 800 mL of water, then 105 mL (concentration 28%) of ammonia water is introduced and heated to 60 DEG C for ammonolysis reaction for 0.5 h, when the pH of the obtained mixture is 7, the supernatant is removed and washed;

[0090] (6) the obtained product of step (5) is removed supernatant and heated to boiling for 1 h, the solid is separated, washed with water until the conductivity is lower than 0.2 μs / cm, and dried at 100 DEG C to obtain crude antimony trioxide;

[0091] (7) the crude antimony trioxide is kept in a calcining furnace at 400 DEG C for 4 h under vacuum at -0.1 MPa to obtain the antimony trioxide powder.

[0092] Comparative Example 3

[0093] A preparation method of antimony trioxide powder, the preparation method comprising the following steps:

[0094] (1) 1 kg of antimony trichloride to be processed is heated to a molten state and divided into five equal parts of antimony trichloride;

[0095] (2) one part of the molten antimony trichloride is mixed with 1600 mL of water and heated to 60 DEG C for hydrolysis reaction for 0.5 h, and the obtained mixture is separated into solid and washed;

[0096] (3) The product after washing in step (2) is put into 800 mL of water, then 85 mL (concentration 28%) of ammonia water is introduced and heated to 60°C for ammonolysis reaction for 0.5 h, when the pH of the resulting mixture is 7, the supernatant is removed and washed;

[0097] (4) A portion of molten antimony trichloride is additionally added to the product after washing in step (3), 1600 mL of water is added and heated to 60°C for hydrolysis reaction for 0.5 h, the resulting mixture is separated and washed;

[0098] (5) The product after washing in step (4) is put into 800 mL of water, then 85 mL (concentration 28%) of ammonia water is introduced and heated to 60°C for ammonolysis reaction for 0.5 h, when the pH of the resulting mixture is 7, the supernatant is removed and washed;

[0099] (6) A portion of molten antimony trichloride is additionally added to the product after washing in step (5), 1600 mL of water is added and heated to 60°C for hydrolysis reaction for 0.5 h, the resulting mixture is separated and washed;

[0100] (7) The product after washing in step (6) is put into 800 mL of water, then 85 mL (concentration 28%) of ammonia water is introduced and heated to 60°C for ammonolysis reaction for 0.5 h, when the pH of the resulting mixture is 7, the supernatant is removed and washed;

[0101] (8) A portion of molten antimony trichloride is additionally added to the product after washing in step (7), 1600 mL of water is added and heated to 60°C for hydrolysis reaction for 0.5 h, the resulting mixture is separated and washed;

[0102] (9) The product after washing in step (8) is put into 800 mL of water, then 85 mL (concentration 28%) of ammonia water is introduced and heated to 60°C for ammonolysis reaction for 0.5 h, when the pH of the resulting mixture is 7, the supernatant is removed and washed;

[0103] (10) A portion of molten antimony trichloride is additionally added to the product after washing in step (9), 1600 mL of water is added and heated to 60°C for hydrolysis reaction for 0.5 h, the resulting mixture is separated and washed;

[0104] (11) The product after washing in step (10) is put into 800 mL of water, then 85 mL (concentration 28%) of ammonia water is introduced and heated to 60°C for ammonolysis reaction for 0.5 h, when the pH of the resulting mixture is 7, the supernatant is removed and washed;

[0105] (12) remove supernatant of the product obtained in step (11) and heat to boiling for 1 h, separate the solid, wash with water until the conductivity is less than 0.2 μs / cm, dry at 100 ℃ to obtain the crude antimony trioxide;

[0106] (13) heat the crude antimony trioxide in a calcining furnace at -0.1 MPa vacuum at 400 ℃ for 4 h to obtain the antimony trioxide powder.

[0107] Comparative Example 4

[0108] A method for preparing an antimony trioxide powder, the method comprising the following steps:

[0109] (1) heat 1 kg of antimony trichloride to be processed to a molten state, and divide it into 5 equal parts of antimony trichloride;

[0110] (2) mix one part of the molten antimony trichloride with 1600 mL of water and heat to 60 ℃, while introducing 85 mL (concentration 28%) of ammonia water and heating to 60 ℃ to react for 0.5 h, when the pH of the obtained mixture is 7, remove the supernatant and wash;

[0111] (3) additionally add one part of the molten antimony trichloride to the product after washing in step (2), mix with 1600 mL of water and heat to 60 ℃, then introduce 105 mL (concentration 28%) of ammonia water and heat to 60 ℃ to react for 0.5 h, when the pH of the obtained mixture is 7, remove the supernatant and wash;

[0112] (4) additionally add one part of the molten antimony trichloride to the product after washing in step (3), mix with 1600 mL of water and heat to 60 ℃, then introduce 125 mL (concentration 28%) of ammonia water and heat to 60 ℃ to react for 0.5 h, when the pH of the obtained mixture is 7, remove the supernatant and wash;

[0113] (5) additionally add one part of the molten antimony trichloride to the product after washing in step (4), mix with 1600 mL of water and heat to 60 ℃, then introduce 145 mL (concentration 28%) of ammonia water and heat to 60 ℃ to react for 0.5 h, when the pH of the obtained mixture is 7, remove the supernatant and wash;

[0114] (6) additionally add one part of the molten antimony trichloride to the product after washing in step (5), mix with 1600 mL of water and heat to 60 ℃, then introduce 165 mL (concentration 28%) of ammonia water and heat to 60 ℃ to react for 0.5 h, when the pH of the obtained mixture is 7, remove the supernatant and wash;

[0115] (7) remove the supernatant of the product obtained in step (6) and heat to boiling for 1 h, separate the solid, wash with water until the conductivity is less than 0.2 μs / cm, dry at 100 ℃ to obtain the crude antimony trioxide;

[0116] (8) calcine the crude antimony trioxide in a calcining furnace at -0.1 MPa vacuum at 400 ℃ for 4 h to obtain the antimony trioxide powder.

[0117] Example 1

[0118] The purity and grain size of the products of the examples and comparative examples were detected, and the results are shown in Tables 1 and 2.

[0119] Table 1

[0120]

[0121]

[0122] Table 2

[0123] Test item Standard Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Crystal grain size (pm) 0.6～0.7 0.66 0.60 0.65 0.47 0.44 0.42 0.45

[0124] As can be seen from Tables 1 and 2, the purity of the antimony trioxide powder prepared by the preparation method of the present application is very high, reaching more than 5N, and the product contains almost no impurities; the preparation method does not use additional processing agents such as complexing agents and transformation agents, so the treatment of waste liquid and waste water produced in production is difficult. In contrast, the product of Comparative Example 1 is not prepared by the batch hydrolysis-ammonolysis step, and part of the soluble impurities in the product originating from the raw material are internally accumulated, and the product purity is low. The number of batches of hydrolysis-ammonolysis in the preparation process of the product of Comparative Example 2 is only 2, and it is still difficult to achieve good impurity separation and isolation effect. In Comparative Example 3, the amount of ammonia water added in each batch is not increased gradually, and as the mass and volume of the product gradually increase, part of the soluble impurities cannot be effectively separated, and the antimony trioxide cannot be completely converted, and the quality of the product is still not as good as that of the product of the examples. Although the product of Comparative Example 4 is prepared by a batch process, the hydrolysis and ammonolysis are carried out simultaneously, and the product still cannot achieve the ideal effect, and the size of the product does not meet the standard.

[0125] Finally, it should be noted that the above examples are only used to illustrate the technical solutions of the present application and not to limit the protection scope of the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the actual technical solutions of the present application.

Claims

1. A method for preparing a powder of antimony trioxide, characterized in that, The method comprises the following steps: (1) heating the antimony trichloride to be processed to a molten state, and dividing the antimony trichloride into several portions of equal mass; (2) mixing and performing hydrolysis reaction on one portion of the molten antimony trichloride with water, and separating and washing the solid obtained from the mixture; (3) placing the product washed in step (2) into water, then introducing ammonia water and performing ammonolysis reaction, and when the pH of the obtained mixture is 7-8, removing the supernatant and washing; (4) additionally adding one portion of the molten antimony trichloride to the product washed in step (3), and then performing corresponding treatment on the obtained mixture according to the method of step (2) and step (3); (5) repeating the method of step (4) for more than 2 times until the portions of the antimony trichloride in step (1) are completely used; (6) removing the supernatant from the product obtained in step (5) and heating to boiling for 1-1.5 h, separating the solid, washing, drying, and obtaining the crude antimony trioxide; (7) heating the crude antimony trioxide to 350-450 ℃ in a vacuum environment for 3.5-4.5 h, and obtaining the antimony trioxide powder; In step (4) and step (5), the volume of the ammonia water used in the ammonolysis reaction is additionally increased by 10-25% of the volume of the ammonia water used in step (3) for each additional portion of the molten antimony trichloride.

2. The method for preparing antimony trioxide powder as described in claim 1, characterized in that, The temperature of the hydrolysis reaction in step (2) is 60-70 ℃, and the reaction time is 0.5-1 h.

3. The method for preparing antimony trioxide powder as described in claim 2, characterized in that, The mass of the antimony trichloride to the volume of the water in the hydrolysis reaction in step (2) is 1 g:(7-9) mL.

4. The method for preparing antimony trioxide powder as described in claim 1, characterized in that, The temperature of the ammonolysis reaction in step (3) is 60-70 ℃, and the reaction time is 0.5-1 h.

5. The method for preparing antimony trioxide powder as described in claim 1, characterized in that, The solid separated in step (6) is washed with water until the conductivity is ≤2 μs / cm.

6. The method for preparing antimony trioxide powder as described in claim 1, characterized in that, The vacuum degree in the vacuum environment in step (7) is ≤-0.1 MPa.

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