METHOD FOR PREPARING TITANIUM METAL BY MOLTEN SALT ELECTROLYSIS

Abstract

A method for preparing titanium metal by molten salt electrolysis is provided. The method includes constructing an electrochemical system, where an anode chamber is filled with an anode molten salt electrolyte that contains a titanium-containing raw material and inserted with an anode, a cathode chamber is filled with a cathode molten salt electrolyte and inserted with a cathode, and the anode molten salt electrolyte and the cathode molten salt electrolyte are not in contact with each other, but are connected by a liquid alloy at the bottom of the electrolytic cell; the system for electrolysis is powered on to obtain the titanium metal product at the cathode. The method of the present disclosure can treat low-quality titanium-containing materials, can be operated continuously, and can obtain relatively high-quality titanium.

Claims

1. A method for preparing a titanium metal by a molten salt electrolysis, wherein: the method is implemented using an electrolytic cell, the electrolytic cell comprises an anode chamber and a cathode chamber, the anode chamber is filled with an anode molten salt electrolyte and inserted with an anode, wherein the anode molten salt electrolyte comprises a titanium-containing raw material, the cathode chamber is filled with a cathode molten salt electrolyte and inserted with a cathode, a bottom of the electrolytic cell is further filled with a liquid alloy, and the anode molten salt electrolyte and the cathode molten salt electrolyte are connected by the liquid alloy and not in contact with each other; the method comprises powering on and running the electrolytic cell, reducing the titanium-containing raw material in the anode chamber to titanium atoms at an interface between the anode molten salt electrolyte and the liquid alloy, and simultaneously dissolving the titanium atoms into the liquid alloy; at the same time, oxidizing the titanium atoms in the liquid alloy are oxidized to titanium ions at an interface between the liquid alloy and the cathode molten salt electrolyte, and simultaneously allowing the titanium ions to enter the cathode molten salt electrolyte and subsequently reducing the titanium ions entered to titanium atoms on a surface of the cathode se as-to form the titanium metal.

2. The method for preparing the titanium metal by the molten salt electrolysis according to claim 1, wherein the titanium-containing raw material is a titanium-containing slag or a titanium-rich slag.

3. The method for preparing the titanium metal by the molten salt electrolysis according to claim 2, wherein the anode molten salt electrolyte further comprises one or more of Al.sub.2O.sub.3, CaO, Na.sub.2O, CaF.sub.2, SiO.sub.2, FeO, and MgO.

4. The method for preparing the titanium metal by the molten salt electrolysis according to claim 3, wherein the anode molten salt electrolyte further comprises TiO.sub.2.

5. The method for preparing the titanium metal by the molten salt electrolysis according to claim 1, wherein the anode is made of a carbon material or is an inert anode; and the cathode is made of one of a stainless steel material, a tungsten material, and a molybdenum material.

6. The method for preparing the titanium metal by the molten salt electrolysis according to claim 1, wherein the cathode molten salt electrolyte is a halide molten salt, wherein the halide molten salt comprises one or more of NaCl, KCl, CaCl.sub.2), MgCl.sub.2, NaF, KF, CaF.sub.2, and MgCl.sub.2, with TiCl.sub.2 and TiCl.sub.3 in different proportions.

7. The method for preparing the titanium metal by the molten salt electrolysis according to claim 1, wherein the liquid alloy is an alloy formed by a solute metal Ti and a solvent metal, a metal activity of the solvent metal is lower than a metal activity of the solute metal Ti, the solvent metal and the solute metal Ti form a low-melting-point alloy with a melting point below 1000? C.

8. The method for preparing the titanium metal by the molten salt electrolysis according to claim 1, wherein when the electrolytic cell works normally, a temperature of the anode molten salt electrolyte is controlled to range from 700? ? C. to 1,400? C., a temperature of the cathode molten salt electrolyte is controlled to range from 400? ? C. to 1,100? C., and an anode current density ranges from 0.01 A/cm.sup.2 to 2 A/cm.sup.2.

9. The method for preparing the titanium metal by the molten salt electrolysis according to claim 7, wherein the liquid alloy is formed by Ti and one or more of Cu, Sn, Sb, Zn, Pb, Bi, Ni, and Co.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The FIGURE is a schematic diagram of a section of the electrolytic cell according to an embodiment of the present disclosure.

[0026] In the FIGURE: 1anode; 2anode molten salt electrolyte; 3liquid alloy; 4inlet of titanium-containing raw material; 5cathode; and 6cathode molten salt electrolyte.

DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] In order to make the objective, technical solutions and advantages of the present disclosure more clear, the technical solutions of the present disclosure will be described in detail below. Obviously, the described examples are only part of the examples of the present disclosure, not the whole examples. Based on the examples in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present disclosure.

[0028] According to the following examples of the present disclosure, methods for preparing titanium metal by molten salt electrolysis are implemented using a U-shaped electrolytic cell shown in the FIGURE. The bottom of the electrolytic cell is filled with a liquid alloy 3. A portion of the electrolytic cell above the liquid alloy 3 is divided into an anode chamber and a cathode chamber. The anode chamber is filled with an anode molten salt electrolyte 2 and has an anode 1. The cathode chamber is filled with a cathode molten salt electrolyte 6 and has a cathode 5. The anode molten salt electrolyte 2 and the cathode molten salt electrolyte 6 are connected by the liquid alloy 3 and not in contact with each other.

Example 1

[0029] This example provides a method for preparing titanium metal by molten salt electrolysis. The method included: 400 g of CuSnTi alloy (Cu:Sn:Ti=73:16:11) was added to the bottom of the electrolytic cell, the alloy was heated to form liquid and completely separate the anode chamber from the cathode chamber; 400 g of anode molten salt electrolyte (anode molten salt consisted of Al.sub.2O.sub.3, SiO.sub.2, CaO and TiO.sub.2 in a mass ratio of 14:57:18:11) was added to the anode chamber, and 400 g of cathode molten salt electrolyte (prepared from NaCl and KCl according to a mass ratio of 1:1, and 7.8 wt % of low-valence titanium chloride consisting of TiCl.sub.2 and TiCl.sub.2 was added, the mass ratio of TiCl.sub.2 to TiCl.sub.3 is 4:1) was added to the cathode chamber; and a graphite anode and a stainless steel cathode were inserted into the anode molten salt electrolyte and cathode molten salt electrolyte, respectively.

[0030] Titanium-containing slag was added to the anode molten salt electrolyte, the temperature of anode molten salt electrolyte was controlled to be 1,400? C., the temperature of cathode molten salt electrolyte was controlled to be 1,000? ? C., and the cathode chamber was protected by argon atmosphere. During this electrolysis process, the current density was controlled to be 0.05 A/cm.sup.2, and the electrolysis was carried out for 24 h. After the cathode was taken out, 14.8 g of titanium metal was obtained, and the electrolysis could be continuously carried out by adding the titanium-containing slag to the anode chamber.

Example 2

[0031] This example provides a method for preparing titanium metal by molten salt electrolysis. The method included: 4 kg of CuSnTi alloy (Cu:Sn:Ti=73:16:11) was added to the bottom of the electrolytic cell, the alloy was heated to form liquid and completely separate the anode chamber from the cathode chamber; 4 kg of anode molten salt electrolyte (anode molten salt consisted of Al.sub.2O.sub.3, SiO.sub.2, CaO and TiO.sub.2 in a mass ratio of 14:57:18:11) was added to the anode chamber, and 4 kg of cathode molten salt electrolyte (prepared from NaCl, and 7.8 wt % of low-valence titanium chloride consisting of TiCl.sub.2 and TiCl.sub.3 was added, the mass ratio of TiCl.sub.2 to TiCl.sub.3 is 4:1) was added to the cathode chamber; and a graphite anode and a stainless steel cathode were inserted into the anode molten salt electrolyte and cathode molten salt electrolyte, respectively.

[0032] Titanium-containing slag was added to the anode molten salt electrolyte, the electrolytic cell is powered on and running, the temperature of anode molten salt electrolyte was controlled to be 1,400? C., the temperature of cathode molten salt electrolyte was controlled to be 1,000? C., and the cathode chamber was protected by argon atmosphere. During this electrolysis process, the current density was controlled to be 0.05 A/cm.sup.2, and the electrolysis was carried out for 24 h. After the cathode was taken out, 149 g of titanium metal was obtained, and the electrolysis could be continuously carried out by adding the titanium-containing slag to the anode chamber.

Example 3

[0033] This example provides a method for preparing titanium metal by molten salt electrolysis. The method included: 400 g of CuSnTi alloy (Cu:Sn:Ti=73:16:11) was added to the bottom of the electrolytic cell, the alloy was heated to form liquid and completely separate the anode chamber from the cathode chamber; 400 g of anode molten salt electrolyte (anode molten salt consisted of Al.sub.2O.sub.3, SiO.sub.2, CaO and TiO.sub.2 in a mass ratio of 9:37:44:10) was added to the anode chamber, and 400 g of cathode molten salt electrolyte (prepared from NaCl and KCl according to a mass ratio of 1:1, and 7.8 wt % of low-valence titanium chloride consisting of TiCl.sub.2 and TiCl.sub.3 was added, the mass ratio of TiCl.sub.2 to TiCl.sub.3 is 4:1) was added to the cathode chamber; and a graphite anode and a stainless steel cathode were inserted into the anode molten salt electrolyte and cathode molten salt electrolyte, respectively.

[0034] Titanium-containing slag was added to the anode molten salt electrolyte, the electrolytic cell is powered on and running, the temperature of anode molten salt electrolyte was controlled to be 1,400? C., the temperature of cathode molten salt electrolyte was controlled to be 1,100? C., and the cathode chamber was protected by argon atmosphere. During this electrolysis process, the current density was controlled to be 0.05 A/cm.sup.2, and the electrolysis was carried out for 24 h. After the cathode was taken out, 15.2 g of titanium metal was obtained, and the electrolysis could be continuously carried out by adding the titanium-containing slag to the anode chamber.

Example 4

[0035] This example provides a method for preparing titanium metal by molten salt electrolysis. The method included: 400 g of CuSnTi alloy (Cu:Sn:Ti=73:16:11) was added to the bottom of the electrolytic cell, the alloy was heated to form liquid and completely separate the anode chamber from the cathode chamber; 400 g of anode molten salt electrolyte (anode molten salt consisted of Al.sub.2O.sub.3, SiO.sub.2, CaO and TiO.sub.2 in a mass ratio of 14:57:18:11) was added to the anode chamber, and 400 g of cathode molten salt electrolyte (prepared from NaCl and KCl according to a mass ratio of 1:1, and 5.2 wt % of low-valence titanium chloride consisting of TiCl.sub.2 and TiCl.sub.3 was added, the mass ratio of TiCl.sub.2 to TiCl.sub.3 is 2:1) was added to the cathode chamber; and a graphite anode and a stainless steel cathode were inserted into the anode molten salt electrolyte and cathode molten salt electrolyte, respectively.

[0036] Titanium-containing slag was added to the anode molten salt electrolyte, the electrolytic cell is powered on and running, the temperature of anode molten salt electrolyte was controlled to be 1,400? C., the temperature of cathode molten salt electrolyte was controlled to be 900? C., and the cathode chamber was protected by argon atmosphere. During this electrolysis process, the current density was controlled to be 0.05 A/cm.sup.2, and the electrolysis was carried out for 24 h. After the cathode was taken out, 15.3 g of titanium metal was obtained, and the electrolysis could be continuously carried out by adding the titanium-containing slag to the anode chamber.

Example 5

[0037] This example provides a method for preparing titanium metal by molten salt electrolysis. The method included: 400 g of CuTi alloy (Cu:Ti=80:20) was added to the bottom of the electrolytic cell, the alloy was heated to form liquid and completely separate the anode chamber from the cathode chamber; 400 g of anode molten salt electrolyte (anode molten salt consisted of Al.sub.2O.sub.3, SiO.sub.2, CaO, MgO and TiO.sub.2 in a mass ratio of 16:24:28:10:22) was added to the anode chamber, and 400 g cathode molten salt electrolyte (prepared from NaCl, KCl and CaF.sub.2 according to a mass ratio of 9:9:2, and 7.8 wt % of low-valence titanium chloride consisting of TiCl.sub.2 and TiCl.sub.3 was added, the mass ratio of TiCl.sub.2 to TiCl.sub.3 is 4:1) was added to the cathode chamber; and a graphite anode and a tungsten cathode were inserted into the anode molten salt electrolyte and cathode molten salt electrolyte, respectively.

[0038] Titanium-containing slag was added to the anode molten salt electrolyte, the electrolytic cell is powered on and running, the temperature of anode molten salt electrolyte was controlled to be 1,400? C., the temperature of cathode molten salt electrolyte was controlled to be 1,000? C., and the cathode chamber was protected by argon atmosphere. During this electrolysis process, the current density was controlled to be 2 A/cm.sup.2, and the electrolysis was carried out for 24 h. After the cathode was taken out, 14.2 g of titanium metal was obtained, and the electrolysis could be continuously carried out by adding the titanium-containing slag to the anode chamber.

Example 6

[0039] This example provides a method for preparing titanium metal by molten salt electrolysis. The method included: 400 g of CuSnTi alloy (Cu:Sn:Ti=73:16:11) was added to the bottom of the electrolytic cell, the alloy was heated to form liquid and completely separate the anode chamber from the cathode chamber; 400 g of anode molten salt electrolyte (anode molten salt consisted of Al.sub.2O.sub.3, SiO.sub.2, CaO and TiO.sub.2 in a mass ratio of 9:37:44:10) was added to the anode chamber, and 400 g of cathode molten salt electrolyte (prepared from NaCl and KCl according to a mass ratio of 1:1 and 7.8 wt % of low-valence titanium chloride consisting of TiCl.sub.2 and TiCl.sub.3 was added, the mass ratio of TiCl.sub.2 to TiCl.sub.3 is 4:1) was added to the cathode chamber; and a CrFe alloy inert anode and a stainless steel cathode were inserted into the anode molten salt electrolyte and cathode molten salt electrolyte, respectively.

[0040] Titanium-containing slag was added to the anode molten salt electrolyte, the electrolytic cell is powered on and running, the temperature of anode molten salt electrolyte was controlled to be 1,400? C., the temperature of cathode molten salt electrolyte was controlled to be 1,000? C., and the cathode chamber was protected by argon atmosphere. During this electrolysis process, a current density was controlled to be 50 mA/cm.sup.2, and the electrolysis was carried out for 24 h. After the cathode was taken out, 15.2 g of titanium metal was obtained, and the electrolysis could be continuously carried out by adding the titanium-containing slag to the anode chamber.

Comparative Example

[0041] This example provides a method for preparing titanium metal by molten salt electrolysis. The method included: 400 g of CuSn alloy (Cu:Sn=3:1) was added to the bottom of the electrolytic cell, the alloy was heated to form liquid and completely separate the anode chamber from the cathode chamber; 400 g of anode molten salt electrolyte (anode molten salt consisted of Al.sub.2O.sub.3, SiO.sub.2, CaO and TiO.sub.2 in a mass ratio of 14:57:18:11) was added to the anode chamber, and 400 g of cathode molten salt electrolyte (prepared from NaCl and KCl according to a mass ratio of 1:1 and 7.8 wt % of low-valence titanium chloride consisting of TiCl.sub.2 and TiCl.sub.3 was added, the mass ratio of TiCl.sub.2 to TiCl.sub.3 is 4:1) was added to the cathode chamber; and a graphite anode and a stainless steel cathode were inserted into the anode molten salt electrolyte and cathode molten salt electrolyte, respectively.

[0042] Titanium-containing slag was added to the anode molten salt electrolyte, the temperature of anode molten salt electrolyte was controlled to be 1,400? C., the temperature of cathode molten salt electrolyte was controlled to be 1,000? ? C., and the cathode chamber was protected by argon atmosphere. Electrolysis was controlled to be carried out under a same cell voltage condition as Example 1, and no titanium metal was obtained on the cathode.

[0043] The above is only the specific embodiments of the present disclosure, but the scope of protection of the present disclosure is not limited to this. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present disclosure, which will be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure is to be based on the scope of protection of the claims.