CN103466621B - The method that titanium source and carbon source prepare TiC powder is respectively with tetrabutyl titanate and pitch - Google Patents

Abstract

The invention discloses a method for preparing TiC powder by using tetrabutyl titanate and pitch as titanium source and carbon source respectively. Weigh tetrabutyl titanate and asphalt according to the mass ratio of 1:5~8, first dissolve the asphalt in absolute ethanol, and then add tetrabutyl titanate to stir and mix to obtain a mixed solution in which the liquid phase is uniformly mixed; mix The solution was dried at 100-150°C for 36-48 hours to obtain a precursor; the precursor was heated to 1500-2000°C under the protection of a hydrogen atmosphere, and kept for 1-2 hours for carbothermal reduction to obtain TiC powder; The purity of the above-mentioned chemical reagents and raw materials are industrial grade and above; the composition of the prepared TiC powder is controlled by the proportion of raw materials added, and the purity and particle size are determined by the order of addition and the preparation process. The method of the invention has the advantages of uniform mixing of raw materials, simple process, low synthesis temperature, short synthesis time, energy saving and environmental protection, and the like.

Description

Method for preparing TiC powder with tetrabutyl titanate and pitch as titanium source and carbon source respectively

technical field

The invention belongs to the technical field of TiC powder preparation, in particular to a method for preparing TiC powder by using tetrabutyl titanate and pitch as titanium source and carbon source respectively.

Background technique

TiC has the characteristics of high melting point, high hardness, high wear resistance and special functionality. It is not only widely used in abrasive tools, cutting tools and reinforcements of composite materials, but also widely used as energy materials, such as nuclear energy materials. Utilization, TiC coating materials can resist H ⁺ ion radiation and resist large temperature gradients and thermal cycles. The anti-tritium permeation layer of these coating materials has stable performance for a long time. In terms of infrared radiation ceramic materials, the cordierite structure TiC is not only introduced as a conductive phase, but also has excellent near-infrared radiation characteristics, and has broad application prospects in new composite electrical contact materials.

The development of modern energy industry urgently needs ultra-fine TiC powder. Traditionally, TiC powder is synthesized by mixing TiO ₂ and carbon solid phase at high temperature. Titanium compounds are used as raw materials and prepared by vapor deposition, plasma heating and other processes. The cost of raw materials and processes is high, which makes ultrafine TiC powder expensive. It is very meaningful to research and apply new technologies for preparing ultrafine TiC at low cost.

At present, most of the TiC powder produced in large-scale industrialization is 2~5μm. With the development of modern industry, especially the development of energy industry, the demand for ultra-fine TiC powder is increasing, and ultra-fine TiC has higher application value. The prospect is broad, but the ultra-fine TiC powder currently available in the market is expensive because of the high cost of raw materials and preparation process. Therefore, the research on low-cost preparation of ultra-fine TiC powder has great practical significance.

The preparation of ultrafine TiC powder is a hotspot of research by material scientists. The research aspects include both raw materials and processes, but different methods have their advantages and disadvantages for industrial production.

The direct carbonization method uses elemental carbon and metal titanium powder (or TiH ₂ ) as raw materials. Under high temperature, inert atmosphere or vacuum, the reactants directly contact and react to form TiC. The product has high purity, large carbon metering ratio, and the process is simple. However, the price of titanium powder is expensive, and the preparation of ultra-fine titanium powder is difficult; the reaction process is difficult to control, and the synthesized TiC needs to be further pulverized and broken, resulting in a decrease in the purity of the product, and further purification is required, so that this method can prepare ultra-fine TiC powder It has not been widely promoted.

The carbothermal reduction method is a traditional method for the industrial production of TiC powder. In this process, TiO ₂ is used as the titanium source, and graphite, carbon black, activated carbon, etc. are used as the C source. Under high temperature and protective atmosphere, TiO ₂ is reduced by C to form TiC powder. , the advantages are: low cost of raw materials; simple process, high production efficiency; the particle size of TiC is micron level, but the uniformity of raw materials is poor through mechanical mixing; the remaining carbon black is processed by combustion method, and TiC is also easily oxidized; as far as the current From the perspective of production technology, the synthesized powder cannot fully meet the requirements of fine ceramics in terms of particle size and purity.

There are other methods to prepare ultrafine TiC, but generally speaking, there are high raw material requirements such as high-purity metal titanium powder, organic compounds of titanium, etc.; the synthesis process is complicated, such as plasma heating, microwave heating, vapor deposition, etc., equipment High-level requirements, complex preparation methods or processes, or limited output lead to high costs. The development of high-efficiency, low-cost TiC ultrafine powder preparation technology is still the focus of research by scientists and business circles in various countries.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for preparing TiC powder with tetrabutyl titanate and pitch as titanium source and carbon source respectively.

The specific steps are:

(1) Weigh tetrabutyl titanate and asphalt according to the mass ratio of 1:5~8, first dissolve the asphalt in absolute ethanol, and then add tetrabutyl titanate to stir and mix to obtain a mixed liquid phase uniformly mixed liquid.

(2) Dry the mixed solution prepared in step (1) at 100-150° C. for 36-48 hours to obtain a precursor.

(3) Heating the precursor prepared in step (2) to 1500-2000°C under the protection of a hydrogen atmosphere, and keeping it warm for 1-2 hours for carbothermal reduction to obtain TiC powder.

The purity of the chemical reagents and raw materials are industrial grade and above.

The composition of the TiC powder prepared by the invention is controlled by the ratio of the added raw materials, and the purity and particle size of the powder are jointly determined by the order of addition and the preparation process.

The advantage of the inventive method:

(1) Using pitch as the carbon source and tetrabutyl titanate as the titanium source, high-purity, ultrafine TiC was prepared at low cost through carbothermal reduction.

(2) Compared with the traditional method of preparing TiC, it has the advantages of uniform raw material mixing, simple process, low synthesis temperature, short synthesis time, energy saving and environmental protection.

detailed description

Example:

(1) Weigh 1 gram of tetrabutyl titanate and 6.5 grams of asphalt, first dissolve the asphalt in absolute ethanol, and then add tetrabutyl titanate to stir and mix to obtain a mixed solution in which the liquid phase is uniformly mixed.

(2) Dry the mixed solution prepared in step (1) at 125° C. for 42 hours to prepare a precursor.

(3) Heat the precursor prepared in step (2) to 1850°C under the protection of a hydrogen atmosphere, and keep it warm for 1 hour and 20 minutes for carbothermal reduction to obtain TiC powder. The obtained TiC powder is analyzed by particle size test. Ultrafine TiC powder with a diameter of 150-300 nanometers.

The purity of the chemical reagents and raw materials are all industrial grade.

Claims (2)

1. prepare a method for TiC powder, it is characterized in that concrete steps are:

(1) take tetrabutyl titanate and pitch according to mass ratio 1:5-8, first pitch is dissolved in dehydrated alcohol, and then add tetrabutyl titanate and be uniformly mixed, the mixed solution of obtained even in liquid phase mixing;

(2) by mixed solution dry 36-48 hour at 100-150 DEG C that step (1) is obtained, obtained presoma;

(3) presoma obtained for step (2) is heated to 1500-2000 DEG C under nitrogen atmosphere protection, is incubated and carries out carbothermic reduction in 1-2 hour, be i.e. obtained TiC powder;

The purity of above raw material is technical grade and above purity.

2. the method preparing TiC powder according to claim 1, is characterized in that: the composition of obtained TiC powder is by the burden control adding raw material, and the purity of powder and granularity are determined jointly by order of addition(of ingredients) and preparation technology.