RU2450091C2 - Electrolytic cell to separate fusible alloys into selective concentrates - Google Patents

Abstract

FIELD: metallurgy.

SUBSTANCE: electrolytic cell comprises heated cathode and anode cavities, separated with at least three porous diaphragms impregnated with electrolyte. Diaphragms are installed vertically and are alternately separated and fixed with gaskets. Gaskets have different angles of inclination of inner walls and lower cuts with formation of channels for drainage of metal concentrates into individual collectors of selective concentrates, with which an electrolytic cell is equipped. Diaphragms with gaskets are installed with sets of 2-3 copies.

EFFECT: electrolytic cell design with vertical diaphragms makes it possible to increase separation of wastes of fusible alloys of a complex composition into several selective metal concentrates.

4 cl, 5 tbl

Description

The invention relates to ferrous metallurgy, in particular to electrochemical methods for the separation of metals from a melt.

Known electrolyzer [1], in which the cathode and the anode are separated by a vertical screen to increase the purity of the cathode metal. The disadvantage of this electrolyzer is that the horizontal anodic and cathodic molten metals are separated by a vertical screen, which requires a large volume of electrolyte with high costs for its preparation.

As a prototype - the closest analogue for the purpose and combination of essential features - is taken electrolyzer separation of fusible alloys into selective concentrates, disclosed in the method [2]. The cell contains heated anode and cathode cavities separated by porous diaphragms soaked in electrolyte.

The disadvantage of this cell is the inability to continuously withdraw the intermediate product and the accumulated electropositive impurities continue to pass to the cathode. This leads to a decrease in the degree of separation of metals.

The technical result consists in increasing the degree of separation of metals into selective concentrates.

The essence of the invention lies in the fact that the electrolyzer is equipped with individual collectors of selective concentrates, and the cathode and anode cavities are separated by at least three porous diaphragms mounted vertically, which are alternately separated and fixed by gaskets having different angles of inclination of the inner walls and lower cutouts with the formation of drain channels metals in the mentioned collections.

In the electrolyzer, the vertical porous diaphragms are separated by gaskets with different angles of inclination of the inner wall.

In addition, diaphragms with gaskets are installed in sets of 2-3

with a shift of the cutouts relative to each other.

Figure 1 shows a longitudinal view of the electrolyzer.

Figure 2 shows the electrolyzer in section aa.

Figure 3 shows the sealing gasket.

Figure 4 shows the cathode gasket (anode).

Figure 5 shows the gasket industrial.

The electrolyzer consists (figure 1, 2) of a fluoroplastic wall of the housing 1 of the bath. The sealing fluoroplastic gasket 2 (FIGS. 2, 3) forms an anode cavity 3 with the wall 1 for the molten starting alloy. A current lead 4 to the anode (stainless steel) is fixed in the anode cavity 3.

On the opposite side of the bath in the cavity formed by the housing 1 and the sealing gasket 2, a cathode 5 made of titanium is fixed. The cathode 5 and the anode cavity 3 are separated by several (at least three) diaphragms 6, 7, 8 made of KT-11-s8 / 3-TO quartz fabric, which alternately separate and fix the fluoroplastic gaskets 9, 10, 11 2-4 thick mm Each gasket (FIGS. 4, 5) has a different angle of inclination of the walls with a cutout in the lower part. This contributes to the drainage of the accumulated metal into separate collectors.

From the side of the anode cavity 3 (Fig. 2), the anode spacer 9 fixes the diaphragm 6 with the formation of a gap between the diaphragms 6, 7 in its cavity, and a cutout 12 is made in the lower part of the anode spacer.

The diaphragm 7 is fixed by the intermediate ring gasket 10 (Fig.2, 5) with the formation in its cavity a of a gap between the diaphragms 7, 8, and a cut 13 is made in the lower part of the cavity in the intermediate gasket.

The diaphragm 8 on the cathode side is fixed by the cathode gasket 11 (Figs. 2, 4) with the formation of a cavity in the gap between the diaphragm 8, the wall 1 and the sealing gasket 2. A cut is made in the lower part of the cathode gasket 14. The cathode gasket 11 with the sealing gasket 2 form with the wall 1 of the housing (figure 2) a cavity for the cathode 5.

The gaskets 9, 10, 11 are mutually arranged so that the cutouts 12, 13, 14 are shifted in length relative to each other to install individual collections. Between gaskets 9-11, diaphragms 6-8, insulating gaskets 2 and walls 1, the gaps during installation are sealed with a high-temperature sealant.

As an additional option, gaskets 9,10, 11 with diaphragms 6, 7, 8 can be made in 2-3 pieces to improve the quality of products depending on the composition of the initial alloy.

Under the slit 12 there is a collection 15 (Fig. 1) for the anode product. Under the slit 13 there is a collection 16 for industrial products. Under the slit 14 there is a collector 17 for the cathode product.

Walls 1 of the bath body with gaskets 9,10,11 are placed in a thermally insulating body 18 with a heater for controlled heating. The current lead of the anode 4 and cathode 5 are connected to a constant current source. The cell operates as follows.

The walls of the housing 1 (figure 1) bathtubs with collectors 14, 15, 16 are heated in a heat-insulating housing 18 to a temperature of 220-240 degrees. A molten electrolyte of the composition, wt.%: 16-18 potassium chloride, 10-12 sodium chloride, the rest is zinc chloride, is poured into the cavity of the anode 3 (Fig. 2), the rest is zinc chloride, for wetting the capillaries of all diaphragms 6, 7, 8 from quartz fabric.

The diaphragm is made of quartz fabric of the KT-11-s8 / 3-TO brand of satin weave, heat-resistant, withstands a layer of 6 cm of metal without permeability, but has a porosity of 50-60% and absorbs electrolyte.

After a single impregnation of the tissues, the initial molten alloy is poured into the cavity of the anode 3 and the anode current lead 4 is inserted. The direct current is turned on and the current strength is set.

From the molten alloy in the anode cavity 3, electronegative metals are ionized and diffuse through the electrolyte in the capillaries of the diaphragm 6 through the by-product diaphragm 7 towards the cathode 5.

At the same time, due to a higher concentration, ionization of a certain amount of more electropositive metals can occur. Ions of electropositive metals also diffuse along the electrolyte in the capillaries of the diaphragms. By changing the voltage at the entrance to the next diaphragm, more electropositive metals are discharged.

At the intermediate diaphragm 7 (Fig. 2), when the voltage drops across the diaphragm, more electropositive metals are deposited, accumulate in the cavity of the gap formed inside the intermediate strip 9 and, as they accumulate, overcome the metal retaining film in the gap and flow down the slot 12 of the intermediate strip into the collector 15 (figure 1) of the anode intermediate.

More electronegative metal ions continue to diffuse in the electrolyte along the by-product diaphragm 7 (figure 2).

A voltage drop is formed on the cathode diaphragm 8 and partially passed more electropositive metals are deposited on the cathode diaphragm 8, accumulate in the cavity of the gap formed inside the intermediate strip 10, and as the metal accumulates in the gap, the slot 13 of the intermediate strip is drained into the collector 16 in the middle section.

More electronegative metal ions continue to diffuse in the electrolyte along the capillaries of the diaphragm 8 into the cathode cavity between the cathode gasket 11 and the cathode 5 and are discharged on the cathode 5. As the metal accumulates in the cathode cavity formed by the gap between the gasket 11, the gasket 2 and the wall 1, the metal flows down the slit of the cutout 14 of the cathode strip into the collector 17 of the cathode product.

The technical result of the distinguishing feature is an increase in the degree of concentration of metals in individual concentrates. More electropositive metals, such as bismuth, antimony, accumulate at the anode, and more electronegative metals, like indium and cadmium, are released at the cathode (collection 17). In inter-diaphragm cavities, metals (lead) are discharged and flow off with an intermediate discharge potential into the anode intermediate product (collection 15), and tin accumulates in the near-cathode intermediate product 16.

The proposed electrolyzer with vertical diaphragms allows the initial multicomponent low-melting alloy of complex composition to be divided into four selective concentrates in which metals are concentrated more than 3 times in comparison with the initial alloy composition.

An example of a test cell: a sample of 100 g of the alloy composition, wt.%: Bi - 46; Sn is 25; Pb - 20; In - 8; Cd - 1.1 was melted and poured into the anode cavity of the electrolyzer body heated to a temperature of 240 ° C. A direct current of 0.5A and a voltage of 20V was brought to the current leads. Electrolysis was carried out for 8.5 hours. At the cathode received 12 g of metal composition,%: indium - 63.1; cadmium - 7.6; lead - 6; tin - 23.1; bismuth - 0.1. Anodic intermediate product obtained 20 g of the composition,%: indium - 0.5; cadmium 0.1; lead - 80.3; tin - 18; bismuth - 1.1. The cathode intermediate product obtained 19 g, composition,%: indium - 2; cadmium - 0.3; lead - 7; tin - 90.2; bismuth - 0.5. The composition of the anode residue, wt.%: Indium - 0.1; cadmium - 0.05; lead - 4.3; tin - 2.1; bismuth - 93.4. An example shows that 4 separate selective concentrates are obtained from an alloy.

Literature

1 - Auth. No. 453448 - application No. 1870379 - M. cl. - C22b 61/06, - Dyakov V.E., Nikitina V.D., Koryukov Yu.S., Yakovlev M.A. - Electrolyzer to produce fusible metal. - publ. 01.20.75 - BI 46-74

2. RU No. 1776093 C, C25C 3/34, publ. 01/02/1991

Claims (4)

1. An electrolyzer for separating low-melting alloys into selective concentrates, containing heated cathode and anode cavities separated by porous diaphragms saturated with electrolyte, characterized in that it is equipped with individual collectors of selective concentrates, and the cathode and anode cavities are separated by at least three porous diaphragms mounted vertically which are alternately separated and fixed by gaskets having different angles of inclination of the inner walls and lower cutouts with the formation of drain channels to metal concentrates in the mentioned collections. 2. The electrolyzer according to claim 1, characterized in that the vertical porous diaphragms are separated by gaskets with different angles of inclination of the inner wall. 3. The cell according to claims 1 and 2, characterized in that the gaskets are placed with a shift of the cutouts relative to each other. 4. The electrolyzer according to claim 3, characterized in that the diaphragms with ring gaskets are made in sets of 2-3 copies.

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