JP6959471B1 - Titanium component recovery method, titanium oxide manufacturing method and alkali metal titanate manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To recover a titanium component or calcium in titanium oxide obtained by using calcium hydroxide as a neutralizing agent in a method for recovering a titanium component from a effluent containing a titanium compound or a method for producing titanium oxide. To provide a method for recovering a titanium component having a low content or a method for producing titanium oxide. SOLUTION: This is a method for recovering a titanium component from a effluent containing a titanium compound, wherein the effluent containing the titanium compound is brought into contact with water to hydrolyze the titanium compound (1). , The hydrolyzed treatment liquid is subjected to a primary neutralization treatment in which calcium hydroxide or calcium oxide is added as a neutralizing agent so that the pH becomes 1.5 or more and less than 2.5, and then the primary neutralizing treatment is performed. The treated solution subjected to the sum treatment is subjected to a secondary neutralization treatment in which calcium hydroxide or calcium oxide is added as a neutralizing agent so that the pH becomes 6.5 or more and 7.5 or less, and then titanium hydroxide is added. In the step (2) of obtaining an agglomerate of titanium hydroxide by performing an agglomeration treatment for aggregating, and in the subsequent stage after the step (2), an acid treatment is performed in which hydrochloric acid is brought into contact with the agglomerate of titanium hydroxide to obtain titanium hydroxide. A method for recovering a titanium component, which comprises the step (3) of obtaining an acid-treated product of the agglomerates of the above. [Selection diagram] Fig. 1

Description

The present invention relates to a method for recovering a titanium component, a method for producing titanium oxide, and a method for producing an alkali metal titanate.

Conventionally, polymerization of olefins such as propylene has been carried out using solid catalyst components for olefin polymerization containing magnesium, titanium, electron donating compounds, halogens and the like, and these solid catalyst components are, for example, solutions. It is produced by contacting a magnesium compound in the form of a magnesium compound and a titanium compound in the form of a solution in the presence of an electron donating compound, if necessary.

When preparing such a solid catalyst component for olefin polymerization or when preparing a catalyst for olefin polymerization from the solid catalyst component, excess titanium compounds not supported by the solid catalyst component and side reactions at the time of preparation Drainage containing other titanium compounds produced by the above will occur.

In the past, the titanium compound was recovered from the waste solution by vacuum distillation, but with this method, solid matter precipitates in the distillation mother liquor or tray, making it difficult to discharge the residual liquid in the distillation pot, and generating differential pressure in the column. As a result, it becomes difficult to continue the distillation. Therefore, the distillation was stopped without sufficiently recovering the titanium compound, and the residual liquid in the distillation pot was discarded.

However, from the viewpoint of effective use of resources, reduction of waste, etc., a method of further recovering the titanium compound from the residual liquid of the distillation pot containing the titanium compound that could not be recovered, a method of reusing the recovered titanium compound, etc. Has come to be required.

As a method for recovering the titanium compound from the residual liquid of the distillation pot containing these titanium compounds, for example, in Patent Document 1, one of the titanium compounds from a waste solution containing the titanium compound generated when a catalyst component for polymer production is prepared. After the part is flash-distilled and recovered, the recovered residue is brought into contact with water, the titanium compound in the recovered residue is hydrolyzed, the aqueous phase is separated and recovered, neutralized with a base, and the solid matter is agglomerated with a flocculant or the like. -A method has been proposed in which the sediment is settled, the sediment is recovered, the water content is reduced to obtain a press cake, and these press cakes are fired to recover the crude titanium oxide.

As the base used for neutralizing the aqueous phase after the separation and recovery, usually, inexpensive and easy-to-handle ammonia water or calcium hydroxide has been preferably used.

However, with the method described in Patent Document 1, a titanium compound having high purity cannot be recovered because nitrogen or calcium is mixed in the recovered crude titanium oxide.

Therefore, in the examples of Patent Document 2, the effluent containing titanium tetrachloride, diethoxymagnesium, toluene and butane generated when the solid catalyst component for olefin polymerization was prepared was brought into contact with water for hydrolysis. Then, sodium hydroxide was added so that the pH became 2, and the primary neutralization treatment was performed. Then, sodium hydroxide was added so that the pH became 6.5, and the secondary neutralization treatment was performed. Titanium oxide is obtained by aggregating titanium oxide.

Japanese Unexamined Patent Publication No. 2001-261340 Japanese Unexamined Patent Publication No. 2018-8806

In the method of Patent Document 2, rutile-type titanium oxide is easily produced instead of anatase-type titanium oxide, and a high-purity titanium compound is obtained in a high yield.

Here, in paragraph No. 0035 of Patent Document 2, "In order to obtain high-purity titanium oxide, in order to suppress the mixing of foreign substances such as nitrogen and calcium in the obtained titanium oxide, ammonia water or water as a neutralizing agent is used. As described in "It is preferable not to use calcium oxide or the like.", In the examples of Patent Document 2, sodium hydroxide is used as a neutralizing agent in order to obtain a high-purity titanium compound.

However, industrially, in order to suppress the wastewater treatment cost, it is necessary to use calcium hydroxide or calcium oxide as the neutralizing agent. Therefore, as a result of studies by the present inventors, when the neutralizing agent used in the method of Examples of Patent Document 2 is changed from sodium hydroxide to calcium hydroxide, aggregation of titanium hydroxide obtained is obtained. It was found that low-water-soluble calcium hydroxide or calcium carbonate remained in the substance, and the calcium component could not be removed by subsequent washing.

As a method of using the recovered titanium oxide, it can be mentioned that it is used as a raw material for producing a calcium titanate alkali metal, but the calcium component mixed in the recovered titanium oxide uses the recovered titanium oxide as a synthetic raw material for the alkali metal titanate. When used, it becomes a source of calcium titanate, which is an impurity, so it is desirable that the recovered titanium oxide has a low calcium content.

Therefore, an object of the present invention is to recover the titanium component from the effluent containing the titanium compound, preferably the effluent containing the titanium compound generated when preparing the solid catalyst component for olefin polymerization or the catalyst for olefin polymerization. Even if calcium hydroxide or calcium oxide is used as a neutralizing agent in the method or the method for producing titanium oxide, the recovered titanium component obtained or the method for recovering the titanium component having a low calcium content in titanium oxide or the production of titanium oxide To provide a method.

As a result of diligent studies by the present inventors in order to solve the above technical problems, the effluent containing the titanium compound was brought into contact with water to hydrolyze the titanium compound, and then calcium hydroxide or calcium oxide was used. The calcium content is low by subjecting the primary neutralization treatment and the secondary neutralization treatment, and then contacting the aggregate of titanium hydroxide formed by aggregating titanium hydroxide with hydrochloric acid having a pH of 5.9 or less. It has been found that an agglomerate of titanium hydroxide can be obtained, and the present invention has been completed based on this finding.

That is, the present invention
(1) A method for recovering a titanium component from a effluent containing a titanium compound.
The step (1) of hydrolyzing the titanium compound by bringing the effluent containing the titanium compound into contact with water.
The hydrolyzed treatment liquid is subjected to a primary neutralization treatment in which calcium hydroxide or calcium oxide is added as a neutralizing agent so that the pH is 1.5 or more and less than 2.5, and then the primary neutralization is performed. The treated liquid is subjected to a secondary neutralization treatment in which calcium hydroxide or calcium oxide is added as a neutralizing agent so that the pH becomes 6.5 or more and 7.5 or less, and then titanium hydroxide is aggregated. Step (2) to obtain agglomerates of titanium hydroxide by performing agglomeration treatment
In the step after the step (2), an acid treatment is performed in which hydrochloric acid is brought into contact with the titanium hydroxide agglutination to obtain an acid-treated product of the titanium hydroxide agglutination.
To have
A method for recovering a titanium component, which is characterized by
(2) After obtaining the concentrate of the titanium hydroxide agglomerate produced by performing the step (2), the concentrate of the titanium hydroxide agglomerate is separated, and then the concentrate of the titanium hydroxide agglomerate is concentrated. The object is characterized by having a step (3A) of contacting an object with hydrochloric acid to perform acid treatment of the titanium hydroxide agglomerate to obtain an acid-treated product of the titanium hydroxide agglomerate. Titanium component recovery method;
(3) In the step (3A), the agglomerate of the titanium hydroxide produced by performing the step (2) is settled to obtain a concentrate of the agglomerate of titanium hydroxide (2). ) Titanium component recovery method,
(4) In the step (3A), after the agglomerates of the titanium hydroxide produced by performing the step (2) are settled, the settling of the agglomerates of titanium hydroxide is separated, and then the titanium hydroxide is settled. A dehydration treatment for removing the liquid phase from the precipitate of the agglomerates of titanium hydroxide is performed to obtain a dehydrated product of the agglomerates of titanium hydroxide, thereby obtaining a concentrate of the agglomerates of titanium hydroxide (1). 2) Titanium component recovery method;
(5) After the titanium hydroxide agglomerates produced by performing the step (2) are precipitated, hydrochloric acid is brought into contact with the titanium hydroxide agglomerates to bring the acid of the titanium hydroxide agglomerates into contact. The method for recovering a titanium component according to (1), which comprises a step (3B) of performing treatment to obtain an acid-treated product of agglomerates of titanium hydroxide;
(6) Titanium according to any one of (1) to (5), which comprises a washing step of washing the acid-treated product of the aggregate of titanium hydroxide with washing water of 6.0 or more and 9.0 or less. Ingredient recovery method;
(7) A method for producing titanium oxide, which produces titanium oxide from a effluent containing a titanium compound.
The step (1) of hydrolyzing the titanium compound by bringing the effluent containing the titanium compound into contact with water.
The hydrolyzed treatment liquid is subjected to a primary neutralization treatment in which calcium hydroxide or calcium oxide is added as a neutralizing agent so that the pH is 1.5 or more and less than 2.5, and then the primary neutralization is performed. The treated liquid is subjected to a secondary neutralization treatment in which calcium hydroxide or calcium oxide is added as a neutralizing agent so that the pH becomes 6.5 or more and 7.5 or less, and then titanium hydroxide is aggregated. Step (2) to obtain agglomerates of titanium hydroxide by performing agglomeration treatment
In the step after the step (2), an acid treatment is performed in which hydrochloric acid is brought into contact with the titanium hydroxide agglutination to obtain an acid-treated product of the titanium hydroxide agglutination.
An oxidation step of oxidizing the acid-treated product of the titanium hydroxide agglomerate to obtain titanium oxide, and
To have
A method for producing titanium oxide, which is characterized by the above;
(8) After obtaining the concentrate of the titanium hydroxide agglomerate produced by performing the step (2), the concentrate of the titanium hydroxide agglomerate is separated, and then the titanium hydroxide agglomerate is separated. It is characterized by having a step (3A) of contacting the concentrate with hydrochloric acid to perform acid treatment of the titanium hydroxide agglomerate to obtain an acid-treated product of the titanium hydroxide agglomerate (7). How to recover the titanium component of
(9) In the step (3A), a concentrate of the titanium hydroxide agglomerates is obtained by precipitating the titanium hydroxide agglomerates produced by performing the step (2) (8). ) Titanium component recovery method;
(10) In the step (3A), after the agglomerates of the titanium hydroxide produced by performing the step (2) are settled, the settling of the agglomerates of titanium hydroxide is separated, and then the titanium hydroxide is settled. A dehydration treatment for removing the liquid phase from the precipitate of the agglomerates of titanium hydroxide is performed to obtain a dehydrated product of the agglomerates of titanium hydroxide, thereby obtaining a concentrate of the agglomerates of titanium hydroxide (1). 8) Method for recovering titanium component;
(11) After the agglomerates of titanium hydroxide produced by performing the step (2) are precipitated, hydrochloric acid is brought into contact with the agglomerates of titanium hydroxide to bring the acid of the agglomerates of titanium hydroxide. The method for producing titanium oxide according to (7), which comprises a step (3B) of performing treatment to obtain an acid-treated product of agglomerates of titanium hydroxide;
(12) The oxidation according to any one of (7) to (11), which comprises a washing step of washing the acid-treated product of the aggregate of titanium hydroxide with washing water of 6.0 or more and 9.0 or less. Titanium manufacturing method;
(13) Titanium hydroxide recovered by the method for recovering the titanium component according to any one of (1) to (6), or titanium oxide obtained by the method for producing titanium oxide according to any one of (7) to (12) as a raw material. A method for producing an alkali metal titanate, which is characterized by being used as
Is to provide.

According to the present invention, a method for recovering a titanium component from a effluent containing a titanium compound, preferably a solid catalyst component for olefin polymerization or a effluent containing a titanium compound generated when a catalyst for olefin polymerization is prepared. In the method for producing titanium oxide, even if calcium hydroxide or calcium oxide is used as a neutralizing agent, the obtained recovered titanium component or the method for recovering the titanium component having a low calcium content in titanium oxide or the method for producing titanium oxide. Can be provided.

It is a flow chart of the form example of the method of recovering a titanium component of this invention. It is a flow chart of the form example of the method of recovering the titanium component of the 1st form of this invention. It is a flow chart of the form example which performs the cleaning step among the method of recovering the titanium component of the 1st aspect of this invention. It is a flow chart of the other form example which performs a cleaning step among the method of recovering a titanium component of the 1st form of this invention. It is a flow chart of the form example of the method of recovering the titanium component of the 2nd form of this invention. It is a flow chart of the form example which performs the cleaning step among the method of recovering the titanium component of the 2nd aspect of this invention. It is a flow chart of the other form example which performs a cleaning step among the method of recovering a titanium component of the 2nd form of this invention. It is a scanning electron micrograph of potassium titanate obtained in Example 1. FIG. 6 is a scanning electron micrograph of commercially available potassium titanate analyzed for comparison in Example 1. It is a scanning electron micrograph of potassium titanate obtained in Example 2. FIG. 2 is a scanning electron micrograph of commercially available potassium titanate analyzed for comparison in Example 2.

First, the method for recovering the titanium component of the present invention will be described.
The method for recovering a titanium component of the present invention is a method for recovering a titanium component from a effluent containing a titanium compound.
The step (1) of hydrolyzing the titanium compound by bringing the effluent containing the titanium compound into contact with water.
The hydrolyzed treatment liquid is subjected to a primary neutralization treatment in which calcium hydroxide or calcium oxide is added as a neutralizing agent so that the pH is 1.5 or more and less than 2.5, and then the primary neutralization is performed. The treated liquid is subjected to a secondary neutralization treatment in which calcium hydroxide or calcium oxide is added as a neutralizing agent so that the pH becomes 6.5 or more and 7.5 or less, and then titanium hydroxide is aggregated. Step (2) to obtain agglomerates of titanium hydroxide by performing agglomeration treatment
In the step after the step (2), an acid treatment is performed in which hydrochloric acid is brought into contact with the titanium hydroxide agglutination to obtain an acid-treated product of the titanium hydroxide agglutination.
To have
It is characterized by.

The method for recovering the titanium component of the present invention will be described with reference to FIG. Here, a form in which calcium hydroxide is applied as a neutralizing agent will be described as an example, but in the present invention, even if calcium oxide is applied as a neutralizing agent, it is the same as when calcium hydroxide is applied. The effect is obtained. FIG. 1 is a flow chart of a mode example of the method for recovering a titanium component of the present invention. In FIG. 1, the drainage 10 containing the titanium compound is transferred to the water receiving tank 1, water 11 is supplied into the water receiving tank 1, the drainage 10 containing the titanium compound and the water 11 are mixed, and hydrolysis treatment is performed. Give. Next, the hydrolyzed treatment liquid is transferred to the primary neutralization treatment tank 2, the calcium hydroxide suspension 12 is supplied to the primary neutralization treatment tank 2, and the treatment liquid in the primary neutralization treatment tank 2 is supplied. The primary neutralization treatment is performed so that the pH of the calcium hydroxide is 1.5 or more and less than 2.5. Next, the treatment liquid subjected to the primary neutralization treatment is transferred to the secondary neutralization treatment tank 3, the calcium hydroxide suspension 13 is supplied to the secondary neutralization treatment tank 3, and the secondary neutralization treatment tank 3 is supplied. Secondary neutralization treatment is performed so that the pH of the treatment liquid in 3 is 6.5 or more and 7.5 or less. Next, the treatment liquid subjected to the secondary neutralization treatment is transferred to the coagulation tank 4, a coagulant is added to the coagulation tank 4, and the titanium hydroxide is coagulated to obtain the titanium hydroxide agglomerate 19. Give rise. Then, after the titanium hydroxide agglomerates 19 are generated, hydrochloric acid 14 is brought into contact with the obtained titanium hydroxide agglomerates 19 to perform acid treatment of the titanium hydroxide agglomerates 19 to obtain titanium hydroxide. An acid-treated product 20 of the agglomerates is obtained.

In the method for recovering a titanium component of the present invention, the target to which the method for recovering a titanium component is applied is a effluent containing a titanium compound, and is not particularly limited as long as it contains a titanium compound. As the effluent containing the titanium compound, the "drainage containing titanium" generated when the solid catalyst component for olefin polymerization or the catalyst for olefin polymerization is prepared is preferable.

In the method for recovering a titanium component of the present invention, when the effluent containing a titanium compound is a solid catalyst component for olefin polymerization or a effluent containing titanium generated when a catalyst for olefin polymerization is prepared, it is used for olefin polymerization. The solid catalyst component or the catalyst for olefin polymerization is not particularly limited as long as it is a solid catalyst component or catalyst containing a titanium component used for the polymerization of olefins. , Post-metallocene, catalysts such as solid titanium catalysts for the production of polyethylene terephthalates, and one or more selected from the solid catalyst components constituting these catalysts, among these, the Ziegler-Natta catalyst used for the production of polyolefins. , Metallocene catalysts and post-metallocene catalysts, and one or more selected from the solid catalyst components constituting these catalysts are preferable, and the Ziegler-Natta catalyst or the solid catalyst component constituting the Ziegler-Natta catalyst is more preferable.

As the solid catalyst component constituting the Ziegler-Natta catalyst or the Ziegler-Natta catalyst, among the above, olefin polymerization prepared by contacting a magnesium compound, a titanium compound and a halogen compound, and if necessary, an electron donating compound. Solid catalyst components for use are suitable.

As the magnesium compound used for preparing the solid catalyst component for olefin polymerization, those containing a halogen and those that change to a halogen-containing magnesium compound by contact reaction with the halogen-containing compound are preferable.
Examples of such magnesium compounds include one or more selected from magnesium dihalogenate such as magnesium chloride, dialkyl magnesium such as alkoxymagnesium halide, and dialkoxymagnesium such as alkylmagnesium halide and diethoxymagnesium, and magnesium chloride. Alternatively, diethoxymagnesium is preferable.

Examples of the titanium compound according to the method for recovering the titanium component of the present invention include the following general formula (1):
Ti (OR) _N X _4-N (1)
(In the formula, R represents a hydrocarbon group, X represents a halogen atom, and when a plurality of Xs are present, each X may be the same or different, and N is an integer of 0 to 4. ), Examples of the titanium compound.

In the titanium compound represented by the general formula (1), R is preferably a hydrocarbon group having 1 to 10 carbon atoms, more preferably a hydrocarbon group having 1 to 6 carbon atoms, and has 1 carbon atom. More preferably, it is a hydrocarbon group of ~ 4.

Specific examples of the titanium compound represented by the general formula (1) include titanium tetrahalide such as titanium tetrachloride, titanium tetrafluoride, titanium tetrabromide, and titanium tetraiodide, methoxytitanium trichloride, and ethoxy. Alkoxytitanium trihalide such as titanium trichloride, propoxytitanium trichloride, N-butoxytitanium trichloride, dimethoxytitanium dichloride, diethoxytitanium dichloride, dipropoxytitanium dichloride, dialkoxytitanium dihalide such as di-N-butoxytitanium dichloride , Trimethoxy Titanium Chloride, Triethoxy Titanium Chloride, Tripropoxy Titanium Chloride, Tri-N-Butoxy Titanium Chloride, etc. Trialkoxy Titanium Halide, etc. Alkoxy Titanium Halide, etc.

Among the above titanium compounds, a halogen-containing titanium compound is preferable, titanium tetrahalide selected from titanium tetrachloride, titanium tetrafluoride, titanium tetrabromide, titanium tetraiodide and the like is more preferable, and titanium tetrachloride is even more preferable.
The titanium compound may be diluted with a hydrocarbon compound, a halogenated hydrocarbon compound, or the like.

The electron donating compound used for preparing the solid catalyst component for olefin polymerization is not particularly limited, but includes alcohols, phenols, ketones, aldehydes, carboxylic acids, acid halides, organic acids or inorganic acids. Examples thereof include one or more selected from esters, ethers, acid amides, acid anhydrides, ammonia, amines, nitriles, isocyanates, nitrogen-containing cyclic compounds, oxygen-containing cyclic compounds, organic silicon compounds and the like.

In the method for recovering the titanium component of the present invention, the effluent containing the titanium compound is an organic solvent component used at the time of cleaning, heat contact, etc. in the step of preparing the solid catalyst component for olefin polymerization, specifically, pentane. , Hexane, heptane, octane, nonane, decane, dodecane, kerosene, cyclopentane, cyclohexane, methylcyclopentane, methylcyclohexane, ethylcyclohexane, 1,2-diethylcyclohexane, methylcyclohexene, decalin, mineral oil and other saturated hydrocarbon compounds. , Aromatic hydrocarbon compounds such as benzene, toluene, xylene, ethylbenzene, orthodichlorobenzene, methylene chloride, 1,2-dichlorobenzene, carbon tetrachloride, dichloroethane, ethylene chloride, chlorobenzene, dichloromethane and other halogenated hydrocarbons. It may contain one or more organic solvent components selected from compounds and the like, aluminum compounds, silicon compounds and the like.

In the method for recovering a titanium component of the present invention, the effluent containing a titanium compound contains magnesium chloride or diethoxymagnesium as a magnesium compound, an alkoxytitanium halogen compound or a titanium halide compound as a titanium compound, and further electron donating property. Those containing a compound and an organic solvent component are preferable.

In the method for recovering the titanium component of the present invention, the effluent containing the titanium compound contains the titanium compound generated by various reactions and the like. The effluent containing a titanium compound is preferably a effluent generated during the preparation of a solid catalyst component for olefin polymerization or a catalyst for olefin polymerization, and such effluent is a titanium compound or a effluent that is not supported by the solid catalyst component. It contains other titanium compounds newly generated by the reaction in the preparation process. In the method for recovering the titanium component of the present invention, the drainage containing the titanium compound preferably contains 0.01 to 3.0% by mass of the titanium compound, more preferably 0.05 to 10.0% by mass. It is preferable, and the one containing 0.10 to 5.0% by mass is more preferable.

The method for recovering a titanium component according to the present invention includes a step (1) in which a effluent containing a titanium compound is brought into contact with water to hydrolyze the titanium compound. In the step (1), the hydrolysis method is not particularly limited, and examples thereof include a method of bringing the wastewater into contact with water separately injected in the water receiving tank.

In the step (1), when the titanium compound is titanium halide, the titanium compound is hydrolyzed to produce hydrogen halide and titanium hydroxide by contacting the effluent containing the titanium compound with water. ..

In the hydrolysis treatment according to the step (1), the pH of the mixed solution of the effluent containing the titanium compound and water is preferably 0.5 or more and 2.0 or less, and 0.7 or more and 1.5 or less. It is more preferable that there is, and it is further preferable that it is about 1.0. When the pH of the mixture of the drainage solution containing the titanium compound and water is in the above range, the titanium hydroxide produced in the mixture is less likely to precipitate, and the subsequent treatment can be smoothly performed.

In step (1), the amount of water contacting the waste solution containing a titanium compound, per drainage 1 m ³ containing a titanium compound is preferably 3 to 10 m ^3, more preferably 4～7M ³ , 5-6 m ³ is more preferred.

In the step (1), the temperature during the hydrolysis treatment is not particularly limited, but is preferably 10 to 90 ° C, more preferably 20 to 70 ° C, and even more preferably 30 to 60 ° C. ..

In the step (1), the contact time between the drainage containing the titanium compound and water is preferably 30 to 60 minutes, more preferably 35 to 55 minutes, and further preferably 40 to 50 minutes. preferable.

In the step (2) according to the method for recovering the titanium component of the present invention, the effluent that has been hydrolyzed in the step (1) is subjected to a primary neutralization treatment, then a secondary neutralization treatment, and then a secondary neutralization treatment. , This is a step of performing a coagulation treatment for coagulating titanium hydroxide to obtain an agglomerate of titanium hydroxide.

In the step (2), first, a primary neutralization treatment in which calcium hydroxide or calcium oxide is added so that the pH of the treatment liquid subjected to the hydrolysis treatment in the step (1) is 1.5 or more and less than 2.5. To give.

In the primary neutralization treatment, the pH of the treatment liquid subjected to the hydrolysis treatment in step (1) is preferably 1.8 or more and 2.3 or less so that the pH is 1.5 or more and less than 2.5. Calcium hydroxide or calcium oxide is added so that the pH is more preferably 1.8 or more and 2.2 or less. When the pH at the time of the primary neutralization treatment is in the above range, aggregation and sedimentation are likely to occur, and the titanium component can be easily recovered from the titanium compound-containing effluent with high purity. On the other hand, if the pH at the time of the primary neutralization treatment is less than 1.5, it becomes difficult to perform the smooth neutralization treatment, and if the pH is 2.5 or more, gel-like titanium hydroxide is produced. Precipitability and filterability are reduced.

The neutralizing agent used in the primary neutralization treatment is calcium hydroxide or calcium oxide. By using calcium hydroxide or calcium oxide as the neutralizing agent in the primary neutralization treatment, the cost of the neutralizing agent can be suppressed, and the sedimentability and filterability of the titanium compound obtained to be neutralized are improved. It has the advantage of. On the other hand, if the neutralizing agent used in the primary neutralization treatment is, for example, sodium hydroxide or potassium hydroxide, the cost of the neutralizing agent increases, and the neutralization and filterability of the titanium compound obtained can be improved. It gets worse and becomes industrially disadvantageous.

In the primary neutralization treatment, the suspension in which calcium hydroxide or calcium oxide is dispersed in water is brought into contact with the hydrolyzed treatment liquid. The content of calcium hydroxide or calcium oxide in the suspension is appropriately selected according to the pH setting value of the aqueous phase in the primary neutralization treatment, and is preferably 10 to 300 g / L. When the content of calcium hydroxide or calcium oxide in the suspension is within the above range, the pH of the hydrolyzed effluent can be easily controlled within a desired range. On the other hand, if the content of calcium hydroxide in the suspension exceeds the above range, it becomes difficult to control the pH of the hydrolyzed effluent, and if it is less than the above range, smooth neutralization treatment is performed. It becomes difficult to do.

The temperature during the primary neutralization treatment is not particularly limited, but is preferably 10 ° C. or higher.

In the primary neutralization treatment, the contact time between the hydrolyzed treatment liquid and calcium hydroxide or calcium oxide is not particularly limited, but is usually about 60 to 120 minutes.

In the step (2), as a method of performing the primary neutralization treatment, calcium hydroxide or calcium oxide is brought into contact with the hydrolyzed treatment liquid in a neutralization tank (primary neutralization treatment tank). This is preferably performed, and the primary neutralization treatment tank may be one tank or a plurality of tanks in communication with each other.

In the step (2), the treatment liquid subjected to the primary neutralization treatment is then subjected to a secondary neutralization treatment in which calcium hydroxide or calcium oxide is added so that the pH is 6.5 or more and 7.5 or less.

At the time of the secondary neutralization treatment according to the step (2), calcium hydroxide or calcium oxide is added to the treatment liquid subjected to the primary neutralization treatment so that the pH is 6.5 or more and 7.5 or less. Then, at the time of the secondary neutralization treatment according to the step (2), calcium hydroxide or calcium oxide is added to the treatment liquid subjected to the primary neutralization treatment so that the pH is 6.5 or more and 7.5 or less. It is preferable to add calcium hydroxide or calcium oxide so that the pH is 6.4 or more and 7.5 or less, and calcium hydroxide or oxidation is more preferable so that the pH is 6.3 or more and 7.5 or less. It is even more preferable to add calcium.

When the pH in the secondary neutralization treatment is in the above range, the calcium content in the agglutination of titanium hydroxide obtained through the agglutination treatment is reduced, and aggregation and sedimentation are likely to occur, so that the titanium compound It becomes easy to recover the titanium component from the contained effluent with high purity. On the other hand, if the pH at the time of the secondary neutralization treatment is less than the above range, it becomes difficult for titanium hydroxide to precipitate, and if it exceeds the above range, calcium in the agglutination of titanium hydroxide obtained through the agglutination treatment The content is too high.

The neutralizing agent used in the secondary neutralization treatment is calcium hydroxide or calcium oxide. By using calcium hydroxide or calcium oxide as the neutralizing agent in the secondary neutralization treatment, the cost of the neutralizing agent can be suppressed, and the sedimentation property and filterability of the titanium compound obtained to be neutralized are improved. Has the advantage of On the other hand, if the neutralizing agent used in the secondary neutralization treatment is, for example, sodium hydroxide or potassium hydroxide, the cost of the neutralizing agent increases, and the neutralizing property of the titanium compound and the filterability of the titanium compound can be obtained. Will be worse and industrially disadvantageous.

In the secondary neutralization treatment, the suspension in which calcium hydroxide or calcium oxide is dispersed in water is brought into contact with the treatment liquid subjected to the primary neutralization treatment. The content of calcium hydroxide or calcium oxide in the suspension is appropriately selected according to the pH setting value of the aqueous phase in the secondary neutralization treatment, and is preferably 10 to 300 g / L. When the content of calcium hydroxide or calcium oxide in the suspension is in the above range, the pH in the treatment liquid subjected to the primary neutralization treatment can be easily controlled within a desired range. On the other hand, if the content of calcium hydroxide or calcium oxide in the suspension exceeds the above range, it becomes difficult to control the pH during the treatment subjected to the primary neutralization treatment, and if it is less than the above range, it is smooth. It becomes difficult to perform neutralization treatment.

The temperature during the secondary neutralization treatment is not particularly limited, but is preferably 10 ° C. or higher.

In the secondary neutralization treatment, the contact time between the treatment liquid subjected to the primary neutralization treatment and calcium hydroxide or calcium oxide is not particularly limited, but is usually about 60 to 120 minutes.

In the step (2), as a method of performing the secondary neutralization treatment, calcium hydroxide or calcium oxide is added to the treatment liquid subjected to the primary neutralization treatment in a neutralization tank (secondary neutralization treatment tank). It is preferable to carry out the process in contact with each other, and the secondary neutralization treatment tank may be one tank or a plurality of tanks in communication with each other.

Further, it is preferable that the treatment liquid after the secondary neutralization treatment does not contain calcium hydroxide. The calcium hydroxide content in the treatment liquid after the secondary neutralization treatment is adjusted by the amount of the neutralizing agent added in the secondary neutralization treatment, the pH setting value in the secondary neutralization treatment, and the like. NS.

In the step (2), an agglutination treatment for agglutinating titanium hydroxide in the treatment liquid subjected to the secondary neutralization treatment is then performed. For the coagulation treatment, a chemical treatment performed using a coagulant such as an anionic polymer coagulant may be applied, or a mechanical treatment (dehydration) using various devices such as a filter press, a liquid cyclone, and a centrifuge may be applied. Processing) may be applied. The method of coagulation treatment may be appropriately selected according to the components and concentration of the waste liquid. By performing the coagulation treatment, the time of the filtration treatment in the subsequent process can be shortened.

In the step (2), it is preferable that the agglutination of titanium hydroxide is carried out in the agglutination tank by feeding the treatment liquid subjected to the secondary neutralization treatment into the agglutination tank. Then, by performing the agglutination treatment, agglomerates of titanium hydroxide are generated.

In step (2), agglomerates of titanium hydroxide are generated by aggregating titanium hydroxide, but after performing step (2), a coagulation treatment liquid containing the generated agglomerates of titanium hydroxide is used. After separating a part or all of the liquid phase, the subsequent step may be performed, or the latter stage may be performed without separating the liquid phase from the coagulation treatment liquid containing the generated agglomerates of titanium hydroxide. You may perform the process of.

In the step (2) or the step after the step (2), the acidity of the aqueous phase separated from the agglutination treatment liquid containing the agglutination of titanium hydroxide is adjusted to neutral (pH 6.5 to 7.5). After that, it is preferable to treat the waste liquid as appropriate.

For example, in the method for recovering the titanium component of the present invention, after performing step (2), the generated titanium hydroxide agglomerates are settled in the settling tank, and the titanium hydroxide agglomerates in the settling tank are settled. By extracting the precipitate, the agglomerates of titanium hydroxide are separated in the state of the agglomerates of titanium hydroxide. The precipitate of the agglomerates of titanium hydroxide contains a liquid phase derived from the treatment up to that point, but in the acid treatment performed after the step (2), the precipitate of the agglomerates of titanium hydroxide is contained. The liquid phase may be provided after removing the liquid phase of the above, or the liquid phase in the precipitate of the aggregate of titanium hydroxide may be provided without being removed.

In the method for recovering the titanium component of the present invention, in the treatment step after the step (2), an acid treatment is performed in which the agglomerates of titanium hydroxide are brought into contact with hydrochloric acid. In the method for recovering the titanium component of the present invention, the time for applying the acid treatment is not particularly limited as long as it is after the step (2). Then, in the method for recovering the titanium component of the present invention, the calcium content in the titanium hydroxide agglutination can be reduced by bringing hydrochloric acid into contact with the titanium hydroxide agglutination.

In the acid treatment according to the method for recovering the titanium component of the present invention, hydrochloric acid is brought into contact with the aggregate of titanium hydroxide obtained in step (2), but at this time, the pH of the liquid phase becomes 5.9 or less. Bring the hydrochloric acid into contact. When the pH of the liquid phase during the acid treatment is in the above range, the calcium content in the titanium hydroxide agglutination can be reduced. On the other hand, if the pH of the liquid phase during the acid treatment exceeds the above range, it becomes difficult to obtain the effect of reducing the calcium content in the aggregate of titanium hydroxide. The upper limit of the pH of the liquid phase during the acid treatment is preferably 5.7 or less, more preferably 5.5 or less, still more preferably 5.3 or less. The lower limit of the pH of the liquid phase during the acid treatment is preferably 2.0 or more, more preferably 3.0 or more.

The acid used for acid treatment is hydrochloric acid. Hydrogen chloride is volatilized and removed from the product when the agglomerates of titanium hydroxide are dried or oxidized after the acid treatment, so that the chlorine content derived from the hydrochloric acid used in the acid treatment is removed. , Hard to remain in the product.

The concentration of hydrochloric acid used for the acid treatment is not particularly limited, but is preferably 1.0 to 8.5 mol / L, preferably 1.5 to 7.0 mol / L, and 2.7 to 5.5. It is more preferably 5 mol / L. When the concentration of hydrochloric acid used for the acid treatment is within the above range, the pH of the liquid phase during the acid treatment can be easily controlled within a desired range. If the concentration of hydrochloric acid used for the acid treatment exceeds the above range, it becomes difficult to control the pH of the liquid phase during the acid treatment, and if it is less than the above range, it becomes difficult to perform a smooth acid treatment.

The temperature during the acid treatment is not particularly limited, but is preferably 10 to 50 ° C, more preferably 15 to 45 ° C, and even more preferably 20 to 40 ° C.

In the acid treatment, the contact time between the agglutinated titanium hydroxide obtained by performing the step (2) and hydrochloric acid is preferably 60 to 120 minutes, more preferably 60 to 100 minutes, and 60 to 80 minutes. Minutes are even more preferred.

In the method for recovering the titanium component of the present invention, the titanium hydroxide produced by acid treatment is Ti (OH) ₄ . That is, in the method for recovering the titanium component of the present invention, the titanium component is recovered from the effluent containing the titanium compound in the state of agglomerates of titanium hydroxide. Then, the recovered agglomerates of titanium hydroxide (acid-treated product) are converted into titanium oxide after drying and oxidation, and used as a raw material for producing various titanium compounds.

In the method for recovering a titanium component of the present invention, wastewater containing a titanium compound is hydrolyzed, and then calcium hydroxide is used as a neutralizing agent to perform a primary neutralization treatment and a secondary neutralization treatment at a specific pH. By sequentially performing the agglomeration treatment and subjecting the obtained agglomerates of titanium hydroxide to an acid treatment in which hydrochloric acid is brought into contact, the calcium content in the agglomerates of titanium hydroxide obtained by the acid treatment can be reduced. Therefore, titanium hydroxide having a low calcium content can be recovered in a high yield. In the method for recovering the titanium component of the present invention, the poorly water-soluble unreacted substance such as calcium hydroxide remaining in the titanium hydroxide agglomerates is dissolved and removed by acid treatment of the titanium hydroxide agglomerates. , The calcium content in the agglomerates of titanium hydroxide can be reduced. From the above, it is considered that titanium hydroxide having a low calcium content can be recovered by the method for recovering the titanium component of the present invention.

In the method for recovering the titanium component of the present invention, the method for performing the acid treatment is not particularly limited and may be appropriately selected, and the time for performing the acid treatment may be any time as long as it is later than the step (2). Further, the method for performing the acid treatment may be any method as long as the aggregate of titanium hydroxide is brought into contact with hydrochloric acid. Examples of the method for recovering the titanium component of the present invention include the following forms.

In the method for recovering the titanium component according to the first aspect of the present invention, the step (2) is carried out to obtain a concentrated titanium hydroxide agglomerate, and then the concentrated titanium hydroxide agglomerate is separated and then. In the form of having a step (3A) of contacting the concentrate of the titanium hydroxide agglomerate with hydrochloric acid to perform acid treatment of the titanium hydroxide agglomerate to obtain an acid-treated product of the titanium hydroxide agglomerate. be.

That is, the method for recovering the titanium component according to the first aspect of the present invention is a method for recovering the titanium component from the effluent containing the titanium compound.
The step (1) of hydrolyzing the titanium compound by bringing the effluent containing the titanium compound into contact with water.
The hydrolyzed treated water is subjected to a primary neutralization treatment in which calcium hydroxide is added as a neutralizing agent so that the pH is 1.5 or more and less than 2.5, and then the primary neutralization treatment is performed. The treated liquid was subjected to a secondary neutralization treatment in which calcium hydroxide was added as a neutralizing agent so that the pH was 6.5 or more and 7.5 or less, and then a coagulation treatment for aggregating titanium hydroxide was performed. Step (2) to obtain agglomerates of titanium hydroxide,
After the step (2) is performed to obtain a concentrate of the titanium hydroxide agglomerate, the titanium hydroxide agglomerate concentrate is separated, and then the titanium hydroxide agglomerate concentrate is added to the concentrate. The step (3A) of contacting with hydrochloric acid to perform acid treatment of the titanium hydroxide agglomerate to obtain an acid-treated product of the titanium hydroxide agglomerate.
To have
It is a method for recovering a titanium component, which is characterized by the above. In the method for recovering the titanium component according to the first aspect of the present invention, after forming a titanium hydroxide agglomerate in the step (2), the titanium hydroxide agglomerate concentrate is separated from the agglomeration treatment liquid, and water is used. This is a form in which an acid treatment is applied to a concentrate of titanium oxide aggregates.

The method for recovering the titanium component according to the first aspect of the present invention will be described with reference to FIG. FIG. 2 is a flow chart of an example of a method for recovering a titanium component according to the first aspect of the present invention. Although a form in which calcium hydroxide is applied as a neutralizing agent will be described here as an example, in the present invention, even if calcium oxide is applied as a neutralizing agent, it is the same as when calcium hydroxide is applied. The effect of is obtained. In FIG. 2, the drainage 10 containing the titanium compound is transferred to the water receiving tank 1, water 11 is supplied into the water receiving tank 1, the drainage 10 containing the titanium compound and the water 11 are mixed, and hydrolysis treatment is performed. Give. Next, the hydrolyzed treatment liquid is transferred to the primary neutralization treatment tank 2, the calcium hydroxide suspension 12 is supplied to the primary neutralization treatment tank 2, and the treatment liquid in the primary neutralization treatment tank 2 is supplied. The primary neutralization treatment is performed so that the pH of the calcium hydroxide is 1.5 or more and less than 2.5. Next, the treatment liquid subjected to the primary neutralization treatment is transferred to the secondary neutralization treatment tank 3, the calcium hydroxide suspension 13 is supplied to the secondary neutralization treatment tank 3, and the secondary neutralization treatment tank 3 is supplied. Secondary neutralization treatment is performed so that the pH of the treatment liquid in 3 is 6.5 or more and 7.5 or less. Next, the treatment liquid subjected to the secondary neutralization treatment is transferred to the coagulation tank 4, a coagulant is added to the coagulation tank 4, and titanium hydroxide is agglomerated to generate agglomerates of titanium hydroxide. Let me. Next, the agglutination treatment liquid containing the generated titanium hydroxide agglomerates is transferred to the settling tank 5, and the titanium hydroxide agglomerates are settled in the settling tank 5 from the lower part or the bottom of the settling tank 5. Extract the sediment of titanium hydroxide agglomerates. Next, the sediment of the titanium hydroxide aggregate extracted from the sedimentation tank 5 is transferred to the sediment storage tank 6. Next, the precipitate of the titanium hydroxide agglomerate is filtered using the filter press device 7, the liquid phase is removed from the precipitate of the titanium hydroxide agglomerate, and the titanium hydroxide agglomerate is filtered out. , Obtain a press cake of agglomerates of titanium hydroxide. Next, the press cake of the agglutinated titanium hydroxide is transferred to the acid treatment tank 8, the hydrochloric acid 14 is supplied to the acid treatment tank 8, the agglutinate of titanium hydroxide and the hydrochloric acid 14 are mixed, and the acid treatment is performed. .. Next, the acid-treated product of the titanium hydroxide aggregate is filtered using the filter press device 9, the liquid phase is removed from the acid-treated product of the titanium hydroxide aggregate, and the acid of the titanium hydroxide aggregate is removed. The treated product is filtered off to obtain a press cake 21 of an acid-treated product of agglomerates of titanium hydroxide.

The method for recovering the titanium component according to the first aspect of the present invention includes steps (1), steps (2), and steps (3A). The steps (1), steps (2), wastewater used, treatment, treatment method, etc. in the titanium component recovery method of the first aspect of the present invention are common to the titanium compound recovery method of the present invention, and details thereof. Is as described in the description of the method for recovering the titanium component of the present invention.

In the step (3A) according to the method for recovering the titanium component of the first aspect of the present invention, after the concentrate of the titanium hydroxide agglomerate produced by performing the step (2) is obtained, the obtained agglomeration of titanium hydroxide is obtained. The concentrate of the product is separated from the coagulation treatment liquid.

In the step (3A), the method for obtaining the concentrate of the titanium hydroxide agglutination from the agglutination treatment liquid containing the titanium hydroxide agglutination after the step (2) is not particularly limited. For example, first, the agglutination treatment liquid containing the titanium hydroxide agglomerates after the step (i) (2) is transferred to a settling tank, and the titanium hydroxide agglomerates are settled in the settling tank. Next, (ii) the sediment of the titanium hydroxide agglomerate was extracted from the lower part or the bottom of the settling tank, the sediment of the titanium hydroxide agglomerate was separated from the coagulation treatment liquid, and the hydroxylation extracted from the settling tank. The sediment of titanium agglomerates is transferred to a sediment storage tank to obtain a precipitate of titanium hydroxide agglomerates, that is, a concentrate of titanium hydroxide agglomerates.

Further, in the step (3A), as a method for obtaining a concentrate of the agglomerates of titanium hydroxide from the agglutination treatment liquid containing the agglutinates of titanium hydroxide after the step (2), for example, , The agglutination treatment liquid containing the agglutination of titanium hydroxide after the step (2) is treated with a liquid cyclone, a screw decanter, etc. to separate the aqueous phase from the agglutination treatment liquid, and the agglutination of titanium hydroxide. There is a method of obtaining the concentrate of.

Further, in the step (3A), as a method of obtaining a concentrate of the agglomerates of titanium hydroxide from the coagulation treatment liquid containing the agglomerates of titanium hydroxide after the step (2), first, the step (2). ) To settle the resulting agglomerates of titanium hydroxide, separate the settling of the agglomerates of titanium hydroxide from the agglomeration treatment liquid, and then remove the liquid phase from the settling of the agglomerates of titanium hydroxide. A method of obtaining a dehydrated product of titanium hydroxide agglomerates, that is, a concentrate of titanium hydroxide agglomerates by performing a dehydration treatment for obtaining a dehydrated product of titanium hydroxide agglomerates can be mentioned. Examples of the dehydration treatment method include a method of filtering using a solid-liquid separator such as a filter press device, a centrifuge device, and a liquid cyclone device.

In the step (3A), hydrochloric acid is then brought into contact with the concentrate of the titanium hydroxide agglutination to perform acid treatment of the titanium hydroxide agglutination.

In the acid treatment according to the step (3A), hydrochloric acid is brought into contact with the dehydrated product of the agglomerates of titanium hydroxide. At this time, the pH of the liquid phase is 5.9 or less, preferably 2.0 or more and 5.5. Hereinafter, hydrochloric acid is contacted so as to be more preferably 3.5 or more and 5.0 or less. When the pH of the liquid phase during the acid treatment is in the above range, the calcium content in the titanium hydroxide agglutination can be reduced. On the other hand, if the pH of the liquid phase during the acid treatment exceeds 5.9, it becomes difficult to obtain the effect of reducing the calcium content in the aggregate of titanium hydroxide.

The acid used for the acid treatment according to the step (3A) is hydrochloric acid. Hydrogen chloride is volatilized and removed from the product when the agglutinate of titanium hydroxide is dried or oxidized after the acid treatment, so that chlorine derived from hydrochloric acid is contained in the product. Hard to remain.

The concentration of hydrochloric acid used for the acid treatment according to the step (3A) is not particularly limited, but is preferably 1.0 to 8.5 mol / L, preferably 1.5 to 7.0 mol / L, and 2 It is more preferably .7 to 5.5 mol / L. When the concentration of hydrochloric acid used for the acid treatment is within the above range, the pH of the liquid phase during the acid treatment can be easily controlled within a desired range. If the concentration of hydrochloric acid used for the acid treatment exceeds the above range, it becomes difficult to control the pH of the liquid phase during the acid treatment, and if it is less than the above range, it becomes difficult to perform a smooth acid treatment.

The temperature during the acid treatment according to the step (3A) is not particularly limited, but is preferably 10 to 50 ° C, more preferably 15 to 45 ° C, and even more preferably 20 to 40 ° C.

In the acid treatment according to the step (3A), the contact time between the dehydrated product of the titanium hydroxide aggregate and hydrochloric acid is preferably 60 to 120 minutes, more preferably 60 to 100 minutes, and 60. It is more preferably ~ 80 minutes.

In the step (3A), as a method of performing the acid treatment, it is preferable to bring the dehydrated product of the titanium hydroxide agglutinate into contact with hydrochloric acid in the acid treatment tank.

In the step (3A), after the acid treatment, the liquid phase is removed from the acid-treated product of the titanium hydroxide agglomerate using a solid-liquid separator, and the acid-treated product of the titanium hydroxide agglomerate is removed. The dehydrated product of No. 1 is obtained, and the dehydrated product is further dried at 60 to 200 ° C. to obtain an acid-treated product of agglomerates of titanium hydroxide. By removing the liquid phase from the acid-treated product of the titanium hydroxide agglomerates and drying, water and hydrogen chloride are removed from the acid-treated product of the titanium hydroxide agglomerates, and the acid-treated product of the titanium hydroxide agglomerates. Is obtained.

In the method for recovering the titanium component of the first aspect of the present invention, the titanium hydroxide obtained by performing the step (3A) is Ti (OH) ₄ . That is, in the method for recovering the titanium component of the present invention, the titanium component is recovered from the effluent containing the titanium compound in the state of agglomerates of titanium hydroxide. Then, the recovered agglomerates of titanium hydroxide (acid-treated product) are converted into titanium oxide after drying and oxidation, and used as a raw material for producing various titanium compounds.

In the method for recovering a titanium component according to the first aspect of the present invention, wastewater containing a titanium compound is first neutralized at a specific pH by using calcium hydroxide or calcium oxide as a neutralizing agent after a hydrolysis treatment. The treatment, the secondary neutralization treatment, and the agglomeration treatment are sequentially performed to form an agglomerate of titanium hydroxide, then the aqueous phase is separated, and the obtained concentrate of the agglomerate of titanium hydroxide is brought into contact with calcium. By subjecting the acid treatment to the acid treatment, the calcium content in the aggregate of titanium hydroxide obtained by the acid treatment can be reduced, so that the titanium hydroxide having a low calcium content can be recovered. In the method for recovering the titanium component according to the first aspect of the present invention, the concentrate of the titanium hydroxide agglomerate produced in the step (2) is treated with an acid to treat the titanium hydroxide agglomerate with an acid. By doing so, the poorly water-soluble unreacted substance such as calcium hydroxide remaining in the titanium hydroxide agglomerates is dissolved, so that the calcium content in the titanium hydroxide agglomerates can be reduced. From the above, it is considered that titanium hydroxide having a low calcium content can be recovered by the method for recovering the titanium component according to the first aspect of the present invention.

The method for recovering the titanium component according to the first aspect of the present invention is an acid-treated product of a titanium hydroxide agglomerate obtained by performing step (3A) in addition to step (1), step (2) and step (3A). Can have a washing step of washing with washing water having a pH of 6.0 or more and 9.0 or less. In the cleaning step, cleaning is performed by bringing the cleaning water into contact with the acid-treated product of the titanium hydroxide agglomerates obtained in the step (3A). The contact method is not particularly limited, and examples thereof include the following methods.

FIG. 3 is a flow chart showing an example of a form in which a cleaning step is performed among the methods for recovering a titanium component according to the first aspect of the present invention. Although a form in which calcium hydroxide is applied as a neutralizing agent will be described here as an example, in the present invention, even if calcium oxide is applied as a neutralizing agent, it is the same as when calcium hydroxide is applied. The effect of is obtained. In FIG. 3, the drainage 10 containing the titanium compound is transferred to the water receiving tank 1, water 11 is supplied into the water receiving tank 1, the drainage 10 containing the titanium compound and the water 11 are mixed, and hydrolysis treatment is performed. Give. Next, the hydrolyzed treatment liquid is transferred to the primary neutralization treatment tank 2, the calcium hydroxide suspension 12 is supplied to the primary neutralization treatment tank 2, and the treatment liquid in the primary neutralization treatment tank 2 is supplied. The primary neutralization treatment is performed so that the pH of the calcium hydroxide is 1.5 or more and less than 2.5. Next, the treatment liquid subjected to the primary neutralization treatment is transferred to the secondary neutralization treatment tank 3, the calcium hydroxide suspension 13 is supplied to the secondary neutralization treatment tank 3, and the secondary neutralization treatment tank 3 is supplied. Secondary neutralization treatment is performed so that the pH of the treatment liquid in 3 is 6.5 or more and 7.5 or less. Next, the treatment liquid subjected to the secondary neutralization treatment is transferred to the coagulation tank 4, a coagulant is added to the coagulation tank 4, and titanium hydroxide is agglomerated to generate agglomerates of titanium hydroxide. Let me. Next, the agglutination treatment liquid containing the generated titanium hydroxide agglomerates is transferred to the settling tank 5, and the titanium hydroxide agglomerates are settled in the settling tank 5 from the lower part or the bottom of the settling tank 5. Extract the sediment of titanium hydroxide agglomerates. Next, the sediment of the titanium hydroxide aggregate extracted from the sedimentation tank 5 is transferred to the sediment storage tank 6. Next, the precipitate of the titanium hydroxide agglomerate is filtered using the filter press device 7, the liquid phase is removed from the precipitate of the titanium hydroxide agglomerate, and the titanium hydroxide agglomerate is filtered out. , Obtain a press cake of agglomerates of titanium hydroxide. Next, the press cake of the agglutinated titanium hydroxide is transferred to the acid treatment tank 8, the hydrochloric acid 14 is supplied to the acid treatment tank 8, the agglutinate of titanium hydroxide and the hydrochloric acid 14 are mixed, and the acid treatment is performed. .. Next, the acid-treated product of the titanium hydroxide aggregate is filtered using the filter press device 9, the liquid phase is removed from the acid-treated product of the titanium hydroxide aggregate, and the acid of the titanium hydroxide aggregate is removed. By filtering the treated product, a press cake of an acid-treated product of agglomerates of titanium hydroxide is obtained. Next, the press cake of the acid-treated product of the titanium hydroxide agglomerates is transferred to the washing tank 31, and the washing water 15 is supplied to the washing tank tank 31, and the acid-treated product and the washing water of the titanium hydroxide agglomerates are supplied. 15 is mixed and washed. Next, the washed product of the acid-treated product of the agglomerates of titanium hydroxide is filtered using the filter press device 33, the liquid phase is removed from the washed product of the acid-treated product of the aggregates of titanium hydroxide, and hydroxylation is performed. By filtering the acid-treated product of the titanium agglomerates, a press cake 22 of the acid-treated product of the titanium hydroxide agglomerates is obtained.

That is, in the first form of the cleaning step, the acid-treated product of the aggregate of titanium hydroxide obtained by performing the step (3A) is subjected to a solid-liquid separation device such as a filter press device, a centrifugation device, and a liquid cyclone device. The acid-treated product of the aggregate of titanium hydroxide is separated from the liquid phase to obtain a dehydrated product such as a press cake, and then the dehydrated product such as a press cake is taken out from the solid-liquid separation device and then dehydrated. It is a form in which washing is performed by bringing the washing water into contact with the treated material.

In the cleaning step of the first embodiment, after the acid-treated product of the titanium hydroxide agglomerate is brought into contact with the cleaning water, a solid-liquid separation device such as a filter press device, a centrifugation device, or a liquid cyclone device is used. The acid-treated product of the titanium hydroxide agglomerates and the washing water are separated to obtain an acid-treated product of the titanium hydroxide agglomerates.

FIG. 4 is a flow chart showing a form example of another form in which the cleaning step is performed among the methods for recovering the titanium component of the first aspect of the present invention. Here, a form in which calcium hydroxide is applied as a neutralizing agent will be described as an example, but in the present invention, the same effect as when calcium hydroxide is applied can be obtained even if calcium oxide is applied. .. In FIG. 4, the drainage 10 containing the titanium compound is transferred to the water receiving tank 1, water 11 is supplied into the water receiving tank 1, the drainage 10 containing the titanium compound and the water 11 are mixed, and hydrolysis treatment is performed. Give. Next, the hydrolyzed treatment liquid is transferred to the primary neutralization treatment tank 2, the calcium hydroxide suspension 12 is supplied to the primary neutralization treatment tank 2, and the treatment liquid in the primary neutralization treatment tank 2 is supplied. The primary neutralization treatment is performed so that the pH of the calcium hydroxide is 1.5 or more and less than 2.5. Next, the treatment liquid subjected to the primary neutralization treatment is transferred to the secondary neutralization treatment tank 3, the calcium hydroxide suspension 13 is supplied to the secondary neutralization treatment tank 3, and the secondary neutralization treatment tank 3 is supplied. Secondary neutralization treatment is performed so that the pH of the treatment liquid in 3 is 6.5 or more and 7.5 or less. Next, the treatment liquid subjected to the secondary neutralization treatment is transferred to the coagulation tank 4, a coagulant is added to the coagulation tank 4, and titanium hydroxide is agglomerated to generate agglomerates of titanium hydroxide. Let me. Next, the agglutination treatment liquid containing the generated titanium hydroxide agglomerates is transferred to the settling tank 5, and the titanium hydroxide agglomerates are settled in the settling tank 5 from the lower part or the bottom of the settling tank 5. Extract the sediment of titanium hydroxide agglomerates. Next, the sediment of the titanium hydroxide aggregate extracted from the sedimentation tank 5 is transferred to the sediment storage tank 6. Next, the precipitate of the titanium hydroxide agglomerate is filtered using the filter press device 7, the liquid phase is removed from the precipitate of the titanium hydroxide agglomerate, and the titanium hydroxide agglomerate is filtered out. , Obtain a press cake of agglomerates of titanium hydroxide. Next, the press cake of the agglutinated titanium hydroxide is transferred to the acid treatment tank 8, the hydrochloric acid 14 is supplied to the acid treatment tank 8, the agglutinate of titanium hydroxide and the hydrochloric acid 14 are mixed, and the acid treatment is performed. .. Next, the acid-treated product of the titanium hydroxide agglomerates is filtered using the filter press device 9, the liquid phase is removed from the acid-treated product of the titanium hydroxide agglomerates, and then the inside of the filter press device 9 is further filtered. The wash water 15 pressurized to 0.2 to 0.5 MPa is supplied to the filter, and the filter is washed by penetrating wash in which the wash water 15 is brought into contact with the filter at high pressure, and the acid of the aggregate of titanium hydroxide is performed. A pressed cake 23 of the processed product is obtained.

That is, in the second form of the cleaning step, the acid-treated product of the titanium hydroxide agglomerates obtained by performing the step (3A) is separated from the liquid phase by filtration using a filter press device. Further, the filter material in the filter press device is supplied with wash water pressurized to 0.2 to 0.5 MPa, and the filter material is brought into contact with the wash water at a high pressure for penetration cleaning. be.

The pH of the washing water used in the washing step may be any pH as long as it can be washed without deteriorating titanium hydroxide, and is usually 6.0 or more and 9.0 or less. The washing water that can be washed without deteriorating titanium hydroxide is not particularly limited, and for example, ion-exchanged water, pure water, ultrapure water, industrial water, well water, tap water, and the like can be applied. ..

The temperature at the time of washing is not particularly limited, but is preferably 10 to 50 ° C, more preferably 15 to 45 ° C, and even more preferably 20 to 40 ° C.

After performing the cleaning step, a solid-liquid separator is used to separate the liquid phase from the cleaning solution containing the acid-treated product of the titanium hydroxide agglomerates after cleaning, and dehydration treatment of the titanium hydroxide agglomerates. The product is then dried at 60-200 ° C. to give an acid-treated product of agglomerates of titanium hydroxide.

In the method for recovering a titanium component according to the first aspect of the present invention, when the effluent containing a titanium compound generated when preparing a solid catalyst component for olefin polymerization or a catalyst for olefin polymerization contains chlorine. By performing the cleaning step, the chlorine content in the agglomerates of titanium hydroxide can be reduced.

In the method for recovering the titanium component of the second embodiment of the present invention, the titanium hydroxide agglomerates produced by performing step (2) are settled, and then hydrochloric acid is brought into contact with the settling of the titanium hydroxide agglomerates. It is a form having a step (3B) of performing acid treatment of agglomerates of titanium hydroxide to obtain an acid-treated product of agglomerates of titanium hydroxide.

That is, the method for recovering the titanium component according to the second aspect of the present invention is a method for recovering the titanium component from the effluent containing the titanium compound.
The step (1) of hydrolyzing the titanium compound by bringing the effluent containing the titanium compound into contact with water.
The hydrolyzed treatment liquid is subjected to a primary neutralization treatment in which calcium hydroxide or calcium oxide is added as a neutralizing agent so that the pH is 1.5 or more and less than 2.5, and then the primary neutralization is performed. The treated liquid is subjected to a secondary neutralization treatment in which calcium hydroxide or calcium oxide is added as a neutralizing agent so that the pH becomes 6.5 or more and 7.5 or less, and then titanium hydroxide is aggregated. Step (2) to obtain agglomerates of titanium hydroxide by performing agglomeration treatment
After the titanium hydroxide agglomerates produced by performing the step (2) are precipitated, hydrochloric acid is brought into contact with the titanium hydroxide agglomerates to carry out acid treatment of the titanium hydroxide agglomerates with water. Step (3B) of obtaining an acid-treated product of titanium oxide agglomerates,
To have
It is a method for recovering a titanium component, which is characterized by the above. In the method for recovering the titanium component of the second aspect of the present invention, after the titanium hydroxide agglomerates are generated in the step (2), the sediment of the titanium hydroxide agglomerates is separated from the agglomeration treatment liquid, and water is used. This is a form in which the sediment of the titanium hydroxide aggregate is subjected to an acid treatment without removing the liquid phase in the precipitate of the titanium oxide aggregate.

The method for recovering the titanium component of the second embodiment of the present invention will be described with reference to FIG. FIG. 5 is a flow chart of an example of a method for recovering a titanium component according to the second aspect of the present invention. Although a form in which calcium hydroxide is applied as a neutralizing agent will be described here as an example, in the present invention, even if calcium oxide is applied as a neutralizing agent, it is the same as when calcium hydroxide is applied. The effect of is obtained. In FIG. 5, the drainage 10 containing the titanium compound is transferred to the water receiving tank 1, water 11 is supplied into the water receiving tank 1, the drainage 10 containing the titanium compound and the water 11 are mixed, and hydrolysis treatment is performed. Give. Next, the hydrolyzed treatment liquid is transferred to the primary neutralization treatment tank 2, the calcium hydroxide suspension 12 is supplied to the primary neutralization treatment tank 2, and the treatment liquid in the primary neutralization treatment tank 2 is supplied. The primary neutralization treatment is performed so that the pH of the calcium hydroxide is 1.5 or more and less than 2.5. Next, the treatment liquid subjected to the primary neutralization treatment is transferred to the secondary neutralization treatment tank 3, the calcium hydroxide suspension 13 is supplied to the secondary neutralization treatment tank 3, and the secondary neutralization treatment tank 3 is supplied. Secondary neutralization treatment is performed so that the pH of the treatment liquid in 3 is 6.5 or more and 7.5 or less. Next, the treatment liquid subjected to the secondary neutralization treatment is transferred to the coagulation tank 4, a coagulant is added to the coagulation tank 4, and titanium hydroxide is agglomerated to generate agglomerates of titanium hydroxide. Let me. Next, the agglutination treatment liquid containing the generated titanium hydroxide agglomerates is transferred to the settling tank 5, and the titanium hydroxide agglomerates are settled in the settling tank 5 from the lower part or the bottom of the settling tank 5. Extract the sediment of titanium hydroxide agglomerates. Next, the sediment of the titanium hydroxide aggregate extracted from the sedimentation tank 5 is transferred to the acid treatment tank 18, and hydrochloric acid 14 is supplied to the acid treatment tank 18, and the sediment of the titanium hydroxide aggregate and hydrochloric acid are supplied. 14 is mixed and subjected to acid treatment. Next, the acid-treated product of the titanium hydroxide agglomerates is filtered using the filter press device 7, the liquid phase is removed from the acid-treated product of the titanium hydroxide agglomerates, and the acid of the titanium hydroxide agglomerates is removed. By filtering the treated product, a press cake 24 of an acid-treated product of agglomerates of titanium hydroxide is obtained.

The method for recovering the titanium component according to the first aspect of the present invention includes steps (1), steps (2), and steps (3B). The steps (1), steps (2), wastewater used, treatment, treatment method, etc. in the titanium component recovery method of the second aspect of the present invention are common to the titanium compound recovery method of the present invention, and details thereof. Is as described in the description of the method for recovering the titanium component of the present invention.

In the step (3B) according to the method for recovering the titanium component of the second aspect of the present invention, the agglomerates of titanium hydroxide produced by performing the step (2) are settled, and then the agglomerates of titanium hydroxide obtained are settled. An acid-treated product of titanium hydroxide agglomerates is obtained by contacting an object with hydrochloric acid to obtain an acid-treated product of titanium hydroxide agglomerates.

In the step (3B), the method for obtaining a precipitate of the titanium hydroxide agglomerates from the agglutination treatment liquid containing the titanium hydroxide agglomerates after the step (2) is not particularly limited. For example, first, the agglutination treatment liquid containing the titanium hydroxide agglomerates after the step (i) (2) is transferred to a settling tank, and the titanium hydroxide agglomerates are settled in the settling tank. Next, (ii) a method of extracting the sediment of the titanium hydroxide aggregate from the lower part or the bottom of the sedimentation tank and transferring the sediment of the titanium hydroxide aggregate extracted from the sedimentation tank to the acid treatment tank can be mentioned. Be done.

Further, in the step (3B), as a method for obtaining a precipitate of the agglomerates of titanium hydroxide from the agglutination treatment liquid containing the agglutinates of titanium hydroxide after the step (2), the step (2) is performed. A method of treating the agglutination treatment liquid containing the agglutination of titanium hydroxide after the treatment with a liquid cyclone, a screw decanter, etc. to separate the aqueous phase from the agglutination treatment liquid to obtain a precipitate of the agglutination of titanium hydroxide. Can be mentioned.

In the step (3B), hydrochloric acid is then brought into contact with the precipitate of the titanium hydroxide agglutination to perform acid treatment of the titanium hydroxide agglutination to obtain an acid-treated product of the titanium hydroxide agglutination.

In the acid treatment according to the step (3B), hydrochloric acid is brought into contact with the precipitate of the aggregate of titanium hydroxide. At this time, the pH of the liquid phase is 5.0 or less, preferably 2.5 or more and 4.5 or less. , More preferably 3.0 or more and 4.0 or less. When the pH of the liquid phase during the acid treatment is in the above range, the calcium content in the titanium hydroxide agglutination can be reduced. On the other hand, if the pH of the liquid phase during the acid treatment exceeds the above range, it becomes difficult to obtain the effect of reducing the calcium content in the aggregate of titanium hydroxide.

The acid used for the acid treatment according to the step (3B) is hydrochloric acid. Hydrochloric acid is volatilized and removed from the product when the titanium hydroxide is dried or oxidized after the acid treatment, so that the acid used for the acid treatment is unlikely to remain in the product.

The concentration of hydrochloric acid used for the acid treatment according to the step (3B) is not particularly limited, but is preferably 1.0 to 8.5 mol / L, preferably 1.5 to 7.0 mol / L. It is more preferably 2.7 to 5.5 mol / L. When the concentration of hydrochloric acid used for the acid treatment is within the above range, the pH of the liquid phase during the acid treatment can be easily controlled within a desired range. If the concentration of hydrochloric acid used for the acid treatment exceeds the above range, it becomes difficult to control the pH of the liquid phase during the acid treatment, and if it is less than the above range, it becomes difficult to perform a smooth acid treatment.

The temperature during the acid treatment according to the step (3B) is not particularly limited, but is preferably 10 to 50 ° C, more preferably 15 to 45 ° C, and even more preferably 20 to 40 ° C.

In the acid treatment according to the step (3B), the contact time between the precipitate of the titanium hydroxide aggregate and hydrochloric acid is preferably 60 to 120 minutes, more preferably 60 to 100 minutes, and 60 to 60 to 100 minutes. It is more preferably 80 minutes.

In the step (3B), as a method of performing the acid treatment, it is preferable to bring hydrochloric acid into contact with the sediment of the titanium hydroxide aggregate in the acid treatment tank.

In step (3B), after acid treatment is performed to obtain an acid-treated product of titanium hydroxide agglomerates, a liquid phase is prepared from the acid-treated product of titanium hydroxide agglomerates using a solid-liquid separator. It is removed to obtain a dehydrated product of the acid-treated product of the aggregate of titanium hydroxide, and further, the dehydrated product is dried at 60 to 200 ° C. to obtain an acid-treated product of the aggregate of titanium hydroxide. By removing the liquid phase from the acid-treated product of the titanium hydroxide agglomerates and drying, water and hydrogen chloride are removed from the acid-treated product of the titanium hydroxide agglomerates, and the acid-treated product of the titanium hydroxide agglomerates. Is obtained.

In the method for recovering the titanium component of the second aspect of the present invention, the titanium hydroxide obtained by performing the step (3B) is Ti (OH) ₄ . That is, in the method for recovering the titanium component of the present invention, the titanium component is recovered from the effluent containing the titanium compound in the state of agglomerates of titanium hydroxide. Then, the recovered agglomerates of titanium hydroxide (acid-treated product) are converted into titanium oxide after drying and oxidation, and used as a raw material for producing various titanium compounds.

In the method for recovering the titanium component of the second embodiment of the present invention, the wastewater containing the titanium compound is subjected to a primary neutralization treatment at a specific pH by using calcium hydroxide as a neutralizing agent after the hydrolysis treatment. The next neutralization treatment and the agglomeration treatment are sequentially performed to generate and settle the agglomerates of titanium hydroxide, and the obtained precipitate of the agglomerates of titanium hydroxide is subjected to an acid treatment in which hydrochloric acid is brought into contact with the acid. Since the calcium content in the aggregate of titanium hydroxide obtained by the treatment can be reduced, the titanium hydroxide having a low calcium content can be recovered. In the method for recovering the titanium component according to the second aspect of the present invention, the agglomerates of titanium hydroxide produced in the step (2) are subjected to acid treatment on the settled precipitates to cause the agglomerates of titanium hydroxide. Since the poorly water-soluble unreacted substance such as calcium hydroxide remaining in the titanium hydroxide is dissolved, the calcium content in the agglomerates of titanium hydroxide can be reduced. From the above, it is considered that the titanium hydroxide component recovery method of the second aspect of the present invention can recover titanium hydroxide having a low calcium content and chlorine content.

The method for recovering the titanium component according to the second aspect of the present invention is an acid-treated product of a titanium hydroxide agglomerate obtained by performing step (3B) in addition to step (1), step (2) and step (3B). Can have a washing step of washing with washing water having a pH of 6.0 or more and 9.0 or less. In the cleaning step, cleaning is performed by bringing the cleaning water into contact with the acid-treated product of the titanium hydroxide agglomerates obtained in step (3B). The contact method is not particularly limited, and examples thereof include the following methods.

FIG. 6 is a flow chart showing an example of a form in which a cleaning step is performed among the methods for recovering a titanium component according to the second aspect of the present invention. In FIG. 6, the drainage 10 containing the titanium compound is transferred to the water receiving tank 1, water 11 is supplied into the water receiving tank 1, the drainage 10 containing the titanium compound and the water 11 are mixed, and hydrolysis treatment is performed. Give. Next, the hydrolyzed treatment liquid is transferred to the primary neutralization treatment tank 2, the calcium hydroxide suspension 12 is supplied to the primary neutralization treatment tank 2, and the treatment liquid in the primary neutralization treatment tank 2 is supplied. The primary neutralization treatment is performed so that the pH of the calcium hydroxide is 1.5 or more and less than 2.5. Next, the treatment liquid subjected to the primary neutralization treatment is transferred to the secondary neutralization treatment tank 3, the calcium hydroxide suspension 13 is supplied to the secondary neutralization treatment tank 3, and the secondary neutralization treatment tank 3 is supplied. Secondary neutralization treatment is performed so that the pH of the treatment liquid in 3 is 6.5 or more and 7.5 or less. Next, the treatment liquid subjected to the secondary neutralization treatment is transferred to the coagulation tank 4, a coagulant is added to the coagulation tank 4, and titanium hydroxide is agglomerated to generate agglomerates of titanium hydroxide. Let me. Next, the agglutination treatment liquid containing the generated titanium hydroxide agglomerates is transferred to the settling tank 5, and the titanium hydroxide agglomerates are settled in the settling tank 5 from the lower part or the bottom of the settling tank 5. Extract the sediment of titanium hydroxide agglomerates. Next, the sediment of the titanium hydroxide aggregate extracted from the sedimentation tank 5 is transferred to the acid treatment tank 18, and hydrochloric acid 14 is supplied to the acid treatment tank 18, and the sediment of the titanium hydroxide aggregate and hydrochloric acid are supplied. 14 is mixed and subjected to acid treatment. Next, the acid-treated product of the titanium hydroxide agglomerates is filtered using the filter press device 7, the liquid phase is removed from the acid-treated product of the titanium hydroxide agglomerates, and the acid of the titanium hydroxide agglomerates is removed. By filtering the treated product, a press cake of an acid-treated product of agglomerates of titanium hydroxide is obtained. Next, the press cake of the acid-treated product of the titanium hydroxide agglomerates is transferred to the washing tank 32, and the washing water 15 is supplied to the washing tank tank 32 to supply the acid-treated product of the titanium hydroxide agglomerates and the washing water. 15 is mixed and washed. Next, the washed product of the acid-treated product of the agglomerates of titanium hydroxide is filtered using the filter press device 33, the liquid phase is removed from the washed product of the acid-treated product of the aggregates of titanium hydroxide, and hydroxylation is performed. By filtering the acid-treated product of the titanium agglomerates, a press cake 25 of the acid-treated product of the titanium hydroxide agglomerates is obtained.

That is, in the first form of the cleaning step, the acid-treated product of the aggregate of titanium hydroxide obtained in the step (3B) is subjected to a solid-liquid separation device such as a filter press device, a centrifugation device, or a liquid cyclone device. Then, the acid-treated product of the aggregate of titanium hydroxide is separated from the liquid phase to obtain a dehydrated product such as a press cake, and then the dehydrated product such as a press cake is taken out from the solid-liquid separation device with washing water. Next, the dehydrated product is brought into contact with the washing water for washing.

In the cleaning step of the first embodiment, after the acid-treated product of the titanium hydroxide agglomerate is brought into contact with the cleaning water, a solid-liquid separation device such as a filter press device, a centrifugation device, or a liquid cyclone device is used. The acid-treated product of the titanium hydroxide agglomerates and the washing water are separated to obtain an acid-treated product of the titanium hydroxide agglomerates.

FIG. 7 is a flow chart showing a form example of another form in which the cleaning step is performed among the methods for recovering the titanium component of the second form of the present invention. In FIG. 7, the drainage 10 containing the titanium compound is transferred to the water receiving tank 1, water 11 is supplied into the water receiving tank 1, the drainage 10 containing the titanium compound and the water 11 are mixed, and hydrolysis treatment is performed. Give. Next, the hydrolyzed treatment liquid is transferred to the primary neutralization treatment tank 2, the calcium hydroxide suspension 12 is supplied to the primary neutralization treatment tank 2, and the treatment liquid in the primary neutralization treatment tank 2 is supplied. The primary neutralization treatment is performed so that the pH of the calcium hydroxide is 1.5 or more and less than 2.5. Next, the treatment liquid subjected to the primary neutralization treatment is transferred to the secondary neutralization treatment tank 3, the calcium hydroxide suspension 13 is supplied to the secondary neutralization treatment tank 3, and the secondary neutralization treatment tank 3 is supplied. Secondary neutralization treatment is performed so that the pH of the treatment liquid in 3 is 6.5 or more and 7.5 or less. Next, the treatment liquid subjected to the secondary neutralization treatment is transferred to the coagulation tank 4, a coagulant is added to the coagulation tank 4, and titanium hydroxide is agglomerated to generate agglomerates of titanium hydroxide. Let me. Next, the agglutination treatment liquid containing the generated titanium hydroxide agglomerates is transferred to the settling tank 5, and the titanium hydroxide agglomerates are settled in the settling tank 5 from the lower part or the bottom of the settling tank 5. Extract the sediment of titanium hydroxide agglomerates. Next, the sediment of the titanium hydroxide aggregate extracted from the sedimentation tank 5 is transferred to the acid treatment tank 18, and hydrochloric acid 14 is supplied to the acid treatment tank 18, and the sediment of the titanium hydroxide aggregate and hydrochloric acid are supplied. 14 is mixed and subjected to acid treatment. Next, the acid-treated product of the titanium hydroxide aggregate is filtered using the filter press device 7, the liquid phase is removed from the acid-treated product of the titanium hydroxide aggregate, and the acid of the titanium hydroxide aggregate is removed. The liquid phase was removed from the acid-treated product of the aggregate of titanium hydroxide by filtering the treated product, and then the filtered product in the filter press device 7 was further pressurized to 0.2 to 0.5 MPa. The washing is performed by penetrating washing in which the washing water 15 is supplied and the washing water 15 is brought into contact with the filter medium at high pressure to obtain a press cake 26 which is an acid-treated product of agglomerates of titanium hydroxide.

That is, in the second form of the cleaning step, the acid-treated product of the titanium hydroxide agglomerates obtained by performing the step (3B) is separated from the liquid phase by filtration using a filter press device. Further, the filter material in the filter press device is supplied with wash water pressurized to 0.2 to 0.5 MPa, and the filter material is brought into contact with the wash water at a high pressure for penetration cleaning. be.

The pH of the washing water used in the washing step may be any pH as long as it can be washed without deteriorating titanium hydroxide, and is usually 6.0 or more and 9.0 or less. The washing water that can be washed without deteriorating titanium hydroxide is not particularly limited, and for example, ion-exchanged water, pure water, ultrapure water, industrial water, well water, tap water, and the like can be applied. ..

The temperature at the time of washing is not particularly limited, but is preferably 10 to 50 ° C, more preferably 15 to 45 ° C, and even more preferably 20 to 40 ° C.

After performing the cleaning step, a solid-liquid separator is used to separate the liquid phase from the cleaning solution containing the acid-treated product of the titanium hydroxide agglomerates after cleaning, and dehydration treatment of the titanium hydroxide agglomerates. The product is then dried at 60-200 ° C. to give an acid-treated product of agglomerates of titanium hydroxide.

In the method for recovering the titanium component of the second embodiment of the present invention, when the effluent containing the titanium compound generated when preparing the solid catalyst component for olefin polymerization or the catalyst for olefin polymerization contains chlorine. By performing the cleaning step, the chlorine content in the agglomerates of titanium hydroxide can be reduced.

In this way, in the method for recovering the titanium component of the present invention, the titanium compound in the effluent containing the titanium compound generated when the solid catalyst component for olefin polymerization or the catalyst for olefin polymerization is prepared is titanium hydroxide. Titanium hydroxide, which has a low calcium content, can be easily recovered in a high yield.

Next, the method for producing titanium oxide of the present invention will be described.
The method for producing titanium oxide of the present invention is a method for producing titanium oxide from a effluent containing a titanium compound.
The step (1) of bringing the effluent containing the titanium compound into contact with water and hydrolyzing the titanium compound.
The hydrolyzed treatment liquid is subjected to a primary neutralization treatment in which calcium hydroxide or calcium oxide is added as a neutralizing agent so that the pH is 1.5 or more and less than 2.5, and then the primary neutralization is performed. The treated liquid is subjected to a secondary neutralization treatment in which calcium hydroxide or calcium oxide is added as a neutralizing agent so that the pH becomes 6.5 or more and 7.5 or less, and then titanium hydroxide is aggregated. The step (2) of obtaining an agglomerate of titanium hydroxide by subjecting the agglomeration treatment to the agglomerate.
In the step after the step (2), an acid treatment is performed in which hydrochloric acid is brought into contact with the aggregate of titanium hydroxide to obtain an acid-treated product, and the step (3).
An oxidation step of oxidizing the titanium hydroxide aggregate to obtain titanium oxide,
To have
It is characterized by. Further, the method for producing titanium oxide of the present invention includes a washing step of washing the acid-treated product of the aggregate of titanium hydroxide obtained by performing the step (3) with washing water having a pH of 6.0 or more and 9.0 or less. be able to.

The method for producing titanium oxide of the present invention includes steps (1), steps (2), and steps (3), except that it has an oxidation step of oxidizing an acid-treated product of titanium hydroxide agglomerates to obtain titanium oxide. ), Step (3A), Step (3B), Cleaning step, Wastewater used, Treatment and treatment method, etc. are common to the method for recovering the titanium compound of the present invention. As described in the explanation of the method.

The oxidation step according to the method for producing titanium oxide of the present invention is a step of obtaining titanium oxide by oxidizing an acid-treated product of agglomerates of titanium hydroxide.

The oxidation conditions in the oxidation step are not particularly limited as long as they are conditions in which titanium hydroxide is oxidized and converted to titanium oxide. For example, the oxidation reaction temperature in the oxidation step is preferably 60 to 1000 ° C. The oxidation reaction time is appropriately selected. The oxidation reaction atmosphere is an oxidizing atmosphere such as an atmospheric atmosphere and an oxygen gas atmosphere. Further, in the oxidation step, oxidation may be performed only once, or oxidation may be performed twice or more at the same temperature or different temperatures.

In the method for producing titanium oxide of the present invention, since the step (3) is performed on the aggregate of titanium hydroxide obtained by performing the steps (1) and (2), the titanium component is removed from the effluent containing the titanium compound. Even if calcium hydroxide is used as a neutralizing agent when recovering and obtaining titanium hydroxide, titanium hydroxide having a low calcium content can be obtained, so that titanium oxide having a low calcium content can be obtained. .. Further, in the method for producing titanium oxide of the present invention, the chlorine content in titanium oxide can be lowered when the effluent containing the titanium compound contains chlorine by further performing a cleaning step.

In this way, in the method for producing titanium oxide of the present invention, the titanium compound in the effluent containing the titanium compound can be recovered as titanium oxide, and the titanium oxide having a low calcium content can be cleaned. When this is done, titanium oxide having a low calcium content and a low chlorine content can be easily recovered.

Next, the method for producing the alkali metal titanate of the present invention will be described.
In the method for producing an alkali metal titanate of the present invention, titanium hydroxide recovered by the method for recovering a titanium component of the present invention or titanium oxide obtained by the method for producing titanium oxide of the present invention is used as a raw material. It is a feature.

The method for producing an alkali metal titanate of the present invention uses titanium hydroxide recovered by the method for recovering a titanium component of the present invention or titanium oxide obtained by the method for producing titanium oxide of the present invention as a raw material. A known method can be adopted except that it is used.

For example, when titanium hydroxide recovered by the method for recovering a titanium component of the present invention is used as a titanium raw material, titanium oxide obtained after oxidizing titanium hydroxide to titanium oxide by an appropriate method is used. Is used as a titanium raw material, and a potassium compound is used as an alkaline raw material, and a raw material mixture containing both is fired and pulverized to produce an alkali metal titanate. When titanium oxide obtained by the method for producing titanium oxide of the present invention is used as the titanium oxide raw material, the titanium oxide obtained by the method for producing titanium oxide of the present invention is used as a titanium oxide raw material and is alkaline. An alkali metal titanate can be produced by using a potassium compound as a raw material and firing and pulverizing a raw material mixture containing both of them.

The obtained alkali metal titanate is suitable as a friction material for friction sliding members such as brake linings, disc pads, and clutch fading, which constitute a braking device in, for example, automobiles, railroad vehicles, aircraft, industrial machinery, and the like. Used.

According to the method for producing an alkali metal titanate of the present invention, a high calcium content obtained from a titanium compound-containing effluent generated when preparing a solid catalyst component for olefin polymerization or a catalyst for olefin polymerization is high. Since a pure titanium compound is used as a raw material, a high-purity alkali metal titanate can be produced at low cost.

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following examples.

(Example 1)
<Synthesis of titanium oxide>
Using the treatment flow shown in FIG. 2, titanium oxide was obtained from the effluent containing a titanium compound.
That is, the wastewater containing titanium tetrachloride, diethoxymagnesium, toluene and heptane, which is generated when the solid catalyst component for olefin polymerization is prepared in the Ziegler-Natta catalyst manufacturing plant, is treated. The drainage was mixed by feeding it into a water receiving tank 1 having a capacity of 250 m ^{3, and hydrolyzed.} At this time, water 11 for hydrolysis was sent into the water receiving tank so that the pH of the drainage liquid in the water receiving tank became 1.
The hydrolyzed treatment liquid was fed into a primary neutralization treatment tank 2 having a capacity of 10 m ^{3 at a rate of 10 m 3} / h, and a 12.5 mol / L calcium hydroxide aqueous solution having a liquid temperature of 25 ° C. was used. The primary neutralization treatment was performed so that the pH of the treatment liquid fed into the primary neutralization treatment tank 2 became 2.0.
Next, the treatment liquid subjected to the above primary neutralization treatment was fed into the secondary neutralization treatment tank 3 having a capacity of 10 m ^{3 at a rate of 10 m 3} / h, and 12.5 mol / L calcium hydroxide having a liquid temperature of 25 ° C. Using an aqueous solution, the secondary neutralization treatment was performed so that the pH of the treatment liquid fed into the secondary neutralization treatment tank 3 became 7.2.
The treated liquid having been subjected to the secondary neutralization treatment and having a liquid temperature of 25 ° C. is fed into the coagulation tank 4 having a capacity of 10 m ^{3 at a speed of 10 m 3} / h, and is used as a coagulant (Kurita Chemical Hokuriku Co., Ltd. After aggregating using the farm PA-833) to obtain a coagulation treatment liquid, the coagulation treatment liquid was transferred to the settling tank 5 and settled in the settling tank 5, and the settling material was extracted from the settling tank 5. .. Next, the sediment extracted from the sedimentation tank 5 is transferred to the sediment storage tank 6, the sediment is filtered using the filter press device 7, the liquid phase is removed from the sediment, and the agglomerates are filtered. Then, a press cake of the agglomerate was obtained. Next, 530 kg of the agglutinated press cake was transferred to the acid treatment tank 8 and diluted with 26,500 kg of ion-exchanged water. Hydrochloric acid 14 was supplied to the acid treatment tank 8 so that the pH of the obtained liquid phase was 5.0, and the aggregate and hydrochloric acid 14 were mixed and subjected to acid treatment. Next, the acid-treated product obtained by subjecting the acid treatment is filtered using a filter press device 9, the liquid phase is removed from the acid-treated product, the acid-treated product is filtered off, and the acid-treated product is filtered. Press cake 21 was obtained. The press cake 21 was dried at 180 ° C. for 16 hours using a hot air circulation dryer to obtain a dried product (titanium hydroxide) of the press cake 21. Next, the obtained dried product (titanium hydroxide) of the press cake 21 was heat-treated at 850 ° C. for 2 hours in an air atmosphere using a shuttle kiln, and then further heat-treated at 950 ° C. for 2 hours. , The target titanium oxide was obtained.
When the crystal structures of the obtained titanium hydroxide and titanium oxide were measured using an X'PERT-PRO-MPD multipurpose X-ray diffractometer (manufactured by PANICAL), the obtained titanium hydroxide was of a rutile type in a small amount. It was confirmed that titanium oxide is a rutile type, whereas titanium oxide is contained but the main crystal system is amorphous.

<Synthesis of potassium titanate>
52.16 kg of the obtained titanium oxide, 52.23 kg of titanium ore, 32.28 kg of potassium carbonate powder, 2.87 kg of titanium powder, and 5.7 kg of wood chips (wood pellets) were added to a vibrating rod mill (manufactured by Chuo Kakoki Co., Ltd.). The mixture was filled therein, and 0.6 kg of lower alcohol was further added thereto, and the mixture was treated with an amplitude of 5 mm for 15 minutes to obtain a raw material mixture.
145 kg of the above raw material mixture was supplied to a rotary kiln at a temperature of 1170 ° C. at a flow rate of 14.4 kg / hr. A synthetic reaction to potassium titanate occurred in this rotary kiln, and it became a fired product and was discharged from the rotary kiln. The discharged fired product was rapidly cooled to room temperature.
Then, the cooled calcined product is crushed with a vibrating rod mill (manufactured by Chuo Kakoki Co., Ltd.) and then crushed with an impact type crusher (manufactured by Hosokawa Micron Co., Ltd., ACM Pulverizer) with a built-in classifier to obtain potassium titanate particles. rice field. Table 1 shows the physical characteristics of the obtained potassium titanate particles. The scanning electron microscope observation result (SEM) is shown in FIG.
For comparison, Table 1 also shows the physical characteristics of commercially available potassium titanate particles (TOFIX-SNR-S manufactured by Toho Titanium Co., Ltd.). The scanning electron microscope observation result (SEM) is shown in FIG.
The measuring device or measuring method used for measuring each physical property is as follows.
<Measuring device>
XRD: X'PERT-PRO-MPD multipurpose X-ray diffractometer (manufactured by PANalytical)
SEM: JSM-7800 (manufactured by JEOL Ltd.)
Specific surface area: monosorb (manufactured by quantachrome)
Average particle size: PITA-3 (manufactured by Seishin Enterprise Co., Ltd.)

１）６ＫＴＯ：６チタン酸カリウム

1) 6KTO: Potassium 6 titanate

As shown in Table 1, it was confirmed that the potassium titanate particles of Example 1 had the same phase composition and powder shape as those of the commercially available product. The specific surface area (standard value: 2 to 3 m ² / g) and average particle size (standard value: 25 to 60 μm) were also within the standard values of commercially available products.

(Test Examples 1 to 5)
The agglutinated press cake (PC) obtained in the same manner as in Example 1 was transferred to the acid treatment tank 8 and diluted with ion-exchanged water. Hydrochloric acid 14 is supplied to the acid treatment tank 8 so that the pH of the obtained diluted solution becomes the predetermined value shown in Table 2, and the mixture is stirred for a predetermined time to mix the agglomerate and hydrochloric acid 14 and subjected to acid treatment. (Test Examples 3 to 5). In Test Examples 1 and 2, hydrochloric acid was not mixed.
Next, the acid-treated product obtained by subjecting the acid treatment is filtered using a filter press device 9, the liquid phase is removed from the acid-treated product, the acid-treated product is filtered off, and the acid-treated product is filtered. Press cake 21 was obtained. The press cake 21 was dried under predetermined conditions to obtain a dried product (titanium hydroxide) of the press cake 21. The conditions for synthesizing the dried product (titanium hydroxide) of the press cake 21 from the aggregated press cake are as shown in Table 2. Further, the dried product (titanium hydroxide) of the obtained press cake 21 was subjected to an ICP emission spectroscopic analysis method (Inductive coupled plasma optical spectrum spectrum; ICP-OES) and contained chlorine (Cl) and calcium (Ca). The results of the measurement are also shown in Table 2.

As shown in Table 2, it was confirmed that the chlorine and calcium contents can be reduced by adjusting the addition amount of water and hydrochloric acid at the time of dilution and lowering the pH of the liquid phase at the time of acid treatment to 5.9 or less. did it.

(Example 2)
<Synthesis of titanium oxide>
Using the treatment flow shown in FIG. 6, titanium oxide was obtained from the effluent containing a titanium compound.
That is, the wastewater containing titanium tetrachloride, diethoxymagnesium, toluene and heptane, which is generated when the solid catalyst component for olefin polymerization is prepared in the Ziegler-Natta catalyst manufacturing plant, is treated. The drainage D was mixed by feeding it into a water receiving tank 1 having a capacity of 250 m ^{3, and hydrolyzed.} At this time, water 11 for hydrolysis was sent into the water receiving tank so that the pH of the drainage liquid in the water receiving tank became 1.
The hydrolyzed treatment liquid was fed into a primary neutralization treatment tank 2 having a capacity of 10 m ^{3 at a rate of 10 m 3} / h, and a 12.5 mol / L sodium hydroxide aqueous solution having a liquid temperature of 25 ° C. was used. The primary neutralization treatment was performed so that the pH of the treatment liquid fed into the primary neutralization treatment tank 2 became 2.0.
Next, the treatment liquid subjected to the above primary neutralization treatment was fed into the secondary neutralization treatment tank 3 having a capacity of 10 m ^{3 at a rate of 10 m 3} / h, and 12.5 mol / L calcium hydroxide having a liquid temperature of 25 ° C. Using an aqueous solution, the secondary neutralization treatment was performed so that the pH of the treatment liquid fed into the secondary neutralization treatment tank 3 became 7.2.
The treated liquid having been subjected to the secondary neutralization treatment and having a liquid temperature of 25 ° C. is fed into the coagulation tank 4 having a capacity of 10 m ^{3 at a speed of 10 m 3} / h, and is used as a coagulant (Kurita Chemical Hokuriku Co., Ltd. After aggregating using the farm PA-833) to obtain a coagulation treatment liquid, the coagulation treatment liquid was transferred to the settling tank 5 and settled in the settling tank 5, and the settling material was extracted from the settling tank 5. .. Next, 4000 kg of the sediment extracted from the sedimentation tank 5 is transferred to the acid treatment tank 18, hydrochloric acid 14 is supplied to the acid treatment tank 18, the sediment and hydrochloric acid 14 are mixed, and the liquid in the acid treatment tank 18 is liquid. Acid treatment was performed so that the pH of the phase became 3.5. Next, the acid-treated product of the obtained agglomerates is filtered using a filter press device 7, the liquid phase is removed from the acid-treated product of the agglomerates, and the acid-treated product of the agglomerates is filtered. As a result, a press cake of an acid-treated product of the aggregate was obtained. Next, the obtained press cake of the acid-treated product of the agglomerates is transferred to the washing tank 32, and 4000 kg of washing water 15 is supplied to the washing tank 32 to wash with the acid-treated product of the titanium hydroxide agglomerates. Water 15 was mixed and washed. Next, the obtained washed product of the acid-treated product of the aggregate is filtered using the filter press device 33, the liquid phase is removed from the washed product of the acid-treated product of the aggregate, and the acid of the aggregate is removed. By filtering the treated product, a press cake 25 of the acid-treated product of the aggregate was obtained. The press cake 25 was dried using a hot air circulation dryer at 180 ° C. for 16 hours to obtain a dried product (titanium hydroxide) of the press cake 25. Next, the dried product (titanium hydroxide) of the obtained press cake 25 was heat-treated at 850 ° C. for 2 hours in an air atmosphere using a shuttle kiln, and then further heat-treated at 950 ° C. for 2 hours. , The target titanium oxide was obtained.
When the crystal structures of the obtained titanium hydroxide and titanium oxide were measured using an X'PERT-PRO-MPD multipurpose X-ray diffractometer (manufactured by PANICAL), the obtained titanium hydroxide was of a rutile type in a small amount. It was confirmed that titanium oxide is a rutile type, whereas titanium oxide is contained but the main crystal system is amorphous.

<Synthesis of potassium titanate>
52.16 kg of the obtained titanium oxide, 52.23 kg of titanium ore, 32.28 kg of potassium carbonate powder, 2.87 kg of titanium powder, and 5.70 kg of wood chips (wood pellets) were placed in a vibrating rod mill (manufactured by Chuo Kakoki Co., Ltd.). Was filled with, and 0.6 kg of lower alcohol was further added thereto, and the mixture was treated with an amplitude of 5 mm for 15 minutes to obtain a raw material mixture.
Approximately 140 kg of the above raw material mixture was supplied to a rotary kiln at a temperature of 1170 ° C. at a flow rate of 14.4 kg / hr. A synthetic reaction to potassium titanate occurred in this rotary kiln, and it became a fired product and was discharged from the rotary kiln. The discharged fired product was rapidly cooled to room temperature.
After that, the cooled calcined product was crushed with a vibrating rod mill (manufactured by Chuo Kakoki Co., Ltd.) and then crushed with an impact type crusher (manufactured by Hosokawa Micron Co., Ltd., ACM Pulverizer) with a built-in classifier to obtain potassium titanate particles. rice field. Table 3 shows the physical characteristics of the obtained potassium titanate particles. The scanning electron microscope observation result (SEM) is shown in FIG.
For comparison, Table 3 also shows the physical characteristics of commercially available potassium titanate particles (TOFIX-SNR-S manufactured by Toho Titanium Co., Ltd.). The scanning electron microscope observation result (SEM) is shown in FIG.
The measuring device or measuring method used for measuring each physical property is as follows.
≪Measuring device≫
XRD: X'PERT-PRO-MPD multipurpose X-ray diffractometer (manufactured by PANalytical)
SEM: JSM-7800 (manufactured by JEOL Ltd.)
Specific surface area: monosorb (manufactured by quantachrome)
Average particle size: PITA-3 (manufactured by Seishin Enterprise Co., Ltd.)

１）６ＫＴＯ：６チタン酸カリウム

1) 6KTO: Potassium 6 titanate

As shown in Table 3, it was confirmed that the potassium titanate particles of Example 2 had the same phase composition and powder shape as those of the commercially available product. The specific surface area (standard value: 2 to 3 m ² / g) and average particle size (standard value: 25 to 60 μm) were also within the standard values of commercially available products.

(Test Example 6 to Test Example 8)
The sediment extracted from the sedimentation tank 5 obtained in the same manner as in Example 2 is transferred to the acid treatment tank 18, hydrochloric acid 14 is supplied to the acid treatment tank 18, and the sediment and hydrochloric acid are stirred for a predetermined time. 14 was mixed, and acid treatment was performed so that the pH of the mixed solution in the acid treatment tank 18 became the predetermined value in Table 4 (Test Examples 7 to 8). In Test Example 6, hydrochloric acid was not mixed.
Next, the acid-treated product of the obtained agglomerates is filtered using a filter press device 7, the liquid phase is removed from the acid-treated product of the agglomerates, and the acid-treated product of the agglomerates is filtered. As a result, a press cake of an acid-treated product of the aggregate was obtained. The press cake was dried under predetermined conditions to obtain a dried product (titanium hydroxide) of the press cake. The conditions for synthesizing the dried product (titanium hydroxide) of the press cake from the sediment extracted from the sedimentation tank 5 are as shown in Table 4. In addition, the results of measuring the calcium (Ca) content of the obtained dried product (titanium hydroxide) using ICP emission spectrometry (ICP-OES) are also included. It is shown in Table 4.

As shown in Table 4, it was confirmed that the calcium content can be reduced by adjusting the addition amounts of water and hydrochloric acid at the time of dilution and setting the pH of the liquid phase at the time of acid treatment to 5.9 or less. ..

From Tables 1 and 3, in Examples 1 and 2, the effluent containing the titanium compound was brought into contact with water, and the titanium compound was subjected to the hydrolysis treatment and then the hydrolysis treatment. The aqueous phase of the effluent is subjected to a primary neutralization treatment in which a neutralizing agent is added so that the pH is 1.5 or more and less than 2.5. A secondary neutralization treatment is performed in which a neutralizing agent is added so as to be 6.5 or more and 7.5 or less, and then agglomerates of titanium hydroxide formed by aggregating titanium hydroxide are subjected to hydrochloric acid having a pH of 5.9 or less. A titanium compound can be easily obtained without using a neutralizing agent such as aqueous ammonia or sodium hydroxide, and a high-purity titanium compound in which impurities such as calcium are suppressed from being mixed can be obtained. It turns out that it can be done.

Further, from Tables 2 and 4, in Test Example 4, Test Example 7 and Test Example 8, the pH of the titanium hydroxide agglomerates formed by aggregating the titanium hydroxide after the secondary neutralization treatment was pH 5.9 or less. It can be seen that impurities such as calcium in the obtained titanium compound are removed by contacting with hydrochloric acid.
On the other hand, in Test Examples 1 to 3 and 5 and Test Example 6, hydrochloric acid having a pH of 5.9 or less was not brought into contact with the aggregate of titanium hydroxide formed by agglutinating titanium hydroxide after the secondary neutralization treatment. From this, it can be seen that impurities such as calcium are not removed from the obtained titanium compound.

According to the present invention, a effluent containing a titanium compound, for example, a effluent containing a titanium compound such as a solid catalyst component for olefin polymerization or a titanium compound-containing effluent generated when a catalyst for olefin polymerization is prepared. Therefore, even if calcium hydroxide or calcium oxide is used as the neutralizing agent, it is possible to provide a method for easily recovering the titanium compound with high purity, and for effluent containing the titanium compound, for example, for olefin polymerization. Even if calcium hydroxide or calcium oxide is used as a neutralizing agent from the effluent containing a titanium compound such as the effluent containing a titanium compound generated when preparing a solid catalyst component or a catalyst for olefin polymerization, the titanium compound can be obtained. It is possible to provide a method for producing a high-purity and simple method, and further, it is possible to provide a method for producing a high-purity alkali metal titanate at low cost.

1 Water receiving tank 2 Primary neutralization treatment tank 3 Secondary neutralization treatment tank 4 Coagulation tank 5 Sedimentation tank 6 Sediment storage tanks 7, 9, 33 Filter press devices 8, 18 Acid treatment tank 10 Drainage containing titanium compounds 11 Water 12, 13 Calcium hydroxide suspension 14 Hydrochloride 15 Washing water 19 Titanium hydroxide compound agglomerates 20 Acid-treated products of titanium hydroxide compound agglomerates 21, 22, 23, 24, 25, 26 Titanium hydroxide compounds Acid-treated agglomerates Press cake 31, 32 Washing tank

Claims (13)

A method for recovering a titanium component from a effluent containing a titanium compound.
The step (1) of hydrolyzing the titanium compound by bringing the effluent containing the titanium compound into contact with water.
The hydrolyzed treatment liquid is subjected to a primary neutralization treatment in which calcium hydroxide or calcium oxide is added as a neutralizing agent so that the pH is 1.5 or more and less than 2.5, and then the primary neutralization is performed. The treated liquid is subjected to a secondary neutralization treatment in which calcium hydroxide or calcium oxide is added as a neutralizing agent so that the pH becomes 6.5 or more and 7.5 or less, and then titanium hydroxide is aggregated. Step (2) to obtain agglomerates of titanium hydroxide by performing agglomeration treatment
In the step after the step (2), an acid treatment is performed in which hydrochloric acid is brought into contact with the titanium hydroxide agglutination to obtain an acid-treated product of the titanium hydroxide agglutination.
To have
A method for recovering a titanium component, which is characterized by. After obtaining the concentrate of the titanium hydroxide agglomerate produced by performing the step (2), the concentrate of the titanium hydroxide agglomerate is separated, and then the concentrate of the titanium hydroxide agglomerate is obtained. The titanium according to claim 1, further comprising a step (3A) of contacting with hydrochloric acid to perform acid treatment of the titanium hydroxide agglomerate to obtain an acid-treated product of the titanium hydroxide agglomerate. How to recover the ingredients. The second aspect of the present invention, wherein in the step (3A), a concentrate of the titanium hydroxide agglomerates is obtained by precipitating the titanium hydroxide agglomerates produced by performing the step (2). How to recover the titanium component. In the step (3A), after the agglomerates of the titanium hydroxide produced by performing the step (2) are settled, the agglomerates of the titanium hydroxide are separated, and then the agglomerates of the titanium hydroxide are separated. 2. The invention according to claim 2, wherein a dehydration treatment for removing the liquid phase from the precipitate of titanium hydroxide is performed to obtain a dehydrated product of the agglomerates of titanium hydroxide, thereby obtaining a concentrate of the agglomerates of titanium hydroxide. How to recover the titanium component of. After the titanium hydroxide agglomerates produced by performing the step (2) are settled, hydrochloric acid is brought into contact with the titanium hydroxide agglomerates to carry out acid treatment of the titanium hydroxide agglomerates. The method for recovering a titanium component according to claim 1, further comprising a step (3B) of obtaining an acid-treated product of agglomerates of titanium hydroxide. The titanium component according to any one of claims 1 to 5, further comprising a washing step of washing the acid-treated product of the titanium hydroxide agglomerate with washing water of 6.0 or more and 9.0 or less. Collection method. A method for producing titanium oxide from a effluent containing a titanium compound.
The step (1) of hydrolyzing the titanium compound by bringing the effluent containing the titanium compound into contact with water.
The hydrolyzed treatment liquid is subjected to a primary neutralization treatment in which calcium hydroxide or calcium oxide is added as a neutralizing agent so that the pH is 1.5 or more and less than 2.5, and then the primary neutralization is performed. The treated liquid is subjected to a secondary neutralization treatment in which calcium hydroxide or calcium oxide is added as a neutralizing agent so that the pH becomes 6.5 or more and 7.5 or less, and then titanium hydroxide is aggregated. Step (2) to obtain agglomerates of titanium hydroxide by performing agglomeration treatment
In the step after the step (2), an acid treatment is performed in which hydrochloric acid is brought into contact with the titanium hydroxide agglutination to obtain an acid-treated product of the titanium hydroxide agglutination.
An oxidation step of oxidizing the acid-treated product of the titanium hydroxide agglomerate to obtain titanium oxide, and
To have
A method for producing titanium oxide. After obtaining the concentrate of the titanium hydroxide agglomerate produced by performing the step (2), the concentrate of the titanium hydroxide agglomerate is separated, and then the concentrate of the titanium hydroxide agglomerate is obtained. The titanium according to claim 7, further comprising a step (3A) of contacting with hydrochloric acid to perform acid treatment of the titanium hydroxide agglomerate to obtain an acid-treated product of the titanium hydroxide agglomerate. How to recover the ingredients. The eighth aspect of the present invention, wherein in the step (3A), a concentrate of the titanium hydroxide agglomerates is obtained by precipitating the titanium hydroxide agglomerates produced by performing the step (2). How to recover the titanium component. In the step (3A), after the agglomerates of the titanium hydroxide produced by performing the step (2) are settled, the agglomerates of the titanium hydroxide are separated, and then the agglomerates of the titanium hydroxide are separated. 8. The eighth aspect of claim 8, wherein a dehydration treatment for removing the liquid phase from the precipitate of titanium hydroxide is performed to obtain a dehydrated product of the agglomerates of titanium hydroxide, thereby obtaining a concentrate of the agglomerates of titanium hydroxide. How to recover the titanium component of. After the titanium hydroxide agglomerates produced by performing the step (2) are precipitated, hydrochloric acid is brought into contact with the titanium hydroxide agglomerates to carry out acid treatment of the titanium hydroxide agglomerates. The method for producing titanium oxide according to claim 7, further comprising a step (3B) of obtaining an acid-treated product of agglomerates of titanium hydroxide. The titanium oxide according to any one of claims 7 to 11, further comprising a washing step of washing the acid-treated product of the aggregate of titanium hydroxide with washing water of 6.0 or more and 9.0 or less. Production method. Using titanium hydroxide recovered by the method for recovering the titanium component according to any one of claims 1 to 6 or titanium oxide obtained by the method for producing titanium oxide according to any one of claims 7 to 12 as a raw material. A method for producing an alkali metal titanate, which is characterized by being used.

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