SU46047A1 - Electrolyzer to get magnesium - Google Patents

Description

A method for producing magnesium from anhydrous carnalite and a method for producing magnesium from anhydrous magnesium chloride are known. The advantage of the carnalite method is the ease of dehydration of hexahydine salt, which is produced by heating the salt, in one or another equipment, and its disadvantage, especially noticeable on a large scale, is the frequency of the electrolysis process, since chlorides accumulate in the electrolyte as magnesium chloride decomposes. alkali metals; When a certain percentage of residual magnesium chloride in the electrolyte is reached, the latter must be removed from the bath. The operation of changing the electrolyte in the bath requires a considerable amount of labor, leads for some time to a breakdown of the bath course, to a drop in the current output and chlorine concentration in chlorine gas, etc.

Electrolysis using anhydrous magnesium chloride is free from these drawbacks, however, the preparation of this product presents great difficulties due to the need to use special hermetic equipment and dehydration in it in an atmosphere of chlorine or hydrogen chloride. Electrolyzers with continuous circulation of molten electrolyte have already been proposed, such electrolyzers consist of

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from a number of chambers communicating between themselves channels in partitions or in electrodes.

According to the invention, channels located horizontally or inclined in the side walls of the bath are used to transfer electrolyte from one cell to another.

In FIG. 1 shows a longitudinal section of the proposed electrolyzer; FIG. 2 is a cross-section of it; FIG. 3-top view of it; FIG. 4-side view of the anode; FIG. 5 is a cross-section of it and FIG. b-longitudinal section of the anode.

The continuous electrolysis process of carnality is carried out because the electrolysis cell of one or another design is divided by partitions 9 into separate cells 7, 2 ... 7, 8 (Figs. 1, 2 and 3). Partitions 9 consist alternately of black metal and graphite. The graphite septum is the anode block JO, arranged in such a way that it is a solid wall, i.e. it consists of either one plate or separate blocks that fit tightly to each other. Chamotte partitions 9 are made either from ordinary masonry, for example, half-brick, or, which is preferable, from chamotte plates of the same thickness.

According to the invention, no electrolyte is formed for the transfer

The cells of the cell are interconnected by channels // located in the lining of the side walls of the bath or in the partitions themselves. These channels // are located either obliquely, connecting the top of one cell with the bottom of another, or horizontally. In view of the insignificant change in the specific gravity of molten carnalite with a change in the concentration of magnesium chloride in it and a rather intensive circulation of electrolyte in the cells, the character of the location of the channels does not matter.

In the last cell there is a sprue 12, the lower edge of which corresponds to the normal electrolyte level.

The electrolysis process is carried out as follows. In the extreme cell / ... opposite to the gate with sprue / 2, carnilit is loaded periodically or continuously. The carnalite can be loaded both in solid form and in the molten state. In this case, channels 7 / cause electrolyte to flow from the first cell to the second, from the second to the third, and so on; from the last cell, upon reaching the normal electrolyte level in it, a certain amount of it through sprue 12 will pour out of the bath. Since each portion of the carnilitite loaded in the bath is somewhat depleted in each cell, the concentration of magnesium chloride in the cells will decrease from the first cell to the last. Changing the magnitude and frequency of carnilit loading and the current strength in the cells makes it possible to work within the desired limits of the percentage of magnesium chloride in the cells.

The device channels in the electrolyzer is intended to increase the difference in concentrations of magnesium chloride in the neighboring cells, since if there are usually proposed holes in the partitions, there will be a significant mixing of the electrolyte of the neighboring cells, and the difference in concentrations of magnesium chloride in them will be very small.

With the carnalite electrolysis process described above, disruptions during electrolysis are eliminated.

associated with scooping up a significant portion of the electrolyte present in the bath; the process of electrolysis proceeds all the time evenly, the feed of the loaded carnilit and the removal of the spent electrolyte can be maximally mechanized.

The long-term operation of the anode device is provided by a special device for supplying current to the anodes (Fig. 4, 5 and 6). Plenum current 13, which in accordance with the preceding one represents a continuous wall, i.e., consisting of one plate or several anodes that are tightly fitted to each other, is poured with iron current-carrying rods 14 into the cast iron shoe 15 to a shallow depth. The pouring depth is determined by the selected current density for the graphite-iron contact and the dimensions of the surface of the anode block. The anode device assembled in this way can be placed either in the floor of the bath, or in its cover, or in the side walls. Aluminum or copper busbars are attached to the 15 current-carrying iron bars 14 emerging from the cast-iron baschak 15. When the anode device is located in one or another part of the bath, it is necessary to protect the cast iron shoes 15 and the iron lead rods 14 in some way or other from the electrolyte and gases produced in the bath, for example, by artificial cooling of the cast iron shoes, removing them from the working space baths, creating any obstacles to penetration to it and to the tires of electrolyte and gases, etc.

If there is no need to assemble the anodes as a solid wall, each anode can be poured into the cast iron shoe separately. In this case, pouring of current-carrying iron rods into the cast iron is not necessary, since aluminum or copper buses can fit directly to the treated surface of the iron.

The arrangement of cast iron shoes in the lining of the bath removes its top from the details, due to which it is possible to achieve tightness of the anode space. When the cast iron shoes are located in the bath lid, tightness can be created by means of hydraulic gates from a suitable liquid, for which the cast iron shoes are provided with corresponding protrusions immersed in the hydraulic gate liquid.

The subject matter of the invention.

Claims (2)

1. Electrolyzer for obtaining magnesium with continuous circulation of molten electrolyte and using anode blocks in the form of solid walls serving as partitions between cells, characterized in that channels // located in the side walls of the bath horizontally to flow electrolyte from one cell to another or obliquely. 2. In the electrolyzer according to claim 1, use at the ends of the anodes / 5 shoes / 5 with the current-carrying rods 14 attached to them (Fig. 4-6). FIG Figg5