CS216282B1 - Method of decreasing the contents of the electropositive metals and cathode metal by making the metals by the electrolysis and facility for executing the same - Google Patents

Description

The present invention relates to a method and apparatus for reducing the content of more electropositive metals in a cathode metal in the production of metals by electrolysis.

Impurities of more electropositive nature than the parent metal, which we produce electrolytically, are very easily eliminated at cathodes even at very low electrolyte concentrations. When electrolyte is introduced into a cathode space formed by a diaphragm containing these metals, these, together with the parent metal, are deposited on the cathode and act as impurities in the parent metal. The content of impurities in the cathode metal is directly dependent on their concentration in the cathode space, and this phenomenon cannot be prevented under the current electrolysis technique.

This drawback is eliminated in the invention describing a method and apparatus for reducing the content of electropositive metals in cathode metal in the production of metals by electrolysis, which is based on the electrolysis of an electrolyte at its flow at a very low current density of 0.1 A. dm ² and electrolysis at a current density

1.52 to 1.56 A. dm ² .

Said method is carried out in an electrolyser device with yard openings for cathode inlet and one anode outlet, with a diaphragm in which the cathode is located and pb on both sides there are auxiliary cathodes with openings, with resistance from the current source it does not regulate a higher current density on the cathode and a low current density on the auxiliary cathodes.

The device operates in such a way that an electrolyte is fed into the cathode space through two openings between the diaphragm walls and the auxiliary cathode. Electropositive impurities than the parent metal precipitate on the auxiliary cathodes and the electrolyte with a reduced concentration of these impurities passes through the holes in the auxiliary cathode to the cathode where the pure parent metal is deposited. This arrangement also prevents diffusion of the electropositive impurities from the anode compartment into the cathode compartment.

The device is shown in Figure 1. In a two-hole electrolyzer 5, a diaphragm 3 is placed into which a cathode 1 and two auxiliary cathodes with holes 2 and 14 are inserted. Auxiliary cathodes 2 and 14 are connected via resistor 11 and ammeter 12 to current source 10 and cathode 1 and anodes 4 and 8 via ammeter 13 to current source 10.

The method of the invention in the apparatus shown in Figure 1 is described in the example without being limited to this example.

Example 1

The device shown was processing an antimony alloy to remove the honey and bismuth. The treated alloy contained 1.43% by weight of media and 3.17% by weight of bismuth. The electrolyte used in the refining had the following composition:

Coll. . H ₂ SO ₄ . . HF. . . . . θβδ.Τ ¹ . . .262 g. 1 * 1. . . 19 g. when After refining using auxiliary cathodes the cathode concentration was as follows: Cu. . . . • 0 g. i-l Bi. . . . . 0.004 g. Γ ¹

and made cathode antimony included

0.0014% Cu .....

Bi. . . . . 0.006%

The cathode current density was 1.52-1.56 A. dm ^{1 2} .

The current density at the auxiliary cathodes was 0.1 A. dm ² .

For comparison, tests without auxiliary cathodes were performed. In refining without auxiliary cathodes, the concentration of Cu and Bi at cathodes was as follows:

Cu ..... 0.0005 g. r ¹

Bi ..... 0.02 g. I ^'1 to give an antimony-containing cathode

Cu. . . . .0,008%

Bi ..... 0.03%

The method and described device of the invention can also be used in the electrolytic production of other metals containing electropositive impurities.

Claims (2)

1. A method for reducing the content of more electropositive metals in cathode metal in the production of metals by electrolysis, characterized in that the electrolyte is electrolyzed at a very low current density of 0.1 A. dm ² and further electrolyzed at a current density of 1.52 to 1; 56 A. dm ² . 2. Apparatus according to claim 1, characterized in that a diaphragm (3) in which the cathode (3) is inserted is placed in an electrolyzer (5) with two electrolyte inlet ports (6, 7) and an electrolyte outlet (9). 1) and two auxiliary cathodes with apertures (2, 14) and further two anodes (4, 8) are inserted into the electrolyzer (5), the auxiliary cathodes (2, 14) being connected via a resistor (11) and an ammeter (13) per current source (10).