JPS6286188A - Electrolyrtic production of metal - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for the electrolytic production of metals from metal halides in the presence of molten salts of one or more alkali metal or alkaline earth metal halides, particularly chlorides, comprising:
An example thereof is a method of converting titanium from titanium tetrachloride.

The extraction of metals by electrolysis in the presence of molten salts is an area of increasing research. An example of this method is described in US-Δ-2757135. In this case, titanium tetrachloride is supplied to the electrolytic cell by introducing it into the molten salt. In practice, however, this method uses a diaphragm that prevents low-valent titanium from flowing into the anode! 2. There is a point. If a diaphragm were not used, the titanium would be reoxidized to tetravalent titanium at the anode, thus resulting in a loss of current and raw material. Furthermore, the accumulation of titanium in the diaphragm shortens the life of the diaphragm, which is extremely disadvantageous.

The present invention provides metal M
The present invention proposes a method for producing an alloy M, Mey, which includes the step of introducing a metal halide HeXn into a cathode composed of a molten metal H or a molten alloy Mex. (Here, Mel, tTi
, If, Ta, AI, Zr, l'l, Nb, V, Mo
jn and Δg) A selected metal, H is Zn, Cd,
a metal selected from Sn, Pb, In, Bi and Ca;
X represents halogen, n represents the valence of metal Me, y
:x) 1), a stage for extracting the alloys M and M(!y) from the cathode, and a stage for recovering the metal Me from the alloy.

The invention will now be explained in more detail with reference to FIGS. 1 and 2, which show examples of possible electrolysis cells for the electrolysis of titanium tetrachloride to produce titanium metal in the cathode of the liquefier 39.

In Figure 1, tank 1 is made of heat insulating material such as refractory brick.
[It is located in Jakera l-2 of [. The cathode 3 is composed of liquid zinc, which is supplied in a stream T via an insulating tube 4 and a supply rod 4a. The supply of titanium tetrachloride takes place via a pipe 5 and a distributor 6, which is composed of, for example, a metal grid or a porous ceramic material (water) with outlets arranged at intervals.

The anode 7 is placed within the electrolyte 8 near the interface 11 between the cathode and the electrolyte. The horizontal surface area of the anode is selected to be large.
壬 um / f 蒐 vocation no ka I no u no, ;
Denkaku Ryo liquid 8 (well, PjlI is 350 ~
Heated to high temperatures of 900°C or higher. The lid 9 has a supply pipe 10 for inert gas such as argon for fPJ.
and a discharge pipe 11 for chlorine gas generated at the anode are inserted. The electric current and supply of titanium tetrachloride are such that all or substantially all of the titanium is reduced in the cathode and
()/ditane are adjusted to be compatible with each other to form an alloy. Therefore, the anode does not need to be protected by a diaphragm. This is achieved, for example, by supplying a current of at least 4 Faradays per mole of 4-H titanium. There is no need to evaporate the titanium tetrachloride before introducing the cathode.If necessary, the cell may be provided with means for precisely controlling the temperature of the process.The space above the electrolyte 8 may be cooled. Alternatively, the evaporated molten salt of zinc may be condensed internally or externally and fed back.The supply and discharge of the cathode liquid is carried out in line 12, especially in continuous embodiments.
and 13.

The titanium content in the 2n/Ti composite can be increased to a certain value, preferably 6-20%. Conventional methods such as cathode evaporation may be used to recover titanium metal from the alloy.

FIG. 2 shows a tank with vertically arranged anodes. Identical components are given the same reference numerals. A tray 14 is placed in the molten salt, and liquid zinc is contained in the tray.

In this case, the titanium tetrachloride vapor can enter through the opening in the lower part of the cofeed pipe 5. The anode 7 is configured as a closed cylinder that completely surrounds the cathode.

The above are the most preferred embodiments of the present invention, namely ? vL (*Although the present invention has been described in detail with respect to a specific example of manufacturing titanium from titanium tetrachloride using a zinc cathode, the present invention is not limited thereto. , lead, bismuth, indium and gallium, of which tin and 59 are preferred. Similarly, tantalum, aluminum, zirconium, tungsten, niobium, vanadium, Other raw materials may be treated such as halides of molybdenum, indium, silver and antimony. Suitable metal halides to be treated are halides of tantalum, tungsten, vanadium and niobium. Molten Salt Composition The preferred halogen atom is chlorine.

It is not known to what extent the production of gold, [Me, proceeds through direct electrolytic conversion of e.g.
If l< is introduced, for example, 2TiCI++Zn-2Ti
As expressed by CIs + ZnCl□, the valence is lowered by chemical reduction of metal Me, and then trivalent titanium is electrolytically reduced to metal (zero-valent) titanium, and at the same time, divalent zinc is reduced to metal (zero-valent) titanium. The cathode material is electrolytically regenerated by reduction to metallic (zerovalent) zinc. The reduction of high valence gold 515Me to zero valence metal through a combination of chemical and electrolytic reductions in this way is certainly within the scope of the present invention.
T in a liquid zinc cathode using entirely chemical reduction with metallic zinc and electrolytic regeneration (reduction) of the cathode material.
Also included within the scope of the present invention is a process for producing zero-valent antimony from aCl. The key point in the present invention is to use an electrolytic cell with a liquid metal or alloy cathode, and to use a metal halide McX in the liquid cathode.
n directly and to produce (zerovalent) metal Me in the cathode material, this last '1g
The test is carried out in a molten salt electrolyte or deposited on a second or auxiliary cathode T1f! ：Other metal M as used
It is distinguished from the manufacturing method of e. The fact that there is no diaphragm in the baking soda, and that the molten salt is free of impurities, is not strictly necessary; on the other hand, in an inert atmosphere such as argon or nitrogen, It is advantageous to operate below. An example of a suitable molten salt is LiCl/NaCl
, NaCl/KCI, LiCl/KCI, LiCl/C
aCl2, NaCl/I) acl□ and KCI/CaC
l2, but as already pointed out, the invention is not limited to these melts.

As a general rule, a suitable processing temperature is above the melting point of the cathode material and below a temperature at which the vapor pressure of the material causes an undesirably large to loss. , 425~ for zinc
890°C, 400-700'C for cadmium. Also, the processing temperature should not be so high that there is a substantial loss of molten salt electrolyte due to evaporation or decomposition.

The electric current and the supply of metal halide raw material are adjusted such that the metal Me is completely reduced in the cathode. Preferably, at least nF is provided per mole of metal halide MeXn, where n is the valence of the metal. However, since it is preferable to deposit as little salt-molten metal as possible on the cathode, the current is limited to a predetermined maximum value. The raw materials should preferably be introduced in such a way that they are evenly distributed in the cathode. The simplest method for this is to use a gaseous raw material when introducing the raw material into the cathode material. It is also within the scope of the present invention. As a result, there is no or substantially no residual metal Me of any valence in the molten salt. Thus, there is no need to use a diaphragm to protect the anode. , thus no undesired current and voltage losses occur, which is extremely beneficial from a technical and economic point of view.A vessel that does not bias the diaphragm is preferred.

In the alloys M and Mey taken out from the electrolytic bath, y represents the atomic ratio of Me and Ag. This ratio is generally kept below 0.5, preferably below 0.3. gold from alloy ffj
, as a simple method for recovering He, it is preferable to treat alloys in which the content of metallic Me is 6 to 20% by weight based on the weight of the alloy.

The present invention will be explained below using a plurality of experiments.

Wheat 11L a, 1.5 kg of co-dispersed LiC1/KCI mixture (5
9:41 mol) to 11C1 for 8 hours at a temperature higher than the melting point.
The mixture was purified by passing gas through it. HCI shifts the following equilibria a) and l+) to the left, so that an anhydrous melt containing almost no oxygen is obtained.

a) CI” + ll2O-IIC1+ ol+-
1J) 2Cl-+ll□0→211CI+02-Then, residual oxygen compounds and metal impurities were removed by vacuum electrolysis at a sliding voltage of 2.7 .

An externally heated stainless steel electrolytic cell is used, with a Δ1□0. A molten zinc cathode (9
0y) was placed. A graphite rod was used as the anode, no diaphragm was used, and 250 g of molten salt was used as the electrolyte. The sliding voltage is 5. Ov, and the cathode potential is -2,OV
(Heg/Δ, CI electrode is used as a reference electrode), and other conditions are shown in Table 1. TiCI= was injected as a liquid in a stream of argon and fed to the cathode.

An argon atmosphere was maintained above the molten salt. A current of 6F per mole of TiC was used in Zenjisun.

Results 3 were determined by cooled solid 3 m microscopy and chemical analysis.

・g1湛−1− 明 0 0 ″r′ b, The alloy gold produced in the first experiment in Table 1 was distilled to remove all zinc. Analysis revealed that the residue was made from very pure titanium. It seemed to be configured.

TiCl was electrolyzed in the same manner as in Example 1a using various cathode materials and under the same conditions except as shown in Table 1.

Example I under the same conditions except as shown in Table 1 using various metal halide raw materials and various cathode materials.
The experiment was conducted in the same way.

[Brief explanation of drawings]

FIGS. 1 and 2 show, by way of example, a possible electrolytic cell for the electrolysis of titanium tetrachloride to produce metallic titanium in a liquid zinc cathode. 1...tank, 2...jacket, 3...
Cathode, 4... Insulation tube, 6... Distributor, 7... Anode, 8... Electrolyte, Cape...
... Lid, 10 ... Supply pipe, 11 ...
・Discharge pipe, 12.13...pipe line, 14...I
・Leh.

Claims (12)

[Claims] (1) A method for producing metal Me by electrolysis in the presence of a molten salt of one or more alkali metals or alkaline earth metal halides, comprising: an alloy M. To produce Me_y, molten metal M or molten alloy M. A step of introducing a metal halide MeX_n into a cathode composed of Me_x (where Me is Ti, Hf, Ta, Al, Zr,
A metal selected from W, Nb, V, Mo, In and Ag, M is a metal selected from Zn, Cd, Sn, Pb, In, Bi and Ca, X represents a halogen, n is a metal Me
(where y:x>1) and the alloy M. The step of extracting Me_y and the step of extracting metal Me from the alloy.
said method comprising the step of recovering. (2) Metal halide Me through the liquid cathode material
2. A method according to claim 1, wherein X_n is distributed in gaseous form. (3) The method according to claim 1 or 2, wherein X is chlorine. (4) The alloy to be extracted contains 6 to 20% by weight of metal Me calculated based on the weight of the alloy, and M
4. A method according to any one of claims 1 to 3, wherein e is titanium. (5) At least nF. 5. The method according to claim 1, wherein a current of mol^-^1 is used (n is the valence of the metal Me in the raw material). (6) The method according to any one of claims 1 to 5, wherein the molten salt is a chloride. (7) The method according to any one of claims 1 to 6, wherein Me is selected from Ti, Ta, W, V, and Nb. (8) The method according to claim 7, wherein the metal Me is Ti. (9) The method according to any one of claims 1 to 8, wherein the metal H is Zn, Sn, or Pb. (10) The method according to claim 9, wherein the metal M is Zn. (11) The method according to any one of claims 1 to 10, which is carried out in an electrolytic cell without a diaphragm. (12) A method according to claim 1, substantially as herein described with reference to the Examples.