阅读说明：本技术 一种含碳耐火浇注料用石墨表面改性方法及其应用 (Graphite surface modification method for carbon-containing refractory castable and application thereof ) 是由 肖国庆 张成林 丁冬海 任耘 于 2019-09-23 设计创作，主要内容包括：本发明公开了一种含碳耐火浇注料用石墨表面改性方法及其应用,该方法以鳞片石墨和钛粉为原料,采用自蔓延高温合成方法进行碳化钛包覆鳞片石墨的制备。按质量百分比计,鳞片石墨27.34％～38.55％,钛粉61.45％～72.66％,上述原料总含量为100％。包括：步骤一：将鳞片石墨、钛粉按照配比混合均匀装料于瓷坩埚得到试样；步骤二：对步骤一得到的试样进行轻压成型；步骤三：结束成型后,将成型后的试样放入自蔓延高温反应炉中,通过引燃剂引燃成型后的试样进行自蔓延高温合成反应；步骤四：反应后将试样粉碎研磨得到碳化钛包覆鳞片石墨。通过该方法得到的碳化钛包覆鳞片石墨,将其引入含碳耐火浇注料中,可显著地改善含碳耐火材料中石墨的润湿性差、分散性差和易氧化等问题。(The invention discloses a graphite surface modification method for a carbon-containing refractory castable and application thereof. 27.34-38.55% of crystalline flake graphite and 61.45-72.66% of titanium powder, wherein the total content of the raw materials is 100% by mass. The method comprises the following steps: the method comprises the following steps: uniformly mixing the flake graphite and the titanium powder according to a ratio, and loading the mixture into a ceramic crucible to obtain a sample; step two: carrying out light press molding on the sample obtained in the step one; step three: after the molding is finished, putting the molded sample into a self-propagating high-temperature reaction furnace, and igniting the molded sample by using an ignition agent to perform self-propagating high-temperature synthesis reaction; step four: and crushing and grinding the sample after reaction to obtain the titanium carbide coated crystalline flake graphite. The titanium carbide coated flake graphite obtained by the method is introduced into the carbon-containing refractory castable, so that the problems of poor wettability, poor dispersibility, easy oxidation and the like of graphite in the carbon-containing refractory material can be obviously improved.)

1. A graphite surface modification method for a carbon-containing refractory castable is characterized in that the method takes crystalline flake graphite and titanium powder as raw materials and adopts a self-propagating high-temperature synthesis method to prepare titanium carbide coated crystalline flake graphite.

2. The method for modifying the surface of graphite for a carbon-containing refractory castable according to claim 1, wherein the amount of flake graphite is 27.34% to 38.55%, the amount of titanium powder is 61.45% to 72.66%, and the total content of the raw materials is 100% by mass.

3. The method for modifying the surface of graphite for a carbon-containing refractory castable according to claim 2, comprising:

the method comprises the following steps: uniformly mixing the flake graphite and the titanium powder according to a ratio, and loading the mixture into a ceramic crucible to obtain a sample;

step two: carrying out light press molding on the sample obtained in the step one;

step three: after the molding is finished, putting the molded sample into a self-propagating high-temperature reaction furnace, and igniting the molded sample by using an ignition agent to perform self-propagating high-temperature synthesis reaction;

step four: and crushing and grinding the sample after reaction to obtain the titanium carbide coated crystalline flake graphite.

4. The method for modifying the graphite surface of a carbon-containing castable refractory according to claim 3, wherein in the third step, an ignition agent is placed on the molded sample, and the self-propagating high-temperature synthesis reaction is initiated by heat generated by the reaction of the ignition agent placed at the upper end of the sample;

the ignition agent comprises a C-Ti ignition agent, wherein the C-Ti ignition agent is prepared by mixing titanium powder and carbon black according to the mass ratio of 4: 1; the reaction of titanium powder and carbon black is initiated by a tungsten wire.

5. The method for modifying the graphite surface for the carbon-containing refractory castable according to claim 3, wherein in the third step, under the conditions of vacuum pumping and argon filling to normal pressure, the sample is ignited and ignited to carry out self-propagating high-temperature synthesis reaction, and then after the furnace temperature is reduced to room temperature, the power supply is turned off, the furnace door is opened, and the material is taken out; the vacuum degree of the vacuum pumping is-0.092 MP.

6. Use of the titanium carbide coated crystalline flake graphite prepared by the graphite surface modification method of the carbon-containing refractory castable material according to any one of claims 1 to 5 for preparing the carbon-containing refractory castable material.

Technical Field

The invention belongs to the technical field of inorganic non-metallic materials, and particularly relates to a graphite surface modification method for a carbon-containing refractory castable and application thereof.

Background

The refractory material is a key structural material of a high-temperature smelting and high-temperature kiln and other thermal equipment, can bear corresponding physical and chemical changes and mechanical action, is an indispensable basic material of a high-temperature technology, and is widely applied to the fields of steel, ceramics, building materials, electronics, petrifaction and the like. Wherein the refractory material consumption in the steel industry is the largest. The conventional oxide refractory is used in a high temperature environment, and must have sufficient structural stability. The traditional oxide refractory material has strong wettability with slag and poor slag corrosion resistance, so that the service life of a furnace lining is greatly reduced.

The graphite and the steel slag are not wetted, the thermal expansion coefficient is small, and the graphite and the steel slag have good thermal conductivity and toughness. Therefore, in the preparation process of the refractory material, the carbon material is properly added to form the carbon-containing refractory material, so that the thermal expansion of the refractory material can be reduced, and the slag resistance, the thermal shock resistance, the thermal conductivity and the impact resistance of the refractory material are improved, thereby prolonging the service life of the furnace lining. However, graphite has a fatal disadvantage of being easily oxidized and having poor hydrophilicity, and thus the exertion of its advantages is limited.

Disclosure of Invention

Aiming at the defects and shortcomings in the prior art, the invention provides a graphite surface modification method for a carbon-containing refractory castable and application thereof.

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

a graphite surface modification method for carbon-containing refractory castable is characterized in that crystalline flake graphite and titanium powder are used as raw materials, and a self-propagating high-temperature synthesis method is adopted to prepare titanium carbide coated crystalline flake graphite.

The invention also comprises the following technical characteristics:

specifically, the weight percentage of the flake graphite is 27.34-38.55%, the weight percentage of the titanium powder is 61.45-72.66%, and the total content of the raw materials is 100%.

Specifically, the method comprises the following steps:

the method comprises the following steps: uniformly mixing the flake graphite and the titanium powder according to a ratio, and loading the mixture into a ceramic crucible to obtain a sample;

step two: carrying out light press molding on the sample obtained in the step one;

step three: after the molding is finished, putting the molded sample into a self-propagating high-temperature reaction furnace, and igniting the molded sample by using an ignition agent to perform self-propagating high-temperature synthesis reaction;

step four: and crushing and grinding the sample after reaction to obtain the titanium carbide coated crystalline flake graphite.

Specifically, in the third step, an ignition agent is placed on the molded sample, and the self-propagating high-temperature synthesis reaction is initiated by heat generated by the reaction of the ignition agent placed at the upper end of the sample;

the ignition agent comprises a C-Ti ignition agent, wherein the C-Ti ignition agent is prepared by mixing titanium powder and carbon black according to the mass ratio of 4: 1; the reaction of titanium powder and carbon black is initiated by a tungsten wire.

Specifically, in the third step, under the conditions of vacuumizing and filling argon to normal pressure, igniting the sample to perform self-propagating high-temperature synthesis reaction, then, after the furnace temperature is reduced to room temperature, closing a power supply, opening a furnace door, and taking out the material; the vacuum degree of the vacuum pumping is-0.092 MP.

The titanium carbide coated crystalline flake graphite prepared by the carbon-containing refractory castable material through a graphite surface modification method is applied to preparation of the carbon-containing refractory castable material.

Compared with the prior art, the invention has the beneficial technical effects that:

according to the self-propagating high-temperature synthesis method, the titanium carbide coated flake graphite can be simply, quickly and efficiently prepared by one step by taking the flake graphite and the titanium powder as raw materials according to the in-situ synthesis theory. Can obviously improve the problems of poor wettability and uneven dispersion of graphite and easy oxidation at high temperature. The titanium carbide coated crystalline flake graphite is used as a carbon source and is introduced into the carbon-containing refractory castable, so that the oxidation resistance and the slag corrosion resistance of the graphite in the carbon-containing refractory castable can be improved,

the titanium carbide coated flake graphite obtained by the graphite surface modification method for the carbon-containing refractory castable material not only keeps the advantages of non-wettability of graphite with steel slag, small thermal expansion coefficient and the like, but also solves the problems of poor wettability, poor dispersibility and easy oxidation of graphite, and can endow the carbon-containing refractory castable material with more excellent oxidation resistance and slag corrosion resistance. If the surface of the graphite is coated and modified by a physical or chemical method, a coating layer is generated on the surface of the graphite, and the problems of poor wettability and easy oxidation of the graphite can be greatly improved. The surface coating layer of the flake graphite mainly comprises oxides and carbides. Compared with the oxide coating layer, the carbide coating layer is continuous, has strong adhesive force and can not react with graphite at high temperature. The existing carbide coating technology is mainly a molten salt method. The self-propagating high-temperature synthesis method is rapid and efficient, simple in process, low in energy consumption, high in product purity and capable of keeping the shape characteristics of carbon particles in shape.

The invention relates to a graphite surface modification method for a carbon-containing refractory castable, which mainly comprises a titanium carbide coating layer and a crystalline flake graphite matrix. The titanium carbide coated flake graphite with good dispersibility, water wettability and oxidation resistance is prepared by adopting a self-propagating high-temperature synthesis method, and has important significance for improving the performance of the carbon-containing refractory castable. Titanium carbide has a smaller water wetting angle than crystalline flake graphite; and the titanium carbide has a higher affinity for oxygen than carbon, and can play a role in inhibiting carbon from being oxidized. Therefore, the graphite surface modification method for the carbon-containing refractory castable can effectively improve the wettability of graphite and improve the oxidation resistance of carbon, further endows the carbon-containing refractory castable with more excellent oxidation resistance and slag corrosion resistance, and makes great contribution to the field of the carbon-containing refractory castable.

Drawings

FIG. 1 is a flow chart of the manufacturing process of the present invention;

FIG. 2 is the SEI diagram of flake graphite in the starting material;

FIG. 3 is an XRD pattern of titanium carbide coated flake graphite prepared in example 1 of the present specification;

FIG. 4 is an SEI diagram (FIG. 4a), a BEI diagram (FIG. 4b), and an EDS diagram (4 c, 4d, respectively) at two points A, B of the titanium carbide-coated flake graphite prepared in illustrative example 1;

FIG. 5 is an XRD pattern of titanium carbide coated flake graphite prepared in example 2 of this specification;

FIG. 6 is an SEI diagram (FIG. 6a) and a BEI diagram (FIG. 6b) for titanium carbide coated flake graphite prepared in illustrative example 2;

FIG. 7 is an XRD pattern of titanium carbide coated flake graphite prepared in example 3 of this specification;

FIG. 8 is an SEI diagram (FIG. 8a) and a BEI diagram (FIG. 8b) for titanium carbide coated flake graphite prepared in illustrative example 3;

FIG. 9 is a graph showing the water wettability of titanium carbide-coated flake graphite prepared in example 2;

FIG. 10 is a graph showing the oxidation resistance of a castable material made of titanium carbide-coated flake graphite prepared in example 2;

FIG. 11 is a graph showing the slag erosion resistance of a castable material made of titanium carbide-coated crystalline flake graphite prepared in example 2.

Detailed Description

The present invention will be described in detail below with reference to the drawings and embodiments, and the embodiments of the present invention are not to be considered limited to the description. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.

In this embodiment:

the titanium carbide coated flake graphite obtained by the graphite surface modification method for the carbon-containing refractory castable material not only keeps the advantages of non-wettability of graphite with steel slag, small thermal expansion coefficient and the like, but also solves the problems of poor wettability, poor dispersibility and easy oxidation of graphite, and can endow the carbon-containing refractory castable material with more excellent oxidation resistance and slag corrosion resistance. If the surface of the graphite is coated and modified by a physical or chemical method, a coating layer is generated on the surface of the graphite, and the problems of poor wettability and easy oxidation of the graphite can be greatly improved. The surface coating layer of the flake graphite mainly comprises oxides and carbides. Compared with the oxide coating layer, the carbide coating layer is continuous, has strong adhesive force and can not react with graphite at high temperature. The existing carbide coating technology is mainly a molten salt method. The self-propagating high-temperature synthesis method is rapid and efficient, simple in process, low in energy consumption, high in product purity and capable of keeping the shape characteristics of carbon particles in shape.

The invention relates to a graphite surface modification method for a carbon-containing refractory castable, which mainly comprises a titanium carbide coating layer and a crystalline flake graphite matrix. The titanium carbide coated flake graphite with good dispersibility, water wettability and oxidation resistance is prepared by adopting a self-propagating high-temperature synthesis method, and has important significance for improving the performance of the carbon-containing refractory castable. Titanium carbide has a smaller water wetting angle than crystalline flake graphite; and the titanium carbide has a higher affinity for oxygen than carbon, and can play a role in inhibiting carbon from being oxidized. Therefore, the graphite surface modification method for the carbon-containing refractory castable can effectively improve the wettability of graphite and improve the oxidation resistance of carbon, further endows the carbon-containing refractory castable with more excellent oxidation resistance and slag corrosion resistance, and makes great contribution to the field of the carbon-containing refractory castable.

The present invention will be described in detail below with reference to the drawings and embodiments, and the embodiments of the present invention are not to be considered limited to the description. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention. The scale graphite and the titanium powder provided by the invention are mixed according to the mass percentage, and the graphite for the novel carbon-containing refractory castable can be prepared by a self-propagating high-temperature synthesis method.