JP3253391B2 - Method for producing titanium oxide enriched material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an industrial production method of a titanium-rich product for producing titanium tetrachloride, which is a raw material of titanium dioxide pigment, metallic titanium and the like, and more specifically, contains a large amount of iron oxide as an impurity. A titanium raw material having the above composition, or a raw material mixed and prepared with such a composition, is selectively chlorinated with a chlorinating gas, and by separating iron and the like as a gaseous chlorinated product, a titanium oxide-rich product And a method for producing the same.

[0002]

2. Description of the Related Art Titanium tetrachloride usually has a titanium grade of 90%.
% Is produced by fluid chlorination of a high-grade titanium raw material that does not contain fine powder of more than 10%. However, in recent years, due to a decrease in resources, a situation has arisen in which a low-grade titanium raw material containing a large amount of iron oxide as an impurity must be used as a raw material for producing titanium tetrachloride. As one of the methods for producing titanium tetrachloride from such low-grade titanium raw material, the iron component in the low-grade titanium raw material is removed by selective chlorination to produce a titanium oxide-enriched product, which is then subjected to tetrachloride. This is a method for providing a titanium gas generation reaction. In this method, selective chlorination is performed at a high temperature without using a reducing agent, and then the obtained iron chloride is oxidized and decomposed, and the recovered chlorine is recycled and used in a selective chlorination step. In addition, there is a method in which coke, carbon, carbon monoxide or the like is used as a reducing agent and the reaction temperature is lowered to perform selective chlorination.

[0003]

However, in the above method, the reaction temperature of the selective chlorination section is, for example, 90 ° C.
When the temperature is higher than 0 ° C., the chlorination reaction of iron oxide is an endothermic reaction, so unless heat is directly supplied to the reactor,
It is necessary to preheat the raw material to 1100 ° C. or higher. However, industrially, it is not easy to supply such a high-temperature heat from the outside of the reactor or to handle the powder or granules at such a high temperature. In the other method, although the reaction in the selective chlorination unit can be performed at a relatively low temperature, gases such as carbon monoxide and carbon dioxide in addition to ferric chloride gas in the product gas after the selective chlorination. Will be included. For this reason, when recovering and using chlorine gas by oxidative decomposition of the ferric chloride gas, the progress of the oxidative decomposition reaction is suppressed,
When recycling recovered chlorine gas to the selective chlorination unit,
Further, when the titanium oxide-rich product is recycled to the chlorinated part, there are various problems such as an increase in the burden of separating carbon dioxide.

[0004]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have conducted various studies, and as a result, have found that a low-grade titanium oxide containing a specific amount or a mixed preparation thereof with a low-grade titanium raw material is used. By selectively chlorinating this, the selective chlorination can be performed at a relatively low temperature without using a carbon-based reducing agent, and furthermore, the recovery and utilization of chlorine gas by oxidative decomposition of the generated ferric chloride. Was found to be extremely easy.

That is, the present invention relates to T.I. Fe (weight percentage in terms of metallic iron) of 7% by weight or more;
TiO ₂ (weight percentage when converted to titanium dioxide)
Is not less than 50% by weight and the lower titanium oxide TiO _x (0
<X <2) is a titanium raw material having 10% by weight or more of 900%
This is a method for producing a titanium oxide-rich product, characterized by selectively chlorinating mainly an iron component at a temperature of not more than ° C to generate and separate a chlorinated substance mainly composed of ferric chloride. In addition, the T
iO _X wt% is equivalent value in the case where all the lower titanium oxide TiO _1.5.

The above-mentioned raw material composition can be obtained by mixing a titanium raw material alone or in a specific amount with a low-grade titanium raw material. For example, (1) T. Fe is 7 to 11% by weight; T
75 to 90% by weight of TiO _{2 and 12} to 35% by weight of TiO _X
Titanium slag alone, (2) a mixture of titanium slag and ilmenite ore so as to be in the specific composition range, (3) T. Fe 0 to 2% by weight; TiO ₂ 100-110% by weight, TiO _X 90-100% by weight
And a mixture of anatase ore and ilmenite ore so as to have the above-mentioned specific composition range.

The selective chlorination reaction in the present invention is 900 ° C.
It is carried out at the following temperatures, usually between 700 and 900C.
In the present invention, if the amount of lower titanium oxide in the titanium raw material is too small than the specific range, the chlorination reaction does not substantially proceed in the above-mentioned temperature range, and furthermore, the reaction proceeds at a reaction temperature of, for example, 1000 ° C. or more. However, it is difficult to maintain a high reaction temperature because of the heavy load on the apparatus.

[0008] The raw material supply temperature and the selective chlorination reaction temperature are as follows:
It is determined according to the lower titanium oxide content in the titanium raw material used, but as the lower titanium oxide content increases,
The reaction temperature for obtaining the same chlorination reaction rate is lower, and the raw material supply temperature required for maintaining the reaction temperature can be further reduced. For example, when titanium slag and ilmenite (for example, T.TiO _{2 is} 50% by weight or more and Fe ₂ O ₃ is 30% by weight or less) are used, the latter is 50% by weight or less. It is economically advantageous that the content is 30% by weight or more. Examples of the chlorinated gas used for the selective chlorination include a chlorine-containing gas such as a chlorine gas and a titanium tetrachloride gas, and it is desirable to use a chlorine gas.

The product gas mainly composed of ferric chloride obtained by the selective chlorination is solid-gas separated from the titanium oxide enriched product, and then oxidized and decomposed by oxygen to be recovered as chlorine gas and ferric oxide. . Since the generated gas does not contain carbon monoxide or carbon dioxide, it is possible to recover a high concentration of chlorine gas at a high oxidative decomposition rate without requiring a large excess of oxygen. The unreacted oxygen hardly exists in the generated chlorine gas.

[0010] On the other hand, the titanium oxide enriched material that has been deiron-separated is discharged together with a high-boiling chloride by a piston flow. Therefore, the reaction can be continued without the high-boiling-point chloride conventionally regarded as a flow inhibiting substance in the flow reactor being concentrated in the reactor. When using the obtained titanium oxide-enriched product for the production of titanium tetrachloride, the high-boiling-point chloride can be easily removed by a treatment such as washing with water.

Next, the present invention will be described with reference to the drawings. FIG. 1 is a schematic view illustrating an apparatus used to produce the titanium oxide-enriched product of the present invention and a configuration of an applied apparatus.
1 shows a selective chlorination-oxidation reactor. The titanium raw material 5 is supplied to the selective chlorination unit 2 and chlorinated by a chlorine gas 6 introduced from the bottom to generate a gas mainly composed of ferric chloride 7 and a titanium oxide-rich product 11.

The ferric chloride gas 7 is sent to the oxidative decomposition section 3 in the upper part of the reactor together with other gaseous substances (chloride gas of an impurity metal such as manganese and magnesium and unreacted chlorine gas). After oxidative decomposition, recovered chlorine 10
And ferric oxide 9 are recovered. The recovered chlorine 10 can be reused in the selective chlorination furnace 2 or the chlorination furnace 4 for producing titanium tetrachloride. The pressure in the selective chlorination section is desirably set so as to maintain a pressure balance such as preheating section> selective chlorination section> oxidative decomposition section, which enables mass transfer by pressure and simplifies equipment. Is done.

On the other hand, the titanium oxide-rich product 11 generated in the selective chlorination section 2 is discharged from the reactor and recovered.
The titanium oxide-enriched product 11 thus obtained can be used for various applications after the high-boiling-point chloride removal treatment, if necessary. However, when it is used as a raw material for producing titanium tetrachloride, It is suitable. Incidentally, some amounts of various reducing agents may be used in the selective chlorination as long as the object of the present invention is not impaired.

[0014]

【Example】

Example 1 A high-grade titanium slag (titanium raw material A) shown in Table 1 was preheated to 700 ° C. in a selective chlorine section 2 and 277 kg / kg was fed from the bottom of the reactor.
Chlorine gas was supplied over a period of time to perform fluid chlorination. The temperature inside the reactor rises due to the exothermic reaction, and when the temperature reaches 850 ° C., the supply of the titanium raw material A preheated to 400 ° C. is reduced to 123 ° C.
Started at 0 kg / hr. As a result, the temperature of the reactor was kept constant at approximately 850 ° C., and after the selective chlorination reaction for a predetermined residence time, the titanium oxide-enriched product became 1060 kg /
Over time the reactor overflowed and the enrichment A was recovered. The composition and the like are shown in Table 2.

Example 2 A titanium raw material B was obtained by mixing a high-grade titanium slag (titanium raw material A) and Indian ilmenite (titanium raw material C) shown in Table 1 at a weight ratio of 7: 3. This is preheated to 800 ° C. in the selective chlorination section 2 and 4 chlorine gases are supplied from the lower part of the reactor.
When the temperature of the selective chlorination unit, which started supplying at 87 kg / hr and was fluidized and chlorinated, reached 850 ° C., the titanium raw material B
Was started at 1350 kg / h. As a result, the temperature of the reactor becomes constant at approximately 850 ° C., and after performing a selective chlorination reaction for a predetermined residence time, the titanium oxide-rich product overflows from the reactor at 1170 kg / hour from 11;
Enrichment B was recovered. The composition and the like are shown in Table 2.

Comparative Example A selective chlorination reactor was filled with Indian ilmenite (titanium raw material C) shown in Table 1 which was preheated to 1000 ° C., and chlorine gas was supplied to perform fluid chlorination. Titanium raw material C at room temperature at 1740 g / hour while controlling heating to 1000 ° C
Supply has begun. After this, keep the temperature of the reactor at 1000 ° C.
After performing a selective chlorination reaction for a predetermined residence time while heating and controlling the temperature, 1390 g of the titanium oxide-enriched product from 11
/ H and the enrichment C was recovered. The composition and the like are shown in Table 2.

[0017]

[Table 1]

[0018]

[Table 2]

The experimental conditions of the examples and comparative examples are summarized in Table 3. As is clear from Table 2, the enriched product A obtained in Example 1 and the enriched product B obtained in Example 2 show a high deironation rate and are suitable as raw materials for producing titanium tetrachloride. However, in particular, the enriched product B is a product which provides sufficient enrichment while diversifying and economically using titanium materials by mixing low-grade titanium materials, and is extremely industrially advantageous. In contrast, the enriched product C obtained in the comparative example
However, even if the reaction is carried out at 1000 ° C., a sufficient iron removal rate cannot be obtained, and a higher reaction temperature is required to obtain a desired titanium oxide-enriched product. The deironing ratio is a value indicating the ratio of the amount of iron removed by selective chlorination to the amount of iron in the raw ore in percentage.

[0020]

[Table 3]

[0021]

According to the present invention, the main iron component in the titanium raw material having a specific composition or mixed and prepared is selectively chlorinated at a temperature of 900 ° C. or less, and the generated iron chloride is removed to remove the titanium oxide-enriched material. It is a manufacturing method. In the present invention, since the selective chlorination reaction is performed without using a carbon-based reducing agent, it is possible to recover a high concentration of chlorine gas at a high oxidative decomposition rate, and to perform the selective chlorination reaction at 900 ° C. or lower. Therefore, a general-purpose heat-resistant material can be used without using a special heat-resistant material as a device material for the selective chlorination furnace or the like. further,
By using a low-grade titanium raw material, a desired titanium oxide-rich product can be produced, which is extremely advantageous in producing industrially inexpensive titanium tetrachloride.

[0022]

[Brief description of the drawings]

FIG. 1 is a schematic view illustrating an apparatus used for producing a titanium oxide-enriched product of the present invention and a configuration of an application apparatus thereof. In the figure, 1 is a selective chlorination-oxidation reactor, 2
Is a selective chlorination unit, 3 is an oxidative decomposition unit, 4 is a chlorination furnace for titanium tetrachloride production, 5 is a titanium raw material, 6 is chlorine gas, 7 is ferric chloride gas, 8 is oxygen, and 9 is ferric oxide. , 10 represents recovered chlorine, and 11 represents titanium oxide-enriched product.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-60-5024 (JP, A) JP-A-62-191425 (JP, A) JP-A-46-3405 (JP, A) JP-A 50-50 57995 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) C01G 1/00-23/08 WPI (DIALOG)

Claims (1)

(57) [Claims] (1) T. Fe (weight percentage in terms of metallic iron) of 7% by weight or more; TiO ₂ (weight percentage in terms of titanium dioxide) is 50% by weight or more and low-grade titanium oxide TiO _x (0 <X <2) is 1
A titanium raw material having a weight of 0% by weight or more is selectively chlorinated mainly at 900 ° C. or less mainly with an iron component to produce a chlorinated substance mainly composed of ferric chloride, and is separated. Manufacturing method.