阅读说明：本技术 一种含碳耐火料用亲水性石墨制备方法 (Preparation method of hydrophilic graphite for carbon-containing refractory material ) 是由 赵明 于 2021-07-05 设计创作，主要内容包括：本发明公开了一种含碳耐火料用亲水性石墨制备方法,通过将镁砂细粉加入到水中,预搅拌,得到混合料A,将混合料A加入到V型搅拌机中,加入石墨、分散剂和水,得到混合料B,向混合料B中加入粘结剂,用制球机制球或压砖机压成砖,将制成的球或砖体进行烘烤,得到混合料C；工艺简单易控,生产周期短,成本低廉,制备过程环保,镁砂细粉水解后生成Mg(OH)-2溶胶体,通过高效搅拌Mg(OH)-2溶胶体包裹在石墨表面,再经过成型烘烤,使溶胶包裹层脱水实现纳米级氧化镁对石墨表面改性,增强石墨亲水性或与其它无机材料的结合强度,从而达到了提升现有石墨产品与水或油的稀释性、润湿性、分散性、流动性的目的。(The invention discloses a preparation method of hydrophilic graphite for a carbon-containing refractory material, which comprises the steps of adding fine magnesia powder into water, pre-stirring to obtain a mixture A, adding the mixture A into a V-shaped stirrer, adding graphite, a dispersing agent and water to obtain a mixture B, adding a binder into the mixture B, pressing the mixture B into bricks by using a ball making machine or a brick pressing machine, and baking the balls or bricks to obtain a mixture C; simple and easily controlled process, short production period, low cost, environment-friendly preparation process, and generation of Mg (OH) after hydrolysis of magnesite fine powder 2 Sol of Mg (OH) by high-efficiency stirring 2 The sol is wrapped on the surface of graphite, and then the sol wrapping layer is dehydrated to realize the modification of the graphite surface by the nano-scale magnesium oxide and enhance the hydrophilicity of the graphite or the bonding strength with other inorganic materials, thereby achieving the purpose of improving the dilutability, wettability, dispersibility and fluidity of the existing graphite product and water or oil.)

1. The preparation method of the hydrophilic graphite for the carbon-containing refractory material is characterized by comprising the following steps of:

s1: adding the fine magnesia powder into water, and pre-stirring for 5-10min to obtain a mixture A;

s2: adding the mixture A into a V-shaped stirrer, adding graphite, a dispersing agent and water, and stirring for 2-4h at the rotating speed of 20-30rpm to obtain a mixture B;

s3: adding a binder into the mixture B, pressing the mixture B into bricks by using a ball making machine or a brick pressing machine, and baking the balls or bricks at the baking temperature of 350-420 ℃ for 4-6h to obtain a mixture C;

s4: and (3) putting the mixture C and the modified phenolic resin into a ball mill for grinding for 2-6h, discharging at the rotating speed of 25-30rpm, and obtaining the hydrophilic graphite for the carbon-containing refractory material, wherein the grain size of the discharged fine powder is 120 meshes.

2. The method for preparing hydrophilic graphite for carbon-containing refractory according to claim 1, wherein the content of magnesium oxide in the magnesite fine powder in step S1 is 95-98.5%, the particle size D50 is less than 1.5 μm, and the mass of water is 10-15% of the mass of the magnesium oxide fine powder.

3. The method for preparing hydrophilic graphite for carbon-containing refractory according to claim 1, wherein the particle size of the graphite in step S2 is 80 meshes, and the mass ratio of the mixture a to the graphite is 15-25: 85-75 percent of water, wherein the weight of the water is 5-10 percent of the total weight of the mixture A and the graphite, and the dispersant is triethanolamine or sodium hexametaphosphate.

4. The method according to claim 1, wherein the binder in step S3 is waste paper pulp, and the ratio of the binder to the mixture B is 1 g: 20 g.

5. The method for preparing hydrophilic graphite for carbon-containing refractory according to claim 1, wherein the amount ratio of the mixed material C to the modified phenolic resin in step S4 is 10 g: 1g of the total weight of the composition.

6. The method for preparing the hydrophilic graphite for the carbon-containing refractory according to claim 1, wherein the modified phenolic resin is prepared by the following steps:

s61: dispersing Fe nano-sheets with the thickness of 60-70nm and the size of 0.1-5 mu m in ethanol, and dispersing for 5-20min under the ultrasonic oscillation condition to obtain a mixture D;

s62: adding the mixture D into thermosetting phenolic resin at the temperature of 80-90 ℃, and stirring for 10-15h by using an electric stirrer to obtain an intermediate B;

s63: adding the intermediate B into metal Al powder and nano carbon black, mixing uniformly, putting into a ball mill, and grinding for 1-2h to obtain the modified phenolic resin.

7. The method for preparing hydrophilic graphite for carbon-containing refractory according to claim 6, wherein the amount ratio of the mixed material D to the thermosetting phenolic resin in step S62 is 2 g: 9g, the solid mass fraction of the thermosetting phenolic resin at 205 ℃ is 78.0-80.0%, and the carbon residue rate at 800 ℃ is 46.0-50.0%.

8. The method of claim 6, wherein the ratio of the intermediate B, the metallic Al powder and the nano carbon black in step S63 is 10 g: 1 g: 5g of the total weight.

Technical Field

The invention relates to the field of graphite, in particular to a preparation method of hydrophilic graphite for a carbon-containing refractory material.

Background

Graphite has the characteristics of high melting point, small thermal expansion coefficient, good thermal conductivity, good thermal stability and chemical stability, and is widely applied to high-temperature resistant materials, but the wettability of graphite with water and oil is poor, so that the materials are dispersed unevenly, the structure is loose, the mechanical stability is poor and the like after the graphite is added, the mechanical property of the materials is reduced, the prior method not only adds organic binders such as resin, asphalt and the like to enhance the combination method of the graphite and a main material, but also adopts a method for surface modification of the graphite, and the adopted modification technology mainly comprises a surfactant method, a granulation method and a graphite surface coating method;

the granulation method has small particle application range, and is not ideal in stability, the surfactant method technology is still in the stage of selecting an active agent with strong binding force, the surface coating method is limited to some laboratory achievements at present, the process is complex and high in cost, the toughness of the material is poor, and the mechanical property cannot meet the use requirement;

therefore, how to improve the dilutability, wettability, dispersibility and fluidity of the existing graphite product and water or oil, which can not be produced in large scale and the mechanical property can not meet the use requirement is the problem to be solved by the invention.

Disclosure of Invention

In order to overcome the technical problems, the invention aims to provide a preparation method of hydrophilic graphite for carbon-containing refractory, which comprises the following steps:

(1) adding fine magnesia powder into water, pre-stirring to obtain a mixture A, adding the mixture A into a V-shaped stirrer, adding graphite, a dispersing agent and water to obtain a mixture B, adding a binder into the mixture B, pressing the mixture B into bricks by using a ball making machine or a brick pressing machine, baking the prepared balls or bricks to obtain a mixture C, and putting the mixture C and modified phenolic resin into a ball mill for grinding to obtain hydrophilic graphite for the carbon-containing refractory material, wherein the problem that the existing graphite product is poor in dilutability, wettability, dispersibility and fluidity with water or oil and cannot be produced on a large scale is solved by preparing the hydrophilic graphite for the carbon-containing refractory material;

(2) the modified phenolic resin is obtained by dispersing Fe nanosheets in ethanol, performing ultrasonic oscillation to obtain a mixture D, adding the mixture D into thermosetting phenolic resin to obtain an intermediate B, adding metal Al powder and nano carbon black into the intermediate B, and grinding.

The purpose of the invention can be realized by the following technical scheme:

a preparation method of hydrophilic graphite for carbon-containing refractory comprises the following steps:

s1: adding the fine magnesia powder into water, and pre-stirring for 5-10min to obtain a mixture A;

s2: adding the mixture A into a V-shaped stirrer, adding graphite, a dispersing agent and water, and stirring for 2-4h at the rotating speed of 20-30rpm to obtain a mixture B;

s3: adding a binder into the mixture B, pressing the mixture B into bricks by using a ball making machine or a brick pressing machine, and baking the balls or bricks at the baking temperature of 350-420 ℃ for 4-6h to obtain a mixture C;

s4: and (3) putting the mixture C and the modified phenolic resin into a ball mill for grinding for 2-6h, discharging at the rotating speed of 25-30rpm, and obtaining the hydrophilic graphite for the carbon-containing refractory material, wherein the grain size of the discharged fine powder is 120 meshes.

As a further scheme of the invention: in the step S1, the content of magnesium oxide in the magnesia fine powder is 95-98.5%, the granularity D50 is less than 1.5 mu m, and the mass of water is 10-15% of the mass of the magnesia fine powder.

As a further scheme of the invention: in the step S2, the particle size of the graphite is 80 meshes, and the mass ratio of the mixture A to the graphite is 15-25: 85-75 percent of water, wherein the weight of the water is 5-10 percent of the total weight of the mixture A and the graphite, and the dispersant is triethanolamine or sodium hexametaphosphate.

As a further scheme of the invention: in the step S3, the binder is waste paper pulp, and the dosage ratio of the binder to the mixture B is 1 g: 20 g.

As a further scheme of the invention: in the step S4, the dosage ratio of the mixture C to the modified phenolic resin is 10 g: 1g of the total weight of the composition.

As a further scheme of the invention: the preparation process of the modified phenolic resin is as follows:

s61: dispersing Fe nano-sheets with the thickness of 60-70nm and the size of 0.1-5 mu m in ethanol, and dispersing for 5-20min under the ultrasonic oscillation condition to obtain a mixture D;

s62: adding the mixture D into thermosetting phenolic resin at the temperature of 80-90 ℃, and stirring for 10-15h by using an electric stirrer to obtain an intermediate B;

s63: adding the intermediate B into metal Al powder and nano carbon black, mixing uniformly, putting into a ball mill, and grinding for 1-2h to obtain the modified phenolic resin.

As a further scheme of the invention: in the step S62, the dosage ratio of the mixture D to the thermosetting phenolic resin is 2 g: 9g, the solid mass fraction of the thermosetting phenolic resin at 205 ℃ is 78.0-80.0%, and the carbon residue rate at 800 ℃ is 46.0-50.0%.

As a further scheme of the invention: in the step S63, the dosage ratio of the intermediate B, the metal Al powder and the nano carbon black is 10 g: 1 g: 5g of the total weight.

The invention has the beneficial effects that:

the preparation method comprises the steps of adding fine magnesia powder into water, pre-stirring to obtain a mixture A, adding the mixture A into a V-shaped stirrer, adding graphite, a dispersing agent and water to obtain a mixture B, adding a binder into the mixture B, pressing the mixture B into bricks by using a ball making machine or a brick pressing machine, baking the balls or bricks to obtain a mixture C, and adding the mixture C and modified phenolic resin into a ball mill for grinding to obtain the hydrophilic graphite for the carbon-containing refractory material₂Sol of Mg (OH) by high-efficiency stirring₂The sol is wrapped on the surface of graphite, and then molding and baking are carried out, so that the modification of the graphite surface by the nanoscale magnesium oxide is realized by dehydrating the sol wrapping layer, the hydrophilicity of the graphite or the bonding strength with other inorganic materials are enhanced, other raw materials and impurities which influence the performance of the refractory material are not introduced in the production process, the production cost and the magnesium content of the product can be adjusted according to the requirements of users, the low-cost hydrophilic graphite for industrial production is realized, and the purposes of improving the dilutability, wettability, dispersibility and fluidity of the existing graphite product and water or oil are achieved;

dispersing Fe nano-sheets in ethanol, performing ultrasonic oscillation to obtain a mixture D, adding the mixture D into thermosetting phenolic resin to obtain an intermediate B, adding metal Al powder and nano-carbon black into the intermediate B, grinding to obtain the modified phenolic resin, reducing the reaction temperature among certain components in the material by introducing a transition metal catalyst, promoting the reaction among the components, oxidizing the added metal Al at high temperature with the atmosphere, generating a new ceramic phase by carbonization or nitridation reaction, pyrolyzing the phenolic resin in the heat treatment process to generate a certain amount of hydrocarbon gas in pores of a matrix, gradually separating out the Fe nano-sheets added into the phenolic resin from the phenolic resin in the curing process of the phenolic resin, distributing the Fe nano-sheets in the pores, and capturing carbon generated by pyrolysis of the phenolic resin by the Fe catalyst in a high-temperature environment, the method comprises the steps of converting hydrocarbon gas into carbon nano tubes, filling pores in a matrix with the added catalyst and secondary carbon converted from the hydrocarbon gas together, and enhancing fracture toughness, so that the thermal shock stability of the material is improved.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1:

the embodiment is a hydrophilic graphite for a carbon-containing refractory, which comprises the following steps:

s1: adding the fine magnesia powder into water, and pre-stirring for 5min to obtain a mixture A;

s2: adding the mixture A into a V-shaped stirrer, adding graphite, a dispersing agent and water, and stirring for 2 hours at the rotating speed of 20rpm to obtain a mixture B;

s3: adding a binder into the mixture B, pressing the mixture B into bricks by using a ball making machine or a brick pressing machine, and baking the balls or bricks at the baking temperature of 350 ℃ for 4 hours to obtain a mixture C;

s4: putting the mixture C and the modified phenolic resin into a ball mill for grinding, grinding for 2h, discharging at the rotating speed of 25rpm, and obtaining hydrophilic graphite for the carbon-containing refractory material, wherein the particle size of discharged fine powder is 120 meshes;

the preparation process of the modified phenolic resin comprises the following steps:

s61: dispersing Fe nano-sheets with the thickness of 60nm and the size of 0.1 mu m in ethanol, and dispersing for 5min under the ultrasonic oscillation condition to obtain a mixture D;

s62: adding the mixture D into thermosetting phenolic resin at the temperature of 80 ℃, and stirring for 10 hours by using an electric stirrer to obtain an intermediate B;

s63: adding the intermediate B into metal Al powder and nano carbon black, uniformly mixing, putting into a ball mill, and grinding for 1h to obtain the modified phenolic resin.

Example 2:

the embodiment is a hydrophilic graphite for a carbon-containing refractory, which comprises the following steps:

s1: adding the fine magnesia powder into water, and pre-stirring for 5min to obtain a mixture A;

s2: adding the mixture A into a V-shaped stirrer, adding graphite, a dispersing agent and water, and stirring for 2 hours at the rotating speed of 20rpm to obtain a mixture B;

s3: adding a binder into the mixture B, pressing the mixture B into bricks by using a ball making machine or a brick pressing machine, and baking the balls or bricks at the baking temperature of 350 ℃ for 4 hours to obtain a mixture C;

s4: putting the mixture C and the modified phenolic resin into a ball mill for grinding, grinding for 2h, discharging at the rotating speed of 25rpm, and obtaining hydrophilic graphite for the carbon-containing refractory material, wherein the particle size of discharged fine powder is 120 meshes;

the preparation process of the modified phenolic resin comprises the following steps:

s61: dispersing a Fe nano sheet with the thickness of 70nm and the size of 5 mu m in ethanol, and dispersing for 20min under the ultrasonic oscillation condition to obtain a mixture D;

s62: adding the mixture D into thermosetting phenolic resin at 90 ℃, and stirring for 15 hours by using an electric stirrer to obtain an intermediate B;

s63: adding the intermediate B into metal Al powder and nano carbon black, uniformly mixing, putting into a ball mill, and grinding for 2h to obtain the modified phenolic resin.

Example 3:

the embodiment is a hydrophilic graphite for a carbon-containing refractory, which comprises the following steps:

s1: adding the fine magnesia powder into water, and pre-stirring for 10min to obtain a mixture A;

s2: adding the mixture A into a V-shaped stirrer, adding graphite, a dispersing agent and water, and stirring for 4 hours at the rotating speed of 30rpm to obtain a mixture B;

s3: adding a binder into the mixture B, pressing the mixture B into bricks by using a ball making machine or a brick pressing machine, and baking the balls or bricks at the baking temperature of 420 ℃ for 6 hours to obtain a mixture C;

s4: putting the mixture C and the modified phenolic resin into a ball mill for grinding, grinding for 6h, discharging at the rotating speed of 30rpm, and obtaining hydrophilic graphite for the carbon-containing refractory material, wherein the particle size of discharged fine powder is 120 meshes;

the preparation process of the modified phenolic resin comprises the following steps:

s61: dispersing Fe nano-sheets with the thickness of 60nm and the size of 0.1 mu m in ethanol, and dispersing for 5min under the ultrasonic oscillation condition to obtain a mixture D;

s62: adding the mixture D into thermosetting phenolic resin at the temperature of 80 ℃, and stirring for 10 hours by using an electric stirrer to obtain an intermediate B;

s63: adding the intermediate B into metal Al powder and nano carbon black, uniformly mixing, putting into a ball mill, and grinding for 1h to obtain the modified phenolic resin.

Example 4:

the embodiment is a hydrophilic graphite for a carbon-containing refractory, which comprises the following steps:

s1: adding the fine magnesia powder into water, and pre-stirring for 10min to obtain a mixture A;

s2: adding the mixture A into a V-shaped stirrer, adding graphite, a dispersing agent and water, and stirring for 4 hours at the rotating speed of 30rpm to obtain a mixture B;

s3: adding a binder into the mixture B, pressing the mixture B into bricks by using a ball making machine or a brick pressing machine, and baking the balls or bricks at the baking temperature of 420 ℃ for 6 hours to obtain a mixture C;

s4: putting the mixture C and the modified phenolic resin into a ball mill for grinding, grinding for 6h, discharging at the rotating speed of 30rpm, and obtaining hydrophilic graphite for the carbon-containing refractory material, wherein the particle size of discharged fine powder is 120 meshes;

the preparation process of the modified phenolic resin comprises the following steps:

s61: dispersing a Fe nano sheet with the thickness of 70nm and the size of 5 mu m in ethanol, and dispersing for 20min under the ultrasonic oscillation condition to obtain a mixture D;

s62: adding the mixture D into thermosetting phenolic resin at 90 ℃, and stirring for 15 hours by using an electric stirrer to obtain an intermediate B;

s63: adding the intermediate B into metal Al powder and nano carbon black, uniformly mixing, putting into a ball mill, and grinding for 2h to obtain the modified phenolic resin.

Comparative example 1:

compared with the example 1, the comparative example does not add the modified phenolic resin, and the rest steps are the same;

comparative example 2:

in the comparative example, hydrophilic graphite for a refractory castable disclosed in chinese patent CN201610808547.3 was used;

the hydrophilic graphite of examples 1 to 4 and comparative examples 1 to 2 was measured for room-temperature compressive strength according to national standard GB/TS072.1-1998, for room-temperature flexural strength according to the three-point bending method specified in national standard GB/T3001-2000, and for high-temperature flexural strength according to the three-point bending method specified in national standard GB/T3002-2004;

the results are shown in the following table:

as can be seen from the above table, the room temperature compressive strength of the experimental example reached 76 to 82MPa, while the room temperature compressive strength of comparative example 1 to which no modified phenolic resin was added was 72MPa, the room temperature compressive strength of comparative example 2 to which hydrophilic graphite for castable refractory disclosed in Chinese patent CN201610808547.3 was used was 60MPa, the room temperature flexural strength of the experimental example was 10 to 14MPa, while the room temperature flexural strength of comparative example 1 to which no modified phenolic resin was added was 8MPa, the room temperature flexural strength of comparative example 2 to which hydrophilic graphite for castable refractory disclosed in Chinese patent CN201610808547.3 was used was 7MPa, the high temperature flexural strength of the experimental example was 11 to 14MPa, while the high temperature flexural strength of comparative example 1 to which no modified phenolic resin was added was 7MPa, the high temperature flexural strength of comparative example 2 to which graphite for castable refractory disclosed in Chinese patent CN201610808547.3 was used was 6MPa, and the data of the experimental example was significantly better than the comparative example, the application of the hydrophilic graphite for the carbon-containing refractory material and the addition of the modified phenolic resin can effectively improve the mechanical property of the material.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The foregoing is illustrative and explanatory only and is not intended to be exhaustive or to limit the invention to the precise embodiments described, and various modifications, additions, and substitutions may be made by those skilled in the art without departing from the scope of the invention or exceeding the scope of the claims.