Preparation method of high-purity sodium phytate

Abstract

The invention discloses a preparation method of high-purity sodium phytate, which comprises the following steps: (1) raw material pretreatment: taking 1 part of plant raw material, refining and degreasing, adding into 2-5 parts of water, adjusting the pH value to 8-11, ultrasonically stirring and soaking for 2-5 hours, and dehydrating to obtain a pretreated material; (2) taking 1 part of the pretreated material, adjusting the pH value to 1-4, then adding the pretreated material into 2-5 parts of a sodium sulfate solution with the concentration of 2-5%, carrying out ball milling for 2-5 hours, unloading, and dehydrating to obtain a filtrate A and a filter residue B; (3) soaking and cleaning the filter residue B with clear water, introducing a cleaning solution into the filtrate A to obtain a mixed solution C, adding a pH regulator into the mixed solution C to adjust the pH to 7-8, adding zirconium modified carbon particles, heating and concentrating the mixed solution C to 1 / 4-1 / 3 of the original volume, stirring while hot, precipitating, and filtering to obtain a precipitate D and filtrate E; and (4) drying the filtrate E to obtain sodium phytate. The invention belongs to the technical field of food additives, and has the characteristics that the equipment process is simple, the purity of the prepared sodium phytate can reach 99.0%, and the yield is high.

Description

Technical Field

[0001] The invention relates to the technical field of food additives, and in particular to a method for preparing high-purity sodium phytate. Background Art

[0002] There are currently two methods for producing sodium phytate. One is to extract phytic acid from phytin, add dilute hydrochloric acid for acid hydrolysis to obtain a mixture of phytic acid and CaCl2, and remove CaCl2 through a cation exchange resin. 2+ , a mixture of phytic acid and HCl was obtained, which was saturated with an acrylic anion resin and washed with water to remove Cl - , then add NaOH, adjust pH, concentrate and crystallize, and obtain sodium phytate after drying. This method requires multiple ion exchange, adsorption, and removal of impurities. Due to the introduction of chloride, it is difficult to remove it. The ion exchange membrane generally has a small capacity and is not suitable for removing high-concentration salts in the solution. CN116102589A discloses a method for extracting sodium phytate from corn soaking liquid, which belongs to the field of sodium phytate extraction technology. The invention uses a one-step resin to adsorb phytic acid from corn soaking water, and then uses membrane separation and chromatography column to remove impurities. Another method is to directly neutralize phytic acid with sodium hydroxide, then concentrate, crystallize, and dry to obtain the final phytic acid product, but the raw material cost of this method is high, so it is not competitive. Summary of the invention

[0003] To this end, the present invention provides a method for preparing high-purity sodium phytate to solve the above problems in the prior art.

[0004] In order to achieve the above object, the present invention provides the following technical solutions: A method for preparing high-purity sodium phytate comprises the following steps: Step (1) raw material pretreatment: take 1 part of plant raw material, refine and defatted, add it into 2-5 parts of water, adjust the pH to 8-11, soak for 2-5 hours with ultrasonic stirring, and dehydrate to obtain pretreated material; Step (2): Take 1 part of the pretreated material, adjust the pH to 1-4, then add it to 2-5 parts of a 2%-5% sodium sulfate solution, ball mill for 2-5 hours, discharge the material, and dehydrate to obtain filtrate A and residue B; Step (3): Soak the filter residue B in clean water and introduce the cleaning liquid into the filtrate A to obtain a mixed liquid C, add a pH adjuster to the mixed liquid C to adjust the pH to 7-8, add zirconium-modified carbon particles, heat and concentrate the mixed liquid C to 1 / 4-1 / 3 of the original volume, stir and precipitate while hot, and then filter to obtain a precipitate D and a filtrate E; Step (4): drying the filtrate E to obtain sodium phytate.

[0005] Plant raw materials are rich in phytic acid calcium and magnesium salts. For example, the content of phytic acid calcium in rice bran can reach 10% to 11%. However, this part of phytic acid calcium and magnesium salts is closely bound to biological raw materials and even wrapped by the cellulose of plant raw materials. Since the distribution of phytic acid calcium and magnesium in plant raw materials is relatively complex and the binding strength varies greatly, it may be difficult to fully dissolve phytic acid calcium and magnesium salts, resulting in a low recovery rate. In order to better extract this part of phytic acid calcium and magnesium salts, this scheme pre-treats it in step (1). The main purpose is to adjust the pH to hydrolyze or swell a part of cellulose, starch and other substances. Pressurized dehydration can make each component squeeze out in a water-filled state, which can reduce the binding strength with phytic acid calcium and magnesium salts. Ultrasonic treatment can introduce cavitation microbubbles, which can further accelerate the detachment of phytic acid calcium and magnesium salts. At the same time, the dehydration process in step (1) also takes away a large amount of soluble substances, such as gluconic acid hydrolyzed from starch, amino acids decomposed from protein, inorganic salts, etc.

[0006] In conventional processes, plant raw materials are subjected to acid leaching to obtain calcium magnesium phytate acid solution, which then needs to be converted into iron phytate by adding ferric chloride, and then the iron ions are replaced by adjusting the pH, which is a cumbersome process. In step (2) of this scheme, calcium magnesium phytate is first dissolved, and then calcium phytate is reacted with sulfate ions to generate calcium sulfate precipitate. Since calcium sulfate itself is slightly soluble, although it is easy to form a precipitate in water, the precipitation effect is not good in an acidic environment, which will affect the separation and purification effect of sodium phytate during the purification process. Therefore, in order to obtain sodium phytate with higher purity, conventional process means do not use the method of reacting sodium sulfate with calcium phytate for purification. In step (1) of this scheme, most of the cellulose and starch have been subjected to water absorption and swelling. The extrusion during the dehydration process reduces the bonding strength of the components. Under the ball milling action of step (2), the bonding of the components is further broken, so that the calcium magnesium phytate in the plant raw material is fully dissolved and reacts with sodium sulfate to generate calcium sulfate. Since ball milling accompanies the entire reaction process and sulfate ions are in excess, calcium sulfate can be precipitated more easily and the plant material will not be wrapped by the generated calcium sulfate. Calcium magnesium phytate dissolves in sulfuric acid to generate phytic acid and calcium sulfate similarly to strong acid to weak acid. Therefore, before pH adjustment in step (3), calcium phytate will not precipitate and the reaction can always proceed. The main ion components in the final filtrate A are phytate, sodium ions, hydrogen ions, magnesium ions (less), sodium ions and calcium ions.

[0007] In step (3), the pH of the mixed solution C is about 4-6. Sodium phytate has a low solubility under acidic conditions, so there is a large amount of residue in the filter residue B. Soaking and washing the filter residue B with clean water can recover the sodium phytate in the filter residue. During the heating, concentration and pH adjustment process, since the main components of the mixed solution C are similar to those of the filtrate A, the metal ions are mainly dissolved sodium, calcium, and magnesium. The calcium ions and magnesium ions can be removed by the pH adjuster. Phytic acid calcium and magnesium no longer precipitate during the heating and concentration process because their solubility increases with increasing temperature, while calcium sulfate is the opposite. Therefore, the precipitate D after filtration is calcium sulfate and zirconium-modified carbon particles that adsorb impurities. After the zirconium-modified carbon particles are used to decolorize and adsorb sulfate ions, the hot mixed solution C is filtered and concentrated, and the filtrate E contains sodium lipate.

[0008] Furthermore, in step (1), the plant raw material is rice bran; and the particle size after refinement and defatting is -100 mesh.

[0009] Furthermore, in step (2), the reagent used to adjust the pH to 1-4 is sulfuric acid.

[0010] Considering that the heat generated by the ball milling process will cause the air pressure inside the ball mill to increase, sulfuric acid is not volatile, so safety is more guaranteed.

[0011] Furthermore, in step (2), the ball mill container is lined with 316L stainless steel, and the balls are zirconium oxide ball particles.

[0012] Since the ball milling material is an acidic substance, there are special requirements for the ball milling device. In this scheme, zirconia balls are preferred, which are acid and alkali resistant.

[0013] Furthermore, in step (1) and step (2), the dehydration method is filter press.

[0014] Furthermore, in step (3), the pH adjuster is sodium hydroxide or sodium carbonate.

[0015] Furthermore, in step (3), the preparation method of the zirconium-modified carbon particles is as follows: add 1-2 parts of a 10%-15% zirconium chloride solution to 1 part of filter residue B, stir thoroughly and let stand for 10-30 minutes in an ammonia atmosphere, then dry in low temperature vacuum, and after drying, calcine for 3-5 hours under inert gas protection, and crush to obtain zirconium-modified carbon particles.

[0016] The zirconium-modified carbon particles of this scheme are mainly used for color removal and adsorption of sulfate ions. This scheme uses filter residue B to prepare zirconium-modified carbon particles. The filter residue B itself has a fine particle size, with an average particle size of 2-3μm. After being fully soaked in a zirconium chloride solution, the zirconium ions are adsorbed by the filter residue particle fibers, converted into zirconium hydroxide under an ammonia atmosphere, and finally converted into zirconium oxide during calcination. During the calcination process, the filter residue B particles are converted into carbon particles, and the zirconium oxide particles are dispersed on the surface of the carbon particles to obtain zirconium-modified carbon particles. Zirconium oxide can adsorb sulfate ions due to the high valence state of zirconium ions. The zirconium-modified carbon particles of this scheme are not disposable. After absorbing sulfate ions, the prepared zirconium oxide particles are filtered and separated, soaked in clean water, and the pH is adjusted to alkaline. At 70-80°C, the sulfate ions will desorb into the water. After separation and drying, the zirconium-modified carbon particles can be reused.

[0017] Furthermore, the temperature of the low-temperature vacuum drying is 60-80°C.

[0018] Furthermore, the calcination temperature is 450-650°C.

[0019] After the ammonia environment is left to stand, ammonium chloride is generated and evaporates at 450-650℃.

[0020] Furthermore, the average particle size of the zirconium-modified carbon particles is 1-5 μm.

[0021] Compared with the prior art, the present invention achieves the following beneficial effects: 1. The equipment and process of this solution are simple, the purity of the obtained sodium phytate can reach 99.0%, and the production rate is also high; 2. This solution can effectively remove the introduced sulfate ions by preparing recyclable zirconium-modified carbon particles for impurity removal, and at the same time has the effect of adsorbing microparticles to ensure product purity. DETAILED DESCRIPTION

[0022] The following is a description of the implementation of the present invention by specific embodiments. People familiar with the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. 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.

[0023] Embodiment 1: A method for preparing high-purity sodium phytate, comprising the following steps: Step (1) raw material pretreatment: take 1 part of rice bran, refine it to -100 mesh, defatted it by mechanical degreasing method, add it into 3 parts of water, adjust the pH to 10, soak it with ultrasonic stirring for 2 hours, and filter press dehydrate to obtain pretreated material; Step (2): Take 1 part of the pretreated material, adjust the pH to 3 with sulfuric acid, then add it to 3 parts of 4% sodium sulfate solution, and ball mill for 3 hours, wherein the ball mill container is lined with 316L stainless steel and the balls are zirconium oxide ball particles, unload the material, and filter press and dehydrate to obtain filtrate A and residue B; Step (3): Soak the filter residue B in clean water to clean it, and introduce the cleaning liquid into the filtrate A to obtain a mixed liquid C, add sodium hydroxide to the mixed liquid C to adjust the pH to 7.5, add zirconium-modified carbon particles, heat and concentrate the mixed liquid C to 1 / 4 of the original volume, stir and precipitate while hot, and then filter to obtain a precipitate D and a filtrate E; Step (4): drying the filtrate E to obtain sodium phytate; In step (3), the preparation method of the zirconium-modified carbon particles is as follows: add 1 part of a 10% zirconium chloride solution to 1 part of filter residue B, stir thoroughly and let stand for 30 minutes in an ammonia atmosphere, then dry at 70°C in a vacuum oven, and after drying, calcine at 600°C for 4 hours under inert gas protection, and crush to obtain zirconium-modified carbon particles with an average particle size of 3 μm.

[0024] Embodiment 2: A method for preparing high-purity sodium phytate, comprising the following steps: Step (1) raw material pretreatment: take 1 part of rice bran, refine it to -100 mesh, defatted it by mechanical degreasing method, add it into 3 parts of water, adjust the pH to 9, soak it with ultrasonic stirring for 2 hours, and filter press dehydrate to obtain pretreated material; Step (2): Take 1 part of the pretreated material, adjust the pH to 4 with sulfuric acid, then add it to 5 parts of 4% sodium sulfate solution, and ball mill for 3 hours, wherein the ball mill container is lined with 316L stainless steel and the balls are zirconium oxide ball particles, unload the material, and filter press and dehydrate to obtain filtrate A and residue B; Step (3): Soak the filter residue B in clean water to clean it, and introduce the cleaning liquid into the filtrate A to obtain a mixed liquid C, add sodium hydroxide to the mixed liquid C to adjust the pH to 8, add zirconium-modified carbon particles, heat and concentrate the mixed liquid C to 1 / 3 of the original volume, stir and precipitate while hot, and then filter to obtain a precipitate D and a filtrate E; Step (4): drying the filtrate E to obtain sodium phytate; In step (3), the preparation method of the zirconium-modified carbon particles is as follows: add 1 part of a 10% zirconium chloride solution to 1 part of filter residue B, stir thoroughly and let stand for 30 minutes in an ammonia atmosphere, then dry at 70°C in a vacuum, and after drying, calcine at 600°C for 4 hours under inert gas protection, and crush to obtain zirconium-modified carbon particles with an average particle size of 3 μm.

[0025] Embodiment 3: A method for preparing high-purity sodium phytate, comprising the following steps: Step (1) raw material pretreatment: take 1 part of rice bran, refine it to -100 mesh, defatted it by mechanical degreasing method, add it into 3 parts of water, adjust the pH to 8, soak it with ultrasonic stirring for 5 hours, and filter press dehydrate to obtain pretreated material; Step (2): Take 1 part of the pretreated material, adjust the pH to 2 with sulfuric acid, then add it to 3 parts of 4% sodium sulfate solution, and ball mill for 3 hours, wherein the ball mill container is lined with 316L stainless steel and the balls are zirconium oxide ball particles, unload the material, and filter press and dehydrate to obtain filtrate A and residue B; Step (3): Soak the filter residue B in clean water to clean it, and introduce the cleaning liquid into the filtrate A to obtain a mixed liquid C, add sodium hydroxide to the mixed liquid C to adjust the pH to 7.5, add zirconium-modified carbon particles, heat and concentrate the mixed liquid C to 1 / 4 of the original volume, stir and precipitate while hot, and then filter to obtain a precipitate D and a filtrate E; Step (4): drying the filtrate E to obtain sodium phytate; In step (3), the preparation method of the zirconium-modified carbon particles is as follows: add 2 parts of a 15% zirconium chloride solution to 1 part of filter residue B, stir thoroughly and let stand for 30 minutes in an ammonia atmosphere, then dry at 70°C in a vacuum oven, and after drying, calcine at 600°C for 4 hours under inert gas protection, and crush to obtain zirconium-modified carbon particles with an average particle size of 3 μm.

[0026] Comparative Example 1: Commercially available sodium phytate.

[0027] Comparative Example 2: A method for preparing high-purity sodium phytate, comprising the following steps: Step (1) raw material pretreatment: take 1 part of rice bran, refine it to -100 mesh, defatted it by mechanical degreasing method, add it into 3 parts of water, adjust the pH to 10, soak it with ultrasonic stirring for 2 hours, and filter press dehydrate to obtain pretreated material; Step (2): taking 1 portion of the pretreated material, adjusting the pH to 3 with sulfuric acid, leaching for 3 hours, and filtering and dehydrating to obtain filtrate A and residue B; Step (3): Soak the filter residue B in clean water to clean it, and introduce the cleaning liquid into the filtrate A to obtain a mixed liquid C, add sodium hydroxide to the mixed liquid C to adjust the pH to 7.5, add zirconium-modified carbon particles, heat and concentrate the mixed liquid C to 1 / 4 of the original volume, stir and precipitate while hot, and then filter to obtain a precipitate D and a filtrate E; Step (4): drying the filtrate E to obtain sodium phytate; In step (3), the preparation method of the zirconium-modified carbon particles is as follows: add 1 part of a 10% zirconium chloride solution to 1 part of filter residue B, stir thoroughly and let stand for 30 minutes in an ammonia atmosphere, then dry at 70°C in a vacuum oven, and after drying, calcine at 600°C for 4 hours under inert gas protection, and crush to obtain zirconium-modified carbon particles with an average particle size of 3 μm.

[0028] Comparative Example 3: A method for preparing high-purity sodium phytate, comprising the following steps: Step (1) raw material pretreatment: take 1 part of rice bran, refine it to -100 mesh, defatted it by mechanical degreasing method, add it into 3 parts of water, adjust the pH to 10, soak it with ultrasonic stirring for 2 hours, and filter press dehydrate to obtain pretreated material; Step (2): Take 1 part of the pretreated material, adjust the pH to 3 with sulfuric acid, then add it to 3 parts of 4% sodium sulfate solution, and ball mill for 3 hours, wherein the ball mill container is lined with 316L stainless steel and the balls are zirconium oxide ball particles, unload the material, and filter press and dehydrate to obtain filtrate A and residue B; Step (3): Soak the filter residue B in clean water to clean it, and introduce the cleaning liquid into the filtrate A to obtain a mixed liquid C, add sodium hydroxide to the mixed liquid C to adjust the pH to 7.5, add activated carbon particles, heat and concentrate the mixed liquid C to 1 / 4 of its original volume, stir and precipitate while hot, and then filter to obtain a precipitate D and a filtrate E; Step (4): drying the filtrate E to obtain sodium phytate.

[0029] Comparative Example 4: A method for preparing high-purity sodium phytate, comprising the following steps: Step (1) raw material pretreatment: take 1 part of rice bran, refine it to -100 mesh, defatted it by mechanical degreasing method, add it into 3 parts of water, adjust the pH to 10, soak it with ultrasonic stirring for 2 hours, and filter press dehydrate to obtain pretreated material; Step (2): taking 1 portion of the pretreated material, adjusting the pH to 3 with sulfuric acid, and ball milling for 3 hours, wherein the ball milling container is lined with 316L stainless steel and the balls are zirconium oxide ball particles, unloading, and filtering and dehydrating to obtain filtrate A and residue B; Step (3): Soak the filter residue B in clean water to clean it, and introduce the cleaning liquid into the filtrate A to obtain a mixed liquid C, add sodium hydroxide to the mixed liquid C to adjust the pH to 7.5, add zirconium-modified carbon particles, heat and concentrate the mixed liquid C to 1 / 4 of the original volume, stir and precipitate while hot, and then filter to obtain a precipitate D and a filtrate E; Step (4): drying the filtrate E to obtain sodium phytate; In step (3), the preparation method of the zirconium-modified carbon particles is as follows: add 1 part of a 10% zirconium chloride solution to 1 part of filter residue B, stir thoroughly and let stand for 30 minutes in an ammonia atmosphere, then dry at 70°C in a vacuum oven, and after drying, calcine at 600°C for 4 hours under inert gas protection, and crush to obtain zirconium-modified carbon particles with an average particle size of 3 μm.

[0030] Comparative Example 5: A method for preparing high-purity sodium phytate, comprising the following steps: Step (1) raw material pretreatment: take 1 part of rice bran, refine it to -100 mesh, defatted it by mechanical degreasing method, add it into 3 parts of water, adjust the pH to 10, soak it with ultrasonic stirring for 2 hours, and filter press dehydrate to obtain pretreated material; Step (2): Take 1 portion of the pretreated material, adjust the pH to 3 with sulfuric acid, then add it to 3 portions of 10% sodium sulfate solution, and ball mill for 3 hours, wherein the ball mill container is lined with 316L stainless steel and the balls are zirconium oxide ball particles, unload the material, and filter press and dehydrate to obtain filtrate A and residue B; Step (3): Soak the filter residue B in clean water to clean it, and introduce the cleaning liquid into the filtrate A to obtain a mixed liquid C, add sodium hydroxide to the mixed liquid C to adjust the pH to 7.5, add zirconium-modified carbon particles, heat and concentrate the mixed liquid C to 1 / 4 of the original volume, stir and precipitate while hot, and then filter to obtain a precipitate D and a filtrate E; Step (4): drying the filtrate E to obtain sodium phytate; In step (3), the preparation method of the zirconium-modified carbon particles is as follows: add 1 part of a 10% zirconium chloride solution to 1 part of filter residue B, stir thoroughly and let stand for 30 minutes in an ammonia atmosphere, then dry at 70°C in a vacuum oven, and after drying, calcine at 600°C for 4 hours under inert gas protection, and crush to obtain zirconium-modified carbon particles with an average particle size of 3 μm.

[0031] Comparative Example 6: A method for preparing high-purity sodium phytate, comprising the following steps: Step (1) raw material pretreatment: take 1 part of rice bran, refine it to -100 mesh, defatted it by mechanical degreasing method, add it into 3 parts of water, adjust the pH to 10, soak it with ultrasonic stirring for 2 hours, and filter press dehydrate to obtain pretreated material; Step (2): Take 1 part of the pretreated material, adjust the pH to 3 with sulfuric acid, then add it to 3 parts of 4% sodium sulfate solution, and ball mill for 3 hours, wherein the ball mill container is lined with 316L stainless steel and the balls are zirconium oxide ball particles, unload the material, and filter press and dehydrate to obtain filtrate A and residue B; Step (3): Soak the filter residue B in clean water to clean it, and introduce the cleaning liquid into the filtrate A to obtain a mixed liquid C, add sodium hydroxide to the mixed liquid C to adjust the pH to 7.5, add zirconium-modified carbon particles, heat and concentrate the mixed liquid C to 1 / 4 of the original volume, stir and precipitate while hot, and then filter to obtain a precipitate D and a filtrate E; Step (4): drying the filtrate E to obtain sodium phytate; In step (3), the preparation method of the zirconium-modified carbon particles is as follows: add 1 part of a 10% zirconium chloride solution to 1 part of filter residue B, stir thoroughly and let stand for 30 minutes in an ammonia atmosphere, then dry at 70°C in a vacuum oven, and after drying, calcine at 700°C for 8 hours under inert gas protection, and crush to obtain zirconium-modified carbon particles with an average particle size of 10 μm.

[0032] Detection method: Purity was tested by high performance liquid chromatography; Production rate: actual production volume / theoretical production volume × 100%.

[0033] The results are shown in Table 1.

[0034] Table 1 Serial number color purity Completion rate Example 1 White 99.1 85.4% Example 2 White 98.9 85.3% Example 3 White 98.8 86.2% Comparative Example 1 White 98.3 / Comparative Example 2 White 92.1 52.1% Comparative Example 3 yellow 76.5 85.2% Comparative Example 4 White 89.5 78.9% Comparative Example 5 White 93.3 84.6% Comparative Example 6 yellow 78.7 84.7% Comparative Example 1 is a reference example. The purity of sodium phytate in Examples 1-3 of this scheme is higher than that in Comparative Example 1, that is, this scheme can produce high-purity sodium phytate.

[0035] Comparative Example 2 lacks the ball milling process of Example 1. Comparative Example 2 is directly leached with sulfuric acid. After the calcium sulfate in the leaching solution is saturated, the calcium sulfate covers the surface of the rice bran particles and the reaction is blocked. Therefore, there are a large number of calcium ions in the filtrate A, while most of the calcium ions in Example 1 have been converted into precipitates through excessive sulfate. In step (3) of Comparative Example 2, both calcium phytate and calcium sulfate are precipitated, which also affects the production rate.

[0036] Comparison between Comparative Example 3 and Example 1 is that the carbon particles are not treated with zirconium-modified carbon particles, so the purity is lower. Due to the higher impurity content, the production rate is higher.

[0037] The difference between Comparative Example 4 and Example 1 is that no sodium sulfate solution is added in step (2), resulting in less calcium sulfate generated during the ball milling process, and pH adjustment in step (3) causes part of the sodium phytate to be converted into calcium phytate, resulting in a decrease in the production rate.

[0038] The difference between Comparative Example 5 and Example 1 is that excessive sodium sulfate solution is added in step (2), resulting in insufficient removal of sulfate ions and the presence of sodium sulfate crystals in the finished product.

[0039] The difference between Comparative Example 6 and Example 1 is that the preparation temperature of the zirconium-modified carbon particles is too high, the insulation time is too long, and the average particle size is too large, resulting in poor adsorption effect. Therefore, the sodium phytate prepared in Comparative Example 6 has lower purity and a higher production rate.

Claims

1. A method for preparing high-purity sodium phytate, characterized in that: The following steps are involved: Step (1) raw material pretreatment: take 1 part of plant raw material, refine and defatted, add it into 2-5 parts of water, adjust the pH to 8-11, soak for 2-5 hours with ultrasonic stirring, and dehydrate to obtain pretreated material; Step (2): Take 1 part of the pretreated material, adjust the pH to 1-4, then add it to 2-5 parts of a 2%-5% sodium sulfate solution, ball mill for 2-5 hours, discharge the material, and dehydrate to obtain filtrate A and residue B; Step (3): Soak the filter residue B in clean water and introduce the cleaning liquid into the filtrate A to obtain a mixed liquid C, add a pH adjuster to the mixed liquid C to adjust the pH to 7-8, add zirconium-modified carbon particles, heat and concentrate the mixed liquid C to 1 / 4-1 / 3 of the original volume, stir and precipitate while hot, and then filter to obtain a precipitate D and a filtrate E; Step (4): drying the filtrate E to obtain sodium phytate.

2. The method for preparing high-purity sodium phytate according to claim 1, characterized in that: In step (1), the plant raw material is rice bran; and the particle size after refinement and defatting is -100 mesh.

3. The method for preparing high-purity sodium phytate according to claim 1, characterized in that: In step (2), the reagent used to adjust the pH to 1-4 is sulfuric acid.

4. The method for preparing high-purity sodium phytate according to claim 1, characterized in that: In step (2), the ball mill container is lined with 316L stainless steel, and the balls are zirconium oxide ball particles.

5. The method for preparing high-purity sodium phytate according to claim 1, characterized in that: In step (1) and step (2), the dehydration method is filter press.

6. The method for preparing high-purity sodium phytate according to claim 1, characterized in that: In step (3), the pH adjusting agent is sodium hydroxide or sodium carbonate.

7. The method for preparing high-purity sodium phytate according to claim 1, characterized in that: In step (3), the preparation method of the zirconium-modified carbon particles is as follows: add 1-2 parts of a 10%-15% zirconium chloride solution to 1 part of the filter residue B, stir thoroughly and let stand for 10-30 minutes in an ammonia atmosphere, then dry at low temperature in a vacuum, and after drying, calcine for 3-5 hours under inert gas protection, and crush to obtain zirconium-modified carbon particles.

8. The method for preparing high-purity sodium phytate according to claim 7, characterized in that: The temperature of the low-temperature vacuum drying is 60-80°C.

9. The method for preparing high-purity sodium phytate according to claim 7, characterized in that: The calcination temperature is 450-650°C.

10. The method for preparing high-purity sodium phytate according to claim 7, characterized in that: The zirconium-modified carbon particles have an average particle size of 1-5 μm.