SU31932A1 - The method of obtaining salts and other compounds from anode-soluble metals - Google Patents

Description

In the industry of inorganic substances, relatively often, there are cases where for the preparation of those or other soluble or insoluble metal compounds, the starting material is heavy metals that undergo dissolution. Thus, for example, most of the lead compounds of silver, copper, etc. are prepared by dissolving metals in strong, acting simultaneously as an oxidizing agent, or other appropriate substances with the assistance of atmospheric oxygen, with subsequent processing of the resulting solvents into the required compounds.

Due to the inconvenience and high cost of this kind of work, methods of direct electrolytic production of the required poorly soluble compounds have repeatedly arisen. For example, methods are known for the electrolytic preparation of white, lead chromate compounds, etc. However, these methods are not widely used due to the difficulties and complications that arise during mass production.

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practical application of them in technology.

The main of these difficulties are the inevitable penetration and retraction of metal ions formed at the anode, or, conversely, penetration of anions and especially hydroxyl ions into the anode space and the formation of insoluble compounds at the anode, which provide significant transient resistance and impeding electrolysis.

The proposed method should enable the anodic dissolution of the metals to be carried out with obtaining their soluble salts or poorly soluble compounds without returning the metal to the cathode, and is as follows.

The preparation of one or another compound, in particular, metal salts, by means of anodic dissolution of the metal can be carried out by precipitating it from an anodic solution, outside of electrolysis, or directly requiring its poorly soluble compound, or

from the beginning of its slightly soluble oxide or hydroxide of oxide, with its subsequent transfer to any insoluble or soluble compound. In this operation, the accumulation of an anodic solution of the amount of ions of this metal is sufficient for the production of planting operations (and the anode solution is not required to saturate), and it is possible to conduct electrolysis with a flow-through electrolyte that prevents the metal ions from penetrating the cathode space them on the cathode.

On the other hand, to achieve the correct quantitative dissolution of the metal at the anode, besides the presence of the usual favorable conditions, such as the required density, temperature, it is necessary to prevent the penetration of hydroxyl horses from the cathode space into the anode, causing contamination of the anode surface and hence the transition resistance and an increase in voltage.

These two conditions are intended to be achieved in the described method by the preparation of metal compounds as follows. The electrolyte solution, which serves as the main current carrier and contains a concentration of the corresponding electrolyte, mainly sodium, potassium, etc., sufficient for good conductivity, with anine forming with this easily soluble metal free of ions of this metal and from hydroxyl ions, comes with a certain adjustable speed in the interdiaphragm chamber. The latter is formed by two parallel diaphragms separating the anode and cathode space A to K.

From this interdiaphragm chamber, the circulating solution percolates through the anode and cathode diaphragms (at appropriate speeds) into the anode and cathode space, where, depending on the current density and the speed of its movement, the corresponding concentrations of ions of the dissolved metal in the anode space accumulate hydroxyl ions in the cathode space. Through holes, for example, at the bottom

the electrolyzer, these two separate solutions, the anolyte and the catholyte, descend from the electrolyzer at specific speeds. The latter correspond in sum to the rate at which the electrolyte solution enters the interdiaphragmatic chamber and is controlled by the height of the drain holes of the siphons connected to the drain holes. Circulation rates are regulated so that the linear velocity of the electrolyte solution through the pores of the diaphragms corresponds to the speed of movement at a given temperature of ions dissolved on the anode, metal and, on the other hand, hydroxyl ions and, thus, prevents the ingress of both, and others into interdiaphragm chamber, and, therefore, their mutual penetration into the cathode and anode space.

At the same time, it is advisable that the rate of circulation of the solution be as low as possible in order to accumulate the highest concentrations of metal ions and hydroxyl ions.

The further direction of work can be, as indicated, different, namely it is possible to separately and directly use the anode solution to obtain the desired salt from the dissolved metal and just as well to separate and directly use the alkali accumulated in the catholyte. On the other hand, in most cases, the following order of work is more expedient: anolyte and catholyte solutions outside the electrolyzer are merged together and the alkali thus obtained at the cathode is used to extract the metal dissolved in the anode as a hydrate of oxide or oxide. , lead, silver, etc.

The metal oxide thus obtained, filtered from the electrolyte solution and washed, is converted by treatment with the appropriate acids and other reagents to the corresponding salts. The remaining electrolyte solution, freed from metal ions and hydroxyl ions, is returned to the circulation again.

According to the proposed method, it is also possible to convert not only pure metals by anodic dissolution into the corresponding compounds, but also their alloys with the subsequent separation of the components in the form of the corresponding compounds either directly from the anodic solution, or by treating the anodic and cathode solutions of the mixture of oxides liberated by mixing .

The subject matter of the invention.

Claims (2)

1, a method for producing salts and other compounds from anode-soluble metals, characterized in that an electrolyte solution containing an anion, which gives easily soluble compounds with a suitable metal, and a cation that does not subtract from electrolytically from aqueous solutions, circulates through the anode and cathode spaces entering the interdiaphragm chamber formed by two parallel or concentrically arranged diaphragms separating the electrode spaces, and seeping through the diaphragms are released separately from the space, together with the anode metal ions soluble in it, and from the cathode space with hydroxyl ions, and then both of these solutions are used either individually or by IR interaction with the release of insoluble Oxide or metal oxide hydrate, which is converted into the desired compound The electrolyte solution, thus freed from hydroxyl ions, returns again to the interdiaphragm chamber for further circulation. 2. Application of the method specified in clause 1 to the processing of metal alloys, characterized in that the mixed anode solution obtained by anodic dissolution according to claim 1 or separated, as such, for example, by planting metals separately, or by mixing with the cathode solution is translated into a mixture of metal oxides separated as such.