阅读说明：本技术 一种矾土基堇青石防爆浇注料 (Alumina-based cordierite explosion-proof castable ) 是由 朱国平 王立旺 李新明 王琪 彭晶晶 方利华 于 2021-08-31 设计创作，主要内容包括：本发明涉及耐热材料领域,尤其涉及一种矾土基堇青石防爆浇注料,按照重量份数计,包括高铝矾土熟料60～80份、堇青石30～50份、二氧化硅微粉10～20份、铝酸盐水泥3～5份、氧化铝粉15～30份、硅单质微粉5～10份、改性碳纤维1～5份；其中,所述改性碳纤维在其外部包覆有一层无机二氧化硅包覆层。本发明中的矾土基堇青石防爆浇注料不仅具有良好的耐高温性能,而且还有很好的抗热震性能,适用于耐剥落及耐磨性优良的衬里部位和对热震性有要求的场合。(The invention relates to the field of heat-resistant materials, in particular to an alumina-based cordierite explosion-proof castable which comprises, by weight, 60-80 parts of high-alumina bauxite clinker, 30-50 parts of cordierite, 10-20 parts of silica micro powder, 3-5 parts of aluminate cement, 15-30 parts of alumina powder, 5-10 parts of simple substance silicon micro powder and 1-5 parts of modified carbon fibers; wherein the modified carbon fiber is coated with an inorganic silica coating layer on the outside thereof. The bauxite-based cordierite anti-explosion castable disclosed by the invention not only has good high-temperature resistance, but also has good thermal shock resistance, and is suitable for lining parts with good stripping resistance and wear resistance and occasions with requirements on thermal shock resistance.)

1. The bauxite-based cordierite anti-explosion castable is characterized by comprising, by weight, 60-80 parts of high-alumina bauxite chamotte, 30-50 parts of cordierite, 10-20 parts of silica micro powder, 3-5 parts of aluminate cement, 15-30 parts of alumina powder, 5-10 parts of simple substance silicon micro powder and 1-5 parts of modified carbon fiber;

wherein the modified carbon fiber is coated with an inorganic silica coating layer on the outside thereof.

2. The bauxite-based cordierite anti-explosion castable material according to claim 1, wherein the modified carbon fiber is prepared by the following method:

(S.1) mixing tetraethoxysilane and triethoxysilane for hydrolysis to obtain silica gel with a silicon-hydrogen containing structure;

(S.2) soaking the carbon fibers in the silica gel, taking out and drying to obtain the carbon fibers coated with the silicon dioxide layer;

and (S.3) soaking the carbon fiber coated with the silicon dioxide layer in a reaction solution containing trimethyl borate and tris (pentafluorobenzene) borane, and drying to obtain the modified carbon fiber.

3. The bauxite-based cordierite anti-explosion castable material according to claim 2, wherein the mass ratio of tetraethoxysilane to triethoxysilane to water in the step (S.1) is 100: (5-15): (30-50) and the hydrolysis temperature is 50-70 ℃.

4. The bauxite-based cordierite anti-explosion castable according to claim 2, wherein the drying temperature in the step (S.2) is 90-110 ℃, and the step (S.2) is repeated 2-5 times.

5. The bauxite-based cordierite anti-explosion castable according to claim 2, wherein the reaction solution in the step (S.3) has a trimethyl borate mass concentration of 20-40% and tris (pentafluorobenzene) borane mass concentration of 0.1%.

6. The bauxite-based cordierite anti-explosion castable according to claim 5, wherein a solvent in the reaction liquid is one of toluene, xylene, n-hexane, dichloromethane or tetrahydrofuran.

7. The bauxite-based cordierite anti-explosion castable material according to claim 2, 5 or 6, wherein the reaction temperature is 30-45 ℃, and the dipping reaction time is 15-60 min.

8. The bauxite-based cordierite anti-explosion castable according to claim 1, wherein the bauxite chamotte comprises 20-35% of aggregates with the thickness of 1-5 mm and 65-80% of bauxite fine powder with the size of 100-300 meshes in percentage by weight.

Technical Field

The invention relates to the field of heat-resistant materials, in particular to a bauxite-based cordierite explosion-proof castable.

Background

The lining of the kiln head cover of the cement kiln is subjected to the effects of wear resistance, frequent cold and hot sudden change and thermal shock, and the composite lining consisting of the calcium silicate plate and the anti-stripping high-alumina bricks frequently falls off in less than one year of use, needs to be stopped for maintenance, seriously influences the normal operation of the rotary kiln and has poor use effect. The kiln head cover of the cement kiln is of an arch structure, in order to improve the overall effect of the lining, high-aluminum casting materials or mullite casting materials are mostly adopted as the lining at present, but the casting materials are high in density and heavy in weight, so that the overall load of the kiln head cover is increased, cracks and peeling are easily generated under the conditions of rapid cooling and rapid heating, and the using effect is influenced.

For example, the invention discloses a refractory material for a coal charging port of a coke oven with the application number of CN200810037994.9, which is the closest comparison document of the invention and comprises the following raw materials in percentage by mass: 35-50% of one or two of flint clay and alumina, 0-20% of waste clay brick, 20-35% of cordierite, 3-5% of silica micropowder, 3-5% of activated alumina micropowder, 3-5% of kyanite, 5-10% of high-alumina cement and 0.2-0.5% of composite polyphosphate. The strength of the castable of the coke oven coal charging port material is more than 70MPa, the thermal shock stability of the castable is very good, and the thermal insulation performance of the castable is better than that of the castable adhered with bricks. The unshaped castable is prepared and poured into a refractory material precast block which meets the appearance requirement of a coal charging port, and the refractory material precast block is dried and baked to replace the original small clay bricks and iron rings and is arranged at the coal charging port for use. The invention is particularly suitable for the use condition of the coal charging port, prolongs the service life of the coal charging port of the coke oven and ensures the smooth production of the coke oven. However, the material does not contain a component having an explosion-proof effect, and therefore, the material may burst during a rapid temperature rise.

Disclosure of Invention

The invention provides an alumina-based cordierite anti-explosion castable, which aims to overcome the defect that the heat-resistant castable used for a cement kiln in the prior art is easy to generate cracks and peel under the conditions of rapid cooling and rapid heating.

In order to achieve the purpose, the invention adopts the following technical scheme:

the bauxite-based cordierite anti-explosion castable is characterized by comprising, by weight, 60-80 parts of high-alumina bauxite chamotte, 30-50 parts of cordierite, 10-20 parts of silica micro powder, 3-5 parts of aluminate cement, 15-30 parts of alumina powder, 5-10 parts of simple substance silicon micro powder and 1-5 parts of modified carbon fiber;

wherein the modified carbon fiber is coated with an inorganic silica coating layer on the outside thereof.

The bauxite-based cordierite anti-explosion castable disclosed by the invention takes high-alumina and cordierite as substrates, wherein the high-alumina mainly comprises aluminum oxide and silicon dioxide, and sometimes contains a small amount of baume and dickite. Various high-alumina bricks made of high-alumina bauxite clinker are refractory or anticorrosive materials widely used in metallurgical industry and other industries, and are used on electric furnace tops, blast furnaces and hot blast stoves.

While the theoretical chemical composition of cordierite is 2A1₂O₃·2MgO·5SiO₂Belonging to a high temperature type (alpha type) structure. It has a low coefficient of thermal expansion (average value of 5X 10 at 25-1000 deg.C)^-6℃^-1) The cordierite-containing refractory material not only has good high-temperature resistance, but also has good thermal shock resistance. The cordierite added into the high-alumina castable can improve the thermal shock resistance of the castable, has higher mechanical strength in a wider temperature range, and is suitable for lining parts with excellent spalling resistance and wear resistance and occasions with requirements on thermal shock resistance.

The invention also adds a certain amount of silicon dioxide micropowder in the formula, and the main function of the invention is to replace part of aluminate cement, thereby reducing the addition of aluminate cement. According to the invention, the bonding strength between the silica micropowder and the rest components can be effectively improved by using the silica micropowder and the aluminate cement as the bonding agent. Meanwhile, because the addition amount of the aluminate cement is less, CaO and Al in the cement are reduced₂O₃The content of the formed low-melting phase substances is greatly improved, so that the thermal stability is greatly improved compared with the castable with high cement content.

Meanwhile, a certain amount of silicon single substance micro powder is added into the castable, and in the sintering process of the castable, the silicon single substance micro powder on the surface layer of the prefabricated part can be oxidized in the sintering process to form silicon dioxide, so that the compactness of the surface layer of the prefabricated part is greatly improved, and simultaneously, the newly generated silicon dioxide and high alumina bauxite and cordierite in the castable further undergo crystal phase transformation to connect various components, so that an integral structure is formed among the components, and the integral heat resistance and the stability of the castable are greatly improved. Even after the surface layer drops, the silicon simple substance inside can be oxidized again after meeting hot air, so that a compact protective layer can be formed again, the self-repairing effect is achieved, and the inside of the kiln head cover of the cement kiln is protected from being corroded.

In addition, a certain amount of modified carbon fibers are added into the formula, so that the tensile effect of the castable can be effectively improved, the effect similar to that of a steel bar in reinforced concrete is achieved, the breaking strength and the compressive strength of the castable can be effectively improved, and the castable can be effectively prevented from cracking in the extremely-rapid temperature rise process. However, conventional carbon fibers have extremely strong mechanical properties and high temperature resistance, but are not resistant to oxidation, and they are oxidized and decomposed in an air atmosphere, resulting in a great decrease in mechanical effect. In order to overcome the defect, the surface of the carbon fiber is coated with the inorganic silicon dioxide coating layer, so that the carbon fiber can be isolated from the outside air, and the oxidation resistance at high temperature is improved. In addition, the silicon dioxide on the surface of the carbon fiber can be connected with the high-alumina and the cordierite in the sintering process, so that the mechanical stability of the whole castable is further improved.

Preferably, the preparation method of the modified carbon fiber comprises the following steps:

(S.1) mixing tetraethoxysilane and triethoxysilane for hydrolysis to obtain silica gel with a silicon-hydrogen containing structure;

(S.2) soaking the carbon fibers in the silica gel, taking out and drying to obtain the carbon fibers coated with the silicon dioxide layer;

and (S.3) soaking the carbon fiber coated with the silicon dioxide layer in a reaction solution containing trimethyl borate and tris (pentafluorobenzene) borane, and drying to obtain the modified carbon fiber.

The silicon dioxide in the modified carbon fiber is obtained by hydrolyzing tetraethoxysilane and triethoxysilane, and the surface of the carbon fiber can be coated with the silicon dioxide after the carbon fiber is soaked in the silicon gel obtained by hydrolysis. Meanwhile, the silicon dioxide layer on the surface contains reactive hydrosilyl groups, and the reactive hydrosilyl groups can react with methoxyl groups in trimethyl borate under the catalysis of tris (pentafluorobenzene) borane to remove methane so as to carry out coupling, so that the surface of the modified carbon fiber contains a certain amount of boric acid structures, and the boric acid structures have certain reactivity and can be connected with a matrix through chemical bonds, and the stability of connection between the boric acid structures and the matrix of the castable can be enhanced. And the boric acid structure can form a ceramic borate structure with silicon dioxide, aluminum oxide and the like at high temperature, so that the thermal stability can be further improved. Meanwhile, the boric acid structure has good affinity with water, and can achieve the effect of a water reducing agent, so that the technical effect of adding the water reducing agent can be omitted.

Preferably, the mass ratio of tetraethoxysilane, triethoxysilane and water in step (s.1) is 100: (5-15): (30-50) and the hydrolysis temperature is 50-70 ℃.

Preferably, the drying temperature in the step (S.2) is 90-110 ℃, and the step (S.2) is repeated for 2-5 times.

After the single flooding, the thickness of the silica membrane on carbon fiber surface layer is thinner, has the inhomogeneous phenomenon of cover simultaneously, and consequently its oxidation resistance is relatively poor, consequently after flooding and drying many times, can effectively promote the thickness of silica membrane to the ability of isolated oxygen has been promoted, has promoted its oxidation resistance.

Preferably, the reaction solution in the step (s.3) includes 20 to 40% by mass of trimethyl borate, 0.1% by mass of tris (pentafluorobenzene) borane, and the balance of an organic solvent.

Preferably, the organic solvent is one of toluene, xylene, n-hexane, dichloromethane or tetrahydrofuran.

Preferably, the reaction temperature is 30-45 ℃, and the dipping reaction time is 15-60 min.

Preferably, the bauxite chamotte comprises 20-35% of 1-5 mm aggregate and 65-80% of 100-300-mesh bauxite fine powder in percentage by weight.

According to the invention, the bauxite chamotte is reasonably prepared into the aggregate and the fine powder, so that the mechanical property after pouring can be effectively improved.

Therefore, the invention has the following beneficial effects:

(1) the bauxite-based cordierite anti-explosion castable disclosed by the invention not only has good high-temperature resistance, but also has good thermal shock resistance, and is suitable for lining parts with excellent stripping resistance and wear resistance and occasions with requirements on thermal shock resistance;

(2) according to the invention, a certain amount of silicon dioxide micropowder is added into the formula, and the silicon dioxide micropowder has the main effect of replacing part of aluminate cement, so that the addition amount of the aluminate cement is reduced, the bonding strength between the silicon dioxide micropowder and the rest components is improved, and the thermal stability of the castable is further improved;

(3) the bauxite-based cordierite explosion-proof castable disclosed by the invention has a self-repairing effect, so that the interior of a kiln head cover of a cement kiln is not corroded.

Detailed Description

The invention is further described with reference to specific examples. Those skilled in the art will be able to implement the invention based on these teachings. Moreover, the embodiments of the present invention described in the following description are generally only some embodiments of the present invention, and not all embodiments. Therefore, all other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without any creative effort shall fall within the protection scope of the present invention.

Example 1

An alumina-based cordierite anti-explosion castable comprises, by weight, 60 parts of bauxite chamotte (including 12 parts of aggregate with the particle size of 1-5 mm and 48 parts of bauxite fine powder with the particle size of 100-300 meshes), 30 parts of cordierite, 10 parts of silica micro powder, 3 parts of aluminate cement, 15 parts of alumina powder, 5 parts of silicon single substance micro powder and 1 part of modified carbon fiber.

The preparation method of the modified carbon fiber comprises the following steps:

(S.1) mixing the components in a mass ratio of 100: 5: 30, sequentially weighing tetraethoxysilane, triethoxysilane and water, and mixing and hydrolyzing at 50 ℃ for 3h to obtain silica gel with a structure containing silicon hydrogen;

(S.2) soaking the carbon fibers in the silica gel, taking out the silicon gel, drying the silicon gel at 90 ℃, and repeating the steps for 2 times to obtain the carbon fibers coated with the silicon dioxide layer;

(S.3) soaking the carbon fiber coated with the silicon dioxide layer in toluene solution containing trimethyl borate with the mass concentration of 20% and tris (pentafluorobenzene) borane with the mass concentration of 0.1%, reacting for 60min at the temperature of 30 ℃, and drying to obtain the modified carbon fiber.

Example 2

An alumina-based cordierite anti-explosion castable comprises, by weight, 80 parts of a high-alumina bauxite clinker (comprising 28 parts of aggregate with the particle size of 1-5 mm and 52 parts of high-alumina bauxite fine powder with the particle size of 100-300 meshes), 50 parts of cordierite, 20 parts of silica micro powder, 5 parts of aluminate cement, 30 parts of alumina powder, 10 parts of silicon single substance micro powder and 5 parts of modified carbon fiber.

The preparation method of the modified carbon fiber comprises the following steps:

(S.1) mixing the components in a mass ratio of 100: 15: 50, sequentially weighing tetraethoxysilane, triethoxysilane and water, and mixing and hydrolyzing at 70 ℃ for 1h to obtain silica gel with a structure containing silicon hydrogen;

(S.2) soaking the carbon fibers in the silica gel, taking out the silicon gel, drying the silicon gel at 110 ℃, and repeating the steps for 5 times to obtain the carbon fibers coated with the silicon dioxide layer;

(S.3) soaking the carbon fiber coated with the silicon dioxide layer in a tetrahydrofuran solution containing trimethyl borate with the mass concentration of 40% and tris (pentafluorobenzene) borane with the mass concentration of 0.1%, reacting at 30 ℃ for 60min, and drying to obtain the modified carbon fiber.

Example 3

An alumina-based cordierite anti-explosion castable comprises, by weight, 70 parts of high-alumina bauxite clinker (including 21 parts of aggregate with the particle size of 1-5 mm and 49 parts of high-alumina bauxite fine powder with the particle size of 100-300 meshes), 40 parts of cordierite, 15 parts of silica micro powder, 4 parts of aluminate cement, 25 parts of alumina powder, 8 parts of silicon single substance micro powder and 3 parts of modified carbon fiber.

The preparation method of the modified carbon fiber comprises the following steps:

(S.1) mixing the components in a mass ratio of 100: 10: 40, sequentially weighing tetraethoxysilane, triethoxysilane and water, and mixing and hydrolyzing at 60 ℃ for 2h to obtain silica gel with a structure containing silicon hydrogen;

(S.2) soaking the carbon fibers in the silica gel, taking out the silicon gel, drying the silicon gel at 100 ℃, and repeating the steps for 3 times to obtain the carbon fibers coated with the silicon dioxide layer;

(S.3) soaking the carbon fiber coated with the silicon dioxide layer in a normal hexane solution containing 30% by mass of trimethyl borate and 0.1% by mass of tris (pentafluorobenzene) borane, reacting at 40 ℃ for 30min, and drying to obtain the modified carbon fiber.

Example 4

An alumina-based cordierite anti-explosion castable comprises, by weight, 65 parts of high-alumina bauxite clinker (including 16 parts of aggregate with the particle size of 1-5 mm and 49 parts of high-alumina bauxite fine powder with the particle size of 100-300 meshes), 35 parts of cordierite, 12 parts of silica micro powder, 3 parts of aluminate cement, 18 parts of alumina powder, 6 parts of silicon single substance micro powder and 2 parts of modified carbon fiber.

The preparation method of the modified carbon fiber comprises the following steps:

(S.1) mixing the components in a mass ratio of 100: 8: 35 sequentially weighing tetraethoxysilane, triethoxysilane and water, and mixing and hydrolyzing at 55 ℃ for 1.5h to obtain silica gel with a silicon-hydrogen containing structure;

(S.2) soaking the carbon fibers in the silica gel, taking out the silicon gel, drying the silicon gel at 95 ℃, and repeating the steps for 3 times to obtain the carbon fibers coated with the silicon dioxide layer;

(S.3) soaking the carbon fiber coated with the silicon dioxide layer in dichloromethane solution containing 25% by mass of trimethyl borate and 0.1% by mass of tris (pentafluorobenzene) borane, reacting at 35 ℃ for 20min, and drying to obtain the modified carbon fiber.

Example 5

An alumina-based cordierite anti-explosion castable comprises, by weight, 75 parts of a high-alumina bauxite clinker (comprising 23 parts of aggregate with the particle size of 1-5 mm and 52 parts of high-alumina bauxite fine powder with the particle size of 100-300 meshes), 45 parts of cordierite, 18 parts of silicon dioxide micro powder, 4.5 parts of aluminate cement, 26 parts of alumina powder, 8 parts of silicon single substance micro powder and 4 parts of modified carbon fibers.

The preparation method of the modified carbon fiber comprises the following steps:

(S.1) mixing the components in a mass ratio of 100: 12: 45, sequentially weighing tetraethoxysilane, triethoxysilane and water, and mixing and hydrolyzing at 65 ℃ for 1.5h to obtain silica gel with a silicon-hydrogen containing structure;

(S.2) soaking the carbon fibers in the silica gel, taking out the silicon gel, drying the silicon gel at 105 ℃, and repeating the steps for 3 times to obtain the carbon fibers coated with the silicon dioxide layer;

(S.3) soaking the carbon fiber coated with the silicon dioxide layer in a toluene solution containing trimethyl borate with the mass concentration of 35% and tris (pentafluorobenzene) borane with the mass concentration of 0.1%, reacting at 40 ℃ for 35min, and drying to obtain the modified carbon fiber.

Comparative example 1

Comparative example 1 the solution of example 2, patent application No. CN200810037994.9, was used.

The method comprises the following specific steps: 40 parts of bauxite, 10 parts of waste clay brick, 31 parts of cordierite, 7 parts of high-alumina cement, 4 parts of silicon dioxide micro powder, 4 parts of active alumina micro powder, 4 parts of kyanite, 0.15 part of sodium tripolyphosphate (added), and 0.15 part of sodium hexametaphosphate (added).

Comparative example 2

An alumina-based cordierite anti-explosion castable comprises, by weight, 70 parts of a high-alumina bauxite clinker (comprising 21 parts of aggregate with the particle size of 1-5 mm and 49 parts of high-alumina bauxite fine powder with the particle size of 100-300 meshes), 40 parts of cordierite, 15 parts of silica micropowder, 4 parts of aluminate cement and 25 parts of alumina powder.

Comparative example 3

An alumina-based cordierite anti-explosion castable comprises, by weight, 70 parts of a high-alumina bauxite clinker (comprising 21 parts of aggregate with the particle size of 1-5 mm and 49 parts of high-alumina bauxite fine powder with the particle size of 100-300 meshes), 40 parts of cordierite, 15 parts of silica micro powder, 4 parts of aluminate cement, 25 parts of alumina powder and 8 parts of silicon single substance micro powder.

Comparative example 4

An alumina-based cordierite anti-explosion castable comprises, by weight, 70 parts of high-alumina bauxite clinker (including 21 parts of aggregate with the particle size of 1-5 mm and 49 parts of high-alumina bauxite fine powder with the particle size of 100-300 meshes), 40 parts of cordierite, 15 parts of silica micro powder, 4 parts of aluminate cement, 25 parts of alumina powder, 8 parts of silicon single substance micro powder and 3 parts of carbon fiber.

Comparative example 5

An alumina-based cordierite anti-explosion castable comprises, by weight, 70 parts of a high-alumina bauxite clinker (comprising 21 parts of aggregate with the particle size of 1-5 mm and 49 parts of high-alumina bauxite fine powder with the particle size of 100-300 meshes), 40 parts of cordierite, 15 parts of silica micro powder, 4 parts of aluminate cement, 25 parts of alumina powder and 3 parts of modified carbon fiber.

And (3) performance testing:

pouring the concrete blocks in the embodiments 1-5 and the comparative examples 1-4 to prepare the precast blocks, wherein the concrete process is as follows: weighing the components in sequence according to the formula, uniformly mixing to obtain a mixture, then adding water accounting for 5% of the total castable, uniformly stirring by a stirrer, pouring, performing layered jolting by using a vibrating rod, standing, demolding to obtain a castable blank, and then baking for 24 hours at 500 ℃ to prepare the precast block.

The test results of the precast blocks prepared in examples 1 to 5 and comparative examples 1 to 5 are shown in the following table:

TABLE 1 mechanical Property test results of examples 1 to 5 and comparative examples 1 to 5

Comparing examples 1-5 with comparative example 1, we find that the technical solution of the present invention has significant advantages in terms of rupture strength, compressive strength, and anti-cracking temperature, compared to comparative example 1, and thus can withstand more complicated use environments.

Comparing the example 3 with the comparative example 2, the comparative example 2 omits the addition of the simple substance silicon micro powder and the modified carbon fiber on the basis of the comparative example 3, and it can be known from the data that after the addition of the two components is reduced, each performance of the two components is obviously reduced, which shows that the addition of the simple substance silicon micro powder and the modified carbon fiber can obviously improve the performance of the two components.

Comparing example 3 with comparative example 3, in comparative example 3, the addition of the modified carbon fiber is omitted on the basis of example 3, and as can be seen from the data in the table above, the mechanical property parameters are relatively improved compared with comparative example 2, but the improvement range is small, which indicates that the fine elemental silicon powder has a certain improvement on the mechanical property, but the improvement range is small. But the silicon single substance micro powder can effectively improve the anti-explosion temperature, which shows that the coating layer formed after the silicon single substance micro powder is oxidized has certain help to improve the anti-explosion performance.

By comparing the example 3 with the comparative example 4, the comparative example 4 is obtained by replacing the modified carbon fiber with the ordinary carbon fiber on the basis of the example 3, and as can be seen from the data in the table above, the flexural strength and the compressive strength of the modified carbon fiber are obviously improved under the low temperature condition (110 ℃x24 h), but the mechanical properties of the modified carbon fiber are improved less than those of other comparative examples along with the temperature increase (1100 ℃x3 h), which indicates that the carbon fiber can undergo an oxidation reaction under the high temperature air atmosphere, so that the reinforcing capability of the carbon fiber is greatly reduced, but the carbon fiber inside the precast block still has a certain anti-explosion effect due to the oxygen isolation condition, so that a certain amount of anti-explosion temperature can be increased.

By comparing the example 3 with the comparative example 5, the comparative example 5 is to delete the elemental silicon micro powder on the basis of the example 3, and as can be seen from the data in the table above, after the elemental silicon micro powder is removed, each performance of the elemental silicon micro powder is reduced by a certain amount, but the reduction range is small, which indicates that the addition of the elemental silicon micro powder is helpful for improving the performance.