Additive for increasing crystal granularity of calcium hydrophosphate and application of additive
By using surfactants such as hexadecylpyridine to mix with lime milk, the particle size of dicalcium phosphate crystals is increased, solving the problem of small particle size in existing technologies and achieving efficient particle size improvement and energy consumption reduction.
Patent Information
- Application Number
- CN202511477135.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-10-16
- Publication Date
- 2026-01-23
AI Technical Summary
In existing technologies, feed-grade dicalcium phosphate has a small crystal particle size, which leads to difficulties in filtration, entrainment of free water, increased energy consumption, and dust generation, affecting the production environment.
Hexadecylpyridine bromide, hexadecyltrimethylammonium bromide, and dodecylbenzyldimethylammonium bromide were used as additives, mixed with lime milk, and then phosphoric acid was added. The particle size of dicalcium phosphate crystals was increased by stirring and aging.
It significantly increases the particle size of dicalcium phosphate, with a maximum increase of over 50%, thereby improving product quality and reducing production energy consumption.
Smart Images
Figure CN121376930A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of inorganic chemical industry, in particular to an additive for increasing the crystal size of calcium hydrogen phosphate and application thereof. BACKGROUND
[0002] Feed-grade calcium hydrogen phosphate (CaHPO4x2H2O, DCP) is an indispensable calcium and phosphorus supplement in animal feed. The phosphorus and calcium elements in its molecules exist in a bioavailable form, can be dissolved by animal gastric acid, and participate in metabolism, promote the synthesis of digestive enzymes and vitamins, enhance bone health, and improve meat, milk, and egg production efficiency. However, existing research shows that the crystal size of feed-grade calcium hydrogen phosphate is generally small in the industrial production. In the production process, small crystals lead to difficulty in filtration and carry a large amount of free water, increasing the energy consumption in the drying process. Meanwhile, as a feed additive, small crystals are prone to cause dust flying in the mixing process, affecting the production environment. Therefore, improving the quality of calcium hydrogen phosphate products and preparing large-particle feed-grade calcium hydrogen phosphate are effective ways to solve the above problems. SUMMARY
[0003] The present application aims to overcome the above technical deficiencies and provide an additive for increasing the crystal size of calcium hydrogen phosphate and application thereof, solving the technical problem of how to increase the crystal size of calcium hydrogen phosphate in the prior art.
[0004] To achieve the above technical purpose, the technical solution of the present application provides an additive for increasing the crystal size of calcium hydrogen phosphate, which is at least one of bromohexadecylpyridine, hexadecyltrimethylammonium bromide, and dodecylbenzyl dimethyl bromide.
[0005] In any embodiment, the additive is any two of bromohexadecylpyridine, hexadecyltrimethylammonium bromide, and dodecylbenzyl dimethyl bromide.
[0006] In any embodiment, the additive is bromohexadecylpyridine, hexadecyltrimethylammonium bromide, and dodecylbenzyl dimethyl bromide.
[0007] In addition, the present application also proposes the application of the above additive in increasing the crystal size of calcium hydrogen phosphate.
[0008] In any embodiment, the calcium hydrogen phosphate is feed-grade calcium hydrogen phosphate.
[0009] In any embodiment, the above application includes the following steps: premixing the additive with lime milk, and then adding phosphoric acid under stirring at 20-60℃ to obtain calcium hydrogen phosphate.
[0010] In any embodiment, the mass ratio of the additive to calcium hydroxide in the milk of lime is (0.25-1.5):100.
[0011] In any embodiment, the stirring speed is 100-500 r / min.
[0012] In any embodiment, the phosphoric acid is added dropwise at a speed of 2-6 mL / min.
[0013] In any embodiment, after the addition of the phosphoric acid, a ripening treatment is further included, and the ripening treatment time is 1-6 h.
[0014] Compared with the prior art, the beneficial effects of the present application include: the additive for increasing the particle size of calcium hydrogen phosphate crystals proposed by the present application can increase the particle size of calcium hydrogen phosphate by more than 50%. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1 The pictures of the feed-grade calcium hydrogen phosphate prepared in the examples of the present application; wherein Figure 1 (a), and Figure 1 (b) are the phase diagram and product picture of the large-particle feed-grade calcium hydrogen phosphate prepared by adding the additive cetyltrimethylammonium bromide in Example 1, respectively; Figure 1 (c), and Figure 1 (d) are the morphology pictures of the large-particle feed-grade calcium hydrogen phosphate prepared by not adding the additive and by adding the additive cetyltrimethylammonium bromide in Example 1, respectively.
[0016] Figure 2 The particle size diagram of the feed-grade calcium hydrogen phosphate prepared in the examples of the present application; wherein Figure 2 (a) is the particle size diagram of the large-particle feed-grade calcium hydrogen phosphate prepared by not adding the additive in Example 1; Figure 2 (b) is the particle size diagram of the large-particle feed-grade calcium hydrogen phosphate prepared by adding the additive cetyltrimethylammonium bromide in Example 6; Figure 2 (c) is the particle size diagram of the large-particle feed-grade calcium hydrogen phosphate prepared by adding the additive cetyltrimethylammonium bromide and bromohexadecylpyridine in Example 9; Figure 2 (d) is the particle size diagram of the large-particle feed-grade calcium hydrogen phosphate prepared by adding the additive cetyltrimethylammonium bromide, bromohexadecylpyridine and dodecylbenzyl dimethyl bromide in Example 11; the results show that bromohexadecylpyridine, cetyltrimethylammonium bromide and dodecylbenzyl dimethyl bromide significantly increase the particle size of the DCP product through electrostatic adsorption. DETAILED DESCRIPTION
[0017] "RANGES" disclosed herein are defined by both a lower and an upper limit, and a given range is defined by selecting a lower limit and an upper limit, which define the boundaries of the particular range. Ranges defined by such limits can be either inclusive or exclusive of the end values, and can be arbitrarily combined, i.e., any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for a particular parameter, it is understood that ranges of 60-110 and 80-120 are also contemplated. Further, if minimum range values of 1 and 2 are listed, and if maximum range values of 3, 4, and 5 are listed, then the following ranges are all contemplated: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5. In this application, unless otherwise indicated, a numerical range "a-b" means a range of any combination of the numbers between a and b, in which a and b are both real numbers. For example, the numerical range "0-5" means that all real numbers between "0-5" have been listed herein, and "0-5" is merely a shorthand for those numerical combinations. Also, when a parameter is stated to be an integer > 2, it is equivalent to state that the parameter is, for example, an integer 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.
[0018] Unless otherwise indicated, the terms "including", "includes" and "contain" in this application are open-ended and also inclusive. For example, the terms "including", "includes" and "contain" can mean that other components not listed can also be included or contained.
[0019] Unless otherwise indicated, the term "or" in this application is inclusive. For example, the phrase "A or B" means "A, B, or both A and B." More specifically, any of the following satisfy the condition "A or B": A is true (or exists) and B is false (or does not exist); A is false (or does not exist) and B is true (or exists); or both A and B are true (or exist).
[0020] The DETAILED DESCRIPTION provides an additive for increasing the particle size of calcium hydrogen phosphate crystals, the additive being at least one of bromohexadecylpyridine (i.e., CPB), hexadecyltrimethylammonium bromide (i.e., CTAB), and dodecylbenzyl dimethyl ammonium bromide (i.e., BZK).
[0021] In some embodiments, the additive is any two of bromohexadecylpyridine, hexadecyltrimethylammonium bromide, and dodecylbenzyl dimethyl ammonium bromide.
[0022] In some embodiments, the additive is all three of bromohexadecylpyridine, hexadecyltrimethylammonium bromide, and dodecylbenzyl dimethyl ammonium bromide.
[0023] The specific embodiment also proposes application of the additive in increasing the grain size of calcium hydrogen phosphate.
[0024] In some embodiments, the calcium hydrogen phosphate is a feed-grade calcium hydrogen phosphate.
[0025] In some embodiments, the application comprises the following steps: premixing the additive with lime milk, then adding phosphoric acid under stirring at 20-60℃, then aging for 1-6 h, then filtering and drying to obtain calcium hydrogen phosphate; the mass ratio of the additive to calcium hydroxide in the lime milk is (0.25-1.5):100; the stirring speed is 100-500 r / min, the phosphoric acid is added dropwise, the dropwise adding speed is 2-6 mL / min; the drying temperature is 60℃, and the drying time is 8 h.
[0026] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application.
[0027] In the present application, “some embodiments”, “the present embodiment” and the like are described, which describe a subset of all possible embodiments, but it can be understood that “some embodiments” can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict.
[0028] If similar descriptions of “first / second” appear in the application file, the following description is added, in the following description, the terms “first\second\third” are only used to distinguish similar objects, and do not represent a specific order of the objects, and it can be understood that “first\second\third” can be interchanged in a specific order or sequence as allowed, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein.
[0029] In the present embodiment, the term “and / or” only describes the association relationship of the associated objects, which means that there can be three relationships, for example, object A and / or object B, which means that there can be three cases: object A exists alone, object A and object B exist together, and object B exists alone.
[0030] Hereinafter, the embodiments of the present application are described. The embodiments described below are exemplary and are used only to explain the present application, and cannot be understood as limiting the present application. If the specific technology or condition is not specified in the embodiments, the technology or condition described in the literature in the art or according to the product manual is used. If the reagent or instrument used is not specified by the manufacturer, it is a conventional product that can be obtained by purchase.
[0031] In the following examples, the concentration of milk of lime is 100 g / L, and the concentration of phosphoric acid is 12%.
[0032] Example 1 This example proposes an additive for increasing the particle size of calcium hydrogen phosphate crystals, which is bromohexadecylpyridine, hexadecyltrimethylammonium bromide, or dodecylbenzyl dimethyl bromide.
[0033] This example also proposes the use of the above-mentioned additive in increasing the particle size of calcium hydrogen phosphate crystals, which includes: adding milk of lime (100 mL, 100 g / L) and 0.5 g of surfactant into a reactor, stirring at 200 r / min, and heating to 40 ℃ using a water bath, then adding 100 mL of dilute phosphoric acid into the reactor at a rate of 2 mL / min using a peristaltic pump. After the titration is completed, solid-liquid separation is performed, and the obtained solid calcium hydrogen phosphate is dried at 60 ℃ for 8 h before particle size analysis. At the same time, a control group without the additive is tested and analyzed for comparison, and the test results are as follows: Table 1. Test results of calcium hydrogen phosphate particle size obtained in Example 1 ; As can be seen from Table 1, when the reaction temperature is 40 ℃, adding 0.5 g of CTAB, CPB, or BZK into milk of lime (100 mL, 100 g / L) can all increase the particle size of calcium hydrogen phosphate. Compared with the group without adding the additive, the particle size of calcium hydrogen phosphate in the three groups with 0.5 g of CTAB, CPB, or BZK added is increased by 22%, 16%, and 13%, respectively. Combined with the above analysis, Figure 1 , it can be seen that the product obtained is calcium hydrogen phosphate.
[0034] Example 2 This example proposes an additive for increasing the particle size of calcium hydrogen phosphate crystals, which is CTAB.
[0035] This example also proposes the use of the above-mentioned additive in increasing the particle size of calcium hydrogen phosphate crystals, which includes: adding milk of lime (100 mL, 100 g / L) and 0.5 g of CTAB into a reactor, stirring at 200 r / min, and heating to a specified temperature (20 ℃, 30 ℃, 40 ℃, 50 ℃, and 60 ℃) using a water bath. Then, 100 mL of dilute phosphoric acid is added into the reactor at a rate of 2 mL / min using a peristaltic pump. After the titration is completed, solid-liquid separation is performed, and the obtained solid calcium hydrogen phosphate is dried at 60 ℃ for 8 h before particle size analysis. Each group is tested and analyzed for comparison, and the test results are as follows: Table 2. Test results of calcium hydrogen phosphate particle size obtained in Example 2 ; As can be seen from Table 2, when the reaction temperature is 40 °C, the lime milk (100 mL, 100 g / L) is stirred with 0.5 g CTAB at a speed of 200 r / min, and dilute phosphoric acid is added into the reactor at a rate of 2 mL / min by peristaltic pump. At this time, the prepared dicalcium phosphate has the largest particle size. Compared with other temperatures, the particle size of dicalcium phosphate prepared at 40 °C is increased by 33-52%.
[0036] Example 3 This example proposes an additive for increasing the crystalline particle size of dicalcium phosphate, which is CTAB.
[0037] This example also proposes the application of the above-mentioned additive in increasing the particle size of the crystalline dicalcium phosphate, which comprises: adding lime milk (100 mL, 100 g / L) and 0.5 g CTAB into the reactor, stirring at 200 r / min, and heating to 40 °C with a water bath. Then 100 mL of dilute phosphoric acid is added into the reactor at a rate of 1-6 mL / min by peristaltic pump. After titration, solid-liquid separation is carried out, and the obtained solid dicalcium phosphate is dried at 60 °C for 8 h and then subjected to particle size analysis. At the same time, a control group with other sample feeding speeds is tested and analyzed for comparison, and the test results are as follows: Table 3. Particle size test results of dicalcium phosphate obtained in Example 3 ; As can be seen from Table 3, when the reaction temperature is 40 °C, the lime milk (100 mL, 100 g / L) is stirred with 0.5 g CTAB at a speed of 200 r / min, and dilute phosphoric acid is added into the reactor at a rate of 3 mL / min by peristaltic pump. At this time, the prepared dicalcium phosphate has the largest particle size. Compared with other sample feeding speeds, the particle size of dicalcium phosphate prepared at a sample feeding speed of 3 mL / min is increased by 3-38%.
[0038] Example 4 This example proposes an additive for increasing the crystalline particle size of dicalcium phosphate, which is CTAB.
[0039] This example also proposes the application of the above-mentioned additive in increasing the particle size of the crystalline dicalcium phosphate, which comprises: adding lime milk (100 mL, 100 g / L) and 0.5 g CTAB into the reactor, stirring at 100-500 r / min, and heating to 40 °C with a water bath. Then 100 mL of dilute phosphoric acid is added into the reactor at a rate of 3 mL / min by peristaltic pump. After titration, solid-liquid separation is carried out, and the obtained solid dicalcium phosphate is dried at 60 °C for 8 h and then subjected to particle size analysis. At the same time, a control group with other stirring speeds is tested and analyzed for comparison, and the test results are as follows: Table 4. Particle size test results of dicalcium phosphate obtained in Example 4 ; As can be seen from Table 4, when the reaction temperature is 40 ℃, the lime milk (100 mL, 100 g / L) is stirred with 0.5 g CTAB at a speed of 400 r / min, and dilute phosphoric acid is added dropwise into the reactor at a rate of 3 mL / min by peristaltic pump. At this time, the prepared dicalcium phosphate has the largest particle size. Compared with other stirring speeds, the particle size of dicalcium phosphate prepared at a stirring speed of 400 r / min is increased by 5-17%.
[0040] Example 5 This example proposes an additive for increasing the crystalline particle size of dicalcium phosphate, which is CTAB.
[0041] This example also proposes the application of the above-mentioned additive in increasing the particle size of dicalcium phosphate, which comprises: adding lime milk (100 mL, 100 g / L) and 0-1.0 g CTAB into the reactor, stirring at a speed of 400 r / min, and heating to 40 ℃ with a water bath. Then, 100 mL of dilute phosphoric acid is added dropwise into the reactor at a rate of 3 mL / min by peristaltic pump. After the titration is completed, the solid-liquid separation is carried out after aging for 5 h, and the obtained solid dicalcium phosphate is dried at 60 ℃ for 8 h and then subjected to particle size analysis. Different groups of CTAB addition amounts are tested and compared, and the test results are as follows: Table 5. Particle size test results of dicalcium phosphate obtained in Example 5 ; As can be seen from Table 5, when the reaction temperature is 40 ℃, the lime milk (100 mL, 100 g / L) is stirred with 0.5 g CTAB at a speed of 400 r / min, and dilute phosphoric acid is added dropwise into the reactor at a rate of 3 mL / min by peristaltic pump. At this time, the prepared dicalcium phosphate has the largest particle size. Compared with other stirring speeds, the particle size of dicalcium phosphate prepared at a stirring speed of 400 r / min is increased by 5-17%.
[0042] Example 6 This example proposes an additive for increasing the crystalline particle size of dicalcium phosphate, which is CTAB.
[0043] This example also proposes the application of the above-mentioned additive in increasing the particle size of dicalcium phosphate, which comprises: adding lime milk (100 mL, 100 g / L) and 0-1.0 g CTAB into the reactor, stirring at a speed of 400 r / min, and heating to 40 ℃ with a water bath. Then, 100 mL of dilute phosphoric acid is added dropwise into the reactor at a rate of 3 mL / min by peristaltic pump. After the titration is completed, the solid-liquid separation is carried out after aging for 5 h, and the obtained solid dicalcium phosphate is dried at 60 ℃ for 8 h and then subjected to particle size analysis. Different groups of CTAB addition amounts are tested and compared, and the test results are as follows: Table 6. Test results of calcium hydrogen phosphate particle size obtained in Example 6 ; As can be seen from Table 6, when the reaction temperature is 40 ℃, the lime milk (100 mL, 100 g / L) is stirred at a speed of 400 r / min, and 0.5 g of CTAB is added, and the dilute phosphoric acid is added dropwise into the reactor at a rate of 3 mL / min, and aged for 5 h. At this time, the particle size of the calcium hydrogen phosphate prepared is the largest. Compared with the case where no additive is added, the particle size of the calcium hydrogen phosphate prepared by adding 0.5 g of CTAB is increased by 45%.
[0044] Example 7 This example proposes an additive for increasing the particle size of calcium hydrogen phosphate crystals, which is CPB.
[0045] This example also proposes the use of the above-mentioned additive in increasing the particle size of calcium hydrogen phosphate crystals, which comprises: adding lime milk (100 mL, 100 g / L) and 0-1.0 g of CPB into a reactor, stirring at a speed of 400 r / min, and heating to 40 ℃ with a water bath. Then, 100 mL of dilute phosphoric acid is added dropwise into the reactor at a rate of 3 mL / min by using a peristaltic pump. After the titration is completed, the solid-liquid separation is carried out after aging for 5 h, and the obtained solid calcium hydrogen phosphate is dried at 60 ℃ for 8 h and then subjected to particle size analysis. At the same time, a control group with other stirring speeds is tested and analyzed for comparison, and the test results are as follows: Table 7. Test results of calcium hydrogen phosphate particle size obtained in Example 7 ; As can be seen from Table 7, when the reaction temperature is 40 ℃, the lime milk (100 mL, 100 g / L) is stirred at a speed of 400 r / min, and 0.75 g of CPB is added, and the dilute phosphoric acid is added dropwise into the reactor at a rate of 3 mL / min, and aged for 5 h. At this time, the particle size of the calcium hydrogen phosphate prepared is the largest. Compared with the case where no additive is added, the particle size of the calcium hydrogen phosphate prepared by adding 0.75 g of CPB is increased by 40%. Example
[0046] This example proposes an additive for increasing the particle size of calcium hydrogen phosphate crystals, which is BZK.
[0047] The present embodiment also proposes the application of the above-mentioned additive in increasing the particle size of calcium hydrogen phosphate crystals, which comprises: adding lime milk (100 mL, 100 g / L) and 0-1.0 g BZK into a reactor, stirring at 400 r / min, and heating to 40°C with a water bath. Then, 100 mL of dilute phosphoric acid is added to the reactor at a rate of 3 mL / min by peristaltic pump. After titration, solid-liquid separation is performed after aging for 5 h, and the obtained solid calcium hydrogen phosphate is dried at 60°C for 8 h before particle size analysis. At the same time, a control group with other stirring speeds is tested and analyzed for comparison, and the test results are as follows: Table 8. Calcium hydrogen phosphate particle size test results obtained in Example 8 ; As can be seen from Table 8, when the reaction temperature is 40°C, lime milk (100 mL, 100 g / L) and 0.75 g BZK are stirred at a speed of 400 r / min, and dilute phosphoric acid is added to the reactor at a rate of 3 mL / min by peristaltic pump. At this time, the particle size of the prepared calcium hydrogen phosphate is the largest. Compared with the case where no additive is added, the particle size of the calcium hydrogen phosphate prepared by adding 0.75 g BZK increases by 40%.
[0048] Example 9 The present embodiment proposes an additive for increasing the particle size of calcium hydrogen phosphate crystals, which is CTAB and CPB, with a mass ratio of 1:1.
[0049] The present embodiment also proposes the application of the above-mentioned additive in increasing the particle size of calcium hydrogen phosphate crystals, which comprises: lime milk (100 mL, 100 g / L) and CTAB and CPB (mass ratio 1:1) are placed in a reactor, stirred at 400 r / min, and heated to 40°C with a water bath. Then, 100 mL of dilute phosphoric acid is added to the reactor at a rate of 3 mL / min by peristaltic pump. After titration, solid-liquid separation is performed after aging for 5 h, and the obtained solid calcium hydrogen phosphate is dried at 60°C for 8 h before particle size analysis. At the same time, a control group with single additive is tested and analyzed for comparison, and the test results are as follows: Table 9. Calcium hydrogen phosphate particle size test results obtained in Example 9 ; As can be seen from Table 9, when the reaction temperature is 40°C, lime milk (100 mL, 100 g / L) and CTAB and CPB are stirred at a speed of 400 r / min, and dilute phosphoric acid is added to the reactor at a rate of 3 mL / min by peristaltic pump. At this time, the particle size of the prepared calcium hydrogen phosphate is the largest. Compared with the case where a single additive is added, the particle size of the calcium hydrogen phosphate prepared by adding 1.00 g of CTAB and CPB increases the most significantly.
[0050] Example 10 This example proposes an additive for increasing the particle size of calcium hydrogen phosphate crystals, which is CPB and BZK, with a mass ratio of 1:1.
[0051] This example also proposes the use of the above-mentioned additive in increasing the particle size of calcium hydrogen phosphate crystals, including: The lime milk (100 mL, 100 g / L) was placed in a reactor with CPB and BZK (mass ratio 1:1) and stirred at 400 r / min, and heated to 40 °C with a water bath. Then 100 mL of dilute phosphoric acid was added to the reactor at a rate of 3 mL / min by peristaltic pump. After titration, the solid-liquid separation was performed after 5 h of aging, and the obtained solid calcium hydrogen phosphate was dried at 60 °C for 8 h before particle size analysis. At the same time, the test analysis comparison was carried out with the control group of single additive, and the test results were as follows: Table 10. Calcium hydrogen phosphate particle size test results obtained in Example 10 ; As can be seen from Table 10, when the reaction temperature is 40 °C, the lime milk (100 mL, 100 g / L) is stirred at 400 r / min, and dilute phosphoric acid is added to the reactor at a rate of 3 mL / min by peristaltic pump, and then aged for 5 h. At this time, the particle size of the prepared calcium hydrogen phosphate is the largest. Compared with the single additive, the particle size of the calcium hydrogen phosphate prepared by adding 1.50 g of CPB and BZK increases the most significantly.
[0052] Example 11 This example proposes an additive for increasing the particle size of calcium hydrogen phosphate crystals, which is CTAB and BZK, with a mass ratio of 1:1, or an additive of CTAB, CPB and BZK, with a mass ratio of 1:1:1.
[0053] This example also proposes the use of the above-mentioned additive in increasing the particle size of calcium hydrogen phosphate crystals, including: The lime milk (100 mL, 100 g / L) was placed in a reactor with CTAB and BZK (mass ratio 1:1) or with CTAB, CPB and BZK (mass ratio 1:1:1) and stirred at 400 r / min, and heated to 40 °C with a water bath. Then 100 mL of dilute phosphoric acid was added to the reactor at a rate of 3 mL / min by peristaltic pump. After titration, the solid-liquid separation was performed after 5 h of aging, and the obtained solid calcium hydrogen phosphate was dried at 60 °C for 8 h before particle size analysis. At the same time, the test analysis comparison was carried out with the control group of single additive, and the test results were as follows: Table 11. Calcium hydrogen phosphate particle size test results obtained in Example 11 ; As shown in Table 11, when the reaction temperature is 40℃, lime milk (100 mL, 100 g / L) is stirred with CTAB and BZK at a speed of 400 r / min, and dilute phosphoric acid is added dropwise into the reactor at a rate of 3 mL / min by peristaltic pump for aging for 5 h. At this time, the prepared dicalcium phosphate has the largest particle size. Compared with the single additive, the particle size of dicalcium phosphate prepared by adding 0.75 g of CTAB and BZK increases more significantly, and the particle size of dicalcium phosphate prepared by adding 0.5 g of CTAB, CPB and BZK increases most significantly. From the above, it can be seen that the additive bromohexadecylpyridine, cetyltrimethylammonium bromide and dodecylbenzyl dimethyl bromide can significantly increase the particle size of DCP product by electrostatic adsorption. Figure 2 As shown in Table 11, when the reaction temperature is 40℃, lime milk (100 mL, 100 g / L) is stirred with CTAB and BZK at a speed of 400 r / min, and dilute phosphoric acid is added dropwise into the reactor at a rate of 3 mL / min by peristaltic pump for aging for 5 h. At this time, the prepared dicalcium phosphate has the largest particle size. Compared with the single additive, the particle size of dicalcium phosphate prepared by adding 0.75 g of CTAB and BZK increases more significantly, and the particle size of dicalcium phosphate prepared by adding 0.5 g of CTAB, CPB and BZK increases most significantly. From the above, it can be seen that the additive bromohexadecylpyridine, cetyltrimethylammonium bromide and dodecylbenzyl dimethyl bromide can significantly increase the particle size of DCP product by electrostatic adsorption.
[0054] As shown in the above examples, the method for increasing the particle size of feed-grade dicalcium phosphate provided by the present application can increase the particle size of dicalcium phosphate, and the maximum increase can be more than 50%. This process can significantly improve the product quality of dicalcium phosphate, increase the product particle size, and also reduce the production energy consumption.
[0055] The specific embodiments of the present application described above do not constitute a limitation on the scope of protection of the present application. Any various other corresponding changes and modifications made according to the technical concept of the present application shall be included in the scope of protection of the claims of the present application.
Claims
1. An additive for increasing the particle size of calcium hydrogen phosphate crystals, characterized by, The additive is at least one of bromohexadecylpyridine, cetyltrimethylammonium bromide and dodecylbenzyl dimethyl ammonium bromide.
2. The additive for increasing the particle size of calcium hydrogen phosphate crystals according to claim 1, characterized by, The additive is any two of bromohexadecylpyridine, cetyltrimethylammonium bromide and dodecylbenzyl dimethyl ammonium bromide.
3. The additive for increasing the particle size of calcium hydrogen phosphate crystals according to claim 1, characterized by, The additive is bromohexadecylpyridine, cetyltrimethylammonium bromide and dodecylbenzyl dimethyl ammonium bromide.
4. Use of the additive of any one of claims 1-3 for increasing the particle size of calcium hydrogen phosphate.
5. Use according to claim 4, characterized in that, The calcium hydrogen phosphate is feed-grade calcium hydrogen phosphate.
6. Use according to claim 4, characterized in that, The method comprises the following steps: premixing the additive with lime milk, and then adding phosphoric acid under stirring at 20-60℃ to obtain calcium hydrogen phosphate.
7. Use according to claim 6, characterized in that, The mass ratio of the additive to calcium hydroxide in the lime milk is (0.25-1.5):
100.
8. Use according to claim 6, characterized in that, The stirring speed is 100-500r / min.
9. Use according to claim 6, characterized in that, The phosphoric acid is added dropwise, and the dropwise adding speed is 2-6mL / min.
10. Use according to claim 6, characterized in that, After the addition of the phosphoric acid, aging treatment is further included, and the aging treatment time is 1-6h.