JPS60186407A - Manufacturing method of zirconium nitride fine powder - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing zirconium nitride.

Zirconium nitride has a high melting point (2982°C), high hardness (microhardness 1500Ic9/-), and is also chemically stable, so it is used as an additive for various cutting tools, wear-resistant tools, and the like.

For zirconium nitride, methods such as (7) direct nitridation of metal zirconium, (a) nitridation of zirconium hydride, (1) nitridation of zirconium oxide in the presence of carbon, and (→ nitridation of zirconium halide) have been proposed. .

Direct nitriding of metallic zirconium (7) is not industrially practical because it requires a great deal of energy to produce metallic zirconium and it is difficult to obtain metallic zirconium powder for nitriding. To obtain fine powdered zirconium nitride,
Although nitriding of zirconium hydride is preferred, nitriding of zirconium hydride is an exothermic reaction and generates a large amount of hydrogen during the reaction, so there is a risk of explosion and is not suitable as an industrial production method.

The nitridation of zirconium oxide in the presence of carbon is 200
It requires a high temperature of around 0° C., and has the disadvantage that the carbon added to the obtained zirconium nitride remains in the form of free carbon or zirconium carbide. Furthermore, the nitriding reaction of zirconium halide is mainly used for coating carbon rods, ceramics, or metals.

The inventor of the present invention conducted extensive research to eliminate such drawbacks, and as a result, discovered a method for producing fine zirconium nitride powder at relatively low temperatures and with high purity.

According to the present invention, single-phase zirconium nitride without residual carbon or carbides can be produced.

The present invention is based on the combination of zirconium oxide powder and alkaline earth metal.
Mix the two or more species, and heat the mixture for 500 minutes under nitrogen gas flow.
It consists of a step of heating at 1200°C to obtain zirconium nitride.

Alkaline earth metals used in the present invention are preferred, and include magnesium, calcium, strontium, barium, and the like. Other metals, such as aluminum and zinc, cannot be used because their reducing power is weaker than that of magnesium, and they also produce zirconium intermediate compounds during the reaction with zirconium oxide. The most preferred alkaline earth metal in the present invention is magnesium. This is because the reaction is relatively mild when this product is used, and by-products can be easily removed in subsequent steps. An example using magnesium will be described next.

The reaction appears to proceed according to the following equation.

ZrO, + Mg-3-)'ZrN-1-MgO-1-
Mg, N.

Magnesium oxide and magnesium nitride as by-products are treated with hydrochloric acid,
By contacting the reaction product with a mineral acid such as sulfuric acid or nitric acid, it can be separated from zirconium nitride by conventional separation methods such as decantation, centrifugation, etc.

The heating temperature may be higher than the temperature at which the reaction starts in the reaction system, but
When using magnesium, the temperature should be 650℃ or higher.
Unnecessary high temperatures are undesirable in terms of energy consumption.

The heating time may be at least 10 minutes, preferably at least 30 minutes.

The amount of alkaline earth metal used in the present invention may be 3 mol or more per 21021 mol, but preferably 5 to 5 mol.
It is in the molar range. In the case of magnesium, adding more magnesium than necessary not only increases the manufacturing cost but also requires more acid than necessary in the pickling process, which is undesirable.

According to the present invention, high purity zirconium nitride can be obtained under relatively mild conditions.

Although the above invention will be illustrated according to specific examples, the present invention is not limited to these examples in any way.

Example 1 ZrO2 powder 1a59 and metal magnesium powder 1a39
(1:5 molar ratio) were thoroughly mixed in a mortar, placed in a quartz boat, and heated at 700°C for 3'f1 minute in a nitrogen stream.

About 449 parts of the obtained product was washed with 1N HOI, thoroughly washed with water, and passed through a Puchner funnel to obtain about 159 parts of zirconium nitride. The chemical analysis value of the obtained zirconium nitride was 13.1% N, which is ZrN. ,. 8. Corresponds to . The crystallite size was calculated from the half width of the X-ray diffraction line to be approximately 200X, and the average particle size measured using a subsieve sizer was a, 3 μm, which was a fine powder.

Example 2 ZrO, powder 12.39 and metallic magnesium powder 9.7
9 (1:4 in molar ratio) and reacted with nitrogen gas at 1000° C. for 30 minutes. The resulting product had a weight of about 269, and the zirconium nitride obtained by acid treatment had a weight of about 109. As shown in the X-ray diffraction diagram (Figure 1), a sharp pattern is obtained. This zirconium nitride is a fine powder with a N content of 150% and a
It corresponded to H6,gB. The crystallite size was about 200 A from the half-value of the X-ray diffraction line, and the average particle size was 0.3 μm as measured by a subsieve sizer.

[Brief explanation of drawings]

FIG. 1 is an X-ray diffraction diagram of the zirconium nitride fine powder of the present invention. Patent applicant: Toyo Soda Kogyo Co., Ltd.

Claims (3)

[Claims] (1) A method for producing fine zirconium nitride powder, which comprises heating zirconium oxide in a nitrogen stream in the presence of one or more alkaline earth metals. (2) The manufacturing method according to claim (1), wherein the molar ratio of zirconium oxide and alkaline earth metal is 1:3 or more. (3) The production method according to claim 1 or 0, wherein the alkaline earth metal is magnesium.