JPS5914556B2 - Metallic diaphragm for electrolytic production of titanium, electrolytic cell using the diaphragm, and method for producing titanium in the electrolytic cell - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a metallic diaphragm for electrolytically producing titanium, an electrolytic cell using the diaphragm, and a method for producing titanium in the electrolytic cell.

Polyvalent metals such as titanium have traditionally been synthesized from their compounds, e.g. titanium tetrachloride, in U.S. Pat.
It is manufactured by the electrolytic method described in No. 2 and No. 3082159.

In general, titanium tetrachloride is electrolytically dissociated by placing it in a molten alkali or alkali metal salt bath by an appropriate method to electrodeposit metallic titanium on the cathode and release elemental chlorine at the anode. Various methods have been used to separate the anode from the cathode in titanium-containing electrolytic cells. A physical barrier, such as a diaphragm, between the anode and cathode chambers is necessary to prevent excessive flow of titanium ions from the cathode chamber to the anode chamber.

If excessive ion flux occurs, the titanium ion
It is oxidized to titanium chloride, thereby reducing cell efficiency. The diaphragm is also required to pass the chloride ion and molten salt bath between the anode and cathode compartments. U.S. Patent No. 278994
The No. 3 diaphragm has a perforated conductive metal structure and is used alternately as an anode or a cathode.

The porosity of the membrane is reduced by using the membrane as a cathode and depositing metallic titanium into its pores. When the diaphragm becomes severely impermeable and the efficiency of the D electrolytic cell decreases, the electrical polarity is reversed and the diaphragm becomes the anode and titanium is then removed. While variable porosity membranes are convenient, a membrane that does not require constant monitoring and occasional electrodeposition and removal of metal is more desirable. Conventional electrolyzers can be used, but the diaphragm between the anode and cathode chambers is generally insufficient for the strength required in industrial electrolyzers, or requires constant attention to porosity adjustment during cell operation. That is.

What is desired is an improved electrolytic cell for the electrolytic production of metals that utilizes a membrane of adequate physical strength and constant porosity that does not require adjustment during operation, and a method of operating the cell. Metals such as titanium have traditionally been produced electrolytically, for example from titanium tetrachloride, in a molten salt bath of a mixture such as potassium chloride and lithium chloride in an electrolytic cell with equipment for supplying metal ions to the anode, cathode and electrolytic bath. There is. In general, such a method is used, for example, in the high-purity titanium 1 electrolytically produced from titanium tetrachloride (J.
．． OfMetals 18, 1967, March), the use of synthetic diaphragms in the electro-production of 6-titanium by Leon et al.
eauOfminesRepOrtRl7648,l9
72) and U.S. Patent No. 2789943, 29430
No. 32 and No. 3082159.

These methods, for example, directly blow titanium tetrachloride gas into molten lithium chloride potassium monochloride catholyte to reduce titanium ions, deposit metallic titanium on the cathode, and release chlorine gas at the anode, generally achieving a satisfactory titanium content. Can be generated. However, there is a need for improved methods for introducing or supplying polyvalent metals, such as titanium, into the molten salt bath of an electrolytic cell. A new and improved method of introducing ionized metal compounds into the electrolyte of an electrolytic cell has now been discovered.

Ionizable metals are at least divalent metals.
The ionizable metal compound conductor equipment or feed cathode comprises a feed tube having at least one inlet and at least one outlet suitable for conveying the metal compound from the metal compound source into the electrolyte.
The supply cathode has a substantially complete enclosure surrounding at least the outlet of the tube. The enclosure consists at least in part of an electrically conductive porous material suitable for passage of electrolyte and polyvalent metal compound ions. During operation, the ionizable polyvalent metal compound passes through the tube and enters the electrolyte. It is believed that upon entering or mixing with the electrolyte, the metal compound dissociates into metal compound ions.
The enclosure element advantageously confines the agitation caused by the gaseous metal compound and/or inert dispersing gas within the feed cathode. A power source is electrically connected to at least the perforated component to provide a sufficient negative charge to the perforated component to lower the metal ions from a high valence state to a low valence state. An electrolytic solution containing dissolved ions from the metal compound enters the deposition cathode chamber through the perforated component and reaches the cathode where solid metal is deposited. Generally, the metal ions will be reduced from a high valence state to a low valence state within or substantially proximate to the supply cathode. More specifically, the present invention relates to 0j. D A titanium perforated part made of a metal having a diaphragm coefficient of up to 0.5 and a flow coefficient in the range of 0.1 to 25, and at least the surface of the perforated part is made of a metal capable of withstanding the corrosive environment of an electrolytic cell. The present invention relates to a metallic diaphragm suitable for separating the anode compartment from the cathode compartment of an electrolytic cell having a molten salt bath for electrolytic production.

The invention further relates to an electrolytic cell for the production of titanium in a molten salt bath, said electrolytic cell comprising a body suitable for containing the bath;
Equipment for isolating the bath from the atmosphere, an anode chamber in the main body,
equipment for removing gas from said anode chamber; a cathode chamber in said body; at least one anode in said anode chamber and at least partially immersed in a bath; at least one deposited cathode immersed in the anode, said anode and a power source connected to the anode, at least one supply facility suitable for supplying polyvalent metal ions to the bath, and for separating the anode chamber from the cathode chamber. at least one metallic perforated diaphragm at least partially immersed in the bath and capable of withstanding the corrosive environment within the vessel; D has a diaphragm coefficient of up to 0.05 and a flow coefficient of 0.1 to 25, and is electrically insulated from the power source outside the anode and cathode room.

The invention also provides a method for producing titanium in an electrolytic cell comprising at least one anode in an anode chamber, at least one cathode in a cathode chamber, and provision for supplying a titanium compound to a molten salt bath in the electrolytic cell. The anode and cathode have at least a surface that can withstand the environment inside the tank, a diaphragm coefficient of up to 0.5, a flow coefficient in the range of 0.1 to 25, and the anode and cathode are electrically insulated from the outdoor power source. The present invention relates to a method for producing titanium, which includes a step of inserting a perforated diaphragm into an electrolytic cell to separate an anode chamber and a cathode chamber, and a step of applying an electromotive force between the anode and cathode. The invention further relates to a feed cathode installation suitable for use in an electrolytic cell with a molten salt bath.

Said equipment incorporates a supply pipe to a bath of polyvalent metal compounds having at least one outlet suitable for conveying said metal compound from a metal compound source to a molten salt bath in an electrolytic cell, and at least an outlet of said pipe. The surrounding part is formed at least in part of an electrically conductive porous material through which polyvalent metal compound ions and electrolyte can pass. The present invention also includes: (a) applying a discrete direct current electromotive force between a primary anode and a primary cathode immersed in a test cell with an electrolyte; (c) measuring the electrical properties in the specified portion of the electrolytic solution using two measuring electrodes that are in communication with the specified portion of the electrolytic solution through a first salt bridge and a second salt bridge having orifices; Inserting a metal diaphragm into the electrolyte between said measuring electrodes having such conductivity that insertion of the metal diaphragm into the liquid between the electrodes results in an insufficient voltage change across the primary electrodes to convert the diaphragm into an intermediate electrode. and (d) relates to a method for preliminary determination of the suitability of a metallic diaphragm for use in an electrolytic cell, comprising re-measuring the electrical properties in a defined portion of the electrolyte as in (b). The electrolytic cell of the invention essentially consists of a combined body suitable for containing a molten salt bath and for isolating the bath from the atmosphere. The anode chamber and the cathode chamber are separated from each other within the main body. The anode chamber and the cathode chamber are electrically insulated from their external power source and separated by at least one perforated metallic diaphragm that is at least partially immersed in the molten salt during cell operation. ing. The flow coefficient of this diaphragm (Cf
) is in the range of 0.1 to 25, it is characterized in that the diaphragm coefficient (Cd) is greater than O and is in the range of 0.5.
Here, Cd is expressed in units of 2.54cr1L, and Cf is B per liter per minute per diaphragm surface area of 194cm2.
It is expressed as the square root of 2.54 CTL units. The diaphragm coefficient can be measured by the following method and is expressed by the following formula: 1.9C between electrodes.
By means of a calomel measuring electrode in communication with the solution in the test cell through a salt bridge with an orifice 71 L away and a distance from the diaphragm between the primary electrodes in operation. The voltage (in volts) in a 1 molar aqueous sodium chloride solution in the test cell when measured.

Let Id-l-s be the 0.002 amp current maintained between the primary electrodes in solution with the diaphragm in position relative to Vd+s.

V8 is the voltage (in volts) measured as Vd+8 without a diaphragm.

Is is the current of 0.002 amps maintained between the primary electrodes in solution when measured as Id-1-s without a diaphragm.

The flow coefficient is expressed by the following equation: where h is the rate of water at approximately 24° C. measured upward from the center line of a circular diaphragm section having an area of 194C7rL2 on one side of the diaphragm section from which the water flow rate measurement through the diaphragm is obtained. 4c
Let the pressure head be m.

F is the current capacity of water flow per minute at approximately 24°C through the diaphragm (
Little).

Depending on the shape and size of the diaphragm, diaphragms smaller or larger than the above 194cTn2 can also be used for water measurement.

When using a small or large diaphragm, F is 194CT above.
! It is necessary to calculate the amount of water flowing through the 12 areas. In a slightly different way, the above formula for determining the diaphragm coefficient is essentially the sum of the resistances of the diaphragm and test cell solutions minus the resistance of the solution and divided by the resistance of the solution.

The value obtained from this calculation is that the salt bridge is 1.9 CTf.
Since the distance is L, the electrical resistance of the diaphragm is expressed by the electrical resistance of the solution 1.9 (177!).

Calculated value of solution? To convert to , just multiply by 1.9. The diaphragm coefficient represents the electrical resistance of the diaphragm in the test cell. The diaphragm coefficient is also believed to be a measure of the resistance of the solution within the pores of the diaphragm. From the point of view that the diaphragm coefficient (Cd) is also a measure of the resistance of the solution in the pores of the diaphragm,
Needless to say, it is desirable that this value be close to O.

However, it is actually impossible to obtain a diaphragm with a diaphragm coefficient of O, and the condition that Cd=O is satisfied only when there is no diaphragm in the electrolytic cell. However, in this case (in the absence of a diaphragm), normal electrolytic operation is impossible and only heat is generated when current is passed through the electrolytic cell. Therefore, the lower limit value of the diaphragm coefficient is determined in the sense that a diaphragm having a value close to 0 is preferable. On the other hand, if the diaphragm coefficient exceeds 0.5, the diaphragm becomes very fluid-tight, i.e. has a very large resistance to the flow of ions, and the current density is completely reduced under normal operating conditions of the electrolyzer. It is not suitable for commercial use since it reduces to values that are not economically interesting. For the above reasons, the diaphragm coefficient of the diaphragm of the present invention must take a value greater than 0 and up to 0.5. Regarding the flow coefficient (Cf), if Cf<0.1, the overall flow of electrolyte through the diaphragm becomes too excessive and extremely inefficient.

In this case, as in the case of CdO, the electrolytic cell approaches a limit value at which only heat is generated. On the other hand, if Cf>25, the overall flow of electrolyte through the diaphragm will be very low.
In such a case, in order to fall within the above Cd value range, the number of pores in the diaphragm per unit area is very large, and the diameter of the pores in the diaphragm is very small. Manufacturing is too expensive making it unsuitable for industrial use. For the above reasons, the flow coefficient of the diaphragm of the present invention must take a value from 0.1 to 25 (under the condition that the diaphragm coefficient must take a value greater than O and up to 0.5). The electrolytic cell of the invention further has at least one anode located within the anode chamber and at least partially immersed in the bath. Also within the cathode chamber is at least one deposited cathode, at least partially immersed in the bath. Appropriate equipment for removing the gas produced at the anode is associated with the anode chamber. at least one metal-containing feed material, such as an ionizable metal compound, suitable for delivering to the bath
Supply equipment and equipment suitable for removing metal deposited on the cathode are combined in the cathode chamber. Additionally, suitable equipment is connected to the anode and cathode to provide sufficient electrical energy to reduce the metal ions from a high valence state to a low valence state and to deposit the metal at the deposition cathode. Preferred apparatus and methods are described for titanium production. The titanium compound supplied to the cathode chamber is characterized by ionization at least partially, preferably substantially completely, in the molten salt bath. Titanium ions are reduced from a high valence state to a low valence state at the cathode. Halogen gases such as chlorine are released at the anode. Gas and titanium metal are removed from the electrolytic cell with suitable equipment.
The accompanying figures further illustrate the invention.

FIG. 1 is a sectional view of an electrolytic cell for producing titanium according to the present invention.

FIG. 2 is a cross-sectional view of another embodiment of the invention.

FIG. 3 is a schematic diagram of the equipment for measuring the water flow rate through the diaphragm of the present invention. FIG. 4 is a schematic diagram of equipment suitable for measuring the diaphragm coefficient of the diaphragm of the present invention.

FIG. 5 shows an embodiment of the feed cathode for use in the electrolytic cell of the invention.

FIG. 6 shows an embodiment of the invention in combination with an electrolytic diaphragm cell.

Identical numbers with suffixes in each figure indicate parts with identical functions in different embodiments.

FIG. 1 shows an electrolytic cell 10 in which a polyvalent metal, such as titanium, is electrolytically produced from its compounds in a molten salt bath. The following description relates to the electrolytic production of titanium. However, this also generally applies to polyvalent metals. The molten or molten salt has properties as a solvent for the titanium compound. These salts or mixtures thereof include, for example, NaCl, LiCl-KCl, LiC]-K
Cl-NaCl, and LiCl-KCl-CaCl2
It is. When recovering titanium from titanium tetrachloride, the molten salt bath preferably contains an alkali or alkaline earth metal chloride, preferably chlorides of lithium and potassium. A eutectic mixture of salts for use in the bath is convenient because it has a low melting point. Electrolytic cell 10 includes a body or vessel 12 suitable for containing a molten chloride salt bath and titanium tetrachloride without substantially adversely affecting the material of vessel 12.

Container 12 is generally made of metal, such as steel or nickel, although many different materials are suitable. The interior of the container 12 is divided into at least an anode chamber 14 and a deposition cathode chamber 16. The anode chamber 14 and the cathode chamber 16 are separated from each other by a perforated metal diaphragm 17. The diaphragm support 15 is optionally combined with the diaphragm 17 to reinforce the diaphragm strength during operation of the electrolytic cell 10.
The diaphragm matrix is a metal mesh with numerous holes or holes throughout;
A plate or a thin film is preferred.

This hole can be formed, for example, by turning, punching, knitting, or sintering. Generally, the pores in the matrix should be substantially uniform in size. Diaphragm 17 is preferably a U.S. standard sieve mesh 50 (297 microns) to 250 (63 microns), coated with sufficient nickel or cobalt by electrolytic or non-electrical methods to provide the desired diaphragm coefficient (Cd) and flow coefficient Cf. is 100
(149 microns) to 200 (74 microns) woven wire mesh is preferred. Preferably, the deposited metal consists essentially of either nickel or cobalt. Suitable deposition methods may be those known in the art suitable for reducing the amount of brightener in the plating solution to produce visually dull or rough surfaces. Table 1 provides examples of non-electrical cobalt and nickel plating solutions suitable for use in plating diaphragm 17. The diaphragm matrix may be ferrous, such as steel or stainless steel, but may also contain cobalt, nickel, or at least about 50% by weight to withstand the corrosive environment within the container 10 and to have sufficient strength at specified temperatures to act as a diaphragm. Metals such as cobalt or alloys thereof containing nickel are preferred.

In particular, the membrane substrate is preferably industrially pure nickel. Anode 1
8 is at least partially immersed in a molten chloride salt bath in the anode chamber 14 during operation of the electrolytic cell 10.

The material of the anode 18 is resistant to the corrosive effects of the molten chloride salt bath and to the elemental chlorine produced at the positively charged anode during bath operation. Suitable anode materials are carbon or graphite. The cathode 20 is at least partially immersed within the cathode chamber 16 in a molten chloride salt bath during operation of the electrolyzer 10 . The deposited cathode 20 is a material such as carbon or a metal such as common carbon steel or titanium, on which titanium metal is deposited and then recovered. The cathode chamber 16 is also equipped with heating equipment (not shown) for heating and cooling the contents of the vessel 10 to the desired temperature, and a bath melting system suitable for delivering a titanium-containing feed material to the halogenide salt bath during operation of the vessel 10. It has a supply facility 22.

During operation, titanium tetrachloride is sent from raw material facility 24 through transport pipe 26 to supply facility 22 where it exits through a number of holes 28 in supply facility 22 into the molten monogenide salt bath in cathode chamber 16. . The container 12 has an anode 18, a cathode 20 and a lid 30, 30a and 30 for supplying equipment 22.
b is added. Lid 30, 30a and 30b are container 1
The container 12 is removable so that a sufficient amount of atmosphere, particularly nitrogen, oxygen, carbon dioxide, and water vapor, does not enter the container 12 during operation to maintain a controlled atmosphere within the container 2 and to substantially reduce operating efficiency. It's attached. The lids 30, 30a and 30b preferably substantially completely exclude oxygen from the chambers 14 and 16. The lid 30a also provides a facility for removing solid titanium metal from the cathode chamber 16 after it has been deposited on the cathode 20. During operation, the atmosphere inside the electrolytic cell 10 is adjusted and the atmospheric gas is limited to a low specified amount. The presence of substantial amounts of oxygen, particularly those approaching the amount normally found in air, is undesirable as it reduces cell efficiency, cell operating life, and titanium product quality. It is therefore preferred h'-to substantially completely exclude oxygen and other reactive gases from chambers 14 and 16. The lid 30a is suitable for excluding oxygen and providing a facility for removing metallic titanium from the cathode chamber 16 after solid elemental titanium has arrived at the deposited cathode 20. Chlorine gas produced at the anode 18 is sent from the anode chamber 14 through chlorine removal equipment or pipe 32 to a condenser or chlorine storage tank (not shown).

An electrical supply, such as a generator or rectifier 34, reduces the titanium ions from a +4 valence state to a lower valence state, depositing metallic titanium on the negatively charged deposition cathode 20 and providing sufficient electrical power to release elemental chlorine at the positively charged anode 18. It is suitable for supplying electrical energy to the electrolytic cell 10. The anode 18, the deposition cathode 20, the supply equipment 22 and the diaphragm 17 are electrically insulated from the container 12 by an insulator 35. Further, the diaphragm 17 has an anode chamber 14 and a cathode chamber 1, such as electrical circuits connected to the anode 18 and the cathode 20.
It is electrically isolated from the external power source of 6. In other words, the diaphragm 17 is located within the container 12 and operates in the electrolytic cell 10 without any connections that impose an electrical load on the diaphragm. The container 12 is optionally provided with suitably spaced flanges 3 that provide a passageway or storage area.
A diaphragm mounting equipment such as 6 is provided, and the diaphragm 17 is attached to it.

The embodiment of FIG. 1 is operated with a second diaphragm (not shown) before removing the diaphragm 17 if it becomes necessary to replace the diaphragm 17.
juxtaposed with the diaphragm 17 in the unused flange 36.
Optionally, by use of flanges 36, V) two or more diaphragms can be used simultaneously. The flange 36 is also provided at least in the cathode compartment 16 and optionally in the anolyte compartment 14 to prevent mechanical damage or physical blockage of the diaphragm 17 by solid materials present in the catholyte or anolyte. (not shown) can be used to attach. FIG. 2 shows a preferred embodiment of the electrolytic cell general equipment 10a, in which the external heating and/or cooling vessel 12a has a catholyte containing potassium chloride, monolithium chloride, titanium dichloride, and titanium trichloride in the cathode chamber 16a. It is suitable for placing a lithium chloride monopotassium chloride electrolyte into the anode chamber 14a.

The anode chamber 14a is separated from the cathode chamber 16a by a porous woven mesh diaphragm 17 surrounding the anode 18a at a distance. To extend the service life of the diaphragm, the distance between the diaphragm and the anode should be at least 14 times, preferably 1/4, the diameter of the anode.
Best is between 1-1/2 times and substantially equal to the diameter. A two-deposition cathode 20a and a titanium ion supply facility or supply cathode 22a are located in the cathode chamber 16a separated from each other and from the diaphragm 17a.

Vessel 12a is also electrically isolated from diaphragm 17a and the various electrical loads of vessel 10c. The container 12a is suitable to be substantially airtight to prevent atmospheric gases from entering the anode chamber 14a and/or the cathode chamber 16a.

A protective gas is introduced into the closed container 12a from the protective gas introduction equipment 37 so that the electrolytic cell 10a can be operated in a regulated substantially inert atmosphere. The controlled atmosphere for titanium is typically a gas such as argon or helium that is substantially inert to the electrolyte and titanium at operating temperatures. When using a lithium chloride potassium monochloride electrolyte with titanium tetrachloride, the operating temperature is usually about 6 ℃ below the eutectic point of the salt mixture (about 348°C).
50°C, preferably 475°C to 575°C.

Of course, operating temperatures will vary depending on the melting point or range of the particular electrolyte used. The anode chamber 14 is arranged so that the anode 18a1 deposited cathode 20a or supply cathode 22a can be removed for replacement or inspection.
It is preferred to provide an airtight chamber, such as air locks 38, 38a and 38b, for removing the cathode and/or anode without contaminating the atmosphere within the cathode chamber 16a or cathode chamber 16a with reactive atmospheric gases. In order to prevent reactive gas from entering the container 12a and contaminating the atmosphere thereof, an anode chamber 14a and a cathode chamber 16a are provided.
Equipment such as a valve 40 suitable for isolating the air from the outside atmosphere is provided. Valve 40 is adapted to close and shut off air locks 38, 38a and 38b when the anode, cathode or diaphragm is removed from or placed into container 12a. The operation of this valve and air lock is well known to those skilled in the art. Conduit 32a for removing generated chlorine gas is at least partially within anode air lock 38b.

Deposition cathode air lock 38a can be used to remove titanium metal from the cathode chamber. At least a portion of the valence electrode 42 is immersed in a melted halogenide electrolyte in order to measure the average valence of titanium ions in the electrolyte during operation of the electrolytic cell 10a.

Valence electrode 42 may be in communication with titanium tetrachloride metering equipment, such as titanium tetrachloride source 24a and pump 44, to control or adjust the titanium ion concentration and therefore the average titanium ion valence within cathode chamber 16a. Metering pump 4
4 is suitable for regulating the titanium tetrachloride supply to the supply cathode 22a through a conduit or pipe 46, thereby adjusting the titanium ion concentration to a specified value. In order to maintain the electrolytic solution in the anode chamber 14a and the cathode chamber 16a at a specified temperature, an electrolysis temperature adjustment facility 47 may be provided.

The temperature regulating equipment 47 can be used to cool or heat the electrolytic solution by selecting a known means such as air, electricity, gas, or oil as required. During operation of electrolytic cell 10a, undesirable oxides, nitrides, and other solid materials such as filth, commonly known in the art as slag, accumulate within vessel 12a.

A valve and pipe combination sludge removal facility 48 may be provided to allow sludge removal manually or mechanically from the electrolytic cell 10a without significant loss of electrolyte. The form of the diaphragm 17a is the most important thing in the writing device. The pores or openings in the diaphragm 17a need to be large enough to prevent blockage by, for example, substantial amounts of titanium metal particles, titanium oxide, or slag.
Additionally, the pores must be of a sufficiently small area to prevent a substantial amount of the molten salt bath containing titanium ions from passing through from the anode chamber 14a to the cathode chamber 16a. At the same time, the anode chamber 14
In order to maintain the desired bath composition in a, the electrolyte is preferably large enough to allow a sufficient amount of the lithium chloride monopotassium chloride electrolyte to enter the anode chamber 14a from the cathode chamber 16a. It has been found that a metal membrane with a cobalt layer deposited, for example electrolytically or non-electrolytically, on a nickel substrate meets the above requirements. The plated diaphragm has a Cd of 0.1 to 0.5, preferably 0.1 to 0.4 when the Cf is 0.1 to 25. However, it has been found that diaphragms with low Cd, such as 0.003, can be satisfactorily used in titanium production and are within the scope of the present invention. Cf is preferably from 0.1 to 8, and more preferably from 0.2 to 1.0 By using the above-mentioned apparatus, especially a perforated diaphragm with specified Cd and Cf, a polyvalent metal such as titanium can be electrolytically sized to a diaphragm pore size of 0.2 to 1. They discovered that they could be manufactured without the need to adjust the temperature.

Furthermore, because the membrane is a reticulated metal matrix with a metal membrane thereon, it can be easily stored before use and is more resistant to mechanical damage than porcelain membranes. FIG. 3 shows a schematic diagram of an installation for measuring the rate of water flow through a diaphragm.

Water maintained at a temperature of about 75° C. is supplied to the diaphragm 52 from the water tank 50 through a conduit 54. The water flow velocity is 25 from the A axis of the conduit 54 in the pipe 56 extending upward to the water surface in the pipe 56.
．． It shall be sufficient to provide a level or head 4 degrees high. The end of tube 56 is open to the atmosphere. Maintaining the head in tube 56 maintains an average head of water on the membrane 52 being tested at approximately 25.4 cTn. The amount of water passing through the diaphragm 194?2 can be measured by receiving it in the container 58.

The measured flow rate t/min can be used to determine the flow coefficient Cf. Now, with respect to the test apparatus or cell of FIG. 4, it has heretofore been difficult, and sometimes impossible, to determine in advance whether a particular diaphragm is suitable for use in an electrolytic cell.

It is known that the membrane material must be substantially non-reactive, ie, physically and chemically inert with the electrolyte in the electrolytic cell. However, there is generally no known means of accurately predicting the influence of the structure and surface properties of a particular porous membrane on tank efficiency. It is therefore highly desirable to have a means of determining whether a diaphragm is valid for the cell prior to inserting the diaphragm into the electrolyzer. In connection with the present invention, a method has been developed to measure the suitability of the diaphragm in the use of cardiotomy baths.

The method consists of applying a divided direct current electromotive force between a primary anode and a primary cathode immersed in a test cell containing an electrolyte. The electrical properties of the electrolyte through a defined portion of the electrolyte are measured using two measuring electrodes located between the secondary anode and the cathode and connected to the defined portion of the electrolyte by a first salt bridge and a second salt bridge separated by a specified distance. and measure. The diaphragm to be measured is inserted between the measurement electrodes, and the electrical characteristics of the electrolyte passing through a specified portion are measured. Changes in the properties of the electrolyte caused by inserting the diaphragm can be measured. The diaphragm in the above measurement method is defined as a porous barrier between the anode and cathode in the electrolytic cell.

This diaphragm can be made of, for example, asbestos, a conductive porous plate or mesh,
Such as sintered porous material. Because the efficiency of a diaphragm depends, at least in part, on its surface properties such as porosity and roughness, only flow tests (measuring the amount of liquid through a known area of a diaphragm in a given time) that can test for porosity are common. However, this is not an accurate measurement of the diaphragm efficiency during electrolyzer operation.

For example, this method of measuring current through pores in a diaphragm has been found to depend on both the physical porosity and surface properties of the diaphragm. It has now been discovered that voltage, resistance and/or current measurements obtained by the above method represent membrane efficiency with surprising accuracy. The above method can be used, for example, for suitability testing of electrolytic membranes or for periodic or continuous monitoring of quality control in the manufacture or operation of such membranes. Primary electrodes, such as primary anode 60 and primary cathode 61 in FIG. 4, are immersed in electrolyte 62 and connected to a power source 64.

A suitable electrolyte is compatible with primary electrodes 60 and 61 and diaphragm 66 and has sufficient electrical conductivity to permit accurate measurement of the electrical effects of inserting diaphragm 66 into electrolyte 62. Primary electrode 6
0 and 61 and electrolyte 62 are selected to form a battery capable of performing reversible electrolytic reactions. Furthermore, when testing a metallic diaphragm, the electrical conductivity of the electrolyte 62 may be such that the insertion of the diaphragm 66 into the electrolyte 62 is insufficient for the primary electrodes 60 and 6 to be such that the metallic diaphragm becomes an intermediate electrode.
It must be such that it causes a voltage change between 1 and 1.
Examples of generally suitable electrolytes include aqueous solutions of inorganic salts such as metal chlorates, chlorides, nitrates and sulfates or acid electrolytes. Suitable metals are, for example, alkali metals, alkaline earth metals and transition metals, such as Li, Na, K,
Alkali and alkaline earth metals such as Rb, Cs, Be, Mg, Ca, Sr and Ba are preferred. The materials used as electrode materials are generally those known in this field for electrodes, such as graphite, Ru, Rh, Pd, Ag, O.
s, Ir, Pt and Au. Silver monochloride electrodes are preferred as they are particularly suitable for use as primary electrodes. The primary electrodes 60 and 61 are substantially non-conductive supports 6
8 and 69 and the surface 65 of the electrode 60 is separated from the surface 67 of the electrode 61 by a defined distance, for example 2.54 CTfL.

Supports 68 and 69 are made of, for example, methyl acrylate plastic and, when one membrane is mounted in contact with the supports, substantially all of the current is passed through membrane 66 to electrodes 60 and 6.
Suitable for passing between 1 and 2. Two attached calomel measuring electrodes 70 and 72 are connected to the electrolyte 62 by a first salt bridge and a second salt bridge.

Orifices 78 and 80 and salt bridges 74 and 76 communicate with electrolyte 62 through supports 68 and 6'9 at defined locations between primary electrodes 60 and 61, respectively.
The orifices 78 and 80 are separated by a distance defined between the centers of the orifices, represented by center lines B and C of the orifices in the electrolyte 62, e.g. The secondary or auxiliary electrodes 70 and 72 are well known. For example, calomel, cadmium, hydrogen, mercury electrodes, etc. can be used as measuring electrodes. In practicing the present invention, the DC electromotive force is replaced by a constant current between the primary electrodes. is applied between the primary anode 60 and the primary cathode 61 to flow.

The electromotive force applied between the primary electrodes 60 and 61 must produce a voltage across the electrolyte that is less than the potential required to decompose the electrolyte 62.

For example, when the electrolyte is an aqueous NaCl solution, the voltage across the electrolyte must be at least lower than the decomposition potential of water. Electrical characteristics, salt bridges 78 and 80
The voltage across a defined distance between measuring electrodes 70 and 72
Measured by

The resistance of electrolyte 62 is determined by dividing the measured voltage between measurement electrodes 70 and 72 by the known current. A diaphragm 66 is placed in the electrolyte 62 between the primary electrodes 60 and 61 and the salt bath fixtures 78 and 80, thereby changing the electrical resistance between the measuring electrodes through a defined distance between the salt bath fixtures 78 and 80. .

As mentioned above, the diaphragm 66 is designed to maximize current flow through the diaphragm area defined by the supports 68 and
8 and the diaphragm 66 or the peripheral edge of the diaphragm 66 in a manner that minimizes current flowing through the gap at the interface. Diaphragm 66 is located between salt bridge fittings 78 and 82 which pass primary electrodes 60 and 61 and measurement electrodes 70 and 72 in electrolyte 62, thereby varying the electrical resistance between the measurement electrodes.

At a known constant current, the voltage change measured by the measuring electrode in a defined portion of the electrolyte 62(7) is a quantitative characteristic of the porosity and surface properties or effectiveness of the diaphragm in the electrolytic diaphragm cell. This diaphragm tank uses chlorine from sodium chloride brine or
Suitable for electrolytic production of metals such as titanium from titanium chloride. This method can be used to test the homogeneity of a diaphragm using a primary electrode sized and shaped such that the direct current generated between the diaphragms passes only over a known area of the diaphragm.

The electrical properties, voltage, resistance or current between the primary electrodes can be measured through the defined area between the electrodes before and after inserting the diaphragm between the primary electrodes. The septum is moved relative to the primary electrode such that after each measurement the next measurement is taken on a different part of the septum. Comparing the results of two or more measurements reveals homogeneity or defects in the permeability and surface properties of the membrane.

This test can be performed at any temperature or pressure as long as they are kept constant. It has been found that the above method can be used with porous metal meshes, plates or grid diaphragms, especially metal-plated porous woven metal meshes.

The following examples illustrate the invention.

Example 1 Using an apparatus substantially as shown in FIG. 1, a 0.1 molar sodium chloride aqueous electrolyte (reagent grade sodium chloride of 99.5% purity by weight dissolved in distilled water), 2.54C! T
Two 4.2 CTs with L spacing! L×1.3? ×Thickness 0.1
6? Square silver silver monochloride primary electrode and sodium chloride 1.
9C! ! 5.1 mm diameter used as an electrolytic cell diaphragm using two standard calomel electrodes physically connected between the primary electrodes by a salt bridge to measure the voltage across a distance of 5.1 mm. The adaptability of the nickel woven net with a cylindrical nickel plating of length 25.4 (177!) was tested.

The silver monochloride electrodes were placed within a methyl acrylate plastic frame in which a reticular diaphragm could be inserted between the electrodes. A DC electromotive force of sufficient voltage was applied to the primary electrodes such that a 2 milliampere (Ma) current flowed between the primary electrodes.

The voltage and direct current between the measurement electrodes were measured before and after inserting the retinal diaphragm between the electrodes. The test was conducted in a fixed room at two temperatures (approximately 20°C).
The test was carried out at 1 atm. The sodium chloride electrolyte voltage was measured to be 68 millivolts (Mv) and the current prior to septum insertion was demonstrated to be 2 ma.

The voltage between the measuring electrodes after inserting the diaphragm into the test cell is 93 mv.
The current was kept constant at 2 ma2. A voltage increase of 25 mv was calculated by the standard method to correspond to an increase in test cell resistance of 12.5 ohms or 0.7 of the sodium chloride electrolyte between the electrodes.

Various diaphragms of the same material were tested as described above.
From titanium chloride to Gata) used in the electrolytic cell. The diaphragm coefficient (CdY or diaphragm electrolyte equivalent in inches) was calculated and compared for satisfactory and unsatisfactory diaphragms according to the following formula. The satisfactory diaphragm coefficient (Cd) was thereby determined.
5 The diaphragm coefficient is expressed by the following formula: where Vd+8 is measured by a measuring electrode communicating with the electrolyte by means of a salt bridge with orifices separated by a specified distance D; This is the voltage (Mv) measured through a defined portion of the electrolyte when it is between the orifices.

d+s is the measured current (Ma) between the primary electrodes in the electrolyte containing the diaphragm as in Vd+s. Vs is V
Measured voltage under the same conditions as d+s but without a diaphragm (
Mv). Is is the measured current (M
a).

D is the prescribed spacing between salt bridges.

Examples 2-4 The coefficients (Cd) of other metal mesh diaphragms were measured by the method described in Example 1.

Test conditions and results are shown in Table... (a) 0.01 mol H2SO4 in the electrolyte and graphite as the primary electrode; and (b) 0.01 mol NaCl in the electrolyte and silver monochloride as the primary electrode. Satisfactory results were obtained when tested.

Example 5-42 Titanium tetrachloride (TiC
14) to produce metallic titanium with a purity of 999% by weight.

The outer diameter of the electrolyzer is 45.6? , height 56? contained in a substantially cylindrical low carbon steel container. A substantially cylindrical diaphragm with a closed lower end of diameter 4.8CTL1 length 16.5C7TL and a diameter of 1.9CTL1 length approximately 45.6? A solid graphite anode was placed around the center. A 15.2 cm length of the anode was immersed in a molten lithium potassium monochloride bath having a near eutectic composition of about 55% by weight LiCl and about 45% by weight KCl. The diaphragm is the desired Cd and C
It was an industrial pure nickel mesh plated electrolytically or non-electrolytically with a sufficient amount of cobalt or nickel to give f. (Table and reference) Plating was carried out in a plating solution that resulted in a rough surface or a surface with low light reflection. In order to extend the service life of the diaphragm, the distance between the diaphragm and the anode was selected to be in the range of 1/4 to 11/'2 times the anode diameter. The deposited cathode has a diameter of 2
．． 54C7TL1 was an industrial mild steel bar with a length of 19 (1-JMoV1).The feeding equipment or feeding cathode was
It was assumed that Cl4 gas was sent. The supply cathode is a stainless steel tube with a ring-shaped cylindrical cobalt, iron or nickel plated electrolytically or non-electrolytically.
It had mesh iron or nickel mesh. The lower end of the net was closed. The Cd of the plated supply cathode network is 0.
1 to 0.6, and Cf was 0.2 to 30. The operation involved pumping liquid TiCl4 to the feed cathode.

When it entered the molten catholyte through the pores of the feed cathode, it was vaporized and reduced to TiCl3 and TiCl2. Sufficient loading was applied to the supply cathode and to the anode and cathode such that chlorine was generated at the anode and titanium metal was deposited on the deposited cathode. Chlorine was continuously removed from the anode chamber by a pipe extending from the cover of the electrolyzer. The titanium was periodically recovered by first removing the deposited cathode from the apparatus, peeling off the solid deposited titanium sponge from the cathode, and then attaching the cathode to the bath. The atmosphere within the anode and cathode chambers was kept substantially inert by constantly passing sufficient argon gas into each chamber to maintain a positive pressure relative to the atmospheric pressure surrounding the chamber. The titanium current efficiency and titanium hardness obtained in Example 5-42 and the parameters of these methods are shown in the table.

It is clear from the table that low hardness, ie high purity metallic titanium can be efficiently produced by the above method.

CdO. in a manner similar to that described in Example 5-42. OO
3 and Cfl. Titanium could be produced satisfactorily using a diaphragm of 1.

Figure 5 is a metal compound delivery cathode suitable for placement in an electrolyte for electrodeposition of metal onto a negatively charged cathode.

The feed cathode comprises a feed conduit, such as tube or pipe 80, through which the ionizable polyvalent metal compound passes. Enclosing and generally surrounding the opening 82 of the pipe 80 where a metal compound such as titanium tetrachloride (TiCl4) exits the pipe 80 in an electrolyte such as a molten mixture of potassium chloride and lithium chloride is an enclosure component 84. .

At least a portion of the enclosure 84 constitutes an electrically conductive perforated element 86 that allows the flow of fluid in the molten electrolytic bath from a supply electrode chamber, such as an annular chamber 88, formed by the exterior of the pipe 80 and the interior of the enclosure 84. It is suitable for delivering ions from the metal compound to the catholyte in an adjacent deposition cathode chamber (not shown). Substantially gas-tight components 90 physically close the upper and lower ends of perforated component 86. A surrounding part 84 is fixed coaxially around the pipe 80 in a known manner.

When a negative charge is applied to the perforated part by the electrically connected negative power supply 94, the pipe 80 from the perforated part 84
Optionally, an electrically insulating component 92 is inserted to leave the pipe 80 open from the surrounding component 84 in order to electrically insulate the pipe 80 . During operation of the embodiment of FIG. 5, the feed cathode is placed in an electrolytic cell such that at least a portion, and preferably substantially all, of the electrically charged portion is below the surface of the molten halide electrolytic bath. An ionizable metal compound, such as titanium tetrachloride, flows or is pumped from a source 24 through a conduit 80 and into a supply electrolyte chamber 88 through an opening 82, as shown in FIG.

When the negative power source 94 is activated, the perforated component 86 becomes a cathode.
The electrically negative perforated component 86 reduces at least some of the titanium ions in and around the supply cathode from high valence to low valence. Apertures of sufficient size to convey molten electrolyte from within the annular chamber 88 into the cathode chamber around the feed cathode without transmission of substantial amounts of physical drainage (e.g., caused by the entry of gaseous TiCl4 into the chamber). By using the perforated component 86, improved utilization of TiCl4 over conventional methods was achieved.

FIG. 6 shows a container 102 and cover 10 of another embodiment of the invention.
FIG. 4 is a diagram of an electrolytic cell 100 with a

The metal deposited cathode 106 is placed in the cathode chamber 108 and in the anode chamber 112.
It is separated by a porous diaphragm 114 from a positively loaded anode 110 located within. Feed cathode 116 is located within electrolytic cell 100 and is at least partially immersed in catholyte within cathode chamber 108 . The supply cathode 116 is immersed in the molten salt electrolyte and has a supply pipe 80a of a material suitable for passing TiCl4. Preferably, the catholyte is a molten monologenide mixture, such as lithium and potassium chlorides. Titanium tetrachloride may be co-flown with an inert gas such as argon through pipe 80a.

The inert gas promotes mixing of TiCl4 or solid metal compounds in the electrolyte. Perforated component 86a substantially completely surrounds lower end 82a of pipe 80a. Part 86a is generally coaxial with pipe 80a and optionally spaced support 1
It is physically supported and electrically connected to 18. Heating equipment 120, such as an electric heater, is optionally placed adjacent between pipe 80a and support 118 to heat the gas passing through support 118 or pipe 80a and to minimize solidification of nearby electrolyte. You can stay there.

A gas outlet 122 is provided in the support 118 to vent excess gas, such as argon, which is not dissolved or dissociated in the electrolyte through the annulus 124 into a suitable container (not shown). The support 118 is optionally provided with a substantially gas-tight component 90a which can be at least partially immersed in the electrolyte to prevent the ingress of excess gas into the atmosphere within the electrolytic cell. Substantially the entire part 86a may be immersed in the electrolyte. The perforated part 86a has a flow coefficient Cf
is within the range of 0.1 to 300, the electrical coefficient Cd
is greater than O up to about 1, preferably in the range of 0.1 to 1.

The modulus of the perforated part can be measured in the same manner as described for measuring the diaphragm modulus. The perforated component 86a may be, for example, a sintered plate, a mesh, a plate, or a thin film having substantially uniform holes or perforations all over its surface.

This hole can be formed, for example, by turning, punching, knitting, or the like. The perforated part 86a is made of a 50 to 250 mesh US standard sieve, preferably 100 to 200 mesh, coated with a sufficient amount of material such as cobalt, iron or nickel by electrolytic or non-electrolytic methods to provide the desired Cd and Cf content. A woven mesh sieve is preferred. Suitable deposition methods are, for example, known methods suitable for reducing the amount of brightener in the plating solution resulting in a visually dull or rough surface. For example, using the following solution:
Satisfactory plating of 0 or 200 mesh carbon steel or industrial pure nickel mesh has been achieved; the matrix of the perforated component can withstand the environment within the electrolytic cell 100 and has the desired physical strength at the operating temperatures within the cell. Materials such as iron, including steel and stainless steel, cobalt or nickel or alloys thereof containing at least 50% by weight cobalt or nickel may be used. The configuration of the perforated component 86a is important in the device described above.

The pores or openings in the perforated component 86a must be large enough so that they do not become clogged with a substantial amount hζ of metallic titanium particles, other polyvalent metals, titanium oxide, or slag. Furthermore, this hole is connected to the supply cathode 116.
The area shall be sufficient to minimize, and if possible substantially completely prevent, the flow of water into the cathode chamber. At the same time, the number of holes is preferably large enough to allow a sufficient amount of lithium chloride potassium chloride electrolyte to enter from the cathode chamber 108 to maintain the desired bath concentration. Plated perforated parts have a Cf of 0.1 to 300.
It is preferable to have a Cd of 1 to 0.6. Cf is preferably 0.2 to 30, and most preferably 0.2 to 8. Supply cathode 1
16 (FIG. 6) is as described in FIG.
Connect to give a positive charge as specified in 10.

When titanium tetrachloride is delivered to the supply cathode, metallic titanium is electrodeposited at the deposition cathode 103 and elemental chlorine is generated at the anode 10 and flows upward to a chlorine reservoir (not shown).

Substantially no titanium metal is deposited on the perforated component 86a. The following examples further illustrate the invention.

Examples 43-49 Titanium metal of approximately 99.9% purity by weight was produced from TiCl4 in a low carbon steel electrolyzer with the same feed cathode as shown in Figure 5, with the anode and cathode separated by a diaphragm.

The electrolyzer was housed in a substantially cylindrical vessel with an outer diameter of 45.6 cTn and a height of 56 cm. Diameter 4.8? , length 16.5C
A substantially cylindrical diaphragm closed at the lower end at T1L was placed substantially parallel to the circumference of a solid graphite anode of diameter 1.9 (7rL1) approximately 45.6CTrL long.Anode length 15.2CTI1 was immersed in a molten bath of lithium chloride and potassium monochloride having approximately the eutectic point composition.The perforated parts were electrolytically or non-electrolytically coated with sufficient amounts of cobalt, iron or nickel to form the Cd and Cf listed in the table. Example 43 was prepared by applying a potential to the anode and cathode using a feed cathode with a perforated mesh component having the properties shown in the table. -49 electrolyzer operations produced satisfactory titanium metal.

Titanium tetrachloride was continuously pumped to the feed cathode, and the titanium was ionized and then passed into the cathode chamber through the numerous holes in the woven perforated part of the feed cathode.

The water flow within the feed cathode that occurred upon entry into the TiCl4 electrolyte was sufficiently retained within the feed cathode. The chlorine generated at the anode and the titanium at the cathode were appropriately removed from the tank. As will be apparent from the above specification, the present invention may be practiced in various ways and modifications other than those described above. For this reason, it will be appreciated that the above specification is to be interpreted as illustrative only and not as limiting the invention.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an electrolytic cell for producing titanium according to the present invention. FIG. 2 is a sectional view of another electrolytic cell of the present invention. FIG. 3 is a schematic diagram of the equipment for measuring the flow velocity of water passing through a diaphragm according to the present invention. FIG. 4 is a schematic diagram of the diaphragm coefficient measurement equipment of the diaphragm of the present invention. FIG. 5 is a schematic diagram of the supply cathode used in the electrolytic cell of the present invention. FIG. 6 is a diagram of another embodiment of an electrolytic device in which the diaphragm of the present invention is combined. Numbers in each figure: 10, 10a,
100... Electrolytic cell, 12, 12a, 102... Container, 14, 14a, 112... Anode chamber, 16, 16a,
108... Cathode chamber, 18, 18a, 110... Anode, 20, 20a, 106... Cathode, 17, 17a, 5
2,66,114...Diaphragm, 22,22a,80,8
0a...TiCl4 supply equipment, 24...TiCl4
Source, 38, 38a, 38b... Air lock, 42.
... Valence electrode, 60... Primary anode, 61... Primary cathode, 74... First salt bridge, 70, 71... Calomel measurement electrode, 76... Second salt bridge, 78, 8
0... Orifice, 68, 69... Support, 80,
80a...pipe, 82, 82a...opening, 84.
... Surrounding parts, 86, 86a... Perforated parts, 116.
...supply cathode, 118... support.

Claims (1)

[Claims] 1 Diaphragm coefficient greater than 0 and up to 0.5 and 0.1 to 25
An anode chamber in an electrolytic cell containing a molten salt bath for electrolytic production of titanium, characterized in that the anode chamber is made of a perforated body having a flow coefficient of A metal diaphragm suitable for isolation from the cathode chamber. 2. The diaphragm according to claim 1, which has a diaphragm coefficient of 0.1 to 0.5 and a flow coefficient of 0.1 to 8. 3. The diaphragm according to claim 1 or 2, which has a diaphragm coefficient of 0.1 to 0.4 and a flow coefficient of 0.2 to 1. 4. A diaphragm according to claim 1, 2 or 3, wherein the diaphragm surface consists essentially of cobalt. 5. The diaphragm according to claim 1, 2 or 3, wherein the diaphragm is a porous metal substrate having a metal coating on its surface. 6 Claim 5 in which the substrate is industrially pure nickel
The diaphragm described in section. 7. A diaphragm according to claim 5, wherein the matrix consists essentially of cobalt or nickel or an alloy thereof. 8. A diaphragm according to claim 5, 6 or 7, wherein the metal coating consists essentially of cobalt or nickel or an alloy of cobalt or nickel. 9. Diaphragm according to claim 5 or 8, in which the metal coating is applied electrolytically or chemically to the substrate. 10 The substrate is iron, cobalt, nickel, or at least 5
A diaphragm according to claim 5, which is a metal selected from an alloy containing 0% by weight of said metal. 11 The substrate has a coating layer consisting essentially of cobalt 5
A diaphragm according to any one of claims 5 to 10, comprising a nickel mesh of 0 to 250 mesh. 12 A body suitable for containing a molten salt bath: Equipment for isolating the bath from the atmosphere: An anode chamber located within the body: Equipment for removing gas from the anode chamber: A deposition cathode chamber located within the body: At least partially located within the anode chamber. at least one anode suitable for being immersed in the bath; at least one deposited cathode located within said cathode chamber and suitable for being at least partially immersed in the bath; a source of electrical energy connected to said anode and cathode; a molten salt comprising: at least one supply facility suitable for supplying titanium ions; and at least one perforated metallic diaphragm suitable for at least a portion of the bath to separate the anode chamber from the cathode chamber. In an electrolytic cell for the production of titanium in a bath: the diaphragm withstands the corrosive environment in the vessel and has a diaphragm coefficient of greater than 0 up to 0.5 and 0.
An electrolytic cell characterized by having a flow coefficient of 1 to 25. 13 Claim 12 includes a member that insulates the diaphragm from the anode, the cathode, the electrolytic cell body, and from the power source outside the electrolytic cell.
Electrolytic cell described in section. 14. The electrolytic cell according to claim 12, which has a diaphragm coefficient of 0.1 to 0.4 and a flow coefficient of 0.1 to 8. 15. The electrolytic cell according to claim 12 or 13, wherein the diaphragm is a porous metal substrate with a metal coating on the surface. 16. The electrolytic cell according to claim 15, wherein the substrate is industrial pure nickel. 17. The electrolytic cell according to claim 15 or 16, wherein the metal coating is electrolessly applied nickel or cobalt. 18. The electrolytic cell according to claim 15 or 16, wherein the substrate is a metal mesh of 50 to 250 (US standard) mesh. 19. An electrolytic cell according to claim 15 or 16, wherein the metal coating is electrolytically applied nickel or cobalt. 20 Claims in which the diaphragm consists of a porous metal matrix consisting essentially of iron, nickel, cobalt or an alloy containing at least 50% by weight of said metals and a metal coating consisting essentially of cobalt or nickel or an alloy of cobalt or nickel. The electrolytic cell according to item 12 or 13. 21. High-temperature operation of electrolytic cell The electrolytic cell according to any one of claims 12 to 20, wherein the diaphragm is supported by a porous body to supplement the physical strength of the intermediate membrane. 22 The distance between the anode and the diaphragm is 1/4 to 1.
Claims 12 to 21 within the range of 1/2
The electrolytic cell described in any of paragraphs. 23. An electrolytic cell according to any of claims 12 to 22, wherein the production of titanium comprises the production of metallic titanium from titanium tetrachloride in a molten salt bath. 24 The part of the electrolytic tank that comes into contact with the electrolyte is NaCl, LiC
l-KCl, LiCl-KCl-NaCl, and Li
24. The electrolytic cell of claim 23, resistant to molten salts and molten salt mixtures selected from the group consisting of Cl--KCl--CaCl_2. 25 The diaphragm consists of a woven metal matrix with a metal coating,
The substrate is nickel, the coating is cobalt or nickel or an alloy of cobalt or nickel, and the diaphragm has a diaphragm coefficient of 0.1 to 0.4 and a flow coefficient of 0.1 to 1. The electrolytic cell according to any one of the ranges 12 to 24. 26. A method for producing titanium in an electrolytic cell having at least one anode in the anode chamber, at least one cathode in the cathode chamber, and supply equipment for supplying a titanium compound to a molten salt bath in the electrolytic cell, comprising: : A perforated diaphragm with at least one surface that can withstand the environment inside the tank, a diaphragm coefficient of greater than 0 up to 0.5, and a flow coefficient of 0.1 to 25 is inserted into the electrolytic cell to transform the anode chamber into a cathode chamber. a step of electrically insulating the diaphragm from an external power source of the anode chamber and the cathode chamber; and a step of applying an electromotive force between the anode and the cathode. Manufacturing method.