JPH0885835A - Production of rare earth-nickel alloy - Google Patents

Abstract

PURPOSE: To produce a rare earth - Ni alloy minimal in impurity content at a low cost by mixing rare earth fluoride, metallic Ca, Ni powder, and CaCl2 in specific ratio and allowing them to react with each other by heating at specific temp. in an inert-gas atmosphere. CONSTITUTION: The fluoride of rare earth elements consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu and including Y is mixed with metallic Ca as a reducing agent for it, Ni powder, and anhydrous calcium chloride as a melting auxiliary. The amounts of metallic Ca, Ni powder, and anhydrous calcium chloride are 1.2-1.8mol, 0.1-4mol, and 0.1-6.6mol per mol of the rare earth fluoride, respectively. A crucible made of Ta is filled with the resulting mixture. Then, heating is performed up to 1000-1500 deg.C, not lower than the melting temp. of the resulting rare earth - Ni alloy, in an inert-gas atmosphere of Ar, etc., to carry out reaction. By this method, the alloy of rare earth element and Ni can be inexpensively produced with high-purity quality minimal in impurity content.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a rare earth element-nickel alloy useful as a hydrogen storage alloy, an alloy for a cold storage material, a heat-resistant alloy and the like with high purity and low cost.

[0002]

2. Description of the Related Art Conventionally, rare earth element-nickel alloys have been manufactured by reducing rare earth fluorides with metal Ca and melting the generated rare earth elements and nickel in a vacuum induction melting furnace or the like.

[0003]

However, the alloy obtained by the prior art was an alloy containing a large amount of impurities due to contamination by the crucible material used for Ca reduction or the crucible material used for melting the alloy. The present invention intends to provide a rare earth element-nickel alloy containing few impurities, which solves the above drawbacks, by simplifying the manufacturing process and at low cost.

[0004]

In order to solve such drawbacks, the inventors of the present invention reviewed the manufacturing process and simplified the conventional two steps of reduction and dissolution into a single step, depending on the crucible material. The present invention has been completed by establishing various conditions by finding that there is little pollution and can be manufactured at low cost, and its gist is to produce a mixture of rare earth fluoride, metallic calcium and nickel powder when manufacturing a rare earth element-nickel alloy. In a method for producing a rare earth element-nickel alloy, which is characterized by heating to a melting point of the rare earth element-nickel alloy with addition of calcium chloride, more specifically, the heating temperature is 1000
It is a method for producing a rare earth element-nickel alloy in which the temperature is ˜1500 ° C. and the heating atmosphere is an inert gas which is not reactive under high temperature.

The present invention will be described in detail below. The production method of the present invention is a rare earth fluoride, metal calcium, nickel and calcium chloride are mixed as a raw material at a predetermined mixing ratio, put in a tantalum crucible, and the melting point of the target rare earth element-nickel alloy is 1000- If heated to 1500 ° C. in an inert gas atmosphere, a rare earth element-nickel alloy can be obtained in one step. The mixing ratio of raw materials is 1.2 to 1.8 moles of metal Ca and 0.1 to 4 moles of Ni with respect to 1 mole of rare earth fluoride Re F ₃ (here, Re is a rare earth element).
Ca chloride is an anhydrous substance and is preferably in the range of 0.1 to 6.6 mol. Metal Ca is a reducing agent and the theoretical amount is 1.5 mol. However, 1.5 mol or more is preferable to increase the yield and 1.5 mol or less is preferable to suppress the impurity Ca of the produced alloy. In order to reduce Ta contamination of the crucible material as much as possible, it is preferable to shift the melting point of the produced alloy to a low temperature range, and mix Ni so as to have the melting point at the eutectic point. Ca chloride is a melting aid and C
It is added in order to lower the melting point of the a F ₂ -Ca Cl ₂ slag to the melting point of the produced alloy. Ca F ₂ 50 mol-Ca C
The melting point of l ₂ 50 mol slag drops to 800 ℃, and even if the reaction temperature is 1000 ℃, it completely separates from the alloy.

The melting heating temperature must be 1000 to 1500 ° C., which is higher than the melting point of the rare earth element-nickel alloy.
Below ℃, the separation of slag and the alloy becomes incomplete, and 1500
When the temperature exceeds ℃, CaCl ₂ evaporates, the separation between the slag and the alloy becomes incomplete, and the contamination from the crucible increases. The heating time is preferably until the raw material powder is completely melted. Incidentally, the melting point of a rare earth element-nickel alloy varies depending on the type of rare earth element and the composition ratio of both, and is represented by a two-element eutectic melting point diagram, and it is desirable to aim at the alloy composition which is the minimum melting point among those minimum melting points. The heating atmosphere is Ar, He, Ne, Kr, X which has no reactivity at high temperature even in the inert gas.
Although e and the like can be used, Ar gas is preferable. The applicable range of the present invention is La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu containing Y as a rare earth element.
It is one kind or two or more kinds of mixed elements selected from the group consisting of.

[0007]

Even if the conventional reduction step and alloy melting step, which are the greatest feature of the present invention, are simplified into one step, the reduction reaction is not hindered and contamination by Ta, which is the material of the crucible, is eliminated. There was an effect. This is considered to be because the solubility of Ta in the alloy was reduced by reacting it at a low temperature.

[0008]

EXAMPLES The embodiments of the present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. (Example 1) (74% Y-26% Ni alloy) (hereinafter,% is% by weight) YF ₃ 100 g, Ca 41.2 g, Ni powder 21.4 g, Ca Cl ₂ 8
Mix 7.0g, put in Ta crucible, 1000 ℃ × 3 in Ar
hr heated. After cooling, Y-Ni alloy is in the crucible bottom, slag (Ca F ₂ -Ca Cl ₂₎ was in the upper part of the alloy. The recovery rate of the alloy is 93%, the impurity Ta is 0.01%, Al
It was <0.001%.

(Comparative Example 1) (74% Y-26% Ni alloy) 100 g of YF ₃ and 41.2 g of Ca were mixed and put in a Ta crucible.
Y metal was obtained by heating at 1500 ° C. for 3 hours in Ar. 54.8 g of the obtained Y metal and 19.3 g of Ni were put into an alumina crucible and melted to obtain 65.2 g of a Y-Ni alloy. 88% alloy recovery
The impurity Ta was 0.96% and Al <0.50%.

(Example 2) (54.2% La-45.8% Ni alloy, La Ni ₂ ) La F ₃ 1000 g, Ca 306.9 g, Ni 599.2 g, Ca Cl ₂ 6
Mix 47.6g, put in Ta crucible, 1000 ℃ × 3 in Ar
After heating and cooling for 1 hr, 1190.6 g of La-Ni alloy was obtained. The recovery rate of the alloy is 91%, the impurity Ta is 0.01%, Al <0.001
%Met.

(Example 3) (89.5% Er -10.5% Ni alloy, Er ₃ Ni) Er F ₃ 5000g, Ca 1340.4g, Ni 437.5g, Ca Cl ₂
2828.9g are mixed, put in a Ta crucible, and 1000 ℃ in Ar
After heating for 5 hours and cooling, 3875.0 g of Er-Ni alloy was obtained.
The recovery rate of the alloy is 93%, the impurity Ta is 0.05%, and Mg <0.
It was 001%.

(Comparative Example 2) (89.5% Er -10.5% Ni alloy, Er ₃ Ni) Er F ₃ 5000g and Ca 1340.0g were mixed, put in a Ta crucible and heated at 1500 ° C for 3 hours to obtain Er metal. . 3356.1 g of the obtained Er metal and 393.7 g of Ni were put into a magnesia crucible and melted to obtain 3149.8 g of Er-Ni alloy. The recovery rate of the alloy was 84%, the impurity Ta was 0.60%, and the Mg was 0.05%.

(Example 4) (88.9% Gd -11.1% Ni alloy, Gd ₃ Ni) Gd F ₃ 5000g, Ca 1403.0g, Ni 458.2g, Ca Cl ₂
Mix 2961.1g, put in Ta crucible, 1000 ℃ in Ar
After heating for 5 hours, 3839.0 g of a Gd-Ni alloy was obtained. The recovery rate of the alloy is 93%, the impurity Ta is 0.02%, Al <0.001%
Met.

[0014]

According to the present invention, the conventional two steps of reduction and dissolution can be simplified into one step, the life of the reducing crucible can be extended and the cost can be reduced, and the contamination by the crucible material is extremely small. An alloy can be produced and its utility value is extremely high in industry.

Claims (3)

[Claims] 1. When manufacturing a rare earth element-nickel alloy,
A method for producing a rare earth element-nickel alloy, which comprises adding calcium chloride to a mixture of rare earth fluoride, metallic calcium and nickel powder and heating the mixture to a temperature equal to or higher than the melting point of the rare earth element-nickel alloy. 2. The heating temperature according to claim 1, wherein the heating temperature is 1000 to 1500.
A method for producing a rare earth element-nickel alloy having a temperature of 0 ° C. 3. The method for producing a rare earth element-nickel alloy according to claim 1, wherein the heating atmosphere is an inert gas having no reactivity at a high temperature.