Cyclic preparation method of sodium antimonate

Abstract

The cyclic preparation method of the sodium antimonate provided by the embodiment of the invention comprises the following steps: adding antimony trioxide and potassium hydroxide into deionized water, stirring, mixing and dissolving, heating and slurrying, and then adding hydrogen peroxide to carry out oxidation reaction to obtain a first potassium antimonate solution; adding sodium hydroxide and a surfactant into the first potassium antimonate solution to carry out replacement reaction, standing, cooling, washing and drying to obtain a sodium antimonate finished product; potassium hydroxide is added into the filtered reaction liquid after standing, a second potassium antimonate solution is obtained, and the second potassium antimonate solution is used for circularly preparing the sodium antimonate finished product. On one hand, the product obtained in each cycle is good in character, the antimony content and the arsenic content basically meet the requirements, and the yield is considerable; on the other hand, the cost can be controlled, and the utilization rate of alkali liquor in the sodium antimonate preparation process is increased.

Description

Technical Field

[0001] The invention relates to the technical field of preparation of sodium antimonate, in particular to a cyclic preparation method of sodium antimonate. Background Art

[0002] Sodium antimonate has a wide range of applications. It is commonly used in the field of opaque fillers for cast iron paints, and is used as a flame retardant in fabrics such as fibers. It also plays an important role in industries such as color TV picture tube glass shells and high-end glass clarifiers. However, the traditional preparation of sodium antimonate uses the sodium salt method, which is to mix antimony trioxide, sodium hydroxide and hydrogen peroxide in a specific proportion and use a one-pot method to react to produce sodium antimonate. Unfortunately, the sodium antimonate obtained by this method has many problems. Its purity is low, the impurity content is high, the particle size of the product particles is large and the deviation is large, which makes it difficult to meet the performance requirements of the high-end market for sodium antimonate.

[0003] In the prior art, antimony trioxide and sodium hydroxide are generally dissolved and heated, and a hydrogen peroxide solution is added to obtain a sodium antimonate precipitate to achieve preliminary separation; the precipitate is then dissolved with concentrated hydrochloric acid and filtered to remove insoluble impurities; sodium hydroxide is then added to neutralize to a specific pH value to precipitate the sodium antimonate, and then washed with distilled water to remove the remaining soluble impurities, and finally dried to obtain a relatively pure sodium antimonate product. However, in the existing preparation method, the alkali solution is difficult to recycle, resulting in a large amount of alkali solution that needs to be processed.

[0004] It can be seen that the existing sodium antimonate preparation process has the problem of low alkali solution utilization rate. Summary of the invention

[0005] The embodiment of the present invention provides a cyclic preparation method of sodium antimonate to solve the problem of low alkali solution utilization rate in the existing sodium antimonate preparation process.

[0006] The embodiment of the present invention provides a cyclic preparation method of sodium antimonate, comprising:

[0007] Add antimony trioxide and potassium hydroxide into deionized water, stir and mix, dissolve, heat to make slurry, and then add hydrogen peroxide to carry out oxidation reaction to obtain a first potassium antimonate solution;

[0008] adding sodium hydroxide and a surfactant to the first potassium antimonate solution to carry out a replacement reaction, standing, cooling, washing, and drying to obtain a finished sodium antimonate product;

[0009] Potassium hydroxide is added to the filtered reaction solution after standing to obtain a second potassium antimonate solution, and the second potassium antimonate solution is used for circulating to prepare the sodium antimonate product.

[0010] Optionally, the step of adding sodium hydroxide and a surfactant to the first potassium antimonate solution to carry out a replacement reaction, standing, cooling, washing and drying to obtain a sodium antimonate product comprises:

[0011] adding sodium hydroxide and a surfactant to the first potassium antimonate solution to carry out a replacement reaction, and obtaining sodium antimonate particles after standing and cooling, wherein the particle size of the sodium antimonate particles is less than or equal to 2 microns;

[0012] The sodium antimonate particles are washed with cold water and hot water successively, and then dried to obtain a finished sodium antimonate product.

[0013] Optionally, washing the sodium antimonate particles with cold water and hot water successively comprises:

[0014] The sodium antimonate particles are washed 2-3 times with cold water, and then washed 2-3 times with hot water at 50° C. to 60° C., with the mass ratio of the washing water to the deionized water being (0.005-0.01):1.

[0015] Optionally, the drying temperature in the drying process is 90° C. to 110° C., and the drying time is 3 hours to 10 hours.

[0016] Optionally, the volume of the second potassium antimonate solution is equal to the volume of the hot slurry solution.

[0017] Optionally, the concentration of potassium hydroxide added in the filtration of the reaction solution after standing is equal to the concentration of potassium hydroxide in the solution obtained by stirring, mixing and dissolving antimony trioxide and potassium hydroxide in deionized water.

[0018] Optionally, the ratio range between the antimony trioxide, the potassium hydroxide, the deionized water and the hydrogen peroxide is: (0.5-1):(0.5-1):(1.5-2):(0.5-1), the stirring and mixing time is 0.5 hour to 2 hours, the heating slurry temperature is 80°C to 90°C, the oxidation reaction time is 1 hour to 2 hours, and the oxidation reaction temperature is 80°C to 95°C.

[0019] Optionally, the excess coefficient of sodium hydroxide is 1.0-1.3, and the reaction temperature is 80°C to 90°C.

[0020] Optionally, the surfactant is at least one of hexadecyl ammonium bromide, ethylene glycol, isopropyl alcohol, tartaric acid, polyvinyl alcohol, and sorbitan decahydrate, and the mass ratio of the surfactant to the antimony trioxide is (0.001-0.01):1.

[0021] Optionally, the finished sodium antimonate product is high-purity ultrafine particle sodium antimonate.

[0022] In the embodiment of the present invention, a cyclic preparation method of sodium antimonate is provided, comprising: adding antimony trioxide and potassium hydroxide to deionized water, stirring and mixing, dissolving, heating and slurrying, and then adding hydrogen peroxide to carry out oxidation reaction to obtain a first potassium antimonate solution; adding sodium hydroxide and a surfactant to the first potassium antimonate solution for replacement reaction, standing, cooling, washing, and drying to obtain a sodium antimonate product; adding potassium hydroxide to the reaction solution after standing to obtain a second potassium antimonate solution, and the second potassium antimonate solution is used for cyclic preparation of the sodium antimonate product. The preparation method uses crude antimony oxide powder, potassium hydroxide, and hydrogen peroxide as raw materials to prepare a potassium antimonate solution, and then replaces it with sodium hydroxide to convert it into a sodium antimonate product after filtering and removing impurities. The process has good impurity removal effect, excellent product quality, high purity, and good color, which greatly improves the product quality. The prepared sodium antimonate particles have uniform particle size, with a particle size of ≤2μm, and can be used as flame retardants in fabrics such as fibers, glass shells of color TV picture tubes, and clarifiers for high-grade glass. The preparation process is simple, the requirements for preparation equipment are low, and the energy consumption is low. Moreover, the preparation method can, on the one hand, ensure that the product properties obtained in each cycle are better, the antimony content and arsenic content basically meet the requirements, and the yield is relatively considerable; on the other hand, it can control the cost and improve the utilization rate of the alkali solution in the preparation process of sodium antimonate. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 It is a flow chart of the cyclic preparation method of sodium antimonate provided in an embodiment of the present invention;

[0025] Figure 2 The electron micrograph of the finished sodium antimonate provided in the embodiment of the present invention. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are 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 ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] The terms "first", "second", etc. in the specification and claims of the present invention are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the structures used in this way can be interchanged where appropriate, so that the embodiments of the present invention can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of the same type, and the number of objects is not limited. For example, the first object can be one or more. In addition, "and / or" in the specification and claims represents at least one of the connected objects, and the character " / " generally indicates that the objects associated with each other are in an "or" relationship.

[0028] The embodiment of the present invention provides a cyclic preparation method of sodium antimonate, such as Figure 1 As shown, including:

[0029] Step 101, adding antimony trioxide and potassium hydroxide into deionized water, stirring and mixing, dissolving, heating to slurry, and then adding hydrogen peroxide to carry out oxidation reaction to obtain a first potassium antimonate solution;

[0030] In this step, antimony trioxide, potassium hydroxide, water and hydrogen peroxide can be added to a reactor in a ratio of 0.5-1:0.5-1:1.5-2:0.5-1 for reaction, and the temperature is raised to 80-90° C. and stirred for slurrying for 0.5-2 hours. After the slurrying reaction, hydrogen peroxide is dripped into the slurry at a uniform speed, and an oxidation reaction is carried out at a temperature of 80-95° C. for 1-2 hours to oxidize trivalent antimony into pentavalent antimony to prepare a potassium antimonate solution.

[0031] The reaction principle is: Sb2O3+2KOH+2H2O2+3H2O=2KSb(OH)6;

[0032] The hydrogen peroxide can be added dropwise at a constant speed using a peristaltic pump, with a dropping speed of 10-50 ml / min and a stirring speed of 100-200 r / min. Under a heat preservation environment, impurities are removed by filtration to obtain a clear first potassium antimonate solution.

[0033] Step 102, adding sodium hydroxide and a surfactant to the first potassium antimonate solution to carry out a replacement reaction, standing, cooling, washing, and drying to obtain a finished sodium antimonate product;

[0034] Sodium hydroxide and a surfactant are added to the first potassium antimonate solution, the excess coefficient of sodium hydroxide is 1-1.3:1, and the mixture is stirred in a replacement crystallization tank to produce precipitation. The stirring speed is 100-20r / min, the replacement is carried out at 80-90°C for 1-2 hours, and the crystallization is carried out for 2-4 hours.

[0035] The reaction principle is: KSb(OH)6+NaOH=NaSb(OH)6+KOH;

[0036] The mass ratio of the amount of surfactant to antimony trioxide is 0.001-0.01:1;

[0037] Among them, the liquid-solid separation can be carried out by filtration in a vacuum pump, the sodium antimonate solid is first washed with cold water for 2-3 times, and then washed with hot water at 50-60°C for 2-3 times, and the filtered crystals are sent to a vacuum drying oven for drying at a temperature of 90-110°C for 3-10 hours; the finished sodium antimonate product is obtained by crushing and packaging, and the liquid after liquid-solid separation is the mother liquor.

[0038] Step 103, adding potassium hydroxide to the filtered reaction solution after standing to obtain a second potassium antimonate solution, and the second potassium antimonate solution is used for circulating to prepare the sodium antimonate product.

[0039] The reaction solution (i.e., mother liquor) after standing is recycled and concentrated to a certain volume. The potassium hydrogen phthalate is titrated by acid-base titration, i.e., the mother liquor is used to titrate potassium hydrogen phthalate, and phenolphthalein is used as an indicator to determine the content of potassium hydroxide in the mother liquor. A certain amount of potassium hydroxide is added to ensure the concentration balance. The above steps are repeated to prepare sodium antimonate in the next cycle.

[0040] In this embodiment, the preparation method uses crude antimony oxide powder, potassium hydroxide, and hydrogen peroxide as raw materials to prepare potassium antimonate solution, which is filtered and removed impurities, and then replaced with sodium hydroxide to convert it into a sodium antimonate product. The process has a good impurity removal effect, and the product is of excellent quality, high purity, and good color, which greatly improves the product quality. The prepared sodium antimonate particles have a uniform particle size of ≤2μm. Figure 2 As shown, it can be used as a flame retardant in fabrics such as fibers, a clarifier for color TV picture tube glass shells and high-grade glass, and has a simple preparation process, low requirements for preparation equipment, and low energy consumption. In addition, the preparation method can make the product properties obtained in each cycle better, the antimony content and arsenic content basically meet the requirements, and the yield is relatively considerable. On the other hand, it can control costs and improve the utilization rate of alkali solution in the preparation process of sodium antimonate.

[0041] Optionally, the step of adding sodium hydroxide and a surfactant to the first potassium antimonate solution to carry out a replacement reaction, standing, cooling, washing and drying to obtain a sodium antimonate product comprises:

[0042] adding sodium hydroxide and a surfactant to the first potassium antimonate solution to carry out a replacement reaction, and obtaining sodium antimonate particles after standing and cooling, wherein the particle size of the sodium antimonate particles is less than or equal to 2 microns;

[0043] The sodium antimonate particles are washed with cold water and hot water successively, and then dried to obtain a finished sodium antimonate product.

[0044] In this way, the impurity removal effect is improved, the product quality is excellent, the purity is high, the color is good, and the product quality is greatly improved. The prepared sodium antimonate particles have uniform particle size, and the particle size is ≤2μm. They can be used as flame retardants in fibers and other fabrics, as clarifiers for color TV picture tubes and high-grade glass. The preparation process is simple, the requirements for preparation equipment are low, and the energy consumption is low.

[0045] Optionally, washing the sodium antimonate particles with cold water and hot water successively comprises:

[0046] After washing the sodium antimonate particles with cold water for 2-3 times, they are then washed with hot water at 50° C. to 60° C. for 2-3 times, and the mass ratio of the washing water to the deionized water is (0.005-0.01): 1. While improving the impurity removal effect, the filtrate can be recovered, thereby improving the utilization rate of the alkali solution in the preparation process of sodium antimonate.

[0047] Optionally, the drying temperature in the drying process is 90° C. to 110° C., and the drying time is 3 hours to 10 hours to improve the drying effect.

[0048] Optionally, the volume of the second potassium antimonate solution is equal to the volume of the hot slurry solution to facilitate the subsequent preparation of the sodium antimonate finished product.

[0049] Optionally, the concentration of potassium hydroxide added in the filtration of the reaction liquid after standing is equal to the concentration of potassium hydroxide in the solution after antimony trioxide and potassium hydroxide are stirred, mixed and dissolved in deionized water, so as to facilitate the subsequent preparation of sodium antimonate finished product.

[0050] Optionally, the ratio range of the antimony trioxide, the potassium hydroxide, the deionized water and the hydrogen peroxide is: (0.5-1):(0.5-1):(1.5-2):(0.5-1), the stirring and mixing time is 0.5 hour to 2 hours, the heating slurry temperature is 80°C to 90°C, the oxidation reaction time is 1 hour to 2 hours, and the oxidation reaction temperature is 80°C to 95°C, thereby improving the preparation efficiency of the potassium antimonate solution.

[0051] Optionally, the excess coefficient of sodium hydroxide is 1.0-1.3, and the reaction temperature is 80° C. to 90° C., so that the product properties are better, the antimony content and arsenic content basically meet the requirements, and the yield is relatively considerable.

[0052] Optionally, the surfactant is at least one of hexadecyl ammonium bromide, ethylene glycol, isopropanol, tartaric acid, polyvinyl alcohol, and sorbitol decahydrate, and the mass ratio of the surfactant to the antimony trioxide is (0.001-0.01):1, so that the product has better properties, the antimony content and arsenic content basically meet the requirements, and the yield is relatively considerable.

[0053] Optionally, the finished sodium antimonate product is high-purity ultrafine particle sodium antimonate, so that the product has better properties, the antimony content and arsenic content basically meet the requirements, and the yield is relatively considerable.

[0054] Example 1

[0055] A cyclic preparation method of sodium antimonate in this embodiment comprises the following steps:

[0056] (1) Add 6000 ml of water to 2250 g of crude antimony oxide powder and 2250 g of potassium hydroxide, stir and mix at 120 r / min to dissolve, and then heat to 85° C. and slurry for 1 hour. Then, use a peristaltic pump to drop 2400 ml of hydrogen peroxide solution at a constant speed of 20 ml / min. After the dropwise addition is completed, oxidize for 1 hour to obtain a potassium antimonate solution, and filter while hot to obtain a potassium antimonate clarified liquid;

[0057] (2) Slowly adding 495 g of sodium hydroxide and 19 g of ethylene glycol surfactant to the potassium antimonate solution obtained in step 1), stirring at 85° C. and 120 r / min to carry out a replacement reaction to obtain sodium antimonate, which was then cooled for later use;

[0058] (3) The reaction liquid in step 2) is separated into solid and liquid to obtain sodium antimonate solid and mother liquor, and the sodium antimonate solid is washed three times with 800 ml of 50° C. hot water to remove the residues of sodium hydroxide, potassium hydroxide, sodium arsenate, etc. mixed in the sodium antimonate. After washing, the solid is spun dry and placed in a dryer at 110° C. for 3 hours to obtain 1845 g of a high-purity ultrafine particle sodium antimonate product, wherein the sodium antimonate particles are uniform and have a particle size of ≤0.2 μm.

[0059] (4) The mother liquor is concentrated to reach the initial volume, and then an acid-base titration experiment is performed three times, and the average value is taken to determine the pH value of the mother liquor. 505 g of KOH is added, 2250 g of crude antimony oxide powder and 6000 ml of water are added to the mother liquor, and the above steps are repeated to prepare sodium antimonate in a cycle.

[0060] In this way, on the one hand, the product properties obtained in each cycle can be better, the antimony content and arsenic content can basically meet the requirements, and the yield is relatively considerable; on the other hand, the cost can be controlled and the utilization rate of the alkali solution in the preparation process of sodium antimonate can be improved.

[0061] Example 2

[0062] A cyclic preparation method of sodium antimonate in this embodiment comprises the following steps:

[0063] (1) 3000 g of crude antimony oxide powder and 3000 g of potassium hydroxide were added to 6000 ml of water, stirred at 120 r / min to mix and dissolve, and then heated to 80° C. for slurrying for 1.5 hours. Then, 3000 ml of hydrogen peroxide solution was added dropwise at a constant speed of 30 ml / min using a peristaltic pump. After the addition was completed, the solution was oxidized for 3 hours to obtain a potassium antimonate solution, which was filtered while hot to obtain a potassium antimonate clarified solution.

[0064] (2) Slowly adding 525 g of sodium hydroxide and 20 g of ethylene glycol surfactant to the potassium antimonate solution obtained in step 1), stirring at 85° C. and 150 r / min to carry out a replacement reaction to obtain sodium antimonate, which was then cooled for later use;

[0065] (3) The reaction liquid in step 2) is separated into solid and liquid to obtain sodium antimonate solid and mother liquor, and the sodium antimonate solid is washed three times with 800 ml of 55° C. hot water to remove the residues of sodium hydroxide, potassium hydroxide, sodium arsenate and the like contained in the sodium antimonate. After washing, the solid is spun dry and placed in a dryer at 110° C. for 3 hours to obtain 2050 g of a high-purity ultrafine particle sodium antimonate product, wherein the sodium antimonate particles are uniform and the particle size is ≤0.2 μm.

[0066] (4) The mother liquor is concentrated to reach the initial volume, and then an acid-base titration experiment is performed three times, and the average value is taken to determine the pH value of the mother liquor. 505 g of KOH is added, 3000 g of crude antimony oxide powder and 6000 ml of water are added to the mother liquor, and the above steps are repeated to prepare sodium antimonate in a cycle.

[0067] In this way, on the one hand, the product properties obtained in each cycle can be better, the antimony content and arsenic content can basically meet the requirements, and the yield is relatively considerable; on the other hand, the cost can be controlled and the utilization rate of the alkali solution in the preparation process of sodium antimonate can be improved.

[0068] It should be noted that, in this article, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element. In addition, it should be pointed out that the scope of the method and device in the embodiment of the present invention is not limited to performing functions in the order discussed, and may also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method may be performed in an order different from that described, and various steps may also be added, omitted, or combined. In addition, the features described with reference to certain examples may be combined in other examples.

[0069] The embodiments of the present invention are described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned specific implementation modes, which are merely illustrative rather than restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms without departing from the scope of protection of the present invention and the claims, all of which are within the protection of the present invention.

Claims

1. A cyclic preparation method of sodium antimonate, characterized in that: include: Add antimony trioxide and potassium hydroxide into deionized water, stir and mix, dissolve, heat to make slurry, and then add hydrogen peroxide to carry out oxidation reaction to obtain a first potassium antimonate solution; adding sodium hydroxide and a surfactant to the first potassium antimonate solution to carry out a replacement reaction, standing, cooling, washing, and drying to obtain a finished sodium antimonate product; Potassium hydroxide is added to the filtered reaction solution after standing to obtain a second potassium antimonate solution, and the second potassium antimonate solution is used for circulating to prepare the sodium antimonate product.

2. The method according to claim 1, characterized in that The method comprises adding sodium hydroxide and a surfactant to the first potassium antimonate solution to carry out a replacement reaction, standing, cooling, washing and drying to obtain a sodium antimonate product, including: adding sodium hydroxide and a surfactant to the first potassium antimonate solution to carry out a replacement reaction, and obtaining sodium antimonate particles after standing and cooling, wherein the particle size of the sodium antimonate particles is less than or equal to 2 microns; The sodium antimonate particles are washed with cold water and hot water successively, and then dried to obtain a finished sodium antimonate product.

3. The method according to claim 2, characterized in that The step of washing the sodium antimonate particles with cold water and hot water in sequence comprises: The sodium antimonate particles are washed 2-3 times with cold water, and then washed 2-3 times with hot water at 50° C. to 60° C., with the mass ratio of the washing water to the deionized water being (0.005-0.01):

1.

4. The method according to claim 2, characterized in that: The drying temperature in the drying process is 90° C. to 110° C., and the drying time is 3 hours to 10 hours.

5. The method according to claim 1, characterized in that The volume of the second potassium antimonate solution is equal to the volume of the hot slurry solution.

6. The method according to claim 1, characterized in that The concentration of potassium hydroxide added during the filtration of the reaction solution after standing is equal to the concentration of potassium hydroxide in the solution after antimony trioxide and potassium hydroxide are stirred, mixed and dissolved in deionized water.

7. The method according to claim 1, characterized in that The ratio range between the antimony trioxide, the potassium hydroxide, the deionized water and the hydrogen peroxide is: (0.5-1):(0.5-1):(1.5-2):(0.5-1), the stirring and mixing time is 0.5 hour to 2 hours, the heating slurry temperature is 80°C to 90°C, the oxidation reaction time is 1 hour to 2 hours, and the oxidation reaction temperature is 80°C to 95°C.

8. The method according to claim 1, characterized in that The excess coefficient of the sodium hydroxide is 1.0-1.3, and the reaction temperature is 80°C to 90°C.

9. The method according to claim 1, characterized in that: The surfactant is at least one of hexadecyl ammonium bromide, ethylene glycol, isopropanol, tartaric acid, polyvinyl alcohol, and sorbitan decahydrate, and the mass ratio of the surfactant to the antimony trioxide is (0.001-0.01):

1.

10. The method according to claim 1, characterized in that The finished product of sodium antimonate is high-purity ultrafine particle sodium antimonate.

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