WO2019062075A1 - Composite aerosol fire extinguishing agent and preparation method therefor - Google Patents

Abstract

A composite aerosol fire extinguishing agent and a preparation method therefor. The composite aerosol fire extinguishing agent comprises, in percentage by weight: 8.6%-20.3% of calcium peroxide, 15.8%-27.7% of calcium sulfite, 8.4%-14.6% of modified starch, 9.2%-15.3% of carbon powder, 2.1%-8.3% of nano-crystalline cellulose, 9.6%-26.4% of basic copper carbonate, 3.5%-23.8% of sodium bicarbonate, 0.6%-3.8% of sodium alginate, and 0.9%-4.6% of epoxy resin. All the components of the aerosol fire extinguishing agent have an obvious synergistic effect, so that the whole aerosol fire extinguishing agent has high fire extinguishing capacity and fire extinguishing efficiency, has the advantages of small amount, high fire extinguishing speed, and high fire extinguishing efficiency, and is particularly suitable for extinguishing of oil fire sources.

Description

Composite aerosol fire extinguishing agent and preparation method thereof Technical field

The invention relates to the field of oil fire extinguishing, in particular to a composite aerosol fire extinguishing agent and a preparation method thereof.

Background technique

At present, the commonly used fire extinguishing agents can be roughly classified into the following categories: water-based fire extinguishing agents, gas fire extinguishing agents, powder fire extinguishing agents, aerosol fire extinguishing agents, and halon fire extinguishing agents. The same performance indicators have their own advantages and disadvantages, among which: Halon fire extinguishing agent has the characteristics of good fire extinguishing effect and high fire extinguishing efficiency.

However, there are chemical components in the halon fire extinguishing agent that have a greater destructive effect on the ozone layer. Since 1987, countries have phased out the production and use of halon fire extinguishing agents under the restriction of the Montreal Protocol on Ozone Depleting Substances. The Chinese government also stopped production of 1211, 1301 fire extinguishing agents in 2010.

In the context of the elimination of halon fire extinguishing agents, other types of fire extinguishing agents have been more widely used. The principle of water-based fire extinguishing agents is mainly through the cooling, suffocation and heat radiation of fine water mist to achieve the purpose of fire extinguishing; The fire extinguishing agent mainly reduces the oxygen content of the fire zone by spraying inert gas to achieve the purpose of suffocating fire; the main principle of the powder fire extinguishing agent is to spray the powder under the action of high pressure gas, consume free radicals in the flame, generate inert gas, etc. The purpose of the fire. However, the use of these fire extinguishing agents requires a high-pressure environment, resulting in a large volume of equipment, and physical explosion hazard during storage and use. In the literature "Safety Analysis of Gas Fire Extinguishing Systems", the dangers of gas fire-extinguishing systems are analyzed. Sex.

The existing aerosol fire extinguishing agents can be mainly divided into S type and K type. These fire extinguishing agents mainly use inert gas and free radicals released by redox reaction to act on the fire area, and pass the inert gas suffocation and free radical chemistry. React to achieve the purpose of fire fighting. The main disadvantages are: the large heat release of the redox reaction, which makes the structure of the aerosol fire extinguishing device have a higher temperature; some aerosol fire extinguishing agents produce aerosols with low efficiency and long time, which is not conducive to timely control of the initial fire.

Therefore, the prior art needs further improvement and development.

Summary of the invention

In view of the above deficiencies of the prior art, the object of the present invention is to provide a composite aerosol fire extinguishing agent and a preparation method thereof, which can improve the fire extinguishing efficiency under the premise of reducing the cost.

In order to solve the above technical problem, the technical solution of the present invention includes:

A composite aerosol fire extinguishing agent comprising, by weight percentages:

The composite aerosol fire extinguishing agent comprises, by weight percentage percentage:

The composite aerosol fire extinguishing agent, wherein the modified starch is a butane butyl succinate graft modified starch, and the structural formula is (C ₆ H ₁₀ O ₅ ) 6nHO (CO(CH ₂ ) ₂ COO ( CH ₂ ) ₄ O)nH, where n>2.

The composite aerosol fire extinguishing agent, wherein the epoxy resin is diluted with dioctyl phthalate as a thinner before use, wherein the mass ratio of the epoxy resin to the dioctyl phthalate thinner is 1-3: 1.

A method of preparing the composite aerosol fire extinguishing agent, comprising the steps of:

A, the above raw material components are weighed according to the corresponding proportions, and the raw material components are respectively ground into powder by a mill; then, after passing through a 500 mesh sieve, the sieved powder is collected and used;

B. Add the collected powder to the tray of the rotary granulator, add 1/3 of the total amount of epoxy resin to the liquid storage tank of the rotary granulator; then, start the rotary granulator, wait After the materials are thoroughly mixed, the spray pump of the rotary granulator is turned on to perform granulation to obtain materials;

C, the above materials are dried in an explosion-proof oven, the explosion-proof oven is heated from room temperature to 40 ° C at a rate of 15 ° C / h, and then dried at 40 ° C constant temperature until the moisture content of the material is less than or equal to 0.8%, to obtain a dry material;

D. The obtained dry material is put into a mixer, and then the remaining epoxy resin is diluted with dioctyl phthalate, and the diluted epoxy resin is added to the mixer to be evenly mixed to obtain a semi-finished product;

E. The prepared semi-finished product is placed in a drug cartridge, placed on a press table, and compacted under a pressure of 5 MPa to obtain the above-mentioned aerosol-type fire extinguishing agent.

The preparation method, wherein the step A further comprises: collecting the remaining material in the sieve pan into the next batch of solid raw materials, and filling the regrind mill to grind.

The preparation method, wherein the step B further comprises: the jet pressure of the rotary granulator is 0.5 Mp, the rotation speed of the spray pump is 5 to 25 r·min ^-1 , and the rotation speed of the feeder is 5 to 25 r·min. ^-1 , the dilution zero density is 0.64g/ml, and the angle of repose is 32°; the particle size control index of granulation is that the yield of the final 28-32 target is greater than 90%.

In the preparation method, the inner diameter of the cartridge in the above step E is 40 mm, the height is 100 mm, and the loading amount is 50-100 g.

The invention provides a composite aerosol fire extinguishing agent and a preparation method thereof, which have the advantages of less dosage, fast fire extinguishing speed and high fire extinguishing efficiency, and are particularly suitable for fire extinguishing of oil fire sources, containing oxidant, combustible agent and combustion regulating agent. , an additive, a modifier and a binder; wherein the oxidant is a mixture of calcium peroxide and calcium sulfite, the combustible agent is modified starch and carbon powder, the combustion regulator is nanocellulose, and the additive is basic copper carbonate and Sodium bicarbonate, the modifier is sodium alginate, and the binder is epoxy resin. The basic copper carbonate and sodium hydrogencarbonate in the composition are thermally decomposed at a high temperature, releasing a large amount of carbon dioxide, which is used for extinguishing fire; in the thermal decomposition process of basic copper carbonate and sodium hydrogencarbonate (basic copper carbonate and sodium hydrogencarbonate) It is decomposed by heat, part of it is carried out in the aerosol fire extinguishing device, and some of it is fired after the spouting.) It needs to absorb a large amount of heat, which can lower the flame temperature at the ignition point, assist in extinguishing the fire, and help to reduce the aerosol fire. The spout temperature of the device effectively ensures the safety of the user of the fire extinguishing device, and brings convenience and safety in use.

As described above, the basic copper carbonate and sodium hydrogencarbonate are thermally decomposed, and the heat absorption causes a decrease in the temperature of the ignition point, which further leads to the combustion of combustible molecules during combustion of the combustion products and the combustion of the gasification. The heat of molecular cleavage into free radicals is reduced, so that the rate of combustion (continued) combustion reaction is somewhat suppressed. Further, the copper oxide formed by the decomposition of the basic copper carbonate can chemically react with carbon in the combustion product to generate carbon dioxide. That is, converting the combustible component (carbon powder) in the combustion product into a non-combustible inert gas (carbon dioxide) is advantageous for delaying the burning rate of the combustion product, reducing the oxygen content of the combustion space, and promoting the fire extinguishing speed and efficiency.

In addition, the combustion products will continue to crack during the fire combustion process (ie, during the process of sustaining the combustion reaction) to generate a large number of active groups such as H, · O, · OH, which are indispensable for combustion. . However, basic copper carbonate and sodium hydrogencarbonate are decomposed at a high temperature, and the resulting copper oxide and sodium oxide are chemically reacted with the above-mentioned reactive groups (ie, active groups such as ·H, ·O, ·OH). Thereby, these reactive groups are partially consumed, and the reaction between these reactive groups is suppressed, thereby interrupting the combustion chain and suppressing the continuation of flame combustion.

The oxidant and reducing agent in the composition are ignited in the aerosol fire extinguishing device after being ignited by the electric starter of the aerosol fire extinguishing device, and a severe redox reaction occurs, releasing a large amount of heat, calcium peroxide in the composition, Calcium sulfite, carbon powder and modified starch then start incomplete combustion, produce a large amount of flue gas, and mix with air to form an aerosol; the nanocellulose component in the composition is flammable, has a low ignition point, and has a large specific surface area. Mainly used as a combustion regulator. That is, it is used to ignite/accelerate the burning rate of the combustible component in the composition to promote the rapid formation of a large amount of aerosol in the container at the beginning of the operation of the aerosol fire extinguishing device. In the fire extinguishing agent composition, the inorganic oxide solid particles generated by decomposition at a high temperature cover the surface of the fired object, further functioning to isolate oxygen on the surface of the fired object, and prompting the flame to extinguish the process due to lack of oxygen and suffocation.

Detailed ways

The present invention provides a composite aerosol fire extinguishing agent and a preparation method thereof, and the present invention will be further described in detail below in order to make the objects, technical solutions and effects of the present invention more clear and clear. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The invention provides a composite aerosol fire extinguishing agent, which comprises: 8.6% to 20.3% of calcium peroxide, 15.8% to 27.7% of calcium sulfite, 8.4% to 14.6% of modified starch, by weight percentage. 9.2% to 15.3% carbon powder, 2.1% to 8.3% nanocellulose, 9.6% to 26.4% basic copper carbonate, 3.5% to 23.8% sodium hydrogencarbonate, 0.6% to 3.8% sodium alginate 0.9% to 4.6% epoxy resin.

More preferably, it is included in parts by weight: 10.5% to 18.3% of calcium peroxide, 17.6% to 25.8% of calcium sulfite, 10.7% to 12.6% of modified starch, and 10.2% to 14.3%. Carbon powder, 3.5% to 6.2% nanocellulose, 10.5% to 22.3% basic copper carbonate, 7.6% to 19.7% sodium hydrogencarbonate, 1.6% to 2.3% sodium alginate, and 1.9% to 3.5% Epoxy resin.

Further, the modified starch is a butane succinate graft modified starch having a structural formula of (C ₆ H ₁₀ O ₅ )6nHO(CO(CH ₂ ) ₂ COO(CH ₂ ) ₄ O)nH, Where n>2. Moreover, the above epoxy resin is diluted with dioctyl phthalate as a thinner before use, wherein the mass ratio of the epoxy resin to the dioctyl phthalate thinner is 1-3:1, which has better cost performance in use. It not only facilitates the bonding and pressing forming operation of the fire extinguishing agent, but also has good press molding quality.

The present invention also provides a method of preparing the above composite aerosol fire extinguishing agent, comprising the steps of:

Step one, weigh the above raw material components according to the corresponding proportions, and respectively grind the raw material components into powder by a mill; then, pass through a 500 mesh sieve, collect the sieved powder, and set aside;

In the second step, the collected powder is separately added to the tray of the rotary granulator, and 1/3 of the total amount of the epoxy resin is added to the liquid storage tank of the rotary granulator; then, the rotary granulator is started. After the materials are thoroughly mixed, the spray pump of the rotary granulator is turned on to perform granulation to obtain materials;

In the third step, the above materials are dried in an explosion-proof oven, and the explosion-proof oven is heated from room temperature to 40 ° C at a rate of 15 ° C / h, and then dried at a constant temperature of 40 ° C until the moisture content of the material is less than or equal to 0.8% to obtain a dry material. ;

Step 4, the obtained dry material is put into a mixer, and then the remaining epoxy resin is diluted with dioctyl phthalate, and the diluted epoxy resin is added to the mixer to be evenly mixed to obtain a semi-finished product;

In step 5, the prepared semi-finished product is placed in a drug cartridge, placed on a press table, and compacted under a pressure of 5 MPa to obtain the above-mentioned aerosol-type fire extinguishing agent.

Further, the above step 1 specifically includes: collecting the remaining material in the sieve pan into the next batch of solid raw materials, and filling the back grinder to grind and repeating. The above step 2 specifically includes: the jet pressure of the rotary granulator is 0.5 Mp, the rotation speed of the spray pump is 5 to 25 r·min ^-1 , the rotation speed of the feeder is 5 to 25 r·min ^-1 , and the dilution zero density is 0.64. g/ml, the angle of repose is 32°; the particle size control index of granulation is that the final yield of 28-32 mesh is greater than 90%. The inner diameter of the cartridge in the above step 5 is 40 mm, the height is 100 mm, and the loading amount is 50-100 g.

In order to further describe the present invention, a more detailed description will be given below. In the following examples, the fire extinguishing application test of the fire extinguishing agent product is carried out by the method specified in GA 499.1-2010 "Aerosol Fire Extinguishing System" Part 1: Hot Aerosol Fire Extinguishing Device, and the fire extinguishing agent is used in an amount of 50 g.

Example 1

The formula of the compound aerosol fire extinguishing agent is: according to the mass fraction, calcium peroxide 12%, calcium sulfite 18%, modified starch 10%, carbon powder 11%, nano cellulose 4%, basic copper carbonate 22% , sodium hydrogencarbonate 19%, sodium alginate 2%, epoxy resin 2% (distilled with dioctyl phthalate as a thinner in a mass ratio of 1:1).

The press-formed product (with a cartridge) is placed in a small aerosol fire extinguishing device, and an electric starter is installed (no coolant or compressed gas in the aerosol fire extinguishing device), and the implementation area is 0.1 m ² oil. The fire extinguishing experiment of the disk, the fuel is commercial grade n-heptane. The quality of the product used in the fire extinguishing experiment was 50g, and the experimental results are shown in Table 1.

Example 2

The compound formula of the compound aerosol fire extinguishing agent is: according to the mass fraction, calcium peroxide 15%, calcium sulfite 19%, modified starch 10%, carbon powder 12%, nano cellulose 5%, basic copper carbonate 17% , sodium hydrogencarbonate 18%, sodium alginate 2%, epoxy resin 2% (diluted with dioctyl phthalate as a thinner in a mass ratio of 1:3).

The press-formed product (with a cartridge) is placed in a small aerosol fire extinguishing device, and an electric starter is installed (no coolant or compressed gas in the aerosol fire extinguishing device), and the implementation area is 0.1 m ² oil. The fire extinguishing experiment of the disk, the fuel is commercial grade n-heptane. The quality of the product used in the fire extinguishing experiment was 50g, and the experimental results are shown in Table 1.

Example 3

The formula of the compound aerosol fire extinguishing agent is: according to the mass fraction, calcium peroxide 16%, calcium sulfite 20%, modified starch 11%, carbon powder 12%, nano cellulose 6%, basic copper carbonate 16% Sodium bicarbonate 14%, sodium alginate 3%, epoxy resin 2% (diluted with dioctyl phthalate as a thinner in a mass ratio of 1:2).

The press-formed product (with a cartridge) is placed in a small aerosol fire extinguishing device, and an electric starter is installed (no coolant or compressed gas in the aerosol fire extinguishing device), and the implementation area is 0.1 m ² oil. The fire extinguishing experiment of the disk, the fuel is commercial grade n-heptane. The quality of the product used in the fire extinguishing experiment was 50g, and the experimental results are shown in Table 1.

Example 4

The compound formula of the compound aerosol fire extinguishing agent is: according to the mass fraction, calcium peroxide 16%, calcium sulfite 22%, modified starch 12%, carbon powder 13%, nano cellulose 4%, basic copper carbonate 15% Sodium bicarbonate 14%, sodium alginate 2%, epoxy resin 2% (diluted with dioctyl phthalate as a thinner at a mass ratio of 1:1.5).

The press-formed product (with a cartridge) is placed in a small aerosol fire extinguishing device, and an electric starter is installed (no coolant or compressed gas in the aerosol fire extinguishing device), and the implementation area is 0.1 m ² oil. The fire extinguishing experiment of the disk, the fuel is commercial grade n-heptane. The quality of the product used in the fire extinguishing experiment was 50g, and the experimental results are shown in Table 1 below.

Comparative Example 1

The fire extinguishing agent is a commercially available S-type fire extinguishing agent, and the mass used for the fire extinguishing experiment is 50g.

Comparative Example 2

The fire extinguishing agent is a commercially available K type fire extinguishing agent, and the mass used for the fire extinguishing experiment is 50g.

Table 1 is a comparison table of the results of the fire-extinguishing comparison test of Example 1 - Example 4 and Comparative Example 1 and Comparative Example 2.

Table 1

As can be seen from Table 1 above, the fire extinguishing success rates of Example 1 - Example 4 were both 100% higher than the commercial K-type fire extinguishing agent of the same type and the commercially available S-type fire extinguishing agent product (average 62.5%).

Example 1 - Example 4 The average aerosol continuous injection time required for fire extinguishing is about 11.4 s. The average aerosol continuous injection time required for fire extinguishing of the same type of commercially available K-type fire extinguishing agent and commercially available S-type fire extinguishing agent product The value is approximately 19.1s. It is shown that the aerosol continuous spraying time required for the fire extinguishing of Example 1 - Example 4 is shortened by about 40.3%.

The specific fire extinguishing mechanism of the present invention is:

The basic copper carbonate and sodium hydrogencarbonate in the composition are thermally decomposed at a high temperature, releasing a large amount of carbon dioxide, which is used for extinguishing fire; in the thermal decomposition process of basic copper carbonate and sodium hydrogencarbonate (basic copper carbonate and sodium hydrogencarbonate) It is decomposed by heat, part of it is carried out in the aerosol fire extinguishing device, and some of it is fired after the spouting.) It needs to absorb a large amount of heat, which can lower the flame temperature at the ignition point, assist in extinguishing the fire, and help to reduce the aerosol fire. The spout temperature of the device effectively ensures the safety of the user of the fire extinguishing device, and brings convenience and safety in use.

As described above, the basic copper carbonate and sodium hydrogencarbonate are thermally decomposed, and the heat absorption causes a decrease in the temperature of the ignition point, which further leads to the combustion of combustible molecules during combustion of the combustion products and the combustion of the gasification. The heat of molecular cleavage into free radicals is reduced, so that the rate of combustion (continued) combustion reaction is somewhat suppressed. Further, the copper oxide formed by the decomposition of the basic copper carbonate can chemically react with carbon in the combustion product to generate carbon dioxide. That is, converting the combustible component (carbon powder) in the combustion product into a non-combustible inert gas (carbon dioxide) is advantageous for delaying the burning rate of the combustion product, reducing the oxygen content of the combustion space, and promoting the fire extinguishing speed and efficiency.

In addition, the combustion products will continue to crack during the fire combustion process (ie, during the process of sustaining the combustion reaction) to generate a large number of active groups such as H, · O, · OH, which are indispensable for combustion. . However, basic copper carbonate and sodium hydrogencarbonate are decomposed at a high temperature, and the resulting copper oxide and sodium oxide are chemically reacted with the above-mentioned reactive groups (ie, active groups such as ·H, ·O, ·OH). Thereby, these reactive groups are partially consumed, and the reaction between these reactive groups is suppressed, thereby interrupting the combustion chain and suppressing the continuation of flame combustion.

The oxidant and reducing agent in the composition are ignited in the aerosol fire extinguishing device after being ignited by the electric starter of the aerosol fire extinguishing device, and a severe redox reaction occurs, releasing a large amount of heat, calcium peroxide in the composition, Calcium sulfite, carbon powder and modified starch then start incomplete combustion, produce a large amount of flue gas, and mix with air to form an aerosol; the nanocellulose component in the composition is flammable, has a low ignition point, and has a large specific surface area. Mainly used as a combustion regulator. That is, it is used to ignite/accelerate the burning rate of the combustible component in the composition to promote the rapid formation of a large amount of aerosol in the container at the beginning of the operation of the aerosol fire extinguishing device. In the fire extinguishing agent composition, the inorganic oxide solid particles generated by decomposition at a high temperature cover the surface of the fired object, further functioning to isolate oxygen on the surface of the fired object, and prompting the flame to extinguish the process due to lack of oxygen and suffocation.

It is not difficult to understand from the analysis of Table 1 and Example 1 to Example 4 that the composite aerosol fire extinguishing agent of the above technical solution can be directly used in the aerosol fire extinguishing device (the gas is generated by combustion in the device to form Certain pressure), no pressure storage required. This effectively enhances the convenience and safety in the storage and use of the fire extinguishing agent, and has a prominent comparative advantage compared with the conventional products of the same type in the prior art.

In the text description of the fire extinguishing mechanism of the composite aerosol fire extinguishing agent, the main chemical reaction equations involved are as follows:

(C ₆ H ₁₀ O ₅ ) _6n HO(CO(CH ₂ ) ₂ COO(CH ₂ ) ₄ O) _n H+Ca(MnO ₄ ) ₂ →H ₂ O↑+CO ₂ ↑+MnO ₂

Cu ₂ (OH) ₂ CO ₃ →CuO+CO ₂ ↑+H ₂ O

NaHCO ₃ →Na ₂ CO ₃ +CO ₂ ↑+H ₂ O

Na ₂ CO ₃ →Na ₂ O+CO ₂ ↑

Na ₂ O+H ₂ O→NaOH

Na ₂ O+·H→NaOH

NaOH+·OH→H ₂ O+Na ₂ O

CuO+C→Cu+CO ₂ ↑

Cu+·OH→Cu(OH) ₂

Cu+·O→CuO

Cu(OH) ₂ +·H→H ₂ O+Cu

Cu(OH) ₂ +·OH→H ₂ O+CuO

CuO+·H→Cu(OH) ₂ .

In summary, it is not difficult to see that the components of the composite aerosol fire extinguishing agent of the above technical solution have a very obvious function and function of "division and cooperation", and the components have obvious synergistic effects. Mutual cooperation and mutual promotion, so that the aerosol fire extinguishing agent as a whole has good fire extinguishing ability and fire extinguishing efficiency, indicating that the fire extinguishing efficiency of the composite aerosol fire extinguishing agent product of the invention is significantly higher than that of the same type of commercially available K type fire extinguishing agent and Commercially available S-type fire extinguishing agent products.

The above description is of course only a preferred embodiment of the present invention, and the present invention is not limited to the above-described embodiments, and all equivalent substitutes made by those skilled in the art under the teachings of the present specification should be explained. The obvious deformation forms are all within the scope of the present specification and are supposed to be protected by the present invention.

Claims (8)

A composite aerosol fire extinguishing agent characterized in that it comprises, by weight percentage:

The composite aerosol fire extinguishing agent according to claim 1, characterized in that it comprises, by weight percentage:

The composite aerosol fire extinguishing agent according to claim 1, wherein the modified starch is a butane butyl succinate graft modified starch having a structural formula of (C ₆ H ₁₀ O ₅ ) 6nHO (CO ( CH ₂ ) ₂ COO(CH ₂ ) ₄ O)nH, where n>2. The composite aerosol fire extinguishing agent according to claim 1, wherein the epoxy resin is dilute with dioctyl phthalate before use, wherein the quality of the epoxy resin and dioctyl phthalate thinner The ratio is 1-3:1. A method of preparing a composite aerosol fire extinguishing agent according to claim 1 comprising the steps of: A, the above raw material components are weighed according to the corresponding proportions, and the raw material components are respectively ground into powder by a mill; then, after passing through a 500 mesh sieve, the sieved powder is collected and used; B. Add the collected powder to the tray of the rotary granulator, add 1/3 of the total amount of epoxy resin to the liquid storage tank of the rotary granulator; then, start the rotary granulator, wait After the materials are thoroughly mixed, the spray pump of the rotary granulator is turned on to perform granulation to obtain materials; C, the above materials are dried in an explosion-proof oven, the explosion-proof oven is heated from room temperature to 40 ° C at a rate of 15 ° C / h, and then dried at 40 ° C constant temperature until the moisture content of the material is less than or equal to 0.8%, to obtain a dry material; D, the obtained dry material into the mixer, and then the remaining diluted epoxy resin is added to the mixer to mix evenly to obtain a semi-finished product; E. The prepared semi-finished product is placed in a drug cartridge, placed on a press table, and compacted under a pressure of 5 MPa to obtain the above-mentioned aerosol-type fire extinguishing agent. The preparation method according to claim 5, wherein the step A further comprises: collecting the remaining material in the sieve pan into the next batch of solid raw materials, and filling the back grinder to grind. The preparation method according to claim 5, wherein the step B further comprises: the jet pressure of the rotary granulator is 0.5 Mp, the rotation speed of the spray pump is 5 to 25 r·min ^-1 , and the speed of the feeder is It is 5~25r·min ^-1 , the dilution zero density is 0.64g/ml, and the angle of repose is 32°; the particle size control index of granulation is the final yield of 28-32 mesh is more than 90%. The preparation method according to claim 4, wherein the inner diameter of the cartridge in the step E is 40 mm, the height is 100 mm, and the loading amount is 50-100 g.