CN111635337A - Preparation method of modified urea - Google Patents
Preparation method of modified urea Download PDFInfo
- Publication number
- CN111635337A CN111635337A CN202010510985.8A CN202010510985A CN111635337A CN 111635337 A CN111635337 A CN 111635337A CN 202010510985 A CN202010510985 A CN 202010510985A CN 111635337 A CN111635337 A CN 111635337A
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- Prior art keywords
- urea
- modifier
- water
- modified urea
- liquid
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- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C273/00—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups
- C07C273/02—Preparation of urea or its derivatives, i.e. compounds containing any of the groups, the nitrogen atoms not being part of nitro or nitroso groups of urea, its salts, complexes or addition compounds
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Fertilizers (AREA)
Abstract
The invention provides a preparation method of modified urea, which comprises the steps of mixing a certain amount of urea with water to ensure that the water content of the urea is 10-20%, heating to 70-80 ℃, and uniformly stirring with heat tracing, or heating and melting the urea to be in a liquid state; the modifier is dissolved in water or melted into liquid; starting spray drying, feeding the modifying agent and the urea solution or the liquid molten urea in a certain proportion, keeping the mixture for 5-10 minutes, and continuously discharging, wherein the solid is the modified urea. The method has the advantages that: 1. the spraying mode enables the modifier to be more uniformly attached to the surface of the urea; 2. the modifier consumption is small, so that the product cost can be reduced, and the subsequent drying process can be reduced; 3. the process flow is simple, and continuous production can be realized.
Description
Technical Field
The invention relates to a preparation method of modified urea, belonging to the technical field of modified urea processing.
Background
Urea, also known as carbamide, is a white crystal. One of the simplest organic compounds. The molecular formula of the carbonic acid diamide is H2NCONH2(CO (NH2) 2). The major nitrogenous end products of metabolic breakdown of proteins in mammals and certain fish. Urea is easily soluble in water, and therefore, it is easily hygroscopic and lumpy at normal temperature. Urea production is normally unstable and is subject to hydrolysis to ammonia and carbon dioxide by heat or in the presence of acids, bases, enzymes.
The urea can be used as an organic fertilizer for farmlands, and can also be used as a production raw material for a plurality of products such as melamine, urea-formaldehyde resin, hydrazine hydrate, tetracycline, phenobarbital, caffeine, vat brown BR, phthalocyanine blue B, phthalocyanine blue Bx, monosodium glutamate and the like. The urea can also be used as a modifier of rubber plastics to accelerate foaming and adjust foaming temperature.
The foaming process of rubber and plastic has requirements on the temperature of the foaming agent, the most common foaming agent in the market at present has a decomposition temperature of more than 200 ℃, and the foaming process of rubber and plastic generally has a temperature of 160-. The activators commonly used in the market at present are mainly zinc salt activators, and different zinc salts can reduce the decomposition temperature of the foaming agent to 160-200 ℃ and the like. Urea can also be used as an activator of the foaming agent, and the decomposition temperature of the foaming agent can be reduced to 130-150 ℃, so that the decomposition temperature of the foaming agent is expanded, and the application range of the foaming agent is enlarged.
However, urea is very soluble in water, and is easy to absorb moisture and agglomerate when stored at normal temperature, so that the use effect of the urea is influenced. For the reasons mentioned above, the invention provides a preparation method of modified urea.
Disclosure of Invention
The invention aims to solve the defects of the prior art and provides a preparation method of modified urea, which sprays a modifying agent on the surface of urea in a water-soluble mode or a molten state by a spray granulation mode to finish the surface modification of the urea.
The technical scheme adopted by the invention for solving the technical problems is as follows:
a preparation method of modified urea comprises the following steps:
A. firstly, mixing a certain amount of urea and water to ensure that the water content of the urea is 10-20%, heating to 70-80 ℃, and uniformly stirring with heat, or heating and melting the urea to be in a liquid state;
B. preparing a liquid modifier, or converting a solid modifier into a liquid state by adopting a water-soluble or molten mode;
C. starting spray drying, feeding the modifying agent and the urea solution or the liquid molten urea in a certain proportion, keeping the mixture for 5-10 minutes, and continuously discharging, wherein the solid is the modified urea.
Preferably, the modifier in step B is organic fatty acid.
More preferably, the modifier in step B is stearic acid and/or a silane coupling agent.
Preferably, the amount of the modifier in the step B is 1-2% of the mass of the urea.
Preferably, in step C, the feeding ratio of the modifier to the urea solution or urea in molten state is: 50-120:1
Preferably, in the step C, after the solid matter is discharged, the solid matter is rapidly cooled in a water cooling mode, so that the material is prevented from being bonded into blocks.
The invention has the beneficial effects that: the method has the advantages that: 1. the spraying mode enables the modifier to be more uniformly attached to the surface of the urea; 2. the modifier consumption is small, so that the product cost can be reduced, and the subsequent drying process can be reduced; 3. the process flow is simple, and continuous production can be realized.
Detailed Description
The technical solution of the present invention will be further specifically described below by way of specific examples.
Example 1
Weighing 1kg of urea in a heat tracing kettle, adding 200g of water, starting stirring, and setting the temperature to be 70 ℃; weighing 10g of stearic acid, heating to a molten state, starting a spray dryer, adding the urea solution and the molten stearic acid into the spray dryer according to the ratio of 120:1, staying the materials in the dryer for 5 minutes, and discharging to obtain the easily dispersible powder.
Example 2
Weighing 1kg of urea in a heat tracing kettle, adding 100g of water, starting stirring, and setting the temperature to 80 ℃; weighing 20g of silane coupling agent, starting a spray dryer, adding the urea solution and the silane coupling agent into the spray dryer according to the ratio of 55:1, staying the materials in the dryer for 10 minutes, and discharging the materials to form easily dispersible powder.
Example 3
Weighing 1kg of urea in a heat tracing kettle, adding 200g of water, starting stirring, and setting the temperature to 80 ℃; weighing 20g of stearic acid, heating to a molten state, starting a spray dryer, adding the urea solution and the molten stearic acid into the spray dryer according to the ratio of 60:1, staying the materials in the dryer for 10 minutes, and discharging to obtain the easily dispersible powder.
Example 4
Weighing 1kg of urea in a heat tracing kettle, heating to a molten state, weighing 20g of stearic acid, heating to the molten state, starting a spray dryer, adding the molten urea and the molten stearic acid into the spray dryer according to the mass ratio of 50:1, staying the materials in the dryer for 10 minutes, and discharging to obtain the easily dispersible powder.
Example 5
The performance of the four samples is tested by placing the four samples with the same mass in a beaker filled with water, and observing that the four samples float on the water. The four samples are placed in an environment with the same humidity for 7 days, the water content of the four samples is measured to be 0.5 percent, 0.45 percent, 0.57 percent and 0.48 percent, the product does not have the moisture absorption phenomenon, and the product still is easily dispersible powder when being viewed on the surface.
The above-described embodiments are only preferred embodiments of the present invention, and are not intended to limit the present invention in any way, and other variations and modifications may be made without departing from the spirit of the invention as set forth in the claims.
Claims (6)
1. The preparation method of the modified urea is characterized by comprising the following steps:
firstly, mixing a certain amount of urea and water to ensure that the water content of the urea is 10-20%, heating to 70-80 ℃, and uniformly stirring with heat, or heating and melting the urea to be in a liquid state;
B. preparing a liquid modifier, or converting a solid modifier into a liquid state by adopting a water-soluble or molten mode;
C. starting spray drying, feeding the modifying agent and the urea solution or the liquid molten urea in a certain proportion, keeping the mixture for 5-10 minutes, and continuously discharging, wherein the solid is the modified urea.
2. The process for preparing modified urea as claimed in claim 1, wherein the modifier in step B is an organic fatty acid.
3. The process for preparing modified urea according to claim 1, wherein the modifier in step B is stearic acid and/or a silane coupling agent.
4. The process for preparing modified urea as claimed in claim 1, wherein the amount of modifier used in step B is 1-2% by mass of urea.
5. The process for preparing modified urea according to claim 1, wherein in step C, the feeding ratio of the modifier to the urea solution or urea in molten state is: 50-120:1.
6. The method for preparing modified urea according to claim 1, wherein in step C, after the solid matter is discharged, the solid matter is rapidly cooled by water cooling to prevent the solid matter from being bonded into blocks.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010510985.8A CN111635337A (en) | 2020-06-08 | 2020-06-08 | Preparation method of modified urea |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010510985.8A CN111635337A (en) | 2020-06-08 | 2020-06-08 | Preparation method of modified urea |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN111635337A true CN111635337A (en) | 2020-09-08 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010510985.8A Pending CN111635337A (en) | 2020-06-08 | 2020-06-08 | Preparation method of modified urea |
Country Status (1)
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| CN (1) | CN111635337A (en) |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1397945A (en) * | 1972-05-04 | 1975-06-18 | Ici Ltd | Process for the manufacture of inorganic acid addition salts of urea |
| CN102001871A (en) * | 2009-12-15 | 2011-04-06 | 深圳市芭田生态工程股份有限公司 | Method for producing granulated compound fertilizer by granulating through urea tower |
| CN105884524A (en) * | 2016-04-18 | 2016-08-24 | 嘉施利（平原）化肥有限公司 | High-tower granulated urinary-chlorine-based compound fertilizer and preparation method thereof |
-
2020
- 2020-06-08 CN CN202010510985.8A patent/CN111635337A/en active Pending
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB1397945A (en) * | 1972-05-04 | 1975-06-18 | Ici Ltd | Process for the manufacture of inorganic acid addition salts of urea |
| CN102001871A (en) * | 2009-12-15 | 2011-04-06 | 深圳市芭田生态工程股份有限公司 | Method for producing granulated compound fertilizer by granulating through urea tower |
| CN105884524A (en) * | 2016-04-18 | 2016-08-24 | 嘉施利（平原）化肥有限公司 | High-tower granulated urinary-chlorine-based compound fertilizer and preparation method thereof |
Non-Patent Citations (1)
| Title |
|---|
| 谢洪勇等: "《粉体粒学与工程》", 31 July 2007, 化学工业出版社 * |
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Application publication date: 20200908 |
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| RJ01 | Rejection of invention patent application after publication |