A production method of highly soluble sodium-potassium cross-linked modified phosphate

Abstract

The present invention discloses a production method of highly soluble sodium-potassium cross-linked modified phosphate. One or several of sodium phosphate salts such as acid sodium pyrophosphate and sodium pyrophosphate, and one or several of potassium phosphate salts such as potassium pyrophosphate and acid potassium pyrophosphate are used as raw materials. Through scientific proportioning, homogeneous emulsification, static mixing, boiling drying, and high-efficiency polymerization, a highly soluble sodium-potassium cross-linked modified phosphate product is produced. This production method has the characteristics of strong product adjustability, good product solubility, and low energy consumption.

Description

Technical Field

[0001] The present invention relates to a method for preparing phosphates, and particularly to a method for producing highly soluble sodium-potassium crosslinked modified phosphates. Background Art

[0002] At present, the functional modification of sodium phosphate salts and potassium phosphate salts mostly adopts a simple physical mixing method for production. Although the technical requirements are low, on the one hand, the poor solubility of the product reduces the effective content during product application, and this problem can only be solved by adding more, which will not only increase the production cost but also bring the risk of over-addition in the food field; on the other hand, the poor stability of the product leads to inconsistent quality of the final product, resulting in a high rework rate.

[0003] CN 1148317C produces compound phosphates by spray drying and polymerization of phosphoric acid and alkali. When producing pyro- and poly-compound phosphates with a pH value less than 9.5 by this method, the content of orthophosphate and insoluble metaphosphate will be relatively high, and it is difficult to control in the process, affecting the solubility and application effect of the product; in addition, organic acids need to be introduced into the raw materials used in this method, and the organic matter decomposes or carbonizes during high-temperature polymerization, making it difficult to meet the application requirements.

[0004] Among sodium phosphate salts, such as sodium tripolyphosphate and sodium pyrophosphate, have good water retention performance and good chelating effect on heavy metal ions, but the solubility of sodium phosphate salts is small and they are prone to caking when dissolved in water, so their efficacy cannot be maximized; potassium phosphate salts have a relatively large solubility and excellent solubility in water, but their efficacy is poor. With the rapid development of food and industrial applications, it is particularly important to invent a highly soluble sodium-potassium crosslinked modified phosphate. Summary of the Invention

[0005] The present invention provides a method for producing highly soluble sodium-potassium crosslinked modified phosphates, which has the characteristics of strong product adjustability, good product solubility, low energy consumption, etc., can produce sodium-potassium crosslinked modified phosphates with different stable efficacies, and is suitable for high-end food manufacturing and industrial production fields.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A method for producing highly soluble sodium-potassium crosslinked modified phosphates, in which sodium phosphate salts and potassium phosphate salts are mixed and then added to water, homogenized and emulsified, and the emulsified material is statically mixed, dried, and polymerized to obtain highly soluble sodium-potassium crosslinked modified phosphates.

[0008] The raw materials of the sodium phosphate salts include but are not limited to one or more of acid sodium pyrophosphate, sodium pyrophosphate, and trisodium monohydrogen pyrophosphate.

[0009] The raw materials of the potassium phosphate salts include but are not limited to one or more of potassium pyrophosphate, acid potassium pyrophosphate, and tripotassium monohydrogen pyrophosphate.

[0010] The molar ratio of the sodium phosphate salt to the potassium phosphate salt is 1 - 2:0.5 - 2.5; the mass concentration formed after adding water to the mixture of the sodium phosphate salt and the potassium phosphate salt is 40 - 60%.

[0011] The sodium phosphate salt is acid pyrophosphate sodium, pyrophosphate sodium, or trisodium monohydrogen pyrophosphate; the potassium phosphate salt is acid pyrophosphate potassium, pyrophosphate potassium, or tripotassium monohydrogen pyrophosphate; then the total molar ratio of acid pyrophosphate sodium and acid pyrophosphate potassium is fixed at 1, and the total molar ratio of pyrophosphate sodium and pyrophosphate potassium is 2 - 4; or the total molar ratio of acid pyrophosphate sodium and acid pyrophosphate potassium is fixed at 1, and the total molar ratio of pyrophosphate sodium and pyrophosphate potassium is 1 - 2.

[0012] Or trisodium monohydrogen pyrophosphate or tripotassium monohydrogen pyrophosphate is selectively added, and the molar ratio of trisodium monohydrogen pyrophosphate or tripotassium monohydrogen pyrophosphate is 0.1 - 0.3.

[0013] After the sodium phosphate salt and the potassium phosphate salt are mixed, they are added to water, and homogeneous emulsification is achieved under the action of high-speed rotary shearing. The rotation speed is 3000 - 5000 r / min. For industrial production, a customized 3000L homogeneous emulsifier is selected, and the stirring method is double - spiral ribbon scraping wall stirring. The rotation speed setting of the homogeneous emulsifier is a key parameter. If the set rotation speed is lower than 3000 r / min, stratification or unevenness will occur, which will not only increase the energy consumption in the subsequent drying and polymerization section but also result in poor solubility of the product; while setting the rotation speed higher than 5000 r / min will not further improve the degree of emulsion homogenization and will increase the energy consumption in the homogenization section. Therefore, at a rotation speed of 3000 - 5000 r / min, it can ensure that the undissolved materials form a homogeneous emulsion. Under the action of this high - speed rotary shearing in this application, the materials can be fully emulsified, significantly improving the clarity of the modified phosphate product solution.

[0014] During the static mixing process, the emulsified materials pass through a static mixer. The static mixer has an SV - type feed pipe with corrugated protrusions inside. The pressure inside the pipe is 1.5 - 2.5 MPa. Under high - pressure conditions, the emulsified materials flow in a Z - shape inside the feed pipe, which can further improve the material uniformity and significantly enhance the dissolution performance of the materials under high dissolution concentration conditions.

[0015] During the drying and polymerization processes described above, the drying temperature is controlled at 100 - 150 °C, and the drying time is 10 - 30 min. The polymerization temperature is controlled at 200 - 320 °C, and the reaction time is 0.5 - 3 h. It can be flexibly adjusted within the range according to the raw material ratio and process to obtain the target modified phosphate product. Among them, the control of the polymerization temperature is more critical. For example, when the total molar ratio of sodium acid pyrophosphate and potassium acid pyrophosphate is 1, and 0.1 - 0.3 molar ratio of trisodium monohydrogen pyrophosphate or tripotassium monohydrogen pyrophosphate is added or not according to the situation, when the total molar ratio of sodium pyrophosphate and potassium pyrophosphate is less than 2, the polymerization temperature is controlled at 200 - 280 °C, and pyrophosphate composite sodium potassium phosphate with a pH of 8 - 9.5 can be obtained; while when the polymerization temperature is controlled at 280 - 320 °C, poly-metaphosphate composite sodium potassium phosphate with a pH of 8 - 9.5 or pyrophosphate poly-metaphosphate composite sodium potassium phosphate with a pH of 8 - 9 can be obtained. The drying tower and polymerization furnace of this application are customized equipment. Jet devices are provided in the upper, middle, and lower sections of the drying tower and the front, middle, and rear sections of the polymerization furnace, which can make the material heat more fully during the drying and polymerization processes and require lower energy consumption. Taking hydrogen as the heat source as an example, compared with the traditional method, the method of the present invention can save about 50 - 60 cubic meters of hydrogen per ton of modified phosphate produced.

[0016] In summary, the outstanding advantages of the present invention are: the product has strong adjustability, and various cross-linked modified phosphate products with stable efficacy of different sodium potassium and pyrophosphate poly-metaphosphate ratios can be flexibly produced according to application requirements and target index requirements; the product has good solubility, especially excellent dissolution performance at high dissolution concentrations; and the production energy consumption is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a dissolution drawing of the sample in Example 1, where A is the dissolution drawing of the sample prepared by traditional mechanical mixing, and B is the dissolution drawing of the sample obtained in the steps of Example 1.

[0018] Figure 2 It is a dissolution drawing of the sample in Example 10. DETAILED DESCRIPTION OF THE INVENTION

[0019] Example 1

[0020] Taking molar ratio as the calculation unit, 0.4 sodium acid pyrophosphate, 0.6 potassium acid pyrophosphate, 0.7 sodium pyrophosphate, 1.5 potassium pyrophosphate and an appropriate amount of water are configured into a mixture with a mass fraction of 50%, which is added into a 3000L homogenizing emulsifier. The rotation speed is set at 3100r / min. After emulsification for 15min, the material is pumped into a static mixer through a high-pressure pump. The pressure in the SV type feed pipe is 1.8MPa, and it is transported to a fluidized bed dryer through the feed pipe. The drying temperature is controlled at 100 - 120°C. The dried material is transported to a high-efficiency polymerization furnace through a screw conveyor. The polymerization temperature is controlled at 260°C. The variable temperature polymerization process is adopted, with an intermittent time of 5min and a total reaction time of 1.5h, and a pyrolytic polymerization compound sodium and potassium phosphate with a pyrolytic polymerization ratio of 0.1:1 and a sodium-potassium ratio of 0.5:1 can be obtained.

[0021] Compare the solubility of the product of Example 1 with the product of the traditional mechanical mixing in the same proportion. Weigh 100g of the sample and dissolve it in 100g of water. Stir at a stirring speed of 250r / min for 3min, and observe the dissolution situation after standing for 1min.

[0022] The method of traditional mechanical mixing is as follows: taking the pyrolytic polymerization ratio of 0.1:1 and the sodium-potassium ratio of 0.5:1 as the indexes, monomer phosphates are mixed to form a pyrolytic polymerization compound phosphate product, and the mixture obtained by stirring at 500r / min for 2h.

[0023] Figure 1 It shows that the solution of the product of Example 1 of the present invention (Figure B) is clear and there is no residue at the bottom of the cup; while the solution of the product produced by traditional mechanical mixing (Figure A) is turbid and there are a large number of insoluble residues at the bottom and on the wall of the cup.

[0024] Example 2

[0025] The method and steps are the same as those of Example 1, only in the homogenizing emulsifier, the rotation speed is set at 2000r / min, emulsify for 15min, weigh 100g of the obtained sample and dissolve it in 100g of water, stir at a stirring speed of 250r / min for 3min, and observe the dissolution situation after standing for 1min. The clarity of the product of Example 2 is not as good as that of the product of Example 1, it is slightly turbid, and there are still some precipitates at the bottom of the cup. However, a complete dissolution effect of 80g / 100g can be achieved.

[0026] Example 3

[0027] The method and steps are the same as those in Example 1. Only in the homogenizing emulsifier, the rotation speed is set to 2500 r / min, and emulsification is carried out for 15 min. 100 g of the obtained sample is weighed and dissolved in 100 g of water. Under the stirring speed of 250 r / min, stirring is carried out for 3 min, and the dissolution situation is observed after standing for 1 min. The clarity of the product in Example 3 is better than that of the product in Example 2. The solution is relatively clear, but not as good as the product in Example 1, and there are still some precipitates at the bottom of the cup. However, a complete dissolution effect of 87 g / 100 g can be achieved.

[0028] Example 4

[0029] The method and steps are the same as those in Example 1. Only in the homogenizing emulsifier, the rotation speeds are set to 3500 r / min and 4000 r / min respectively, and emulsification is carried out for 15 min. 100 g of the obtained sample is weighed and dissolved in 100 g of water. Under the stirring speed of 250 r / min, stirring is carried out for 3 min, and the dissolution situation is observed after standing for 1 min. The clarity of the product in Example 45 is the same as that of the product in Example 1.

[0030] Example 5

[0031] The method and steps are the same as those in Example 1. Only in the homogenizing emulsifier, the rotation speeds are set to 4500 r / min and 5000 r / min, and emulsification is carried out for 15 min. 100 g of the obtained sample is weighed and dissolved in 100 g of water. Under the stirring speed of 250 r / min, stirring is carried out for 3 min, and the dissolution situation is observed after standing for 1 min. The clarity of the product in Example 5 is the same as that of the product in Example 1. However, when 115 g of the obtained sample is weighed and dissolved in 100 g of water, the clarity of the product in Example 5 is slightly better than that of the products in Example 1 and Example 4.

[0032] Example 6

[0033] The method and steps are the same as those in Example 1. Only in the homogenizing emulsifier, the rotation speed is set to 5500 r / min, and emulsification is carried out for 15 min. 110 g of the obtained sample is weighed and dissolved in 100 g of water. Under the stirring speed of 250 r / min, stirring is carried out for 3 min, and the dissolution situation is observed after standing for 1 min. The clarity of the product in Example 6 is the same as that of the product in Example 5. When the sample dissolved in 100 g of water is adjusted to the maximum demand of 120 g, it is found that the clarity of the product in Example 6 is the same as that of the product in Example 5.

[0034] Example 7

[0035] Taking molar ratio as the calculation unit, 0.6 acid sodium pyrophosphate, 0.4 acid potassium pyrophosphate, 0.2 trisodium hydrogen pyrophosphate, 0.8 sodium pyrophosphate, 0.8 potassium pyrophosphate and appropriate amount of water are added into a 3000L homogenizing emulsifier. The rotation speed is set at 3500 r / min. After emulsifying for 20 min, the material is pumped into a static mixer through a high-pressure pump. The pressure in the SV type feed pipe is 2.0 MPa. The drying temperature is controlled at 120 - 130 °C. The dried material is conveyed to a high-efficiency polymerization furnace through a screw conveyor. The polymerization temperature is controlled at 310 - 320 °C. The variable temperature polymerization process is adopted, with an intermittent time of 10 min and a total reaction time of 2 h, and then poly-metaphosphate composite sodium potassium phosphate with a sodium-potassium ratio of 1.25:1 can be obtained. Weigh 60 g of the sample and dissolve it in 100 g of water. Stir at a stirring speed of 250 r / min for 3 min, and then let it stand for 1 min and observe the dissolution situation. The product solution of Example 7 is clear and there is no residue at the bottom of the cup.

[0036] Example 8

[0037] The method and steps are the same as those in Example 7, except that the static mixer uses a common feed pipe with a smooth inner wall. Weigh 60 g of the obtained product and dissolve it in 100 g of water. Stir at a stirring speed of 250 r / min for 3 min, and then let it stand for 1 min and observe the dissolution situation. It is found that the product solution of Example 8 is slightly turbid. After multiple solubility tests, it is found that for the product obtained by using a common feed pipe, to make the aqueous solution clear after dissolution, at most about 48 g of the sample can be dissolved in 100 g of water.

[0038] Example 9

[0039] Taking molar ratio as the calculation unit, 0.7 acid sodium pyrophosphate, 0.3 acid potassium pyrophosphate, 1.2 sodium pyrophosphate, 0.5 potassium pyrophosphate and appropriate amount of water are added into a 3000L homogenizing emulsifier. The rotation speed is set at 4100 r / min. After emulsifying for 25 min, the material is pumped into a static mixer through a high-pressure pump. The pressure in the SV type feed pipe is 2.2 MPa. It is conveyed to a fluidized bed dryer through the feed pipe. The drying temperature is controlled at 110 - 120 °C. The dried material is conveyed to a high-efficiency polymerization furnace through a screw conveyor. The polymerization temperature is controlled at 300 - 310 °C. The variable temperature polymerization process is adopted, with an intermittent time of 10 min and a total reaction time of 2 h, and then poly-metaphosphate composite sodium potassium phosphate with a sodium-potassium ratio of 2.4:1 can be obtained. Weigh 50 g of the sample and dissolve it in 100 g of water. Stir at a stirring speed of 250 r / min for 3 min, and then let it stand for 1 min and observe the dissolution situation. The product solution of Example 9 is clear and there is no residue at the bottom of the cup.

[0040] Example 10

[0041] The method and steps are the same as those in Example 9, except that the polymerization temperature is adjusted to 340 - 350 °C. Weigh 50 g of the obtained product and dissolve it in 100 g of water. Stir at a stirring speed of 250 r / min for 3 min, and then observe the dissolution situation after standing for 1 min. The obtained product solution is clear, but there are always a few insoluble substances at the bottom of the cup, as Figure 2 shown.

[0042] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made without exceeding the technical solutions described in the claims shall be included within the protection scope of the present invention.

Claims

1. A production method of highly soluble sodium-potassium crosslinked modified phosphate, characterized in that: Mix sodium phosphate salts and potassium phosphate salts and then add them to water, homogenize and emulsify. The emulsified material is statically mixed, dried, and polymerized to obtain a highly soluble sodium-potassium cross-linked modified phosphate. The polymerization temperature is controlled at 200-320 °C, and the reaction time is 0.5-3 h. After mixing sodium phosphate salts and potassium phosphate salts and adding them to water, homogenization and emulsification are achieved under the action of high-speed rotary shearing, and the rotation speed is 3000-5000 r / min. During the static mixing process, the emulsified material passes through a static mixer. The static mixer has an SV-type feed pipe with a corrugated convex structure inside. Under high-pressure conditions, the emulsified material flows in a Z-shaped pattern in the feed pipe, and the pressure inside the static mixer is 1.5-2.5 Mpa. In the drying tower used for drying and the polymerization furnace used for polymerization, jet devices are provided in the upper, middle, and lower sections of the drying tower and the front, middle, and rear sections of the polymerization furnace, so that the material is heated more sufficiently during the drying and polymerization processes.

2. A production method of a highly soluble sodium-potassium cross-linked modified phosphate according to claim 1, characterized in that: The raw materials of sodium phosphate salts include one or more of acid pyrophosphate sodium, pyrophosphate sodium, and trisodium monohydrogen pyrophosphate; The raw materials of potassium phosphate salts include one or more of acid pyrophosphate potassium, pyrophosphate potassium, and tripotassium monohydrogen pyrophosphate.

3. The production method of a highly soluble sodium-potassium cross-linked modified phosphate according to claim 2, characterized in that: The molar ratio of sodium phosphate salts to potassium phosphate salts is 1-2:0.5-2.5; the mass concentration formed by mixing sodium phosphate salts and potassium phosphate salts with water is 40-60%.

4. The production method of a highly soluble sodium-potassium crosslinked modified phosphate according to claim 3, characterized in that, The sodium phosphate salts are acid pyrophosphate sodium and pyrophosphate sodium; the potassium phosphate salts are acid pyrophosphate potassium and pyrophosphate potassium. Then the total molar ratio of acid pyrophosphate sodium and acid pyrophosphate potassium is fixed at 1, and the total molar ratio of pyrophosphate sodium and pyrophosphate potassium is 2-4; or the total molar ratio of acid pyrophosphate sodium and acid pyrophosphate potassium is fixed at 1, and the total molar ratio of pyrophosphate sodium and pyrophosphate potassium is 1-2.

5. The production method of a highly soluble sodium-potassium cross-linked modified phosphate according to claim 4, characterized in that, Calculated in molar ratio, acid pyrophosphate sodium is 0.4, acid pyrophosphate potassium is 0.6, pyrophosphate sodium is 0.7, and pyrophosphate potassium is 1.

5.

6. The production method of a highly soluble sodium-potassium crosslinked modified phosphate according to claim 4, characterized in that, Calculated in molar ratio, acid pyrophosphate sodium is 0.7, acid pyrophosphate potassium is 0.3, pyrophosphate sodium is 1.2, and pyrophosphate potassium is 0.

5.

7. A production method of a highly soluble sodium-potassium cross-linked modified phosphate according to claim 3, characterized in that, Calculated in molar ratio, acid pyrophosphate sodium is 0.6, acid pyrophosphate potassium is 0.4, trisodium monohydrogen pyrophosphate is 0.2, pyrophosphate sodium is 0.8, and pyrophosphate potassium is 0.

8.

8. A production method of a highly soluble sodium-potassium crosslinked modified phosphate according to claim 1, characterized in that: The drying temperature is controlled at 100-150 °C, and the drying time is 10-30 min.

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