JP5038251B2 - Titanium tetrachloride distillation purification apparatus, maintenance method of the apparatus, and purification method of titanium tetrachloride using the apparatus - Google Patents

Description

  The present invention relates to a distillation purification apparatus for titanium tetrachloride produced by a chlorination reaction of titanium ore, a maintenance method for the apparatus, and a purification method for titanium tetrachloride using the apparatus.

  Titanium tetrachloride is widely used as a raw material for titanium metal, titanium oxide or electronic material. Titanium tetrachloride is usually produced by a chlorination reaction of titanium ore containing titanium oxide as a main component. This crude titanium tetrachloride includes not only titanium ore and fine powder of coke used for the chlorination reaction. Impurity metal components contained in the titanium ore are also dissolved.

  Thus, prior to shipment of such crude titanium tetrachloride, impurity components dissolved in titanium tetrachloride are separated and removed by being subjected to distillation purification equipment.

  The distillation purification equipment is equipped with a titanium tetrachloride evaporator called a reboiler at the bottom, and above that is a packed bed filled with a packing for uniformly dispersing titanium tetrachloride, and a plurality of shelves inside. And a rectifying tower provided with stages. Titanium tetrachloride gas vaporized from the reboiler ascends the rectifying column constituting the distillation purification equipment, and reaches the top of the rectifying column, and then is cooled and liquefied to counteract liquid titanium tetrachloride flowing down. By doing so, the low boiling point impurities and the high boiling point impurities in titanium tetrachloride are efficiently separated and purified. Impurity components having a boiling point higher than that of titanium tetrachloride are accumulated at the bottom of the distillation purification equipment, and components having a lower boiling point are concentrated and separated at the top.

  However, when the above-mentioned distillation purification equipment is operated over a long period of time, the pressure loss in the distillation purification equipment may tend to increase gradually, and the cause is impurities contained in titanium tetrachloride. Often deposits on the flow path.

  For this reason, when the tendency of the pressure loss of the distillation purification equipment as described above to increase is significant, it is necessary to dismantle the distillation purification equipment and prepare a rectification column and its internal shelf. When carrying out maintenance work, it is necessary to stop the operation of the distillation purification equipment, and as a result, productivity is lowered, which is undesirable.

  In addition, the impurity chloride contained in the titanium tetrachloride gas is cooled while the titanium tetrachloride gas generated in the reboiler at the bottom of the distillation purification equipment rises up the rectification tower, and solids are generated in the middle of the rectification tower. In some cases, precipitates are formed, which causes clogging of the rectification tower and is required to be improved.

  In many cases, the rectification column is blocked in a packed bed provided on the way from the reboiler to the top of the rectification column. The packed bed described above has the effect of uniformly dispersing the titanium tetrachloride vapor generated by the reboiler and enabling smooth contact between the titanium tetrachloride gas and the liquid titanium tetrachloride.

  Therefore, if the packed bed is removed, blockage in the rectification column can be avoided, but if the packed bed is not used, there arises a new problem that the purity of titanium tetrachloride decreases. Thus, there is a demand for an efficient method for purifying titanium tetrachloride while avoiding blockage in the rectification column as much as possible.

  Further, after the packed bed arranged in the rectifying column is taken out of the column, the impurities deposited in the packed bed are pickled or washed with water, and then returned to the original rectifying column if not dried. There is another issue that cannot be done.

  Furthermore, since the deposit is composed of a soft solid or a highly sticky substance, it may take a long time to remove the substance by washing with water, and improvements are required.

  With respect to this point, a method of cleaning the components of the used rectifying column with crude titanium tetrachloride has been disclosed (see, for example, Patent Document 1), but impurities are contained in the crude titanium tetrachloride as a cleaning liquid. Since it is contained in a large amount, the components of the rectifying column may be contaminated instead, and there is a need for improvement.

JP 2006-055740 A

  As mentioned above, the clogging in the packed bed installed in the rectification column, which is a distillation purification facility for titanium tetrachloride, is avoided as much as possible, and the once clogged packed bed is efficiently maintained and restored to its original state. The technology to make it want is desired.

  The present invention has been made in view of the above-mentioned problems of the prior art, wherein impurities in titanium tetrachloride are separated as solids to obtain high-purity titanium tetrachloride. It aims at providing the method which can maintain the used packed bed efficiently.

  As a result of intensive studies based on such circumstances, an impurity separation device composed of an irregular packing layer and an ordered packing layer is disposed in a rectifying column that constitutes a distillation purification facility for titanium tetrachloride. It has been found that the impurity gas contained in titanium tetrachloride can be decomposed and separated and recovered as a solid, and the present invention has been completed.

That is, the present invention relates to a reboiler that vaporizes titanium tetrachloride , an irregular packed bed in which the packed product can be desorbed , a regular packed bed, and a distillation purification apparatus equipped with a rectifying column. A purification method, wherein titanium tetrachloride gas is generated in a reboiler, titanium tetrachloride gas is guided to the irregular packing layer, and then titanium tetrachloride gas is guided to the regular packing layer, and purified titanium chloride from the rectifying column. It is characterized by obtaining.

  In the above-described method for purifying titanium tetrachloride, the impurity gas contained in the titanium tetrachloride gas is decomposed in the irregular packing layer or the ordered packing layer, and is precipitated and separated on the packing as an impurity solid. This is a preferred embodiment.

  Further, in the above-described method for purifying titanium tetrachloride, the packing in the regular packing layer is composed of plate-like members arranged apart from each other in the vertical direction, and the plate-like member is A preferred embodiment is a metal plate.

  Further, in the method for purifying titanium tetrachloride, the packing of the irregular packing layer is constituted by a hollow ring body, the hollow ring body is a granular porous body, and the granular shape It is preferable that the porous body is made of metal or ceramics.

The distillation purification apparatus of the present invention comprises a reboiler for vaporizing titanium tetrachloride , an irregular packed bed in which a packed product can be desorbed , a regular packed bed, and a rectifying column. It is.

  Further, in the above-described titanium tetrachloride distillation purification apparatus, the packing of the regular packing layer is composed of plate-like members disposed apart from each other in the vertical direction, and the plate-like member. Is a metal plate.

  Furthermore, in the distillation purification apparatus for titanium tetrachloride, the packing of the irregular packing layer is constituted by a hollow ring body, the hollow ring body is a granular porous body, and the granular shape It is preferable that the porous body is made of metal or ceramics.

  The maintenance method of the titanium tetrachloride distillation purification apparatus of the present invention is specifically a maintenance method of the irregular packing used in the distillation purification apparatus, and desorbs the irregular packing arranged in the distillation purification apparatus. It is characterized by maintenance.

  In the maintenance method of the titanium tetrachloride distillation purification apparatus, a preferred embodiment is that the packing in the irregular packing layer desorbed from the distillation purification apparatus is washed with titanium tetrachloride.

  According to the present invention, in addition to the effect that the impurities in the titanium tetrachloride can be separated and removed efficiently, the effect that the dismantling maintenance of the impurity separation device can be advanced efficiently is achieved.

The best embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 schematically shows a titanium tetrachloride distillation purification apparatus R according to the present invention.
The distillation purification apparatus R includes a rectifying column 1, a reboiler 2, a condenser 3, an ordered packing layer 4, and an irregular packing layer 5. The reboiler 2 holds raw material titanium tetrachloride 6, The temperature is maintained at a boiling point of titanium tetrachloride or higher in a heating furnace (not shown).

  In the present invention, prior to supplying the raw material titanium tetrachloride 6 to be purified to the rectification column 1, it is preferable to introduce it to an impurity separation device. The impurity separation device in the present invention is preferably arranged at the bottom of the rectifying column 1 by connecting the ordered packing layer 4 and the irregular packing 5 in series.

  In the present invention, by using the equipment as described above, the impurities contained in the raw material titanium tetrachloride can be precipitated and separated as solids, and further, in the titanium tetrachloride. The contained hydrogen sulfide gas can also be effectively separated.

  The hydrogen sulfide gas is used to remove vanadium contained in the raw material titanium tetrachloride prior to distillation purification, and the gas not subjected to the reaction remains in the raw material titanium tetrachloride.

  The hydrogen sulfide gas contained in the titanium tetrachloride gas can be decomposed into a simple substance of sulfur and hydrogen gas by contacting the irregularly packed layer 5 or the orderedly packed layer 4. Solid sulfur precipitated in the irregular packing layer 5 or the ordered packing layer 4 can be efficiently separated by washing with water.

  In addition to the sulfur, the solid matter may be supplemented with aluminum, silicon, or niobium chloride in titanium tetrachloride. In that case, it is preferable to wash with water followed by pickling with hydrochloric acid. By performing the above-described washing operation, there is an effect that aluminum, silicon or niobium chloride can be separated and removed efficiently.

  In the present invention, it is preferable that the raw material titanium tetrachloride 6 or the titanium tetrachloride gas held in the reboiler 2 is first passed through the irregular packing layer 5 and then passed through the regular packing layer 4. .

  By performing the operations in the order described above, prior to supplying the raw material titanium tetrachloride to the main body of the rectifying column 1, the impurity gas contained in the raw material titanium tetrachloride is decomposed and separated and recovered as solid impurities. There is an effect that it is possible. As a result, it is possible to suppress the precipitation of impurities in the rectifying column 1 main body.

  In the present invention, the irregular filler layer 5 is preferably configured to be filled with a hollow ring body. Specifically, the hollow ring body preferably means, for example, a packing for a general rectification tower, which means a donut-shaped ring body and is called by a name such as Raschig ring. Can do.

  In this invention, it is preferable to arrange | position the said irregular packing layer 5 directly on the reboiler 2 arrange | positioned in the bottom part of the distillation purification apparatus R of titanium tetrachloride. By disposing the irregular packing layer 5 immediately above the reboiler 2, it is possible to efficiently capture the liquid titanium tetrachloride scattered in the titanium tetrachloride vapor evaporated from the reboiler 2. It is what you play.

  Further, the raw material titanium tetrachloride 6 is preferably passed through the irregular filler layer 4 after passing through the irregular filler layer 5 as described above.

  Since the irregularly packed layer 5 is exposed to the high-temperature titanium tetrachloride gas as described above, it is preferable that the irregularly packed layer 5 is made of a corrosion-resistant substance. The substance is preferably composed of a corrosion-resistant metal or ceramic. The corrosion-resistant metal is preferably made of stainless steel, and is preferably made of SUS304, SUS316, or the like. On the other hand, the ceramic having corrosion resistance is preferably composed of silicon nitride or aluminum nitride.

  The size of the hollow ring body according to the present invention is preferably configured in the range of an outer diameter of 25 mm to 100 mm. By forming the irregular packing layer 5 with the granular porous body having the granular size as described above, there is an effect that the liquid titanium tetrachloride scattered from the reboiler 2 can be efficiently captured. Is.

  It is preferable to fill the porosity of the granular porous body so that the porosity of the irregular filler layer 5 is in the range of 30% to 60%. By configuring with the porosity and porosity as described above, not only can the liquid titanium tetrachloride scattered from the reboiler 2 be efficiently captured, but also the passage of titanium tetrachloride gas evaporating from the reboiler 2 is efficient. There is an effect that it can be advanced well.

  In this invention, it is preferable to provide the opening part which is not shown in the side wall of the rectification column 1 in which the irregular packing layer 5 is arrange | positioned. By providing the above-described opening on the side wall of the rectifying column 1, the granular porous body filled in the irregular packing layer 5 can be efficiently scraped to the outside. The hollow ring body scraped to the outside can be efficiently washed with solid impurities deposited inside the porous body by washing with water or pickling.

  In the present invention, it is preferable to arrange the ordered filler layer 4 immediately above the irregular filler layer 5. By disposing the regular packing layer 4 as described above, the liquid titanium tetrachloride that has passed through the irregular packing layer 5 is surely captured, and only the gaseous titanium tetrachloride gas is passed through the rectifying column 1. The effect is that it can be passed upward. As a result, the quality contamination of purified titanium tetrachloride due to mixing of liquid titanium tetrachloride can be effectively suppressed.

  The regular packing layer 4 is composed of a plate-like member (sometimes referred to as a sulzer packing) in which corrugated folded plates are laminated, and is arranged so that the circulation ports are staggered as shown in FIG. However, the above-described effects can be obtained even if other members are used.

  With the configuration described above, countercurrent contact between the titanium tetrachloride gas generated from the reboiler 2 and the liquid titanium tetrachloride flowing down from the top of the rectifying column 1 can be efficiently advanced. As a result, there is an effect that impurities in the titanium tetrachloride gas can be efficiently moved with respect to the liquid titanium tetrachloride.

  In the present invention, it is preferable that a liquid titanium tetrachloride supply nozzle 8 is disposed on the side wall of the rectifying column 1 so as to correspond directly to the ordered packing layer 4 disposed in the distillation purification apparatus R. By disposing the nozzle as described above, liquid titanium tetrachloride can flow down into the ordered packing layer 5. As a result, the impurities deposited in the ordered filler layer 5 can be effectively cleaned.

  By the operation described above, substances having a boiling point lower than that of titanium tetrachloride are concentrated on the top of the rectifying column 1, and substances having a boiling point higher than that of titanium tetrachloride are concentrated on the bottom of the rectifying column 1. Therefore, by extracting the titanium tetrachloride gas generated inside the rectifying column 1 from the side wall of the rectifying column 1 whose temperature distribution in the rectifying column corresponds exactly to the boiling point of titanium tetrachloride, High titanium tetrachloride can be recovered.

  The washed liquid titanium tetrachloride in which the impurities are dissolved returns to the inside of the reboiler 2 and is evaporated again, and the inside of the rectifying column 1 is raised and purified. On the other hand, solids out of impurities contained in the washed liquid titanium tetrachloride are deposited on the bottom of the reboiler 2 and separated from the titanium tetrachloride. Therefore, it is preferable to periodically extract the residue accumulated at the bottom of the reboiler 2 to the outside.

  The maintenance method of the titanium tetrachloride distillation purification apparatus according to the present invention is characterized in that maintenance is performed after extracting the hollow ring body filled in the irregular packing layer 5 to the outside. As a result, it is possible to efficiently maintain the hollow ring body without damaging the main body of the rectifying column 1.

  Further, as described above, the regular packed bed 4 according to the present invention can be supplied by supplying a large amount of liquid titanium tetrachloride from above without taking it out of the rectifying column 1. 4 has an effect that the impurities deposited inside 4 can be efficiently cleaned.

  In this invention, it is preferable to wash | clean the granular porous body extracted outside by the said method with refined titanium tetrachloride. The washed titanium tetrachloride contains a large amount of impurities, but the washed titanium tetrachloride is spray-dried to a cooling system of tetrachloride gas generated in a chlorination furnace, so that the titanium tetrachloride Impurities contained therein can be separated and removed, and the titanium tetrachloride from which the impurities are separated can be recovered as purified titanium tetrachloride by returning to the rectifying column 1 and purifying it again. It is.

  By using the above-described distillation purification apparatus for titanium tetrachloride, it is possible to produce purified titanium tetrachloride efficiently. Furthermore, the maintenance method can efficiently maintain the irregular packing layer 4 and the regular packing layer 5 and recycle the distillation production equipment.

[Example 1]
The specifications of the apparatus configuration shown in the embodiment of the present invention are shown below.
1. Rectifying column Material: SUS304L
2. Regular packing layer Material: SUS304
Structure: horizontal laminated plate3. Irregular packing layer Material: SUS304
Structure: Hollow ring body Size: Outer diameter 25mm
4). Reboiler temperature 136 ° C (boiling temperature of titanium tetrachloride)
5. Capacitor temperature 105 ° C

  With the apparatus configuration described above, titanium tetrachloride produced in a chlorination furnace was used as a raw material and purified using the distillation purification apparatus shown in FIG. 1, and the product titanium tetrachloride was continuously purified. Since the pressure loss of the regular packing layer and the irregular packing layer increased during the purification process of titanium tetrachloride, liquid titanium tetrachloride was supplied from the outside over the regular packing layer 4 to clean the packing layer. did. As a result, the pressure loss recovered to the original state.

  When the irregularly packed bed or the solid matter deposited on the ordered packed bed was analyzed, sulfur was detected. Besides sulfur, iron, aluminum and niobium were detected. It was confirmed that sulfur, iron, aluminum, and niobium in titanium tetrachloride purified by distillation in this embodiment were effectively reduced as compared with those before distillation purification. Table 1 shows the impurity concentration in the titanium tetrachloride after purification when the impurity concentration in the titanium tetrachloride before purification is 100.

[Example 2]
When the operation was further continued under the conditions of Example 1, the pressure loss of the irregular filler layer 5 increased again, so that the hollow ring body was extracted from the irregular filler layer 5 to the outside, and then the granular The porous material was washed with purified titanium tetrachloride. Next, after washing with dilute hydrochloric acid, it was washed with water and dried to return to the original irregularly packed layer. As a result, the pressure loss recovered to the original state.

[Comparative Example 1]
In Example 1, only the regular packing layer 4 was disposed without attaching the irregular packing layer 5, and the titanium tetrachloride was distilled and purified. However, the impurity concentration of distilled and purified titanium tetrachloride was not satisfactory. Further, when the subsequent operation was continued, the pressure loss of the ordered packed bed 4 tended to increase. Then, when liquid titanium tetrachloride was supplied from the nozzle 8 provided on the side wall of the rectifying column 1 from above the ordered packed bed 4, the pressure loss of the ordered packed bed 4 decreased. However, it did not recover to its original state. Therefore, it was unavoidable that the operation of the distillation purification apparatus R was stopped and the regular packing layer 4 was prepared. As a result, the pressure loss was restored to the original state. However, the distillation purification apparatus R had to be stopped for 90 days.

  From the above test results, in the method for purifying titanium tetrachloride according to the present invention, the irregular packed bed disposed in the titanium tetrachloride distillation purification device is effective in reducing impurities in the purified titanium tetrachloride. In addition, it was confirmed that the maintenance of distillation purification equipment can be labor-saving.

  The present invention provides a structure, operation method, and maintenance method of a distillation purification apparatus capable of producing high-purity titanium tetrachloride over a long period of time.

It is a schematic cross section which shows the distillation purification apparatus of the titanium tetrachloride of this invention.

Explanation of symbols

R ... distillation purification apparatus, 1 ... rectification tower, 2 ... reboiler, 3 ... condenser, 4 ... regular packed bed, 5 ... irregular packed bed, 6 ... raw material titanium tetrachloride, 7 ... shelf, 8 ... liquid Titanium tetrachloride supply nozzle.

Claims (21)

A refining method for vaporizing titanium tetrachloride, a method for purifying titanium tetrachloride using a distillation purification apparatus equipped with an irregular packing layer in which the packing included can be desorbed , a regular packing layer, and a rectifying column. ,
Titanium tetrachloride gas is generated by the reboiler,
Leading the titanium tetrachloride gas to the irregular packing layer,
Next, the titanium tetrachloride gas is guided to the ordered packing layer,
A method for purifying titanium tetrachloride, comprising obtaining purified titanium chloride from the rectifying column.
  2. The irregularly packed bed or the ordered packed bed, wherein an impurity gas contained in a titanium tetrachloride gas is decomposed and precipitated and separated as a solid substance of impurities on the filler. The method for purifying titanium tetrachloride as described.   The method for purifying titanium tetrachloride according to claim 2, wherein the impurity gas is hydrogen sulfide, aluminum chloride, silicon chloride, or niobium chloride.   3. The method for purifying titanium tetrachloride according to claim 2, wherein the packing of the ordered packing layer is composed of plate-like members that are spaced apart from each other in the vertical direction.   The method for purifying titanium tetrachloride according to claim 4, wherein the plate member is a metal plate.   The method for purifying titanium tetrachloride according to claim 2, wherein the packing of the irregular packing layer is formed of a hollow ring body.   The method for purifying titanium tetrachloride according to claim 6, wherein the hollow ring body is a granular porous body.   The method for purifying titanium tetrachloride according to claim 7, wherein the granular porous body is made of metal or ceramics.   The method for purifying titanium tetrachloride according to claim 8, wherein the metal is stainless steel.   The method for purifying titanium tetrachloride according to claim 8, wherein the ceramics is silicon nitride or aluminum nitride. An apparatus for distilling and purifying titanium tetrachloride, comprising a reboiler for vaporizing titanium tetrachloride , an irregularly packed bed from which the packed material can be desorbed , an ordered packed bed, and a rectifying column.
  12. The apparatus for distillation and purification of titanium tetrachloride according to claim 11, wherein the packing of the ordered packing layer is composed of plate-like members disposed apart from each other in the vertical direction. .   The apparatus for distillation and purification of titanium tetrachloride according to claim 12, wherein the plate-like member is a metal plate.   The apparatus for distillation and purification of titanium tetrachloride according to claim 11, wherein the packing of the irregular packing layer is formed of a hollow ring body.   The apparatus for distillation and purification of titanium tetrachloride according to claim 14, wherein the hollow ring body is a granular porous body.   The apparatus for distillation and purification of titanium tetrachloride according to claim 15, wherein the granular porous body is made of metal or ceramics.   The apparatus for distillation and purification of titanium tetrachloride according to claim 16, wherein the metal is stainless steel.   The apparatus for distillation and purification of titanium tetrachloride according to claim 16, wherein the ceramic is silicon nitride or aluminum nitride.   A method for maintaining a used irregular packing constituting the distillation purification apparatus for titanium tetrachloride according to any one of claims 11 to 18, wherein the irregular packing disposed in the distillation purification apparatus is used. A maintenance method for a titanium tetrachloride distillation purification device characterized by desorption and maintenance.   20. The maintenance method for a titanium tetrachloride distillation purification apparatus according to claim 19, wherein the irregular packing desorbed from the distillation purification apparatus is washed with titanium tetrachloride.   20. The titanium tetrachloride according to claim 19, wherein the titanium tetrachloride after washing the irregular packing is spray-dried in a titanium tetrachloride gas cooling facility constituting a titanium tetrachloride production apparatus. Maintenance method of distillation purification equipment.

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