Preparation method of eutectic zinc oxide

Abstract

The invention discloses a preparation method of eutectic zinc oxide, which comprises the following steps: step 1, grinding feed-grade zinc oxide to obtain a first material; step 2, adding an eutectic former into the first material, stirring and mixing, and reacting to obtain a second material; 3, the second material is cooled, smashed and screened, and then the eutectic zinc oxide target object is obtained.The feed-grade zinc oxide and the eutectic forming object are subjected to the eutectic reaction, the obtained eutectic zinc oxide is high in purity, copolymer molecules generated through eutectic can play a role of a zinc oxide molecule carrier, permeation and dissolution of the zinc oxide molecules are facilitated, and the eutectic zinc oxide is obtained. According to the present invention, the dissolution and the absorption of the zinc oxide in the gastrointestinal tract of the piglet are promoted, the high bioavailability can be obtained, and the process combining dry grinding, liquid adding grinding and polymer auxiliary grinding is adopted, such that the process is stable, and the method is suitable for large-scale industrial production.

Description

Technical Field

[0001] The invention relates to the technical field of feed additive preparation, and in particular to a method for preparing eutectic zinc oxide. Background Art

[0002] Cocrystal technology is a technology that combines two or more molecules to form crystals through non-ionic and non-covalent bonds. The formation of cocrystals is mainly due to thermodynamic stability. Most cocrystals have lower energy and are more stable than their single components. The molecular stacking mode of cocrystals is different from that of single-component crystals. It mainly relies on intermolecular interactions such as hydrogen bonds, halogen bonds, and π-π stacking. Cocrystals can improve the solubility, dissolution rate, bioavailability, etc. of compounds, and related reports have been reported in pharmaceutical synthesis.

[0003] Zinc oxide is a traditional additive for piglets to prevent diarrhea and improve growth performance, and has been widely used in feed production practice. However, due to the low absorption and utilization rate of ordinary feed-grade zinc oxide in organisms, in order to improve the absorption of zinc by living organisms, people increase the zinc oxide dosage or organicize the zinc source to change its absorption amount. However, doing so will not only cause biological toxicity, environmental pollution and waste caused by high zinc, but will also greatly increase feed costs. Summary of the invention

[0004] The purpose of the present invention is to solve the above-mentioned problem of zinc oxide as a feed additive and to propose a method for preparing eutectic zinc oxide.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A method for preparing eutectic zinc oxide comprises the following steps:

[0007] Step 1: Grinding feed-grade zinc oxide to obtain a first material;

[0008] Step 2: adding the eutectic former to the first material, stirring and mixing, and obtaining the second material after reaction;

[0009] Step 3: Cooling, crushing and screening the second material to obtain the target eutectic zinc oxide.

[0010] Specifically, feed-grade zinc oxide is first added to a high-efficiency grinding and stirring kettle, the speed is controlled to 800-1500rpm, and stirring is performed for 0.5-1.5 hours. Then, the eutectic former is added to the high-efficiency grinding and stirring kettle, and stirring is continued at 800-1500rpm for 2-3 hours, at which time the material temperature reaches 70-130°C, stirring is maintained at this temperature for 1-3 hours, and then the reaction is stopped. After the material is cooled, crushed, and sieved, the eutectic zinc oxide target is obtained.

[0011] Preferably, the mass ratio of the feed-grade zinc oxide to the eutectic former is 100:(1-5).

[0012] Preferably, the mass ratio of the feed-grade zinc oxide to the eutectic former is 100:3.

[0013] Preferably, the zinc oxide content of the feed-grade zinc oxide is 95%-98%, and the particle size is 80 meshes-200 meshes.

[0014] Preferably, the feed-grade zinc oxide has a zinc oxide content of 98% and a particle size of 100 meshes.

[0015] Preferably, the eutectic former includes water and one or more combinations of octadecyl acrylate, tetradecyl acrylate, acrylic resin, and silicone emulsion.

[0016] Preferably, the molecular weight of the acrylic resin is 1000-2000.

[0017] Preferably, the organosilicon emulsion is prepared by emulsifying dimethyl silicone oil, and the molecular weight of the dimethyl silicone oil is 300-2000.

[0018] Preferably, the eutectic former comprises water, octadecyl acrylate and silicone emulsion, and the mass ratio of water, octadecyl acrylate and silicone emulsion is 1:1:1.

[0019] Preferably, in the step 1, the grinding of feed-grade zinc oxide is achieved by a grinding and stirring kettle, which is cylindrical, has a high-efficiency crusher on the side of the kettle wall, and a high-speed mixer in the middle of the bottom of the kettle. The stirring paddle in the middle is an axe-type inclined paddle, and the inclination of the inclined paddle is 30-45 degrees.

[0020] The maximum speed of the high-efficiency crusher on the side of the kettle wall of the above-mentioned grinding and stirring kettle is 1500rpm, and the maximum speed of the high-speed stirrer in the middle of the kettle bottom is 1800rpm. Preferably, in step one, the speed of the high-efficiency crusher on the side of the kettle wall is 1000rpm, and the speed of the high-speed stirrer in the middle of the kettle bottom is 1300rpm.

[0021] The beneficial effects of the present invention are:

[0022] 1. The eutectic zinc oxide prepared by the preparation method of eutectic zinc oxide has a zinc oxide purity of more than 90%, and the product purity, output and yield are high. The crystal form of the obtained eutectic zinc oxide is more regular than the crystal form of the existing feed-grade zinc oxide, and the product stability is good. The copolymer molecules produced by the eutectic may play the role of "carrier" of zinc oxide molecules, which is beneficial to the penetration and dissolution of zinc oxide molecules, promotes the dissolution and absorption of zinc oxide in the gastrointestinal tract of piglets, and can obtain higher bioavailability.

[0023] 2. The preparation method of eutectic zinc oxide adopts a process combining dry grinding, liquid grinding and polymer-assisted grinding to carry out eutectic reaction on feed-grade zinc oxide and eutectic formers. It is economical and environmentally friendly, has a stable process, and is suitable for large-scale industrial production.

[0024] 3. The feed-grade zinc oxide and the eutectic former in the preparation method of eutectic zinc oxide can be processed and synthesized in a grinding and stirring tank, which is simple to operate, has low energy consumption, and has significant cost advantages and economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is the XRD diffraction pattern of eutectic zinc oxide and feed grade zinc oxide;

[0026] Figure 2 This is the infrared spectrum of eutectic zinc oxide and feed-grade zinc oxide;

[0027] Figure 3 This is the SEM scanning electron microscope image of eutectic zinc oxide;

[0028] Figure 4 This is a SEM scanning electron microscope image of feed-grade zinc oxide. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0030] Feed grade zinc oxide is a zinc oxide. Compared with other types of zinc oxide, it has special requirements on indicators: the zinc oxide content cannot be less than 95%, the zinc content cannot be less than 76.3%, and the heavy metal content of lead, arsenic and cadmium cannot be greater than 10 ppm. The present invention uses feed grade zinc oxide raw material to process zinc oxide eutectic.

[0031] Example 1

[0032] The preparation method of eutectic zinc oxide in this embodiment is as follows: first, 100 kg of feed-grade zinc oxide (content 98%, particle size 80 mesh) is put into a high-efficiency grinding and stirring kettle with side crushing, and stirring is turned on. The speed of the side crusher is adjusted to 1000 rpm, and the speed of the middle stirrer at the bottom of the kettle is adjusted to 1300 rpm, and the stirring reaction is carried out for 1 hour. Then 3 kg of the prepared eutectic former is added, and the stirring reaction is continued for 3 hours. The eutectic formation is prepared according to the mass ratio of water, octadecyl acrylate, and silicone emulsion of 1:1:1. Finally, the material is cooled by air flow, crushed by a pulverizer, and sieved with an 80-mesh screen to obtain 101.85 kg of eutectic zinc oxide finished product.

[0033] Example 2

[0034] The preparation method of eutectic zinc oxide in this embodiment is as follows: first, 100 kg of feed-grade zinc oxide (content 98%, particle size 100 mesh) is put into a high-efficiency grinding and stirring kettle with side crushing, and stirring is turned on. The speed of the side crusher is adjusted to 1000 rpm, and the speed of the middle stirrer at the bottom of the kettle is adjusted to 1300 rpm, and the stirring reaction is carried out for 1 hour. Then 3 kg of the prepared eutectic former is added, and the stirring reaction is continued for 3 hours. The eutectic formation is prepared according to the mass ratio of water, tetradecyl acrylate, and silicone emulsion of 1:1:1. Finally, the material is cooled by air flow, crushed by a pulverizer, and sieved with an 80-mesh screen to obtain 101.57 kg of eutectic zinc oxide finished product.

[0035] Example 3

[0036] The preparation method of eutectic zinc oxide in this embodiment is as follows: first, 100 kg of feed-grade zinc oxide (content 95%, particle size 100 mesh) is put into a high-efficiency grinding and stirring kettle with side crushing, and stirring is turned on. The speed of the side crusher is adjusted to 1000 rpm, and the speed of the middle stirrer at the bottom of the kettle is adjusted to 1300 rpm, and the stirring reaction is carried out for 1 hour. Then 2 kg of the prepared eutectic former is added, and the stirring reaction is continued for 3 hours. The eutectic formation is prepared according to the mass ratio of water and acrylic resin of 1:1. Finally, the material is cooled by air flow, crushed by a pulverizer, and sieved with an 80-mesh screen to obtain 100.68 kg of eutectic zinc oxide finished product.

[0037] Example 4

[0038] The preparation method of eutectic zinc oxide in this embodiment is as follows: first, 100 kg of feed-grade zinc oxide (content 95%, particle size 80 mesh) is put into a high-efficiency grinding and stirring kettle with side crushing, and stirring is turned on. The speed of the side crusher is adjusted to 800 rpm, and the speed of the middle stirrer at the bottom of the kettle is adjusted to 1000 rpm, and the stirring reaction is carried out for 1 hour. Then 3 kg of the prepared eutectic former is added, and the stirring reaction is continued for 3 hours. The eutectic formation is prepared according to the ratio of water, octadecyl acrylate, and acrylic resin in a ratio of 1:1:1. Finally, the material is cooled by air flow, crushed by a pulverizer, and sieved with an 80-mesh screen to obtain 101.73 kg of eutectic zinc oxide finished product.

[0039] Example 5

[0040] The preparation method of eutectic zinc oxide in this embodiment is as follows: first, put 100 kg of feed-grade zinc oxide (content 95%, particle size 80 mesh) into a high-efficiency grinding and stirring kettle with side crushing, turn on the stirring, wherein the speed of the side crusher is adjusted to 800 rpm, and the speed of the middle stirrer at the bottom of the kettle is adjusted to 1000 rpm, and stir to react for 1 hour. Then add 3 kg of the prepared eutectic former, and continue to stir and react for 3 hours. The eutectic is prepared according to the ratio of water, octadecyl acrylate, and tetradecyl acrylate of 1:1:1. Finally, the material is cooled by air flow, crushed by a grinder, and sieved with an 80-mesh screen to obtain 101.84 kg of eutectic zinc oxide finished product.

[0041] The test data of Examples 1-5 and Comparative Examples are shown in Table 1 below. Wherein, yield = actual yield / feeding amount*100%.

[0042] Table 1 Test data and results of Examples 1-5

[0043]

[0044] It can be found from Table 1 that the content of zinc oxide in the eutectic zinc oxide prepared by the technical solution provided by the present invention is above 90%. The actual content (in terms of ZnO) of the products of Examples 1-5 is higher than the theoretical content, because the eutectic formed in the feed contains water, and under the high-speed stirring reaction, the material heats up and evaporates the water.

[0045] In order to further illustrate the difference between the eutectic zinc oxide prepared by the technical solution provided by the present invention and ordinary feed-grade zinc oxide, XRD diffraction, infrared spectroscopy and SEM scanning electron microscopy analysis were performed on the eutectic zinc oxide prepared in the example and the ordinary feed-grade zinc oxide.

[0046] refer to Figure 1 It can be found that the XRD diffraction patterns of the eutectic zinc oxide prepared in the embodiment and the feed-grade zinc oxide are completely consistent, and the eutectic zinc oxide and the feed-grade zinc oxide have the same zinc oxide active ingredient.

[0047] refer to Figure 2 , Figure 3 and Figure 4 , infrared spectrum and SEM scanning electron microscope images show that the crystal structure of eutectic zinc oxide is different from that of feed-grade zinc oxide, and the crystal form of eutectic zinc oxide is more regular. Since eutectic zinc oxide is synthesized by eutectic of feed-grade zinc oxide and eutectic former, the eutectic processing changes the crystal structure of feed-grade zinc oxide, and the arrangement of zinc oxide molecules is more compact. At the same time, the copolymer molecules produced by the eutectic may play the role of "carrier" of zinc oxide molecules, promote the dissolution of zinc oxide molecules, and facilitate the penetration and dissolution of zinc oxide molecules. The eutectic zinc oxide improves the solubility and dissolution rate of the drug through the eutectic, which can promote the dissolution and absorption of zinc oxide in the gastrointestinal tract of piglets, thereby improving its bioavailability.

[0048] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing eutectic zinc oxide, characterized in that: The following steps are involved: Step 1: Grinding feed-grade zinc oxide to obtain a first material; Step 2: adding the eutectic former to the first material, stirring and mixing, and obtaining the second material after reaction; Step 3: Cooling, crushing and screening the second material to obtain the target eutectic zinc oxide.

2. The method for preparing eutectic zinc oxide according to claim 1, characterized in that: The mass ratio of the feed-grade zinc oxide to the eutectic former is 100:(1-5).

3. The method for preparing eutectic zinc oxide according to claim 2, characterized in that: The mass ratio of the feed-grade zinc oxide to the eutectic former is 100:

3.

4. The method for preparing eutectic zinc oxide according to claims 1-3, characterized in that: The zinc oxide content of the feed-grade zinc oxide is 95%-98%, and the particle size is 80 meshes-200 meshes.

5. The method for preparing eutectic zinc oxide according to claim 4, characterized in that: The feed-grade zinc oxide has a zinc oxide content of 98% and a particle size of 100 meshes.

6. The method for preparing eutectic zinc oxide according to claim 5, characterized in that: The eutectic former includes water and one or more combinations of octadecyl acrylate, tetradecyl acrylate, acrylic resin and silicone emulsion.

7. The method for preparing eutectic zinc oxide according to claim 6, characterized in that: The molecular weight of the acrylic resin is 1000-2000.

8. The method for preparing eutectic zinc oxide according to claim 6, characterized in that: The organic silicon emulsion is prepared by emulsifying dimethyl silicone oil, and the molecular weight of the dimethyl silicone oil is 300-2000.

9. The method for preparing eutectic zinc oxide according to claim 8, characterized in that: The eutectic former includes water, octadecyl acrylate and silicone emulsion, and the mass ratio of the water, octadecyl acrylate and silicone emulsion is 1:1:

1.

10. The method for preparing eutectic zinc oxide according to claim 9, characterized in that: In the step 1, the grinding of feed-grade zinc oxide is achieved by a grinding and stirring kettle, which is cylindrical, has a high-efficiency crusher on the side of the kettle wall, and a high-speed mixer in the middle of the bottom of the kettle. The stirring paddle in the middle is an axe-type inclined paddle with an inclination of 30-45 degrees.

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