US2809887A - Method of alloying reactive metals with aluminum or beryllium - Google Patents

Description

METHOD OF ALLOYING REACTIVE METALS WITH ALUMINUM OR BERYLLIUM Oliver J. C. Runnalls, Deep River, Ontario, Canada, as-

signor, by mesne assignments, to the United States of America as represented by the United States Atomic Energy Commission No Drawing. Application October 18, 1954, Serial No. 463,047

SClaims. c1. 7s-122.1 V

active metals neptunium, cerium and/or americium and to provide a method whereby compounds of these metals may be simultaneously reduced and alloyed with alumi-. num or beryllium;

It has been found that aluminum and beryllium each act as a reducing agent for halides of the reactive metals, producing a volatile halide which is readily removed from the alloy formed during the reducing reaction.

In accordance with the invention a halide of one or more of the reactive metals, neptunium, cerium and americium is mixed with aluminum or beryllium. The mass is heated at 700 to 1200 C., while maintaining a substantial vacuum of about 10- mm. of mercury or better, until the halide of the reactive metal is reduced and the metal itself alloys with the reducing metal. Although the halides of these reactive metals are more stable, thermodynamically, than the halides of aluminum and beryllium the reducing reaction proceeds efliciently due to the volatilization of the halides of the reducing metal, aluminum 7 or beryllium.

The following examples illustrate the method.

(1) In preparing a neptunium-aluminum alloy containing 75% by weight of neptunium, 54 parts by weight of neptunium fluoride were mixed with 32.6 parts of aluminum powder. The mixture was heated under vacuum in a beryllium oxide crucible for two hours at 900 C. to reduce the neptunium fluoride and alloy the metal with the aluminum according to the reaction Most of the aluminum fluoride product sublimed during the first half hour of heating. 95% of the original neptunium appeared in the fluoride-free alloy. The amount of aluminum used may be varied as required by the alloy desired.

The aluminum halides produced in this reduction of the reactive metal halides are a mixture of the monovalent and trivalent forms. The monovalent halide predominates in the gaseous sublimate at the lower reducing temperatures. Since the aluminum monohalides are appreciably more volatile than the trihalides, the preferred heating temperature is in the region where the monohalide predominates 'in'the etfluent. The reduction and alloying method is further illustrated by the reaction CeFa+xAl- CeAl(=-s)+3AlF. Upon condensation the United States Patent The alloy, 60.5 parts by weight was loosely sintered and crystalline and was readily removed from the crucible. The chemical yield for the reaction was about 97%.

A significant advantage of the method resides in the fact that the halogenated reducing agent, aluminum or beryllium, is capable of being removed from the alloy formed by mere distillation leaving no compounds. Since aluminum monofluoride disproportionates on condensation two-thirds of the aluminum is recoverable as metal.

The alloy may be heated at a temperature at which the reducing metal distills to produce the reactive metal. When the alloy of Examples 1 and 2 were heated in vacuum at a temperature in excess of 1250 C. the aluminum or beryllium was distilled 01f freeing the neptunium. This aflords a method of recovering the reactive metal from its halide, although more expensive than other reducing methods.

I claim:

1. A method of alloying reactive metal from the group consisting of neptunium, cerium and americium with one of a group of reducing metals consisting of aluminum and beryllium which comprises mixing ahalide of the reactive metal with the reducing metal, heating the mass at 700 to 1200 C. in vacuum to reduce said halide and form an alloy while distilling ofl the halide of the reducing metal formed during the reaction.

2. The method defined in claim 1 wherein the distilled halide is condensed to recover reducing metal therein.

3. A method of making a neptunium-aluminum alloy which comprises mixingneptunium fluoride with aluminum, heating the mixture under vacuum at about 900 C. to reduce the fluoride and form an alloy while subliming ofi the aluminum fluoride formed.

4. The method defined in claim 3 wherein the distilled aluminum fluoride is condensed to recover two-thirds of the aluminum metal for reuse.

5. A method of making a neptunium-beryllium alloy which comprises mixing neptunium fluoride with finely divided beryllium metal, heating the mixture under vacuum at 1100-1200 C. to reduce the neptunium fluoride and form an alloy while distilling the beryllium fluoride formed.

References Cited in the file of this patent UNITED STATES PATENTS 2,586,134 Winter Feb. 19, 1952 2,604,394 Emley' July 22, 1952 2,607,674 Winter Aug. 19, 1952 2,678,267 Saunders May 1 1, 1954 FOREIGN PATENTS 489,155 France Aug. 31, 1918 627,286 Great Britain Aug. 5, 1949

Claims (1)

1. A METHOD OF ALLLOYING REACTIVE METAL FROM GROUP CONSISTING OF NEPTUNIUM,CERIUM AND AMERICIUM WITH ONE OF A GROUP OF REDUCING METALS CONSISTING OF ALUMINUM AND BERYLLIUM WHICH COMPRISES MIXING A HALIDE OF THE REACTIVE METAL WITH THE REDUCING METAL, HEATING THE MASS AT 700 TO 1200*C. IN VACUUM TO REDUCE SAID HALIDE AND FORM AN ALLOY WHILE DISTILLING OFF THE HALIDE OF THE REDUCING METAL FORMED DURING THE REACTION.