US2258374A

US2258374A - Process for the production of magnesium by means of thermic reduction

Info

Publication number: US2258374A
Application number: US315849A
Authority: US
Inventors: Amati Luigi
Original assignee: Individual
Current assignee: Individual
Priority date: 1939-07-01
Filing date: 1940-01-26
Publication date: 1941-10-07
Anticipated expiration: 1958-10-07

Description

Oct. 7, .1941. L. AMAT I 2,258,374 PBOQESS FOR THE PRODUCTION fi l MAGNE$IUM DY MEANS OF THERMIC REDUCTION Filed Jan. 26, 1940 4 :2 h f m Patented Oct. 7, 19 41- NESIUM BY MEANS OF THEBMIO TION REDUC- m1 Amati, Padova, Italy Application January 2c, 1940, Serial No. $15,849 in Italy July 1,1939

1 Claim. (01, 15-6 '1) The present invention relates to a process for the production of magnesium by thermic reduction, under vacuum or reduced pressure, of magnesium-containing raw materials, by means of reducers such as silicon, ferro-silicon, aluminum or similar reducing substances which do not generate gaseous products oxidation.

As is well known, various difficulties are encountered in the production of magnesium by thermic reduction which make it impossible to carry out such a process in continuous manner on an industrial scale. The art has therefore resorted to intermittent processes comprising the following cycle of operations: charge of the material to be treated, heating of the material, distillation, condensation, and discharge of the resultant magnesium and of the exhausted residu al material.

The magnesium distilling from the reaction zone is condensed in a suitable zone at a temperature of about 500"- In order to extract the magnesium from this zone, it is necessary to wait until'it cools to a temperature below 80-100 0., since otherwise the magnesium would react with the atmospheric air and be covered by a layer. of nitride and oxide or greater or less thickness,

quence ot'this arrangement is that, as soon as the thermic reduction has been completed, the apparatus may at once be used for a new operation, as hereinafter explained.

' The aforesaid process may be the aid of the apparatus hereinafter carried out with described and illustrated, solely by wayot example, in the thereby greatly reducing the yieldgoi metallic magnesium. Thereaction with the air may be so violent that themagnesium may be set on fire and be totally converted into oxide.

In practice, the condensation zone is externally cooled. and this cooling has to be continued even after the reduction reaction has been completed. However, this procedure, the object of which is to shorten the duration of the period or cooling of the condensed magnesium, also incidentally cools the reaction chamber. This results in a considerable loss of heat'so that large additional quantities of heat have to be supplied during subsequent reduction operations, thereby unfavorably afiecting the heat consumption.

The process of thepresent invention makes it possible to obviate, in simple manner, the aboveenumerated detects and disadvantages, and to reduce thermic losses and the time required for carrying out thewhole operative cycle to a minimum. The present process is characterized by the fact that the magnesium produced by the' thermic reduction is extracted in a condensation which is under a degree or vacuum substantially corresponding to the degree or vacuum prevailing in the reduction chamber, the condensation chamber being subsequently made entirely independent of thereduction chamber. The consesingle flgureon the accompanyin sheet or drawing The said figure of drawing is a diagrammatic longitudinal sectional view 0! the aforesaid apparatus, and reference character I. represents an electric furnace, 2 a heating coil, 3 a reaction chamber, 4 a receptacle containing the reaction mass, I a condenser for the resultant magnesium, l a closure device for the condenser 5, I means for controlling the closure device Ii, 8 a cover for closing the outer end or the condenser 5 and the reaction chamber 3, and O a valved conduit leading to a vacuum-producing means (not shown). v

The procedure according to the present invention is as follows:

Theraw material, intimately mixed with the reducer and generally briquetted, is charged into the receptacle 4 and introduced into the re- 14 actionchamber I where it is heated under vacuum or at a reduced pressure at a temperature depending upon the type c! reducer employed. The evolved magnesium is condensedin condenser l. As soon as. the reaction ends, the closing device i is actuated by lever 1, cutting of! communication between the condenser E and the reaction chamber I. Then the wing nuts which afllx the cover 0 to the reaction chamber are unscrewed and the condenser I is removed, the ma nesium contained therein undergoing no chemical alteration notwithstanding the fact that it last a high temperature. The reaction chamber, after removal therefrom oi the recep; tacle 4, may immediately be utilized again for a new operation by-fllling it with a new charge and removing the condenser I and thus permitting the immediate re-utilization of the apparatus, re-

sults in an appreciable reduction in the time of interruption or the productive cycle. Moreover, the removal of the condenser containing the magnesium, according to the atoredescribed method, makes it possible to avoid supplementary cooling which, as above stated, is indispensable according to prior processes. while according to the prior processes the reaction chamber is cooled with the aidof a cooler annexed to the condensation zone, this is avoided according tothe present invention and, consequently, there is a substantial reduction in the quantity 01' heat which has to be supplied to the apparatus ior subsequent thermic reduction operations. In addition, no heat is lost as a result of long delays during which the apparatus has to remain inactive, waiting for the magnesium produced therein to reach -such a temperature that it may be removed with no danger whatsoever oioxidation.

I claim:

A process for the production of magnesium by thermic reduction in a reduction zone at reduced pressure, which comprises condensing the The result is that.'

evolved magnesium in a condensation zone juxtaposed to and in communication with said reduction zone at a pressure substantially equal to that prevailing in the reduction zone, cutting 01! the communication between the reduction zone and condensation zone while maintaining the juxtaposition thereot whereby the atmosphere and pressure prevailing in the condensation zone are rendered independent of the atmosphere and pressure prevailing in the reduction zone without change in such pressure, and dissociating the condensation zone from said reduction zone whereby the latter may immediately be reassociated with a newcondensation zone, the pressure prevailing in the condensation zone after said dissociation being substantially the same as that prevailing in the system during the reduction'process.

- LUIGI AMATI.