US1941387A - Anode for fused bath electrolysis - Google Patents

Description

Dec. 26, 1933- p CAMESCASSE 1,941,387

ANOQDEUFYOR Fusrm BATH ELECTROLYSIS v Filed May 28, 1930 Patented Dec. 26, 1933 I UNITED STA A NODE FOR FUSED BATH ELECTROLYSIS Pierre Camescasse, Paris, France, asslgnor to The Magn land esium Production 00., Ltd, London, Eng- Application May 28; 1930, Serial No. 456,721, and

' in France December 4, 1929 Claims.

In electric furnaces for the electrolysis of melted substances, use is frequently made of anodes of graphite or amorphous carbon which are immersed-to a certain depth in the bath of melted 5 salt. However, such anodes are subject to a rapid wear, and this represents a considerable part of the expense of the electrolysis. r

In certain cases, the part of the anode im-' mersedv in the bath may be protected against 10 premature wear, and chiefly in the case of the electrolysis of melted magnesium chloride, by 'a very complete drying of the salt under treatment. However, in all cases the portion of the anode extending above the bath is prematurely oxidized,

for it is practically impossible to maintain an atmosphere entirely free from oxygen above the bath.

For this reason it is the part of the anode situated outside the bath, or the inoperative part, that is prematurely burned. v The presentinvention relates to a construction for the anodes of electrolytic furnaces especially applicable to the electrolysis of magnesium chloride for the obtainment of pure magnesium, and

it is characterized by the fact that the anode consists of two parts, one of which is immersed in the bath and consists of ,graphite or amorphous carbon, the other part being situated above the bath and consisting of a substance which cannot be oxidized. e

a The upper part of the anode preferably consists of a refractory insulating substance reinforced by longitudinal iron rods which may serve at the same time as conductors for the current. The following description and accompanying drawing which are given by way of example relate to a particular form of anodes in conformity to the invention. a Figure 1 is a cross section on a horizontal plane. Figure 2 is a cross section ona vertical axial plane.

Into the block of graphite 1 adapted for immersion into the liquid bath are inserted iron rods 2; these latter are then imbedded in a refractory insulating substance 3, and the whole device is suspended in the furnace in the known manner, for instance by means of a collar 4 resting through the medium of an asbestos ring 5 upon supports 6.

If the refractory substance will not withstand the temperature of the furnace, it can be readily replaced at acomparatively small cost.

I claimzl 1. An anode for use in electrolytic baths of fused MgClz and the like and comprising a lower section of carbon, an upper section of non-con-j ductive refractory oxide, resistant to the heat of the bath and the liberated gases, and a conductor 'rod extending downwardly through the upper section and having its lower end imbedded in the lower section, said upper and lower sections being of substantially equal and uniform horizontal cross-sectional area throughout.

2. An anode for use in electrolyte baths of fused MgClz and comprising a lower section of carbon, an upper section of a refractory and nonconductive oxide, and reinforcing rods of conductive material extending vertically therein, their upperportion being imbedded in said refractory oxide and their lower ends imbedded in the lower section.

3. An anode for use in electrolytic baths of fused MgCls and comprising a lower section of I carbon, an upper section of a refractory and nonconductive oxide, and reinforcing elements of conductive material extending vertically through the, upper section and having their lower ends imbedded in the lower section, said upper and lower sections being of equal and uniform crosssectional area throughout. I

fused MgClz and comprising a lower active section of carbon, an upper section of a refractory and non-conductive oxide entirely covering the upper end of the carbon, and reinforcing rods of conductive material extending vertically through the .80 4. An anode for use in electrolyticb'aths of upper section and having their lower ends imbedded in the lower'section.

5. In electrolytic apparatus for the electrolysis of fused MgClz, the herein described anode which comprises a rod. of carbon substantially all of which is within the fused MgClz and a part which is above the bath of MgClz, the latter part being composed largely of a refractory oxide which is electrically non-conductive, and a conductive metallic rod extending downwardly through and tightly embedded within said refractory oxide part, the lower end of said metallic rod being tightly imbedded in said carbon rod, at least the part of said metallic rod which is within the electrolytic apparatus being wholly so imbedded and insulated by said refractory oxide coating, against the gases liberated at said anode.

PIERRE CAMESCASSE.

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