Preparation method and application of spontaneous combustion prevention three-phase foam material
By adding fly ash, compound of formula I and foaming agent to the three-phase foam to form a stable film layer, the problems of three-phase foam stability and fire prevention and extinguishing duration are solved, and better anti-spontaneous combustion effect is achieved.
Patent Information
- Application Number
- CN202510588173.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-08
- Publication Date
- 2025-08-15
AI Technical Summary
The existing three-phase foam has a short duration and poor stability in fire prevention and extinguishing effects, which limits its effectiveness in anti-spontaneous combustion applications.
The formula containing fly ash, a compound of formula I, xanthan gum and a foaming agent with a specific structure is prepared by stirring, and the anti-spontaneous combustion three-phase foam material is used to form a stable film layer on the foam surface using the hydrophilic and electronegative groups of the compound of formula I to enhance the binding force with the silica surface, and improve stability and flame retardant effect.
It significantly improves the stability and flame retardant effect of three-phase foam, extends the fire prevention and extinguishing duration, and is suitable for anti-spontaneous combustion applications in coal goaf and phosphorus-containing soil.
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Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of fire extinguishing materials, and particularly relates to a preparation method and application of a self-ignition resistant three-phase foam material. Background Art
[0002] Compared to traditional two-phase foam, three-phase foam combines the advantages of solid, liquid, and gaseous firefighting materials. Therefore, three-phase foam is more competitive and advantageous in the precise control and disaster reduction of coal. The significant improvement in the firefighting performance of three-phase foam is due to the full utilization of the covering properties of non-combustible solid particles, the asphyxiating properties of inert gases, and the heat-absorbing and cooling properties of water. While the introduction of solid particles into two-phase foams offers some benefits, it also has certain impacts on the foam's drainage rate and stability. The stability of three-phase foams depends largely on the size, shape, and concentration of the solid particles. Researchers have further identified solid phases such as silica, calcium carbonate, alumina, and fly ash that can be used in three-phase foam systems. Professor Wang Deming of the China University of Mining and Technology first added fly ash (yellow mud) as a solid phase to foam, successfully preparing a three-phase foam. This foam possesses excellent firefighting properties and is now used in a variety of firefighting practices.
[0003] Fire accidents caused by spontaneous combustion of phosphorus-contaminated soil often produce large amounts of thick smoke, polluting the environment and threatening human health. Similarly, spontaneous combustion of coal underground during coal mining seriously endangers life and safety. Three-phase foam is of great significance in preventing spontaneous combustion in the above scenarios.
[0004] However, three-phase foam usually has defects when used, including poor foam stability and short duration of fire extinguishing effect, which limits its application effect in preventing spontaneous combustion. Summary of the Invention
[0005] In view of this, the object of the present invention is to provide a three-phase foam material that prevents spontaneous combustion, improves foam stability and prolongs the duration of fire extinguishing effect, thereby enhancing the anti-spontaneous combustion effect.
[0006] To solve the above problems, the present invention provides the following solutions:
[0007] The first aspect of the present invention is to provide an anti-spontaneous combustion three-phase foam material comprising, by weight, 5-15% fly ash, 0.5-2% of a compound represented by Formula I, 0.1-2% xanthan gum, 5-12% of a foaming agent, and the balance water;
[0008]
[0009] In formula I, X1 and X3 are each independently selected from any one of halogen; X2 and X4 are each independently selected from any one of hydrogen, alkyl or halogen; R1 is an alkane chain containing more than 2 carbon atoms, and n is an integer of 5-12.
[0010] Furthermore, in the formula I, X1 and X3 are each independently selected from F, Cl or Br; X2 and X4 are each independently selected from hydrogen or alkyl.
[0011] Preferably, X2 and X4 are both hydrogen atoms.
[0012] Furthermore, the foaming agent includes sodium dodecylbenzenesulfonate and sodium α-olefin sulfonate; preferably, the mass ratio of the sodium dodecylbenzenesulfonate to the sodium α-olefin sulfonate is (2-4):1.
[0013] A second aspect of the present invention is to provide a method for preparing the self-ignition resistant three-phase foam material described in the first aspect, comprising the following steps:
[0014] 1) Under an inert atmosphere, fly ash, foaming agent, xanthan gum and water are mixed in proportion and stirred to prepare a three-phase foam;
[0015] 2) adding the compound represented by formula I into the obtained three-phase foam and continuing to stir to obtain a self-ignition resistant three-phase foam material.
[0016] Furthermore, in step 1), the stirring speed is 4000-8000 r / min, and the time is 30-60 min.
[0017] Furthermore, in step 2), the stirring speed is 3000-5000 r / min, and the time is 10-20 min.
[0018] The third aspect of the present invention is to propose the use of the anti-spontaneous combustion three-phase foam material described in the first aspect in flame retardancy or fire extinguishing.
[0019] Furthermore, the anti-spontaneous combustion three-phase foam material is used to prevent spontaneous combustion in coal goaf or phosphorus-contaminated soil. Preferably, the anti-spontaneous combustion three-phase foam material is used to spray onto the surface of coal goaf or phosphorus-contaminated soil.
[0020] Compared with the prior art, the present invention has the following beneficial effects:
[0021] The anti-spontaneous combustion three-phase foam material proposed by the present invention contains a compound of formula I with a special structure. The compound has a certain hydrophilicity, a certain chain length, and contains a large number of halogens, which are both electronegative and flame retardant. Due to the generated electrical repulsion, a stable film layer is stably formed on the surface of the three-phase foam system. Since coal mining and phosphorus-containing soil contain a large amount of silica, their surface contains a large number of silanol (-Si-OH) groups. This electronegative film layer can generate a strong binding force with the silanol group, thereby reducing the loss or failure of the three-phase foam caused by external forces, greatly improving the stability and flame retardant effect of the three-phase foam, and has significant application prospects. DETAILED DESCRIPTION
[0022] The following examples are provided to illustrate the present invention but are not intended to limit the scope of the present invention. Without departing from the spirit and substance of the present invention, modifications or substitutions made to the methods, steps or conditions of the present invention are within the scope of the present invention.
[0023] In one embodiment, a self-ignition resistant three-phase foam material is provided, comprising, by weight, 5-15% fly ash, 0.5-2% of a compound represented by Formula I, 0.1-2% xanthan gum, 5-12% of a foaming agent, and the balance water;
[0024]
[0025] In formula I, X1 and X3 are each independently selected from any one of halogen; X2 and X4 are each independently selected from any one of hydrogen, alkyl or halogen; R1 is an alkane chain containing 2 carbon atoms; and the degree of polymerization n is an integer of 5-12.
[0026] In the above embodiment, the compound of formula I contains a hydrophilic amino group, which has a certain chain length and contains a large number of electronegative groups. Due to its electrical repulsion ability, it can stably form a stable film layer on the surface of the three-phase foam system; since coal mine goafs or phosphorus-containing soils contain a large amount of silica, their surface contains a large number of silanol groups (-Si-OH), and the electronegative film layer can produce a strong binding force with the silanol group, thereby reducing the loss or failure of the three-phase foam caused by external forces, thereby greatly improving the stability and flame retardant effect of the three-phase foam.
[0027] In a preferred embodiment, in Formula I, X1 and X3 are each independently selected from F, Cl or Br; X2 and X4 are each independently selected from hydrogen or alkyl, and the degree of polymerization n is an integer of 200-500 to form an oligomer.
[0028] In a preferred embodiment, taking the structural formula II as an example:.
[0029]
[0030] The synthesis method comprises mixing a halogen-containing monomer X1CH=CHX3, an organic solvent, an amino-containing chain transfer agent SR1NH2, and an initiator, and allowing a polymerization reaction to occur at an appropriate temperature. The chain transfer agent used in the reaction can be selected from common 2-mercaptopropylamine, mercaptoethylamine, or 3-mercaptopropylamine; the initiator used can be selected from commonly used azobisisobutyronitrile, azobisisoheptylonitrile, dibenzoyl peroxide, or dicumyl peroxide. A polymerization inhibitor can be added during the polymerization process to control the appropriate degree of polymerization, if necessary.
[0031] In a preferred embodiment, the foaming agent includes sodium dodecylbenzenesulfonate and sodium α-olefin sulfonate; preferably, the mass ratio of the sodium dodecylbenzenesulfonate to the sodium α-olefin sulfonate is (2-4): 1. A suitable surfactant can provide sufficient foaming effect on the one hand, and can also play a solubility-promoting role on the other hand.
[0032] In another embodiment, the anti-spontaneous combustion three-phase foam material described in the above embodiment can be used in coal mining or to prevent spontaneous combustion of phosphorus-containing soil. For example, by spraying the foam into coal seams, goafs, cracks and fractures in coal walls and pillars, high-temperature and high-risk areas, and coal storage bins, the three-phase foam can be evenly applied to the coal surface, isolating the coal from air, reducing oxidation reactions on the coal surface, and improving fire resistance.
[0033] The reagents used in the following examples are commonly used in the art and are commercially available standards unless otherwise specified. Unless otherwise specified, the experimental methods used are methods known in the art.
[0034] Example 1
[0035] A self-ignition-proof three-phase foam material is prepared by mixing the following ingredients in parts by weight: 8 parts of fly ash, 1 part of a compound represented by Formula I, 0.5 parts of xanthan gum, 6 parts of sodium dodecylbenzenesulfonate, 1.5 parts of sodium α-olefinsulfonate, and 83 parts of water.
[0036] The preparation method is as follows: 1) under a nitrogen atmosphere, fly ash, a foaming agent, xanthan gum and water are mixed, and stirred at 6000 r / min for 50 minutes to prepare a three-phase foam; 2) the compound represented by formula I is then added to the obtained three-phase foam, and stirring is continued at 4000 r / min for 20 minutes to obtain an anti-spontaneous combustion three-phase foam material.
[0037] Example 2
[0038] A self-ignition-proof three-phase foam material is prepared by mixing the following ingredients in parts by weight: 10 parts of fly ash, 1.5 parts of a compound represented by Formula I, 0.2 parts of xanthan gum, 6.3 parts of sodium dodecylbenzenesulfonate, 2 parts of sodium α-olefinsulfonate, and 80 parts of water.
[0039] The preparation method is as follows: 1) under a nitrogen atmosphere, fly ash, a foaming agent, xanthan gum and water are mixed, and stirred at 7000 r / min for 40 minutes to prepare a three-phase foam; 2) the compound represented by formula I is then added to the obtained three-phase foam, and stirring is continued at 5000 r / min for 15 minutes to obtain an anti-spontaneous combustion three-phase foam material.
[0040] Example 3
[0041] A self-ignition-proof three-phase foam material is prepared by mixing the following ingredients in parts by weight: 5 parts of fly ash, 2 parts of a compound represented by Formula I, 1 part of xanthan gum, 8 parts of sodium dodecylbenzenesulfonate, 2 parts of sodium α-olefinsulfonate, and 82 parts of water.
[0042] The preparation method is as follows: 1) under a nitrogen atmosphere, fly ash, a foaming agent, xanthan gum and water are mixed, and stirred at 5000 r / min for 60 minutes to prepare a three-phase foam; 2) the compound represented by formula I is then added to the obtained three-phase foam, and stirring is continued at 4000 r / min for 20 minutes to obtain an anti-spontaneous combustion three-phase foam material.
[0043] Comparative Example 1
[0044] A three-phase foam material is different from Example 1 in that the formula does not contain the compound of formula I, and the other ingredients and amounts remain unchanged, and the preparation method remains unchanged.
[0045] Comparative Example 2
[0046] A three-phase foam material, which differs from Example 1 in that the compound of formula I does not contain a halogen substituent, and the other components and amounts remain unchanged, and the preparation method remains unchanged.
[0047] Comparative Example 3
[0048] A three-phase foam material is different from Example 1 in that sodium dodecylbenzenesulfonate is not contained, the amount of sodium α-olefinsulfonate is adjusted to 7.5 parts, the other components and their proportions remain unchanged, and the preparation method remains unchanged.
[0049] In the above examples, the compounds of formula I used are shown in Table 1:
[0050] Table 1:
[0051]
[0052] Experimental example
[0053] 1. Stability assessment
[0054] In this experiment, a water bath was used as the heating device. The temperature of the water bath was adjusted and maintained constant. With the same total mass of ingredients, the three-phase foam materials described in Examples 1-3 and Comparative Examples 1-3 were fully foamed to the same volume using a magnetic stirrer and then placed in water baths set at 25°C, 30°C, and 35°C, respectively. 300 mL of foam was added to a graduated measuring cup. The time required for the foam to reach half its volume at each temperature was recorded (in hours). A longer half-life indicates better thermal resistance. The results are shown in Table 2.
[0055] Table 2: Stability test
[0056]
[0057] As can be seen from Table 2, the half-lives of the self-ignition-resistant three-phase foam materials prepared in Examples 1-3 all exceeded 20 hours at 25-35°C. While the amount of Compound I added increased in each of Examples 1-3, the half-lives remained largely unchanged. This may be due to the different electronegativity of the halogens in the respective Compounds I. In Comparative Example 1, the absence of Compound I prevented the formation of a surface protective layer due to the lack of the hydrophilicity of the amino group and the repulsive effect of the halogen electronegativity, leading to a significant decrease in foam stability. The lack of electronegative repulsive effect in Comparative Example 2, when no halogen substituents were present, also led to a decrease in stability. In Comparative Example 3, the use of sodium dodecylbenzenesulfonate as the foaming agent also resulted in a decrease in stability, possibly due to the synergistic stabilization of Compound I by sodium dodecylbenzenesulfonate.
[0058] 2. Flame retardant performance evaluation
[0059] Spontaneous combustion of coal is caused by continuous slow oxidation at a certain temperature, and CO will be continuously released during the oxidation process. Therefore, the flame retardant performance can be evaluated by measuring the CO resistance rate. The specific method is: under the premise of the same total mass of ingredients, the three-phase foam materials described in Examples 1-3 and Comparative Examples 1-3 are fully foamed to the same volume with a magnetic stirrer. Then, a PG-250A flue gas analyzer is used to measure the amount of CO released per unit time during the 80°C low-temperature oxidation process before and after spraying the three-phase foams obtained in Examples 1-3 and Comparative Examples 1-3 on the coal surface under the same conditions, and the CO resistance rate is measured. The calculation formula is: Resistance rate (%) = (bare coal CO release - CO release after spraying three-phase foam) / bare coal CO release. The results are shown in Table 3.
[0060] Table 3: Flame retardancy evaluation
[0061]
[0062] As shown in Table 3, the CO inhibition rate of the three-phase foam materials for preventing spontaneous combustion prepared in Examples 1 to 3 exceeds 90% at 80°C. The amount of compound I added in Examples 1 to 3 increases successively, but the CO inhibition rate is not much different. The possible reason is that the electronegativity of the halogen in the compound I used is different, which is consistent with the stability law in Table 2. In Comparative Example 1, no compound I is added. Due to the lack of amino hydrophilicity and the repulsive effect of the halogen electronegativity, it cannot form a surface protective layer, and lacks the electronegativity to bind to the coal surface, which leads to a significant decrease in its CO inhibition rate. In Comparative Example 2, the loss of electronegativity when no halogen substituent is included also leads to a decrease in inhibition rate. In Comparative Example 3, when the foaming agent is adjusted to a single sodium dodecylbenzenesulfonate, the inhibition rate also decreases. The possible reason is that the solubility of compound I decreases in the absence of sodium dodecylbenzenesulfonate, resulting in the inability to fully exert the role of compound I.
[0063] The present invention is not limited to what is described in the specification and implementation modes, and therefore, additional advantages and improvements can be easily realized by those skilled in the art. Therefore, without departing from the spirit and scope of the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details, representative schemes and described embodiments.
Claims
1. A three-phase foam material that prevents spontaneous combustion, characterized in that: The invention comprises, by weight percentage, 5-15% fly ash, 0.5-2% of the compound represented by formula I, 0.1-2% of xanthan gum, 5-12% of a foaming agent and the balance of water; In formula I, X1 and X3 are each independently selected from any one of halogen; X2 and X4 are each independently selected from any one of hydrogen, alkyl or halogen; R1 is an alkyl chain containing more than 2 carbon atoms; and n is an integer of 5-12.
2. The anti-spontaneous combustion three-phase foam material according to claim 1, characterized in that: In the formula I, X1 and X3 are each independently selected from F, Cl or Br; X2 and X4 are each independently selected from hydrogen or alkyl.
3. The anti-spontaneous combustion three-phase foam material according to claim 1, characterized in that: The foaming agent includes sodium dodecylbenzenesulfonate and sodium α-olefinsulfonate.
4. The anti-spontaneous combustion three-phase foam material according to claim 3, characterized in that: The mass ratio of the sodium dodecylbenzenesulfonate to the sodium α-olefinsulfonate is (2-4):
1.
5. The method for preparing the anti-spontaneous combustion three-phase foam material according to claim 1, characterized in that the steps include: 1) Under an inert atmosphere, fly ash, foaming agent, xanthan gum and water are mixed in proportion and stirred to prepare a three-phase foam; 2) adding the compound represented by formula I into the obtained three-phase foam and continuing to stir to obtain a self-ignition resistant three-phase foam material.
6. The preparation method according to claim 5, characterized in that In step 1), the stirring speed is 4000-8000 r / min, and the time is 30-60 min.
7. The preparation method according to claim 5, characterized in that In step 2), the stirring speed is 3000-5000 r / min, and the time is 10-20 min.
8. Use of the anti-spontaneous combustion three-phase foam material according to any one of claims 1 to 4 in flame retardancy or fire extinguishing.
9. The use according to claim 8, characterized in that The anti-spontaneous combustion three-phase foam material is used to prevent spontaneous combustion in coal goafs or phosphorus-contaminated soil.
10. The use according to claim 9, characterized in that The anti-spontaneous combustion three-phase foam material is used for spraying onto coal goaf areas or the surface of phosphorus-contaminated soil.