KR100604607B1 - Various efficiency modifiers of the reduction-carbonization process of tungsten oxide for the production of tungsten carbide for nanoparticles. - Google Patents

Abstract

The present invention relates to an efficiency improving agent for improving the efficiency in the reduction-carbonization process of tungsten oxide using carbon monoxide. In the process of producing ultrafine tungsten carbide using carbon monoxide in the reduction-carbonization process of tungsten oxide, various X and Y types of zeolites are mixed as an efficiency improving agent and carried out at a reaction temperature of 300 to 750 degrees Celsius. The efficiency of each efficiency improver was compared with the efficiency of a single tungsten oxide reduction-carbonization process. This improvement improves the use of carbon monoxide for the production of unit tungsten carbide, reduces heat consumption and operating time, resulting in a reduction of more than 50%. Cost-saving effects can be expected, enabling the production of tungsten carbide at low temperatures, maximizing the added value of the final product through the production of high quality nanoparticle tungsten carbide below 100nm.

Tungsten Oxide, Nanoparticles, Tungsten Carbide, Reduction Process, Carbonization Process                                                      

Description

Various efficiency modifiers of the reduction-carbonization process of tungsten oxide for the production of tungsten carbide for nanoparticles. {The various promoters for the reduction-carburization of WO3 by using carbon monoxide to manufacture the nano-particle WC}

Figure 1 is a table showing the relative efficiency value for each temperature calculated by measuring the efficiency improvement effect of the efficiency improving agent at each temperature in the reduction-carbonization process of tungsten oxide of the present invention and the effect on zeolite NaX as 100.

2 is a particle size table of tungsten carbide prepared at various temperatures for the use of an efficiency improving agent in the reduction-carbonization process of tungsten oxide of the present invention.

Figure 3 is produced by mass-spectroscopy of the reaction efficiency of the representative zeolite HX, NaX and KX addition and the reaction efficiency in the tungsten oxide alone experiment that was excellent in the efficiency-improving agent of the tungsten oxide reduction-carbonization process of the present invention It is a graph showing the amount of carbon dioxide produced.

The present invention relates to a method for improving efficiency of a reduction-carbonization process of tungsten oxide, and more particularly, to maximize production efficiency by using an efficiency improving agent in a process of producing tungsten carbide by reducing-carbonization of tungsten oxide with carbon monoxide. The particle size of the tungsten carbide product is intended to maximize added value by using nanoparticles.

High density, high hardness tungsten carbide is used in various industrial fields. It is widely used as a raw material for cemented carbide tools, wear-resistant mechanical parts, and sintered base materials, and the demand is rapidly increasing. In particular, tungsten carbide of nanoparticles is used in various processes such as polishing and polishing processes in the semiconductor industry.

Such tungsten carbide has conventionally produced tungsten carbide by reducing-carbonizing tungsten oxide in one-step using carbon monoxide.

According to the present invention, tungsten carbide is obtained through carbonization at a high temperature through a one-step process using carbon monoxide and hydrogenation using hydrogen in the process of producing tungsten carbide by reducing-carbonizing the conventional tungsten oxide. It can be divided into two-step process. The one-step process using carbon monoxide can be carbonized at low temperatures, which is advantageous for the production of fine tungsten carbide, but has a disadvantage of low economical efficiency due to lower efficiency and higher carbon monoxide than the two-step process.

Therefore, the present invention compensates the disadvantages of the present by presenting a variety of efficiency improving agent in the reduction-carbonization process of tungsten oxide using carbon monoxide, and compared with the efficiency improving agent proposed to date, the efficiency is better than the current efficiency improving agent Present the improver.

In order to achieve the above object, the efficiency improving agent added for improving the efficiency of the reduction-carbonization process using carbon monoxide of tungsten oxide of the present invention is zeolite NaX and zeolite HX, zeolite LiX, zeolite KX, zeolite CsX, Zeolite MgX, zeolite CaX and zeolite NaY and zeolite HY, zeolite LiY, zeolite KY, zeolite CsY, zeolite MgY, zeolite CaY and the like prepared by ion exchange were used.

The tungsten carbide produced at the reaction temperature of 650 ℃ by the use of the efficiency improving agent in the above it is another feature of the present invention that the particles are 100 nm or less.

The efficiency improving agent is not limited to tungsten oxide, but may be used in a process of reducing Ta, Ti, Si, Mo, V, Nb, and Zr oxides to carbonization or metal.

With reference to the accompanying drawings, the experimental method and the efficiency improvement effect of the efficiency improving agent of the tungsten oxide reduction-carbonization process of the present invention will be described in more detail.

1 is a table showing the temperature-specific efficiency calculated on the basis of the effect on the zeolite NaX efficiency of the efficiency improving agent in the reduction-carbonization process of the tungsten oxide of the present invention based on 100 and Figure 2 is a reduction of the tungsten oxide of the present invention The particle size table of tungsten carbide prepared at the filter temperature for the efficiency improving agents of the carbonization process. 3 is an electric furnace for comparing the reaction efficiency of the representative zeolite HX, NaX and KX addition in the efficiency-improving agent of the tungsten oxide reduction-carbonization process of the present invention and the reaction efficiency in the tungsten oxide alone experiment The graph shows a comparison of the amount of carbon dioxide produced using a mass-spectroscopy analysis device connected on-line while the reaction proceeds in a U-shaped reactor.

The efficiency improving agent of the reduction-carbonization process of the tungsten oxide of the present invention aims at increasing the efficiency of the process and lowering the light-off temperature at which the reduction-carbonization reaction is initiated to enable the production of tungsten carbide of nano-particles. It demonstrates with the Example according to a specific experiment.

Experimental Example 1

To 25 g of tungsten oxide, each of the efficiency improving agents of the following examples was added at the same weight as the weight of tungsten oxide, mounted in a 1 inch alumina reactor, 75 ml of carbon monoxide, and 25 ml of helium as a reference for accurate analysis of gas chromatography. / min is introduced into the reactor.

The reaction temperature at this time was from 300 to 750 degrees Celsius and the temperature increase rate was 2 degrees Celsius / min. And the experiment on the particle size change of tungsten carbide according to the temperature change was carried out, the reaction gas conditions are the same as the above conditions, but the experiment was carried out for 5 hours by changing the reaction temperature as 650, 700, 750 degrees Celsius.

Since the product is a powder, in order to facilitate the separation of the product and the efficiency improving agent, all efficiency improving agents were used having a particle size of 1 mm or more in diameter.

The gas components after the reaction were analyzed and calculated on-line by gas chromatography (manufactured by Shimadzu Corporation, using GC-14B TCD), and the particle size was measured using a scanning microscope for all the produced tungsten carbides.

Experimental Example 2

In order to determine in more detail the efficiency increase of the efficiency improving agent showed an excellent reaction efficiency in Experimental Example 1 was carried out through mass-spectroscopy analysis. The experiment was carried out to 725 degrees Celsius while heating the temperature from 300 degrees Celsius to 1 degree Celsius by using a temperature control electric furnace equipped with a U-shaped quartz reactor by mixing 100mg of the efficiency improver 100mg tungsten.

In particular, the generated carbon dioxide gas at the outlet was automatically analyzed by on-line mass spectroscopy.

In this case, only 50 ml / min of carbon monoxide was used, and the efficiency improving agent used was a powdery material to facilitate mixing.

Example 1

Tungsten oxide alone without the efficiency improving agent was carried out under the conditions of Experimental Example 1.

Example 2

The experiment was performed under the conditions of Experimental Example 1 using Zeolite HX as an efficiency improving agent.

Example 3

The experiment was performed under the conditions of Experimental Example 1 using Zeolite LiX as an efficiency improving agent.

Example 4

The experiment was performed under the conditions of Experimental Example 1 using Zeolite NaX as an efficiency improving agent.

Example 5

The experiment was performed under the conditions of Experimental Example 1 using Zeolite KX as an efficiency improving agent.

Example 6

The experiment was performed under the conditions of Experimental Example 1 using Zeolite CsX as an efficiency improving agent.

Example 7

The experiment was performed under the conditions of Experimental Example 1 using Zeolite MgX as an efficiency improving agent.

Example 8

The experiment was performed under the conditions of Experimental Example 1 using Zeolite CaX as an efficiency improving agent.

Example 9

The experiment was performed under the conditions of Experimental Example 1 using Zeolite HY as an efficiency improving agent.

Example 10

The experiment was performed under the conditions of Experimental Example 1 using Zeolite LiY as an efficiency improving agent.

Example 11

The experiment was performed under the conditions of Experimental Example 1 using Zeolite NaY as an efficiency improving agent.

Example 12

The experiment was performed under the conditions of Experimental Example 1 using Zeolite KY as an efficiency improving agent.

Example 13

The experiment was performed under the conditions of Experimental Example 1 using Zeolite CsY as an efficiency improving agent.

Example 14

The experiment was performed under the conditions of Experimental Example 1 using Zeolite MgY as an efficiency improving agent.

Example 15

The experiment was performed under the conditions of Experimental Example 1 using Zeolite CaY as an efficiency improving agent.

Example 16

Tungsten oxide alone was performed under the conditions of Experimental Example 2 without an efficiency improving agent.

Example 17

The experiment was performed under the conditions of Experimental Example 2 using Zeolite HX as an efficiency improving agent.

Example 18

The experiment was performed under the conditions of Experimental Example 2 using Zeolite NaX as an efficiency improving agent.

Example 19

The experiment was performed under the conditions of Experimental Example 2 using Zeolite KX as an efficiency improving agent.

In the above embodiment,

FIG. 1 shows that the modified zeolites X and Y show better efficiencies than tungsten oxide alone, especially in the zeolites of X-type including zeolite HX.

In addition, FIG. 2 is a table in which the particle size of the produced tungsten carbide after each efficiency improvement additive experiment experimented under the conditions of Experimental Example 1 was examined by scanning microscope analysis, regardless of the type of efficiency improvement agent at the same temperature. It can be seen that the production of tungsten oxide is significantly smaller than the tungsten carbide particle size.

FIG. 3 is a graph showing the amount of carbon dioxide generated in the zeolite X-types showing excellent reaction characteristics in FIG. 1 under the conditions of Experimental Example 2 for HX, NaX, KX and tungsten oxide alone and analyzed by mass-spectroscopy. As a graph showing the trend, when the efficiency improving agent is used, the reaction starts at 300 degrees Celsius and the reaction efficiency at each temperature point is superior to that of the tungsten oxide alone.

In the above, the production of tungsten carbide using tungsten oxide and carbon monoxide has been exemplarily described, but for the same reason,

It is apparent that the carbide or metal powder can be produced by carbonizing or reducing the oxides of Ta, Ti, Si, Mo, V, Nb and Zr, which are analogous materials, instead of the above-mentioned tungsten oxide. Of course, the features are applied as it is.

Reduction-carbonization process of the tungsten oxide of the present invention as described above is zeolite HX, zeolite LiX, zeolite KX, zeolite CsX, zeolite MgX, zeolite CaX and zeolite NaY and ion exchange produced by low-cost zeolite NaX and ion exchange it By using synthetic zeolites such as zeolite HY, zeolite LiY, zeolite KY, zeolite CsY, zeolite MgY, zeolite CaY, etc., the reaction efficiency is increased and the particle size is greatly reduced to improve the physical properties. It is a useful invention that can be manufactured and the efficiency improving agent can be used repeatedly is more effective in reducing the process cost.

Claims (3)

In the process of producing tungsten carbide through the reduction-carbonization process of tungsten oxide using carbon monoxide, The process is zeolite NaX and zeolite HX, zeolite LiX, zeolite KX, zeolite CsX, zeolite MgX, zeolite CaX and zeolite NaY prepared by ion exchange and zeolite HY, zeolite LiY, zeolite KY, zeolite CsY Reducing-carbonization process of tungsten oxide, comprising mixing at least one of the zeolite MgY, zeolite CaY synthetic zeolite with a reaction temperature of 300 to 800 degrees Celsius. The tungsten oxide reduction-carbonization process according to claim 1, wherein the particle distribution of tungsten carbide produced by the process using the efficiency improving agent is 30 to 500 nm. In the process of preparing metal carbides of Ta, Ti, Si, Mo, and V oxides through a reduction-carbonization process using carbon monoxide, the process is zeolite HX, zeolite LiX, zeolite KX, zeolite CsX, zeolite MgX, zeolite CaX And a reduction-carbonation process for improving reaction efficiency by mixing at least one of zeolite NaY and zeolite HY, zeolite LiY, zeolite KY, zeolite CsY, zeolite MgY, and zeolite CaY prepared by ion exchange with the metal oxide.

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