A method for preparing titanium carbide powder

Abstract

The present invention relates to a method for preparing titanium carbide powder, and belongs to the technical field of metallurgy and hard alloy preparation. The present invention uses titanium dioxide powder and calcium carbide as main raw materials, mixes them evenly in a certain proportion, presses them into tablets, and calcines them under the protection of argon. Because calcium carbide has high reducibility and reaction activity, the preparation method can undergo a reduction reaction at a relatively low calcination temperature, remove oxygen from titanium dioxide and form titanium carbide and calcium oxide. The product is crushed, washed, and calcium oxide and other impurities are removed to obtain high-purity titanium carbide powder. The titanium carbide preparation method proposed in the present invention can effectively control the impurity content in titanium carbide because of its simple raw material composition, and the experimental equipment is simple and the operation is easy to control, so it has high production efficiency and economic benefits, and is suitable for mass production.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy and hard alloy preparation, and particularly relates to a method for preparing titanium carbide powder. Background Art

[0002] Titanium carbide has the characteristics of high melting point (3065-3275℃), high hardness, high wear resistance, low resistance (60-250μΩ·cm), good thermal conductivity and high thermal shock resistance. When it is used in cutting tools, it can significantly improve the cutting performance of cutting tools, reduce their weight and increase their durability. In addition, titanium carbide is also widely used as a reinforcement for polishing pastes, abrasive tools, anti-fatigue materials and composite materials, as a surface coating to improve the wear resistance of materials, and as a filler for plastics and rubber.

[0003] At present, the methods for synthesizing titanium carbide mainly include: (1) carbon thermal reduction of titanium dioxide with carbon or carbon-containing organic matter. Patent CN109231209A discloses a method for preparing titanium carbide, in which titanium tetrachloride and alkane are mixed in a closed container, and reacted at 1050-1190°C under airtight conditions to obtain titanium carbide powder. The method of the present invention can effectively reduce the impurity content in titanium carbide. (2) Sol-gel method is used to prepare a polymer precursor of inorganic matter and carbon-containing organic matter, and then carbon thermal reduction is used to prepare titanium carbide powder; Patent CN111675221A discloses a method for preparing titanium carbide hollow spheres, which uses Ti3AlC2 powder as a precursor to prepare a dispersion of few-layer titanium carbide nanosheets, and then rapidly freezes titanium carbide of different concentrations in liquid nitrogen, and then uses freeze-drying method to prepare titanium carbide hollow spheres. (3) Direct reaction of titanium and carbon (SHS or MA method).

[0004] The above methods all have the problems of high production cost and low yield when preparing titanium carbide, and the preparation is only suitable for laboratory research and some are limited to the preparation of titanium carbide protective film. Summary of the invention

[0005] The object of the present invention is to provide a method for preparing titanium carbide powder, so as to achieve low-temperature and high-efficiency preparation of titanium carbide powder.

[0006] The present invention is achieved by the following technical scheme: A method for preparing titanium carbide powder, using titanium dioxide and calcium carbide as raw materials, calcining under argon protection to obtain titanium carbide powder, specifically comprising the following steps:

[0007] (1) titanium dioxide and calcium carbide are uniformly mixed in a mass ratio of 1:1 to 1:2, and pressed into a block at a pressure of 3 to 8 MPa;

[0008] (2) sintering the block prepared in step (1) at 600-800° C. for 1-3 h under argon protection;

[0009] (3) grinding the reaction product obtained in step (2) into powder; because calcium carbide easily reacts with water to generate acetylene, a saturated sodium chloride solution needs to be prepared in advance to remove excess calcium carbide in the raw material and control the reaction rate; under ventilation conditions, slowly pour the calcium carbide into the saturated sodium chloride solution for washing, and slowly stir for 0.5 to 2 hours;

[0010] (4) filtering and separating the product in step (3) to obtain an leaching solution and a solid product, and stirring and leaching the solid product in a hydrochloric acid solution with a pH range of 0.5 to 1 for 4 to 8 hours, and controlling the stirring speed to be 300 to 500 r / min;

[0011] (5) The solid product in step (4) is filtered and repeatedly washed with deionized water and anhydrous ethanol until the filtrate is neutral, and the filter cake is dried at 40-80° C. for 8-16 h to obtain titanium carbide powder.

[0012] The particle size of the raw titanium dioxide and calcium carbide powders in step (1) is 300-500 meshes.

[0013] The heating rate of sintering in step (2) is 5°C / min.

[0014] The liquid-to-solid ratio during washing in step (3) is greater than 10:1.

[0015] During the stirring leaching in step (4), the liquid-to-solid ratio is greater than 15:1.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] (1) Simple process and short flow. The present invention uses titanium dioxide as raw material, adds calcium carbide and directly heat treats to prepare titanium carbide. Compared with the titanium carbide preparation method currently used in industry, this method has the advantages of simple process, short preparation flow, easy control of reaction process, simple operation, etc.

[0018] (2) High product quality. The raw material components used in the preparation of titanium carbide in the present invention are relatively simple, the introduction of impurities is avoided during the reaction, and the reduction process is easy to control, thereby obtaining high-quality titanium carbide powder with low impurity content such as oxygen and nitrogen.

[0019] (3) Low cost. Compared with the currently used titanium carbide preparation method, the present invention prepares titanium carbide by direct reaction of calcium carbide and titanium dioxide. Since titanium carbide has strong reactivity, the reaction temperature can be significantly reduced, and ultimately, while achieving product quality, energy consumption and raw material costs are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the process flow of the present invention. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the embodiments.

[0022] Example 1

[0023] (1) titanium dioxide with a particle size of 300-500 mesh and calcium carbide are uniformly mixed in a mass ratio of 1:1, and pressed into a block under a pressure of 3 MPa;

[0024] (2) placing the block prepared in step (1) in a graphite crucible, and placing it in a sintering furnace, and sintering at 700° C. for 3 h at a heating rate of 5° C. / min under argon protection;

[0025] (3) grinding the reaction product obtained in step (2) into powder in an agate mortar; because calcium carbide easily reacts with water to generate acetylene, a saturated sodium chloride solution needs to be prepared in advance to remove excess calcium carbide in the raw material and control the reaction rate; under ventilation conditions, slowly pour the calcium carbide into the saturated sodium chloride solution for washing, and slowly stir for 1 hour, and the liquid-to-solid ratio during washing is greater than 10:1;

[0026] (4) filtering and separating the product in step (3) to obtain a leachate and a solid product, and stirring and leaching the solid product in a hydrochloric acid solution with a pH range of 0.5 for 4 hours, controlling the stirring speed to 300 r / min, and the liquid-to-solid ratio during stirring and leaching is greater than 16:1;

[0027] (5) The solid product in step (4) is filtered and repeatedly washed with deionized water and anhydrous ethanol until the filtrate is neutral, and the filter cake is placed in a vacuum drying oven and dried at 40° C. for 16 h to obtain titanium carbide powder.

[0028] Example 2

[0029] (1) titanium dioxide with a particle size of 300-500 mesh and calcium carbide are uniformly mixed in a mass ratio of 1:1.5, and pressed into a block under a pressure of 5 MPa;

[0030] (2) placing the block prepared in step (1) in a graphite crucible, and placing it in a sintering furnace, and sintering at 700° C. for 2 h at a heating rate of 5° C. / min under argon protection;

[0031] (3) grinding the reaction product obtained in step (2) into powder in an agate mortar; because calcium carbide easily reacts with water to generate acetylene, a saturated sodium chloride solution needs to be prepared in advance to remove excess calcium carbide in the raw material and control the reaction rate; under ventilation conditions, slowly pour the calcium carbide into the saturated sodium chloride solution for washing, and slowly stir for 2 hours, and the liquid-to-solid ratio during washing is greater than 10:1;

[0032] (4) filtering and separating the product in step (3) to obtain a leachate and a solid product, and stirring and leaching the solid product in a hydrochloric acid solution with a pH range of 1 for 6 hours, controlling the stirring speed to 400 r / min, and the liquid-to-solid ratio during stirring and leaching is greater than 15:1;

[0033] (5) The solid product in step (4) is filtered and repeatedly washed with deionized water and anhydrous ethanol until the filtrate is neutral, and the filter cake is placed in a vacuum drying oven and dried at 60° C. for 12 h to obtain titanium carbide powder.

[0034] Example 3

[0035] (1) titanium dioxide with a particle size of 300-500 mesh and calcium carbide are uniformly mixed in a mass ratio of 1:2, and pressed into a block under a pressure of 8 MPa;

[0036] (2) placing the block prepared in step (1) in a graphite crucible, and placing it in a sintering furnace, and sintering at 600° C. for 3 h at a heating rate of 5° C. / min under argon protection;

[0037] (3) grinding the reaction product obtained in step (2) into powder in an agate mortar; because calcium carbide easily reacts with water to generate acetylene, a saturated sodium chloride solution needs to be prepared in advance to remove excess calcium carbide in the raw material and control the reaction rate; under ventilation conditions, slowly pour the calcium carbide into the saturated sodium chloride solution for washing, and slowly stir for 0.5h, and the liquid-to-solid ratio during washing is greater than 10:1;

[0038] (4) filtering and separating the product in step (3) to obtain a leachate and a solid product, and stirring and leaching the solid product in a hydrochloric acid solution with a pH range of 1 for 8 hours, controlling the stirring speed to 500 r / min, and the liquid-to-solid ratio during stirring and leaching is greater than 15:1;

[0039] (5) The solid product in step (4) is filtered and repeatedly washed with deionized water and anhydrous ethanol until the filtrate is neutral, and the filter cake is placed in a vacuum drying oven and dried at 80° C. for 8 h to obtain titanium carbide powder.

[0040] Example 4

[0041] (1) titanium dioxide with a particle size of 300-500 mesh and calcium carbide are uniformly mixed in a mass ratio of 1:1.5, and pressed into a block under a pressure of 5 MPa;

[0042] (2) placing the block prepared in step (1) in a graphite crucible, and placing it in a sintering furnace, and sintering at 800° C. for 1 h at a heating rate of 5° C. / min under argon protection;

[0043] (3) grinding the reaction product obtained in step (2) into powder in an agate mortar; because calcium carbide easily reacts with water to generate acetylene, a saturated sodium chloride solution needs to be prepared in advance to remove excess calcium carbide in the raw material and control the reaction rate; under ventilation conditions, slowly pour the calcium carbide into the saturated sodium chloride solution for washing, and slowly stir for 1 hour, and the liquid-to-solid ratio during washing is greater than 10:1;

[0044] (4) filtering and separating the product in step (3) to obtain a leachate and a solid product, and stirring and leaching the solid product in a hydrochloric acid solution with a pH range of 1 for 6 hours, controlling the stirring speed to 400 r / min, and the liquid-to-solid ratio during stirring and leaching is greater than 15:1;

[0045] (5) The solid product in step (4) is filtered and repeatedly washed with deionized water and anhydrous ethanol until the filtrate is neutral, and the filter cake is placed in a vacuum drying oven and dried at 60° C. for 12 h to obtain titanium carbide powder.

[0046] Comparative Example 1: The method in patent application CN103193231A was used.

[0047] Comparative Example 2: The method in patent application CN111675221A was used.

[0048] Comparative Example 3: The method in patent application CN109231209A was used.

[0049] Comparative Example 4: The method in patent application CN105200458A was used.

[0050] Comparative Example 5: The method in patent application CN165439146A was used.

[0051] Table 1 Comparison of the preparation methods of titanium carbide materials disclosed in Example 2 and some patents

[0052]

[0053]

[0054] Note: “-” means that the literature does not provide the corresponding data.

[0055] It can be seen from the above table that the present application directly synthesizes titanium carbide powder using TiO2 and CaC2 as raw materials. Compared with the process using TiCl4 as raw material, the present method can effectively simplify the preparation process, that is, it eliminates the chlorination process of TiO2, avoids the use of harmful gas chlorine, and the product has a higher purity; in addition, compared with the electrolytic method for preparing titanium carbide, the present method can effectively reduce energy consumption, shorten the reaction time and simplify the reaction process; finally, compared with the process of preparing titanium carbide using TiO2, carbonaceous material and metal reducing agent as raw materials, the present method can significantly reduce the reaction temperature, and can obtain a titanium carbide product with a higher purity while reducing energy consumption.

Claims

1. A method for preparing titanium carbide powder, characterized in that The specific steps include: (1) Titanium dioxide and calcium carbide are uniformly mixed in a mass ratio of 1:1 to 1:2, and pressed into a block at a pressure of 3 to 8 MPa; (2) sintering the block prepared in step (1) at 600-800° C. for 1-3 h under argon protection; (3) Grinding the reaction product obtained in step (2) into powder; slowly pouring the calcium carbide into a saturated sodium chloride solution for washing under ventilation conditions, and slowly stirring for 0.5 to 2 hours; (4) filtering and separating the product in step (3) to obtain a leachate and a solid product, and stirring and leaching the solid product in a hydrochloric acid solution with a pH range of 0.5 to 1 for 4 to 8 hours, and controlling the stirring speed to 300 to 500 r / min; (5) filtering the solid product in step (4) and repeatedly washing with deionized water and anhydrous ethanol until the filtrate is neutral, and drying the filter cake at 40-80° C. for 8-16 h to obtain titanium carbide powder; The particle size of the raw titanium dioxide and calcium carbide powders in step (1) is 300-500 mesh; the heating rate of sintering in step (2) is 5°C / min; the liquid-to-solid ratio during washing in step (3) is greater than 10:1; and the liquid-to-solid ratio during stirring and leaching in step (4) is greater than 15:1.

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