Blue tungsten powder with low oxygen index, needle-shaped surface and high specific surface area

Abstract

Main performance index parameters of the blue tungsten powder are as follows: the oxygen index of the blue tungsten powder is 2.90-2.94, the microcosmic surface of blue tungsten powder particles is in a shape of being full of fine needle-shaped tungsten oxide, the specific surface area of the blue tungsten powder reaches 10-14 m < 2 > / g, and the surface area of the blue tungsten powder is 10-14 m < 2 > / g. The method is suitable for producing high-quality fine, superfine and nano-particle tungsten powder, tungsten carbide powder, corresponding hard alloy and other products.

Description

Technical Field

[0001] The invention relates to the field of preparation of tungsten oxide, in particular to a blue tungsten powder with a low oxygen index and a needle-shaped surface and a high specific surface area. Background Art

[0002] With the development and progress of high-end fine, ultrafine and nano cemented carbides at home and abroad, the high-end demand for raw materials is becoming more and more stringent, especially the demand for the stability of micro-morphology and microstructure is becoming stronger and stronger. A special purple tungsten product specially used for the production of ultrafine nano tungsten powder has an oxygen index of about 2.72. The low oxygen index can reduce the difficulty of hydrogen reduction; the surface of the microscopic particles of purple tungsten is needle-shaped, and the needle-shaped morphology is easy to break into many uniform small grains after reduction, reducing the agglomeration of tungsten powder, thereby improving the quality of tungsten powder, but the specific surface area of ​​purple tungsten is not high, resulting in insufficient permeability from the surface to the inside, and the reduction effect of internal tungsten oxide is limited; therefore, most manufacturers in the industry usually use high specific surface area blue tungsten to replace purple tungsten to produce ultrafine nano tungsten powder. However, the oxygen index of traditional high specific surface area blue tungsten is generally between 2.95-2.98. The higher the oxygen index, the greater the difficulty of hydrogen reduction, and its microscopic surface morphology is generally a flat plate with a few cracks. The flat plate without cracks is not conducive to the entry of hydrogen and the reaction with the oxygen atoms inside the particles. This shows that it is difficult for traditional high specific surface area blue tungsten to achieve a significant reduction in oxygen index and the simultaneous existence of a needle-like surface microstructure.

[0003] Low oxygen index can not only reduce the proportion of oxidation volatilization deposition growth in the blue tungsten reduction process, but also effectively reduce the hydrogen consumption and power consumption levels; the needle-shaped micro-morphology on the surface can improve the micro-morphology fineness of fine-grained tungsten powder, and the needle-shaped morphology is easy to break into many uniform small grains after reduction, reducing the agglomeration of tungsten powder, thereby improving the quality of tungsten powder and promoting hydrogen permeation reduction; high specific surface area fine blue tungsten is conducive to accelerating the hydrogen permeation rate, improving the hydrogen reduction efficiency, and increasing the water discharge rate, reducing the water volatilization deposition growth ratio. Therefore, the present invention provides a low oxygen index surface needle-shaped high specific surface area blue tungsten powder, which is suitable for producing high-quality fine, ultrafine and nano-particle tungsten powder, tungsten carbide powder and corresponding cemented carbide products. Summary of the invention

[0004] The object of the present invention is to provide a blue tungsten powder with a low oxygen index and a needle-shaped surface and a high specific surface area.

[0005] The oxygen index of the low oxygen index surface needle-shaped high specific surface area blue tungsten powder is 2.90-2.94, and the microscopic surface is fine needle-shaped tungsten oxide with a specific surface area of ​​10-14m 2 / g.

[0006] The present invention provides a low oxygen index surface needle-shaped high specific surface area blue tungsten powder, which has the following beneficial effects: The invention provides a blue tungsten powder with a low oxygen index, a needle-shaped surface and a high specific surface area, which has three characteristics of low oxygen index, needle-shaped surface and high specific surface area, and is suitable for producing high-quality fine, ultrafine and nano-particle tungsten powder, tungsten carbide powder and corresponding cemented carbide products. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 This is a 1000-fold magnification of a blue tungsten powder with a low oxygen index and a high specific surface area and a scanning electron microscope; Figure 2 This is a 10,000-fold magnified image of a blue tungsten powder with a low oxygen index and a high specific surface area and a needle shape provided in Example 1 of the present invention; Figure 3 This is a 1000-fold magnified image of a blue tungsten powder with a low oxygen index and a high specific surface area and a needle shape provided by Example 2 of the present invention; Figure 4 This is a 10,000-fold magnified image of a blue tungsten powder with a low oxygen index and a high specific surface area and a needle shape provided by Example 2 of the present invention; Figure 5 This is a 1000-fold magnified image of a blue tungsten powder with a low oxygen index and a high specific surface area and a needle shape provided by Example 3 of the present invention; Figure 6 This is a 10,000-fold magnified image of a blue tungsten powder with a low oxygen index and a high specific surface area and a needle shape provided by Example 3 of the present invention; Figure 7 This is a 1000-fold magnified image of a blue tungsten powder with a low oxygen index and a high specific surface area and a needle shape provided by Example 4 of the present invention; Figure 8 This is a 10,000-fold magnified image of a blue tungsten powder with a low oxygen index and a high specific surface area and a needle shape provided by Example 4 of the present invention; Fig. 9 This is a 1000-fold magnified image of a blue tungsten powder with a low oxygen index and a high specific surface area and a needle shape provided by Example 5 of the present invention; Fig.10 This is a 10,000-fold magnified image of a blue tungsten powder with a low oxygen index and a high specific surface area and a needle shape provided by Example 5 of the present invention; Fig.11 This is a 1000-fold magnified image of a blue tungsten powder with a low oxygen index and a high specific surface area and a needle shape provided by Example 6 of the present invention; Fig.12 This is a 10,000-fold magnified image of a blue tungsten powder with a low oxygen index and a high specific surface area and a needle shape provided by Example 6 of the present invention; Fig.13 This is a 1000-fold magnified image of a blue tungsten powder with a needle-shaped surface and a high specific surface area and a low oxygen index provided by Example 7 of the present invention; Fig.14 This is a 10,000-fold magnified scanning electron microscope image of the low oxygen index surface needle-shaped high specific surface area blue tungsten powder provided in Example 7 of the present invention. DETAILED DESCRIPTION

[0008] In order to make the purpose and effect of the present invention easy to understand, the following is a further description of the needle-shaped blue tungsten powder with low oxygen index and high specific surface area provided by the present invention in combination with specific embodiments.

[0009] Example 1

[0010] First, the ammonium paratungstate raw material is placed in a rotary calcining furnace, and then the corresponding furnace temperature, feeding frequency, furnace rotation frequency, negative pressure and other process parameters are adjusted. After continuous calcination in the rotary furnace for a certain period of time, it is cooled by cooling water at the tail of the furnace, and then taken out of the furnace from the tail of the furnace. After that, it is sieved by a sieve machine, and finally a low oxygen index surface needle-shaped high specific surface area blue tungsten powder is obtained.

[0011] The provided low oxygen index surface needle-shaped high specific surface area blue tungsten powder has an oxygen index of 2.92 and a specific surface area of ​​11.46m 2 / g, the specific parameters are shown in Table 1, and Figure 1 and Figure 2 As shown, the surface of the blue tungsten powder particles with low oxygen index and high specific surface area provided in Example 1 is needle-shaped.

[0012] Example 2

[0013] First, the ammonium paratungstate raw material is placed in a rotary calcining furnace, and then the corresponding furnace temperature, feeding frequency, furnace rotation frequency, negative pressure and other process parameters are adjusted. After continuous calcination in the rotary furnace for a certain period of time, it is cooled by cooling water at the tail of the furnace, and then taken out of the furnace from the tail of the furnace. After that, it is sieved by a sieve machine, and finally a low oxygen index surface needle-shaped high specific surface area blue tungsten powder is obtained.

[0014] The provided low oxygen index surface needle-shaped high specific surface area blue tungsten powder has an oxygen index of 2.91 and a specific surface area of ​​11.29m 2 / g, the specific parameters are shown in Table 1, and Figure 3 and Figure 4 As shown, the surface of the blue tungsten powder particles with low oxygen index and high specific surface area provided in Example 2 is needle-shaped.

[0015] Example 3

[0016] First, the ammonium paratungstate raw material is placed in a rotary calcining furnace, and then the corresponding furnace temperature, feeding frequency, furnace rotation frequency, negative pressure and other process parameters are adjusted. After continuous calcination in the rotary furnace for a certain period of time, it is cooled by cooling water at the tail of the furnace, and then taken out of the furnace from the tail of the furnace. After that, it is sieved by a sieve machine, and finally a low oxygen index surface needle-shaped high specific surface area blue tungsten powder is obtained.

[0017] The provided low oxygen index surface needle-shaped high specific surface area blue tungsten powder has an oxygen index of 2.93 and a specific surface area of ​​10.76m 2 / g, the specific parameters are shown in Table 1, and Figure 5 and Figure 6 As shown, the surface of the blue tungsten powder particles with low oxygen index and high specific surface area provided in Example 3 is needle-shaped.

[0018] Example 4

[0019] First, the ammonium paratungstate raw material is placed in a rotary calcining furnace, and then the corresponding furnace temperature, feeding frequency, furnace rotation frequency, negative pressure and other process parameters are adjusted. After continuous calcination in the rotary furnace for a certain period of time, it is cooled by cooling water at the furnace tail, and then discharged from the furnace tail discharge end, and then sieved by a sieve machine, finally a low oxygen index surface needle-shaped high specific surface area blue tungsten powder is obtained.

[0020] The provided low oxygen index surface needle-shaped high specific surface area blue tungsten powder has an oxygen index of 2.94 and a specific surface area of ​​12.27m 2 / g, the specific parameters are shown in Table 1, and Figure 7 and Figure 8 As shown, the surface of the blue tungsten powder particles with low oxygen index and high specific surface area provided in Example 4 is needle-shaped.

[0021] Example 5

[0022] First, the ammonium paratungstate raw material is placed in a rotary calcining furnace, and then the corresponding furnace temperature, feeding frequency, furnace rotation frequency, negative pressure and other process parameters are adjusted. After continuous calcination in the rotary furnace for a certain period of time, it is cooled by cooling water at the furnace tail, and then discharged from the furnace tail discharge end, and then sieved by a sieve machine, finally a low oxygen index surface needle-shaped high specific surface area blue tungsten powder is obtained.

[0023] The provided low oxygen index surface needle-shaped high specific surface area blue tungsten powder has an oxygen index of 2.92 and a specific surface area of ​​13.26m 2 / g, and if Fig. 9 and Fig.10 As shown, its surface is needle-shaped.

[0024] Example 6

[0025] First, the ammonium paratungstate raw material is placed in a rotary calcining furnace, and then the corresponding furnace temperature, feeding frequency, furnace rotation frequency, negative pressure and other process parameters are adjusted. After continuous calcination in the rotary furnace for a certain period of time, it is cooled by cooling water at the furnace tail, and then discharged from the furnace tail outlet, and then sieved by a sieve machine, finally a low oxygen index surface needle-shaped high specific surface area blue tungsten powder is obtained.

[0026] The provided low oxygen index surface needle-shaped high specific surface area blue tungsten powder has an oxygen index of 2.9 and a specific surface area of ​​10m 2 / g, and if Fig.11 and Fig.12 As shown, its surface is needle-shaped.

[0027] Example 7

[0028] First, the ammonium paratungstate raw material is placed in a rotary calcining furnace, and then the corresponding furnace temperature, feeding frequency, furnace rotation frequency, negative pressure and other process parameters are adjusted. After continuous calcination in the rotary furnace for a certain period of time, it is cooled by cooling water at the furnace tail, and then discharged from the furnace tail discharge end, and then sieved by a sieve machine, finally a low oxygen index surface needle-shaped high specific surface area blue tungsten powder is obtained.

[0029] The provided low oxygen index surface needle-shaped high specific surface area blue tungsten powder has an oxygen index of 2.93 and a specific surface area of ​​14m 2 / g, and if Fig.13 and Fig.14 As shown, its surface is needle-shaped.

[0030] Table 1 Various indicators of low oxygen index surface needle-shaped high specific surface area blue tungsten powder of Examples 1-7 serial number Oxygen Index <![CDATA[Specific surface area (m 2 / g)]]> Example 1 2.92 11.46 Example 2 2.91 11.29 Example 3 2.93 10.76 Example 4 2.94 12.27 Example 5 2.92 13.26 Example 6 2.9 10 Example 7 2.93 14 The oxygen index detection method in Table 1 adopts the titration method commonly used in the industry to detect the oxygen index of tungsten oxide, and the specific surface area detection adopts the nitrogen adsorption specific surface area detection analyzer commonly used in the industry for detection.

Claims

1. A blue tungsten powder with low oxygen index and high specific surface area and needle-shaped surface, characterized in that: The oxygen index of the low oxygen index surface needle-shaped high specific surface area blue tungsten powder is 2.90-2.94, the microscopic surface is fine needle-shaped, and the specific surface area is 10-14m 2 / g.

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