JPS6287416A - Production of high-purity niobium iodide - Google Patents

Abstract

PURPOSE:To obtain high-purity niobium iodide directly from ferroniobium with simple procedure, by iodinating ferroniobium and subjecting the resultant mixed iodide to the separation of volatile iodide, removal of iron and then removal of tantalum. CONSTITUTION:An iron alloy containing >=50wt% niobium is iodinated with iodine and the resultant mixed iodide is subjected to the step to separate volatile iodide as impurity, the step to remove iron and the step to remove tantalum. The above mixed iodide is preferably treated by the following procedure to obtain high-purity niobium iodide. (1) Ferroniobium is completely reacted with iodine and volatile titanium tetraiodide, tin tetraiodide and aluminum triiodide are separated from the resultant mixed iodide by controlling the temperature of collecting part. (2) obtained mixed iodide is heated to reduce iron triiodide to hardly volatile iron diiodide, which is separated from mixed iodide composed of niobium pentaiodide and tantalum pentaiodide. (3) A mixed iodide composed of niobium pentaiodide and tantalum pentaiodide is heated to reduce niobium pentaiodide to hardly volatile niobium triiodide, which is separated from tantalum pentaiodide.

Description

[Detailed Description of the Invention] [Industrial Application Field] Metal iodides such as niobium are widely used in pharmaceuticals, catalysts, sensors, and the like.

In particular, in recent years, high-purity niobium iodide has been required for electronic materials and the production of high-purity niobium metal.

[Conventional technology] Conventionally, in order to produce high-purity niobium iodide, the methods used were to react iodine with metal niobium of the highest possible purity, or to iodine it with high-purity niobium pentachloride or hydrogen iodide. It's here.

These methods require high raw material costs and require complicated distillation operations to improve purity.

[Problem that the invention seeks to solve]

The object of the present invention is to produce high-purity niobium iodide directly from 7-elonium niobium by a simple operation, which has not been possible with the prior art.

[Means to solve problems]

The present invention uses less than 50% by weight of iron and tantalum.

Volatile (high vapor pressure) iodides such as titanium iodide (TtT4), tin iodide (TSnT4) and aluminum triiodide are obtained by iodizing with ferroniodine containing impurities such as titanium and tin and controlling the collection temperature. After separating (mu4T, ), the obtained mixed iodide [niobium pentaiodide n1b
r,) 15 tantalum iodide lTa. ) Thirteen iron iodide (F6
．． T,
For,) KW is separated and then the tantalum-containing niobium iodide obtained here is heated to convert NbQ to niobium Misawa (
An object of the present invention is to provide a method for producing high-purity niobium iodide, which is characterized by reducing Nbr, )K and separating it from TaT4.

[Operations and Effects of the Invention] Each step of the present invention is shown in the following reaction formula. (↓
indicates low volatility and ↑ indicates volatility. ) (1) Iodination/dealumination, titanium, tin process Wb + 5/2r,
−+NbI.

Ta +s7'2Tt-+ Ta16 Fe +3/2r, -+ Fed.

2mu t-4-5r, →A4T4↑ Sn +2T, -+8nT4↑ Ti+2T, →TiT4↑ (21 Iron removal process Wb-→Nbllll Tal6→T&I.

1! e engineering, → FeT4↓+1/24 (3) Detantalization process Nb-→Nb engineering, ↓+4 '1"aI6-+"ll (4) Re-iodination process ybx, +T*-+Aim 1 Next, the present invention will be specifically explained for each step.

The ferroniobium used as a starting material in the present invention contains less than 50% iron and 1% tantalum and aluminum.
It contains the following elements, including titanium, tin, etc.

(1) Iodination-dealumination titanium-tin step The iodination reaction can be carried out either batchwise or continuously, but the continuous method is preferred from the viewpoints of productivity and economy.

There is no particular restriction on the reaction temperature as long as it is 300°C or higher, since the rate of iodination increases rapidly if the reaction temperature is 300°C or higher, but a temperature of 4000 to 600°C is usually adopted. After the reaction is complete, the mixed iodide is purified by distillation to obtain A/J, , TiT
4. Volatile iodides with high vapor pressure, such as SnI, are separated. This temperature should be 100℃ or higher, but if it is too high, reduction of ν・−→Si1 will occur at this stage, so 1
The temperature is preferably 50' to 250°C.

(2) Deiron removal process Mixed iodide (NbI, -1-TaI) obtained in the previous step.

+IP6D,) is heated to 200° to 400°C under an inert gas atmosphere or hydrogen gas atmosphere or under reduced pressure to form IFeI.
, is reduced to less volatile Fed, and separated from tantalum niobium iodide (NbT, 10T a ]1.).

If the heating temperature is low, the reduction of 1) eT is insufficient, and if the temperature is high, some of the NbI will also be reduced, so the heating temperature is 250
°~550°C is preferred. (When hydrogen gas is used, the temperature is preferably 2500 to 500°C.) (3) De-tantalum step Tantalum-containing niobium iodide (Nbr,
+TaT4 heat treatment to convert Nb4 to non-volatile NbI4
It is reduced to T&T and separated.

Heating is performed at 300° to 600°C, preferably 350° to 45°C under an inert gas atmosphere or hydrogen gas atmosphere or under reduced pressure.
It is carried out at 0°C. If the heating temperature is low, the reduction will be insufficient, and if it is high, NbI will be produced.

This is because the proportion of niobium that is scattered as it is with Tag increases, and the yield of niobium decreases.

(4) Re-iodination step Since the niobium iodide obtained in the tantalum removal step is in the form of NbI, it has extremely high purity and is relatively stable in the atmosphere, so this step is not always necessary, but When used as a raw material for niobium gas phase pyrolysis, Nb is more active and has a higher vapor pressure.
I.

is more advantageous.

The reaction between Nb- and t may also be carried out at a temperature of 500°C or higher, but a temperature of 400° to 600°C is usually adopted.

[Explanation of effects]

As is clear from the above description, according to the present invention, (2) highly purified niobium iodide can be obtained from (0) inexpensive 7-eroniobium by a simple operation of changing the heating temperature.

〔Example〕

The present invention will be explained below using batch-type examples, but the present invention is not limited to these examples in any way.

Example 1 All steps were carried out in a vacuum-sealed Pyrex glass tube containing the raw materials 7-Eloniobium and iodine.

Figure 1 shows the Pyrex reaction tube A used for the reaction.

It was divided into southwest rooms B, O, and D, and an electric furnace made by Kuchitatsu, whose temperature could be controlled separately for each room, was used for heating.

The Pyrex tube has a diameter of 50. Each chamber had a length of 200 mm and was connected with a 20wJφ pipe.

(1) Iodination: Dealumination, titanium, and tin process 1,00 g of iodine in room A, 150 g of 7-d rhoniobium in room D
and apply 10-' Torr from the opening with a rotary pump.
The mixture was ground and sealed for 1 hour until r.

Place this in a mouth furnace, chamber A at 180℃, chamber B at 550℃,
Room 0 and room D were heated to 500°C and maintained for 24 hours. After cooling (Fig. 1-b), chamber A contains unreacted iodine A/, I6,
TiI4 and Sn4■ remained, and a small amount of unreacted 7E0=of■ remained in chamber D. Chamber 0 was empty, and mixed iodide (NbT, +Fa + TaTi) was aggregated in chamber B.

Rooms A and D have been sealed off.

(2) Deiron removal process Room B was kept at 300°C and room 0 was kept at room temperature for 24 hours. After cooling (FIG. 1-0), 'fats-■' was aggregated in chamber B, and niobium iodide (libT, +T&4)■ containing tantalum was aggregated in chamber B.

(3) Detantalization process Room B was kept at room temperature, 400° C., for 24 hours. After cooling (FIG. 1-d), TaT, a small amount of Nt+T, and ■ were aggregated in chamber B, and Wb and ■ were aggregated in chamber 0.

The tube was opened in the group box and N'bT in chamber 0 was taken out. NbI was obtained at 3509, and the niobium yield was 70
%Met.

The analytical values of the raw material 7-eroniobium and the obtained niobium iodide were as follows.

NbF@TIL At an Ti
65 30 [1) 4[
144α14 As can be seen from the results of concavity 7 and above, extremely high purity niobium iodide was obtained.

Example 2 High purity niobium iodide was produced in a continuous manner. Examples will be described based on the drawings. Figure 2 shows the raw NK iodination process of 7-Eloniobium, dealluminization, and titanium.

This is an equipment that continuously performs the tin process, iron removal process, and tantalum removal process.

In Figure 2, 1) is an iodine pot, 12 is a sealed iodine feeder (for example, an electromagnetic feeder),
Powdered iodine is quantitatively supplied into 15 iodine vaporizers. The gaseous iodine here is sent to the reactor 14,
It reacts with the ferroniobium which is quantitatively supplied from the ferroniobium bottle 15 and falls into the mezzara 16 to produce iodide. The generated mixed iodide is deironated in the deironation tower 17. The iron diiodide produced at this time is deposited in the lower collection bot 18 and collector 19.

Here, excess iodine, volatile titanium tetraiodide (TiI4)
, tin tetraiodide (llinx4) and aluminum triiodide (AA) are recovered in 22 cold wraps.

The mixed iodide collected in step 19 is fed in solid form to the detantalizing tower in step 20. MR gas is supplied from the lower part of the detantalizing tower, and the mixed iodide becomes fluid, and 1l of Nbl is reduced to niobium pentaiodide (Nbr), which is then transferred to the lower recovery box.
It will be collected on the 21st. Ta′1. is deposited in the collector 23 and collected in the collection pot 24 at the bottom. N
When bI is reduced to NbI, the iodine produced is 25
collected in a cold trap.

As a more specific operating method, the entire system is 10-2 to
Evacuate to below rr, heat and maintain at about 500°C or above to degas.

Next, an appropriate amount of iodine is supplied to an iodine vaporizer heated above its boiling point to create an iodine atmosphere in the reactor. Furthermore, after each part reaches a predetermined temperature, ferroniodine is supplied and iodized.

In the figure, 26.27 indicates the inflow of Ar gas, and 28.29 indicates the flow of exhaust gas.

Using the apparatus shown in Figure 2, high purity niobium iodide was exhausted under the following conditions.

(Conditions) Iodine supply rate 1597 win Ferron niobium supply rate 19/min Iodine vaporizer temperature 200°C Reactor temperature 500°C De-iron tower temperature 300°C Mixed iodide collector temperature 150°C Detantalist tower temperature 450°C Collector Temperature: Room temperature recovery pot temperature: Room temperature cold trap: Liquid nitride: The grade of high purity niobium iodide produced under the above conditions and the composition of the raw material ferroniobium were as follows.

Wb ]Fe Setting Atan 'I'1 Ferroniobium (vrt%) 65 30 α14 [1
44α14 (The balance after operating for 12,710 hours was as follows.

Ferroniobium 600g Iodine 7.8009 High purity niobium iodide 1. zao91Nb19.2%, engineering8α8%) Niobium yield 63%

[Brief explanation of drawings]

FIG. 1 shows an example of a batch-type iodination reactor used in the present invention, and FIG. 2 shows an example of a continuous-type iodination reactor. 1...Iodine 2...7 Eloniobium, 2'...Feroniobium balance 3
...Mixture of arzenium triiodide, titanium tetraiodide and tin quaternary 4...51 Ihiniobium, ichtantal and = trab iron C agamma 5... iron diiodide 6 ...Mixture 7 of niobium pentaiodide and tantalum pentaiodide
... Tantalum pentaiodide 8 ... Niobium pentaiodide 1) ... Iodine pot 13 ... Iodine volatilizer 14 ... Reactor 15 ... Ferroniobium pot 17 ... De-iron removal tower 20・・・Detaching/Taru Tower

Claims (4)

[Claims] (1) A step of iodizing an iron alloy containing at least 50% by weight of niobium with iodine to separate volatile iodide impurities;
A method for producing high-purity niobium iodide, which is characterized by performing an iron removal step and then a tantalum removal step. (2) The mixed iodide produced by reacting the entire amount of ferroniobium with iodine is converted into volatile titanium tetraiodide by controlling the temperature of the collection section.
A method for producing high-purity niobium iodide according to claim (1), which separates tin tetraiodide and aluminum triiodide. (3) Heat-treating the mixed iodide in a vacuum or in an inert gas or hydrogen gas stream to reduce iron triiodide to less volatile iron diiodide and mixing niobium pentaiodide and tantalum pentaiodide. A method for producing high-purity niobium iodide according to claim (1) or (2), in which niobium iodide is separated from iodide. (4) A mixed iodide of niobium pentaiodide and tantalum pentaiodide is heat-treated in a vacuum or in an inert gas or hydrogen gas stream to reduce niobium pentaiodide to less volatile niobium triiodide. A method for producing high-purity niobium iodide according to claim 1, 2 or 3, wherein the niobium iodide is separated from tantalum iodide.