JP2023095797A - Method for recovering titanium components, method for producing titanium dioxide, method for producing alkali titanate, method for producing friction materials, and method for producing titanium tetrachloride raw materials - Google Patents

Abstract

To provide a method for recovering titanium components capable of reducing the chlorine content in recovered titanium components.SOLUTION: A method for recovering titanium components includes: a primary step of supplying a suspension containing the acid-treated titanium hydroxide aggregate into the space in a compression section of a filter press apparatus, filling the suspension containing the acid-treated titanium hydroxide aggregate in the compression section, and compressing the compression section and the suspension at 0.10 to 1.00 MPa by a pressurized filtration chamber to remove water from the suspension to obtain a primary pressed material; a through washing step of performing through washing on the primary pressed material to obtain a through-washed product; and a secondary pressing step of pressing the compression section and the through-washed product through the pressurized filtration chamber to remove water from the through-washed product to obtain an acid-treated cake of titanium hydroxide aggregates.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to a method for recovering a titanium component from waste liquid.

Conventionally, titanium oxysulfate and polymerized silicic acid are used in combination, and added to and mixed with the sludge to be treated at a molar ratio of 1 to 10 for silicon to titanium in the titanium oxysulfate to agglomerate the inorganic particles, followed by a filter press. There is known a method for dewatering sludge mainly composed of inorganic particles, which is characterized by performing mechanical dewatering treatment such as.

In this method, titanium oxysulfate is added to and mixed with wastewater or sludge, which is mainly composed of inorganic particles generated in water purification treatment and civil engineering work, and then pH is adjusted to 8 using an alkaline agent such as caustic soda or sodium carbonate. Adjust to ~11. As a result, hydrous titanium oxide is produced and the inorganic particles are agglomerated. Next, polymerized silicic acid is added in such a range that the molar ratio to titanium in the previously added titanium oxysulfate is 1 or more and 10 or less, and the mixture is sufficiently mixed and stirred to form flocs, followed by a filter press. Dehydrate with a centrifuge or the like.

Japanese Patent Application Laid-Open No. 2001-137900

By the way, in order to recover a titanium component from a waste liquid containing titanium tetrachloride instead of titanium oxysulfate, the following steps are generally performed. That is, the titanium tetrachloride in the waste liquid containing titanium tetrachloride is hydrolyzed, and then a calcium hydroxide suspension is supplied to the hydrolyzed waste liquid so that the pH of the waste liquid is approximately 1 to 1. After adjusting to 6 and adding a flocculating agent to flocculate titanium hydroxide, the agglomerate of titanium hydroxide is allowed to settle in a sedimentation tank. Next, the precipitated titanium hydroxide agglomerates are transferred to an acid treatment tank, hydrochloric acid is supplied into the acid treatment tank, and the titanium hydroxide agglomerates and hydrochloric acid are mixed to acid-treat the titanium hydroxide agglomerates. . Next, the treatment liquid containing the acid-treated titanium hydroxide agglomerates is filtered using a filter press to filter out the acid-treated titanium hydroxide agglomerates, and the titanium hydroxide agglomerates. The titanium component is recovered by obtaining a presscake of the acid treated material. At this time, chlorine content remains in the recovered titanium component derived from calcium chloride generated in the neutralization step or hydrochloric acid used for acid washing. There is a demand to reduce the chlorine content.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method for recovering a titanium component that can reduce the chlorine content in the recovered titanium component.

In order to solve the above technical problems, the present inventors have made intensive studies and have arrived at the following configuration.

That is, the present invention
(1) A method for recovering a titanium component from a waste liquid containing a titanium compound, comprising:
The waste liquid containing the titanium compound is subjected to at least hydrolysis, primary neutralization using calcium hydroxide or calcium oxide as a neutralizing agent, and secondary neutralization using calcium hydroxide or calcium oxide as a neutralizing agent. a titanium hydroxide aggregation treatment step for obtaining a titanium hydroxide aggregate by performing a treatment and an aggregation treatment for aggregating titanium hydroxide;
After the titanium hydroxide agglomeration treatment step, the titanium hydroxide agglomerate is subjected to an acid treatment in which hydrochloric acid or titanium chloride is brought into contact with the acid treatment step to obtain a suspension containing the acid-treated titanium hydroxide agglomerate. and,
In a space in the compression section of a filter press device having a pressurization-type filtration chamber and a compression section provided inside the pressurization-type filtration chamber, having a filtration membrane, and filled with a substance to be filtered, the A suspension containing an acid-treated titanium hydroxide agglomerate is sent, the compression section is filled with the suspension containing an acid-treated titanium hydroxide agglomerate, and then the pressurized filtration chamber passes through the pressurized filter chamber. a primary pressing step of compressing the compressed portion and the suspension at 0.10 to 1.00 MPa to remove moisture from the suspension to obtain a primary pressed product of the acid-treated titanium hydroxide agglomerate; ,
Washing water is supplied to the inside of the pressurized filtration chamber and the outside of the compression section so that the washing liquid penetrates the compression section and the primary compressed product of the acid-treated titanium hydroxide agglomerate therein. a penetration cleaning step of penetrating and cleaning the primary pressed product of the acid-treated titanium hydroxide agglomerate to obtain a penetration-washed product of the acid-treated titanium hydroxide agglomerate;
The pressurized filtration chamber squeezes the compressed portion and the acid-treated titanium hydroxide agglomerate through-washed material to remove water from the acid-treated titanium hydroxide agglomerate-through-washed material. a secondary pressing step for obtaining a cake of an acid-treated titanium oxide aggregate;
A method for recovering a titanium component, characterized by having
(2) Recovery of the titanium component according to (1), characterized in that the insertion pressure of the cleaning water in the through-cleaning step is 0.10 to 0.60 MPa, and the cleaning time is 17 to 60 minutes. Method;
(3) The method for recovering a titanium component according to (1) or (2), wherein the pressing pressure in the secondary pressing step is 0.10 to 1.00 MPa;
(4) The method for recovering a titanium component according to any one of (1) to (3), wherein the pressing time in the secondary pressing step is longer than the pressing time in the primary pressing step. :
(5) The method for recovering a titanium component according to any one of (1) to (4), wherein the pressure of the washing water in the through washing step is 0.10 to 0.60 MPa;
(6) A method for producing titanium oxide by producing titanium oxide from a waste liquid containing a titanium compound,
The waste liquid containing the titanium compound is subjected to at least hydrolysis, primary neutralization using calcium hydroxide or calcium oxide as a neutralizing agent, and secondary neutralization using calcium hydroxide or calcium oxide as a neutralizing agent. a titanium hydroxide aggregation treatment step for obtaining a titanium hydroxide aggregate by performing a treatment and an aggregation treatment for aggregating titanium hydroxide;
After the titanium hydroxide agglomeration treatment step, the titanium hydroxide agglomerate is subjected to an acid treatment in which hydrochloric acid or titanium chloride is brought into contact with the acid treatment step to obtain a suspension containing the acid-treated titanium hydroxide agglomerate. and,
The space in the compression section of a filter press device having a pressurization type filtration chamber and a compression section provided inside the pressure type filtration chamber, having a filtration membrane, and filled with a substance to be filtered, is filled with the water. A suspension containing an acid-treated titanium oxide agglomerate is sent, the compression part is filled with a suspension containing an acid-treated titanium hydroxide agglomerate, and then the pressurized filtration chamber is used for the compression. a primary pressing step of pressing the part and the suspension at 0.10 to 1.00 MPa to remove moisture from the suspension to obtain a primary pressed product of the acid-treated titanium hydroxide agglomerate;
Washing water is supplied to the inside of the pressurized filtration chamber and the outside of the compression section so that the washing liquid penetrates the compression section and the primary compressed product of the acid-treated titanium hydroxide agglomerate therein. a penetration cleaning step of penetrating and cleaning the primary pressed product of the acid-treated titanium hydroxide agglomerate to obtain a penetration-washed product of the acid-treated titanium hydroxide agglomerate;
The pressurized filtration chamber squeezes the compressed portion and the acid-treated titanium hydroxide agglomerate through-washed material to remove water from the acid-treated titanium hydroxide agglomerate-through-washed material. a secondary pressing step for obtaining a cake of an acid-treated titanium oxide aggregate;
a baking step of baking the acid-treated titanium hydroxide agglomerate after the secondary pressing step to obtain titanium oxide;
A method for producing titanium oxide, comprising:
(7) Titanium hydroxide recovered by the method for recovering a titanium component of any one of (1) to (5) or titanium oxide obtained by the method for producing titanium oxide of (6) is used as a raw material. A method for producing an alkali titanate;
(8) A method for producing a friction material, characterized in that the alkali titanate obtained by the method for producing an alkali titanate of (7) is used as a raw material;
(9) A method for producing a raw material for titanium tetrachloride, characterized by using, as a raw material, titanium hydroxide recovered by the method for recovering a titanium component according to any one of (1) to (5);
It provides

ADVANTAGE OF THE INVENTION According to this invention, the recovery method of the titanium component which can reduce the content of chlorine in a recovered titanium component can be provided.

1 is a flow diagram of an example of a method for recovering a titanium component according to the present invention; FIG. FIG. 1 is a detailed flow chart of an embodiment of the method for recovering a titanium component of the present invention, in which a suspension containing an acid-treated titanium hydroxide agglomerate is treated and a cake of the acid-treated titanium hydroxide agglomerate is obtained. be. FIG. 4 is a cross-sectional view schematically showing a penetration cleaning step of the present invention; It is sectional drawing which shows typically the forward cleaning process used by a comparative example. FIG. 4 is a flow diagram of another embodiment of the method for recovering a titanium component of the present invention. FIG. 4 is a flow diagram of another embodiment of the method for recovering a titanium component of the present invention. 10 shows XRD measurement results of potassium titanate particles of Example 5. FIG. 4 is an SEM image of potassium titanate particles of Example 5. FIG. 1 is an SEM image of commercially available potassium titanate particles. 10 shows XRD measurement results of sodium titanate particles of Example 6. FIG. 10 shows XRD measurement results of barium titanate particles of Example 7. FIG. 10 shows XRD measurement results of calcium titanate particles of Example 8. FIG.

A method for recovering a titanium component of the present invention is a method for recovering a titanium component from a waste liquid containing a titanium compound, comprising:
The waste liquid containing the titanium compound is subjected to at least hydrolysis, primary neutralization using calcium hydroxide or calcium oxide as a neutralizing agent, and secondary neutralization using calcium hydroxide or calcium oxide as a neutralizing agent. a titanium hydroxide aggregation treatment step for obtaining a titanium hydroxide aggregate by performing a treatment and an aggregation treatment for aggregating titanium hydroxide;
After the titanium hydroxide agglomeration treatment step, the titanium hydroxide agglomerate is subjected to an acid treatment in which hydrochloric acid or titanium chloride is brought into contact with the acid treatment step to obtain a suspension containing the acid-treated titanium hydroxide agglomerate. and,
In a space in the compression section of a filter press device having a pressurization-type filtration chamber and a compression section provided inside the pressurization-type filtration chamber, having a filtration membrane, and filled with a substance to be filtered, the A suspension containing an acid-treated titanium hydroxide agglomerate is sent, the compression section is filled with the suspension containing an acid-treated titanium hydroxide agglomerate, and then the pressurized filtration chamber passes through the pressurized filter chamber. a primary pressing step of compressing the compressed portion and the suspension at 0.10 to 1.00 MPa to remove moisture from the suspension to obtain a primary pressed product of the acid-treated titanium hydroxide agglomerate; ,
Washing water is supplied to the inside of the pressurized filtration chamber and the outside of the compression section so that the washing liquid penetrates the compression section and the primary compressed product of the acid-treated titanium hydroxide agglomerate therein. a penetration cleaning step of penetrating and cleaning the primary pressed product of the acid-treated titanium hydroxide agglomerate to obtain a penetration-washed product of the acid-treated titanium hydroxide agglomerate;
The pressurized filtration chamber squeezes the compressed portion and the acid-treated titanium hydroxide agglomerate through-washed material to remove water from the acid-treated titanium hydroxide agglomerate-through-washed material. a secondary pressing step for obtaining a cake of an acid-treated titanium oxide aggregate;
characterized by having

An overview of the titanium component recovery method 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. effect is obtained. FIG. 1 is a flow diagram of an embodiment of the method for recovering a titanium component of the present invention. In FIG. 1, a waste liquid 10 containing a titanium compound is transferred to a water receiving tank 1, water 11 is supplied into the water receiving tank 1, and the water 11 is mixed with the waste liquid 10 containing a titanium compound for hydrolysis treatment. Apply. Next, the treated liquid of the hydrolyzed waste 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 liquid in the primary neutralization treatment tank 2 is A primary neutralization treatment is carried out so that the pH of the waste liquid from is 1.5 or more and less than 2.5. Next, the treated 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 is Secondary neutralization treatment is performed so that the pH of the waste liquid in 3 becomes 2.5 or more and 7.5 or less. Next, the treated liquid subjected to the secondary neutralization treatment is transferred to the flocculation tank 4, a flocculant is added to the flocculation tank 4, and the titanium hydroxide is flocculated, and then transferred to the precipitation tank 5 to precipitate. A titanium hydroxide agglomerate is allowed to settle in the tank 5 . The precipitated titanium hydroxide agglomerates are then transferred to sediment storage tank 6 . Next, the precipitate is transferred to an acid treatment tank 7, and hydrochloric acid 14 is supplied to the acid treatment tank 7 to acid-treat the titanium hydroxide agglomerate, thereby obtaining a suspension containing the acid-treated titanium hydroxide agglomerate. A turbid liquid is obtained. Next, the suspension containing the acid-treated titanium hydroxide agglomerates is subjected to a primary pressing step, a penetration washing step, and a secondary pressing step using a filter press device 8 to obtain a press cake 20 of titanium hydroxide agglomerates. get In the embodiment shown in FIG. 1, among the above steps, the step of obtaining titanium hydroxide aggregates from the waste liquid containing the titanium compound is referred to as the titanium hydroxide aggregation treatment step. The details of the titanium hydroxide aggregation treatment step and the acid treatment step will be described later.

In the method for recovering a titanium component of the present invention, the object to be subjected to the method for recovering a titanium component is waste liquid containing a titanium compound, and is not particularly limited as long as it contains a titanium compound. As the waste liquid containing a titanium compound, "a waste liquid containing titanium" generated during preparation of a solid catalyst component for olefin polymerization or a catalyst for olefin polymerization is preferable.

In the method for recovering a titanium component of the present invention, when the waste liquid containing a titanium compound is a waste liquid containing titanium generated during the preparation of a solid catalyst component for olefin polymerization or a catalyst for olefin polymerization, it is suitable for olefin polymerization. The solid catalyst component or catalyst for olefin polymerization is not particularly limited as long as it is a solid catalyst component or catalyst containing a titanium component that is used for the polymerization of olefins. For example, Ziegler-Natta catalysts and metallocene catalysts used for polyolefin production , Postmetallocene, catalysts such as solid titanium catalysts for polyethylene terephthalate production, and one or more selected from solid catalyst components constituting these catalysts. Among them, Ziegler-Natta catalysts used for polyolefin production , metallocene catalysts, post-metallocene catalysts, and solid catalyst components constituting these catalysts are preferable, and Ziegler-Natta catalysts or solid catalyst components constituting Ziegler-Natta catalysts are more preferable.

The Ziegler-Natta catalyst or the solid catalyst component constituting the Ziegler-Natta catalyst includes, among the above, a magnesium compound, a titanium compound, a halogen compound, and, if necessary, an electron-donating compound. is preferred.

As the magnesium compound used for the preparation of the above-mentioned solid catalyst component for polymerization of olefins, it is preferable to use a magnesium compound containing halogen or a magnesium compound which can be converted into a halogen-containing magnesium compound by contact reaction with a halogen-containing compound.
Examples of such magnesium compounds include one or more selected from magnesium dihalides such as magnesium chloride, dialkylmagnesium such as alkoxymagnesium halides, dialkoxymagnesium such as alkylmagnesium halides and diethoxymagnesium, and magnesium chloride. Or diethoxymagnesium is preferred.

As the titanium compound related to the method for recovering the titanium component of the present invention, for example, the following general formula (1):
Ti(OR) _{Nx4 -N} (1)
(In the formula, R is a hydrocarbon group, X is a halogen atom, and when there are multiple Xs, each X may be the same or different, and N is an integer of 0 to 4. ) and titanium compounds represented by

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. ∼4 hydrocarbon groups are more preferred.

Specific examples of the titanium compound represented by the general formula (1) include titanium tetrahalides such as titanium tetrachloride, titanium tetrafluoride, titanium tetrabromide, titanium tetraiodide, methoxytitanium trichloride, ethoxy Alkoxytitanium trihalides such as titanium trichloride, propoxytitanium trichloride and N-butoxytitanium trichloride, dialkoxytitanium dihalides such as dimethoxytitanium dichloride, diethoxytitanium dichloride, dipropoxytitanium dichloride and di-N-butoxytitanium dichloride , tetraalkoxytitanium such as alkoxytitanium halide such as trimethoxytitanium chloride, triethoxytitanium chloride, tripropoxytitanium chloride, tri-N-butoxytitanium chloride and other trialkoxytitanium halides.

Among the above titanium compounds, halogen-containing titanium compounds are preferred, titanium tetrahalides selected from titanium tetrachloride, titanium tetrafluoride, titanium tetrabromide, titanium tetraiodide and the like are more preferred, and titanium tetrachloride is even more preferred.
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 alcohols, phenols, ketones, aldehydes, carboxylic acids, acid halides, organic acids or inorganic acids. One or more selected from esters, ethers, acid amides, acid anhydrides, ammonia, amines, nitriles, isocyanates, nitrogen-containing cyclic compounds, oxygen-containing cyclic compounds, organosilicon compounds, and the like.

In the method for recovering the titanium component of the present invention, the waste liquid containing the titanium compound is used in the preparation process of the solid catalyst component for olefin polymerization. , hexane, heptane, octane, nonane, decane, dodecane, kerosene, cyclopentane, cyclohexane, methylcyclopentane, methylcyclohexane, ethylcyclohexane, 1,2-diethylcyclohexane, methylcyclohexene, decalin, saturated hydrocarbon compounds such as mineral oil , benzene, toluene, xylene, ethylbenzene and other aromatic hydrocarbon compounds, ortho-dichlorobenzene, methylene chloride, 1,2-dichlorobenzene, carbon tetrachloride, dichloroethane, ethylene chloride, chlorobenzene, dichloromethane and other halogenated hydrocarbons Compounds may contain one or more organic solvent components selected from aluminum compounds, silicon compounds and the like.

In the method for recovering a titanium component of the present invention, the waste liquid 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 is electron-donating. Those containing compounds and organic solvent components are preferred.

In the method for recovering the titanium component of the present invention, the waste liquid containing the titanium compound is the waste liquid generated by various reactions, for example, the waste liquid generated during the preparation of the solid catalyst component for olefin polymerization and the catalyst for olefin polymerization. and is not particularly limited as long as it contains a titanium compound. The wastewater containing a titanium compound is preferably a wastewater generated during the preparation of a solid catalyst component for olefin polymerization or a catalyst for olefin polymerization. and other titanium compounds newly generated by reactions during the preparation process. In the method for recovering a titanium component of the present invention, the waste liquid containing a titanium compound preferably contains 0.01 to 35.0% by mass, more preferably 0.05 to 10.0% by mass, of the titanium compound. More preferably, it contains 0.10 to 5.0% by mass.

The details of the method for recovering the titanium component of the present invention will be described below with reference to FIG. In the method for recovering the titanium component according to the present invention, the suspension containing the acid-treated titanium hydroxide agglomerate in the acid treatment tank 7 is treated in the filter press device 8 . Then, as shown in FIG. 2, in the method for recovering the titanium component according to the present invention, the suspension containing the acid-treated titanium hydroxide agglomerate is washed with water in the filter press device 8 without pre-washing. A suspension containing an acid-treated titanium oxide agglomerate is subjected to a primary pressing step, a penetration washing step and a secondary pressing step to wash the agglomerate of titanium hydroxide, and acid-treat the agglomerate of titanium hydroxide. Get a cake of things. Next, a cake discharge step is performed in which the obtained titanium hydroxide agglomerate is taken out of the filter press apparatus. That is, in the method for recovering a titanium component of the present invention, a waste liquid containing a titanium compound is subjected to a titanium hydroxide aggregation treatment step and an acid treatment step, and a suspension containing an acid-treated titanium hydroxide aggregate is obtained. The liquid is subjected to the primary pressing process, the penetration cleaning process and the secondary pressing process without being subjected to forward washing.

As the suspension containing the acid-treated titanium hydroxide aggregate according to the method for recovering the titanium component of the present invention, the waste liquid containing the titanium compound is at least hydrolyzed, and calcium hydroxide or calcium hydroxide is used as a neutralizing agent. A primary neutralization treatment using calcium oxide, a secondary neutralization treatment using calcium hydroxide or calcium oxide as a neutralizing agent, and an aggregating treatment for aggregating titanium hydroxide are performed to form titanium hydroxide agglomerates. A titanium hydroxide agglomeration treatment step to obtain titanium hydroxide agglomeration treatment, and an acid treatment of contacting the titanium hydroxide agglomerate with hydrochloric acid or titanium chloride in the latter stage of the titanium hydroxide agglomeration treatment step to obtain titanium hydroxide agglomeration, which is an agglomerate of titanium hydroxide. and an acid treatment step of obtaining a suspension containing an acid-treated titanium hydroxide agglomerate. The titanium hydroxide aggregation treatment step and the acid treatment step will be described later.

The primary compression step according to the method for recovering the titanium component of the present invention includes a pressurized filtration chamber, and a compression section provided inside the pressurized filtration chamber, having a filtration membrane, and filled with a substance to be filtered. A suspension containing an acid-treated titanium hydroxide agglomerate is fed into the space in the compression section of the filter press device having , and the compression section is filled with the suspension containing the acid-treated titanium hydroxide agglomerate. Next, the compression part and the suspension are compressed at 0.10 to 1.00 MPa in a pressurized filtration chamber to remove water from the suspension, and the primary compressed product of the acid-treated titanium hydroxide aggregate is obtained. is the process of obtaining

As shown in FIG. 3, the filter press device 8 is provided inside the filtration chamber 31 and the pressurized filtration chamber 31, and constitutes a compression section 36 having a filtration membrane 32 and a part of the partition wall of the filtration chamber 31. a filter plate 33 , another portion 35 of the partition wall of the filtration chamber 31 , and a compression membrane 34 provided in the filtration chamber 31 and configured to be movable so as to pressurize the inside of the filtration chamber 31 . The compression unit 36 has a filtration membrane 32, and the filtration membrane 32 is located at a position where the suspension containing the acid-treated titanium hydroxide agglomerate is sandwiched at least during the primary compression step, that is, the suspension. This is a position between the turbid liquid and the filter plate 33, and is arranged at a position where washing water is supplied to or discharged from the primary pressed product of the acid-treated titanium hydroxide aggregate during penetration washing. The filtration membrane 32 is a general filtration membrane for filter press devices, and is made of a material such as polyester, nylon-6, or polypropylene.

The filter plate 33 and the compression membrane 34 may have an uneven surface at a location that contacts the filtration membrane 32 . The compression film 34 can be moved back and forth by a diaphragm mechanism (not shown) or the like. By driving the diaphragm mechanism, the compression membrane 34 advances with respect to the filtration membrane 32, thereby squeezing and filtering the suspension containing the acid-treated titanium hydroxide agglomerate in the filtration membrane 32 to remove the Moisture can be removed. As a result, a primary pressed product of the acid-treated titanium hydroxide agglomerate can be obtained.

In the primary pressing step, first, an acid-treated titanium hydroxide agglomerate is placed in a space within a compression section of a filter press device having a pressure-type filtration chamber and a compression section provided inside the pressure-type filtration chamber. A suspension containing titanium hydroxide agglomerate is fed, and the compression section is filled with the suspension containing an acid-treated titanium hydroxide aggregate. The compression part has a filtration membrane. The filtration membrane is located at a position where it sandwiches the suspension containing the acid-treated titanium hydroxide agglomerate at least during the primary pressing step, that is, the suspension containing the acid-treated titanium hydroxide agglomerate and the hydroxide. It is a position between a member that applies a pressing force to the suspension containing the acid-treated titanium hydroxide agglomerate, and during the penetration cleaning, the primary squeezed product of the acid-treated titanium hydroxide agglomerate is added with washing water. is placed at the position where the is supplied or discharged.

The suspension of the acid-treated titanium hydroxide agglomerate is filled into the compression section so that the acid-treated titanium hydroxide agglomerate in the filtration chamber is in a homogeneous state as a whole. In the case of a suspension containing acid-treated titanium hydroxide aggregates, the suspension (cake) of the acid-treated titanium hydroxide aggregates often fills the filtering chamber (compressing section). In such a state that the suspension (cake) of the acid-treated titanium hydroxide agglomerate is filled, the suspension (cake) of the acid-treated titanium hydroxide agglomerate contains It is not possible to secure a cleansing water flow path. Therefore, in the case of a suspension (cake) containing an acid-treated titanium hydroxide agglomerate, first, the suspension of the acid-treated titanium hydroxide agglomerate is first pressed to obtain a hydroxylation. It is suitable to make the acid-treated titanium agglomerate into a cake and then perform the penetration cleaning described below. In general, penetration cleaning has the advantage of requiring less cleaning water than normal cleaning.

In the first pressing step, the compressed portion and the suspension are then pressed at 0.10 to 1.00 MPa in a pressurized filtration chamber to remove moisture from the suspension, and acid-treated titanium hydroxide aggregates. to obtain a primary press of The pressing pressure in the first pressing step is 0.10 to 1.00 MPa, preferably 0.20 to 1.00 MPa, more preferably 0.30 to 1.00 MPa. The pressing time in the primary pressing step is 30 seconds to 10 minutes, preferably 1 to 5 minutes, most preferably 2 to 4 minutes.

The filter press device used in the primary compression step has a pressurized filtration chamber, pressurizes the compression part filled with the object to be filtered in the filtration chamber, and presses the filtrate in the object to be filtered through the filtration membrane of the compression part. It is not particularly limited as long as it can be separated by filtration and the penetration cleaning described later can be performed on the filtration target in the filtration chamber after performing the primary compression. Examples of such a filter press include Model HJMF manufactured by Kurita Machinery Co., Ltd. and Model ISD manufactured by Ishigaki.

The filtration membrane of the compression part provided in the filter press device is capable of separating the filtrate from the object to be filtered by filtration during the primary compression and secondary compression, and is capable of supplying or supplying washing water during penetration washing. The material is not particularly limited as long as it can be discharged and through-cleaned, and examples of the material include polyester, nylon, polypropylene, and the like.

In the through cleaning step according to the method for recovering the titanium component of the present invention, cleaning water is supplied to the inside of the pressurized filtration chamber and the outside of the filtration membrane of the compression section to remove titanium hydroxide aggregates in the compression section and its interior. A washing liquid is passed through the primary pressed acid-treated product to penetrate and wash the primary pressed acid-treated titanium hydroxide aggregate, and the through-washed acid-treated titanium hydroxide aggregate. is the process of obtaining

Penetration cleaning in the penetration cleaning step will be described with reference to FIG. In through cleaning, as indicated by arrows in FIG. 3, cleaning water is supplied from the filtration membrane 32 on the compression membrane 34 side, for example. At that time, the wash water passes through the filtration membrane 32 and the primary pressed product (cake) of the acid-treated titanium hydroxide aggregate, as indicated by the arrows in the figure. As a result, the mother liquor of the primary pressed product of the acid-treated titanium hydroxide agglomerate is replaced with the washing water. The washing water replaced in the primary compressed product of the flocculate flows into the filtration chamber 31 from the filtration membrane 32 on the side of the filter plate 33 opposite to the side of the compression membrane 34, for example, as indicated by the arrow in the figure. Ejected. The wash water discharged into the filter chamber 31 is appropriately discharged to the outside of the filter chamber 31 through the discharge channel.

The washing water in the through washing step is not particularly limited as long as it can wash titanium hydroxide without deteriorating its properties. Examples include ion-exchanged water, pure water, ultrapure water, industrial water, well water, and tap water. water and the like. The pressure of the washing water in the through washing step is 0.10 to 1.00 MPa, preferably 0.20 to 0.70 MPa, more preferably 0.30 to 0.70 MPa. The washing time in the through washing step is 17-60 minutes, preferably 18-27 minutes, most preferably 20-25 minutes. Even if the washing time is 60 minutes or longer, the washing effect can be ensured, but washing for 60 minutes is sufficient from the viewpoint of reducing industrial costs and protecting water resources.

The pH of the cleaning water used in the penetration cleaning step may be any pH that allows cleaning without deteriorating the titanium hydroxide, and is usually 6.0 or more and 9.0 or less.

The temperature during penetration 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.

Next, with reference to FIG. 4, forward cleaning will be described as a counterpoint to penetration cleaning. In forward washing, washing water is supplied using a supply line that supplies suspension containing an acid-treated titanium hydroxide aggregate into the filtration chamber 31 . In the forward washing, washing water is supplied to the central portion of the filtration membrane 32 in a state where the inside of the filtration membrane 32 is not completely filled with the suspension (cake) of the acid-treated titanium hydroxide aggregate, and the cake is A channel for washing water is formed in the center of the This allows the wash water to pass in the same direction as the filtration. The wash water passes through the cake in the direction of the filter membrane, as indicated by the arrows in FIG. , is discharged into the filtration chamber 31 . The wash water discharged into the filter chamber 31 is appropriately discharged to the outside of the filter chamber 31 through the discharge channel. Since the thickness of the cake is thinner in forward cleaning, the cleaning time is shorter than in through cleaning if the cleaning pressure and the flow rate of cleaning water are the same.

In the secondary squeezing step related to the method for recovering the titanium component according to the present invention, the compression part and the acid-treated titanium hydroxide agglomerate are squeezed by a pressurized filtration chamber to compress the titanium hydroxide agglomerate. This is a step of obtaining an acid-treated cake of titanium hydroxide agglomerates by removing moisture from the perforated wash of the acid-treated product.

For example, after penetrating cleaning, the pressurized filter chamber 31 presses the compressing portion 36 and the acid-treated titanium hydroxide agglomerate, and presses the acid-treated titanium hydroxide agglomerate. Removal of water from the permeate wash yields an acid treated cake of titanium hydroxide agglomerates.

The pressing pressure in the secondary pressing step is equal to or higher than the pressing pressure in the primary pressing step. More specifically, the pressing pressure in the secondary pressing step of the present invention is preferably 0.10 to 1.00 MPa, more preferably 0.20 to 1.00 MPa, and 0.30 to 1.00 MPa. 00 MPa is more preferable.

The pressing time in the secondary pressing step is preferably longer than the pressing time in the primary pressing step. More specifically, the pressing time in the secondary pressing step is preferably 3 to 14 minutes, more preferably 5 to 12 minutes, even more preferably 6 to 11 minutes, and 7 to 10 minutes. is most preferred.

In the secondary pressing process, similarly to the primary pressing process, the pressing membrane 34 can be advanced and retracted by a diaphragm mechanism (not shown) or the like. By driving the diaphragm mechanism, the compression film 34 advances with respect to the compression section 36, thereby squeezing and filtering the acid-treated titanium hydroxide agglomerates in the compression section 36, thereby squeezing and filtering the titanium hydroxide agglomerates. water can be removed from the acid-treated product of As a result, a cake of acid-treated titanium hydroxide aggregates can be obtained.

Next, each step in the titanium hydroxide aggregation treatment step will be described. In the method for recovering a titanium component of the present invention, the suspension of the acid-treated titanium hydroxide agglomerate treated in the primary pressing step is applied to the waste liquid containing the titanium compound in the titanium hydroxide agglomeration treatment step and It is a suspension of an acid-treated titanium hydroxide agglomerate obtained by performing an acid treatment step. The titanium hydroxide flocculation treatment step has a step A in which the titanium compound-containing waste liquid is brought into contact with water to hydrolyze the titanium compound. In the step A, the hydrolysis method is not particularly limited, and examples include a method of contacting the waste water with separately injected water in a water receiving tank for receiving the waste water.

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

In the hydrolysis treatment according to step A, the pH of the mixture of the titanium compound-containing waste liquid and water is preferably 0.5 or more and 2.0 or less, and is 0.7 or more and 1.5 or less. is more preferable, and about 1.0 is even more preferable. When the pH of the mixed liquid of the waste liquid containing the titanium compound and water is within the above range, the titanium hydroxide produced in the mixed liquid is less likely to precipitate, and the subsequent treatment can be performed smoothly.

In step A, the amount of water to be brought into contact with the titanium compound-containing waste liquid is preferably 3 to 10 m ³ , more preferably 4 to 7 m ³ , per 1 m ³ of the titanium compound-containing waste liquid. More preferably ~6 m ³ .

In step A, 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 step A, the contact time between the titanium compound-containing waste liquid and water is preferably 30 to 60 minutes, more preferably 35 to 55 minutes, and even more preferably 40 to 50 minutes.

The titanium hydroxide aggregation treatment step has a step B. In step B, which relates to the titanium hydroxide flocculation treatment step, the waste liquid that has undergone hydrolysis treatment in step A is subjected to primary neutralization treatment and then to secondary neutralization treatment to obtain titanium hydroxide. be.

In step B, first, a primary neutralization treatment is performed by adding calcium hydroxide or calcium oxide to the treated liquid of the wastewater that has been hydrolyzed in step A so that the pH becomes 1.5 or more and less than 2.5. Apply.

In the primary neutralization treatment, the treated liquid of the wastewater that has been hydrolyzed in step A has a pH of 1.5 or more and less than 2.5, preferably 1.8 or more and 2.3 or less. Calcium hydroxide or calcium oxide is added so that the pH becomes 1.8 or more and 2.2 or less. When the pH in the primary neutralization treatment is within the above range, aggregation and sedimentation are likely to occur, making it easy to recover a high-purity titanium component from the titanium compound-containing waste liquid. On the other hand, if the pH during the primary neutralization treatment is less than the above range, smooth neutralization treatment becomes difficult. Reduces filterability.

The neutralizing agent used in the primary neutralization treatment is calcium hydroxide or calcium oxide. By using calcium hydroxide or calcium oxide as a neutralizing agent in the primary neutralization treatment, the cost of the neutralizing agent can be suppressed, and the sedimentation and filterability of the titanium compound obtained by neutralization are improved. has the advantage of On the other hand, when 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 sedimentation and filterability of the titanium compound obtained by neutralization deteriorate. deteriorate and become industrially disadvantageous.

In the primary neutralization treatment, a suspension in which calcium hydroxide or calcium oxide is dispersed in water is brought into contact with the treatment liquid of the hydrolyzed wastewater. 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 waste liquid can be easily controlled within the desired range. On the other hand, if the content of calcium hydroxide in the suspension exceeds the above range, it will be difficult to control the pH of the hydrolyzed waste liquid, and if it is less than the above range, smooth neutralization will occur. difficult to perform.

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 treatment solution of the hydrolyzed wastewater and calcium hydroxide or calcium oxide is not particularly limited, but is usually about 60 to 120 minutes.

In step B, as a method of performing the primary neutralization treatment, calcium hydroxide or calcium oxide is brought into contact with the treated liquid of the hydrolyzed wastewater in a neutralization tank (primary neutralization treatment tank). The primary neutralization treatment tank may be one tank, or a plurality of tanks may be connected.

In step B, secondary neutralization is then performed by adding calcium hydroxide or calcium oxide to the treated liquid that has been subjected to primary neutralization so that the pH becomes 6.5 or more and 7.5 or less.

During the secondary neutralization treatment in step B, calcium hydroxide or calcium oxide is added to the treatment liquid that has been subjected to the primary neutralization treatment so that the pH becomes 2.5 or more and 7.5 or less. Then, at the time of the secondary neutralization treatment in step B, the treated liquid subjected to the primary neutralization treatment preferably has a pH of 3.0 to 7 so that the pH is 2.5 or more and 7.5 or less. Calcium hydroxide or calcium oxide is added to give a pH of .5, more preferably a pH of 3.5 to 7.5, more preferably a pH of 6.5 to 7.5.

When the pH in the secondary neutralization treatment is within the above range, the calcium content in the titanium hydroxide agglomerate obtained through the flocculation treatment is reduced, and flocculation and sedimentation are likely to occur, resulting in a titanium compound-containing It becomes easy to recover the titanium component with high purity from the waste liquid. On the other hand, if the pH during the secondary neutralization treatment is less than the above range, titanium hydroxide will be difficult to precipitate, and if it exceeds the above range, the resulting titanium hydroxide will contain too much calcium.

A neutralizing agent used in the secondary neutralization treatment is calcium hydroxide or calcium oxide. By using calcium hydroxide or calcium oxide as a neutralizing agent in the secondary neutralization treatment, the cost of the neutralizing agent can be suppressed, and the sedimentation and filterability of the titanium compound obtained by neutralization are improved. have 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 sedimentation and filterability of the titanium compound that can be neutralized. becomes worse and is industrially disadvantageous.

In the secondary neutralization treatment, a suspension of calcium hydroxide or calcium oxide dispersed in water is brought into contact with the treatment liquid that has undergone 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 within the above range, the pH of the hydrolyzed waste liquid can be easily controlled within the desired range. On the other hand, if the content of calcium hydroxide in the suspension exceeds the above range, it will be difficult to control the pH of the hydrolyzed waste liquid, and if it is less than the above range, smooth neutralization will occur. difficult to perform.

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 step B, as a method of performing secondary neutralization treatment, calcium hydroxide or calcium oxide is brought into contact with the treatment liquid that has been subjected to primary neutralization treatment in a neutralization tank (secondary neutralization treatment tank). The secondary neutralization treatment tank may be one tank, or a plurality of tanks may be connected.

Moreover, it is preferable that calcium hydroxide is not contained in the treatment liquid after the secondary neutralization treatment. The content of calcium hydroxide in the treated liquid after the secondary neutralization treatment is adjusted by the amount of neutralizing agent added in the secondary neutralization treatment, the pH setting value in the secondary neutralization treatment, and the like. be.

The titanium hydroxide aggregation treatment step has a step C. In the step C related to the titanium hydroxide flocculation treatment step, the treatment liquid subjected to the secondary neutralization treatment in the step B is subjected to flocculation treatment to flocculate the titanium hydroxide in the treatment liquid to obtain a titanium hydroxide flocculation. is the process of obtaining The flocculation treatment is preferably performed using a flocculant such as an anionic polymer flocculant.

In step C, when the titanium hydroxide in the treatment liquid subjected to the secondary neutralization treatment is aggregated using a flocculant, the treatment liquid subjected to the secondary neutralization treatment is added with an anionic polymer flocculant or the like. By adding a flocculating agent to flocculate titanium hydroxide, titanium hydroxide is obtained in the form of titanium hydroxide aggregates. Aggregation of titanium hydroxide is preferably carried out in a flocculation tank by feeding the treatment liquid that has undergone secondary neutralization treatment into the flocculation tank. Then, by performing the aggregation treatment, titanium hydroxide aggregates are produced.

In step C, the aqueous phase obtained after separating the titanium hydroxide is preferably adjusted to neutral acidity (pH 6.5 to 7.5) and then appropriately treated as a waste liquid.

In the method for recovering a titanium component of the present invention, wastewater containing a titanium compound is subjected to hydrolysis treatment, then using calcium hydroxide or calcium oxide as a neutralizing agent at a specific pH for primary neutralization and secondary neutralization. By successively applying the sum treatment, the calcium content in the resulting titanium hydroxide can be reduced, making it easier to agglomerate or precipitate the titanium hydroxide. can be done. In the method for recovering the titanium component of the present invention, the pH of the secondary neutralization treatment is adjusted to 2.5 or more and 7.5 or less, preferably 3.0 to 7.5, more preferably 3.0 to 7.5. .5 to 7.5, more preferably 6.5 to 7.5, reduces unreacted calcium hydroxide and forms titanium hydroxide with good agglomeration or sedimentation properties. Therefore, the calcium content in titanium hydroxide or titanium hydroxide aggregates can be reduced, and titanium hydroxide can be easily aggregated or precipitated. From the above, it is considered that the titanium component recovery method of the present invention can recover titanium hydroxide having a low calcium content.

In the method for recovering the titanium component of the present invention, after performing the titanium hydroxide aggregation treatment step, the resulting titanium hydroxide aggregate is allowed to settle in the sedimentation tank, and the sediment of the titanium hydroxide aggregate in the sedimentation tank is obtained. is withdrawn to separate the titanium hydroxide agglomerate in the form of a sediment of the titanium hydroxide agglomerate. The sediment of this titanium hydroxide agglomerate contains a liquid phase derived from the treatment up to that point. It may be provided after removing the liquid phase inside, or may be provided without removing the liquid phase in the sediment of titanium hydroxide aggregates.

In the method for recovering a titanium component of the present invention, in the treatment step subsequent to the titanium hydroxide aggregation treatment step and prior to the primary pressing step, the titanium hydroxide agglomerates are subjected to acid treatment by contacting them with hydrochloric acid or titanium chloride. carry out the process. In the method for recovering the titanium component of the present invention, the timing of performing the acid treatment step is not particularly limited as long as it is after the titanium hydroxide aggregation treatment step and before the primary pressing step. In the method for recovering the titanium component of the present invention, the calcium content in the titanium hydroxide agglomerate can be reduced by bringing the agglomerate of titanium hydroxide into contact with hydrochloric acid or titanium chloride.

In the acid treatment step according to the method for recovering a titanium component of the present invention, the titanium hydroxide agglomerate obtained by the titanium hydroxide agglomeration treatment step is brought into contact with hydrochloric acid or titanium chloride. Hydrochloric acid or titanium chloride is brought into contact so that it becomes 5.9 or less. When the pH of the liquid phase during the acid treatment is within the above range, the calcium content in the titanium hydroxide aggregates can be reduced. On the other hand, when 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 titanium hydroxide aggregates. The upper limit of the pH of the liquid phase during acid treatment is preferably 5.7 or less, more preferably 5.5 or less, and still more preferably 5.3 or less. The lower limit of the pH of the liquid phase during acid treatment is preferably 2.0 or higher, more preferably 3.0 or higher.

The acid used for acid treatment is hydrochloric acid or titanium chloride. Titanium chloride hydrolyzes to produce hydrochloric acid and titanium hydroxide when the pH of the liquid phase is 2.0 or higher. The same acid treatment effect as that obtained by As the titanium chloride, a waste liquid containing a titanium compound in which the titanium compound is a titanium chloride is preferable because the production cost can be reduced.

The concentration of hydrochloric acid used for acid treatment is not particularly limited, but is preferably 1.0 to 13.0 mol/L, more preferably 1.5 to 12.0 mol/L, and 2.7 to 12.0 mol/L. 0 mol/L is more preferred. 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 the 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 below the above range, it becomes difficult to carry out the acid treatment smoothly.

The concentration of titanium chloride used for acid treatment is not particularly limited, but the concentration of hydrochloric acid generated by hydrolysis is preferably 1.0 to 13.0 mol/L, more preferably 1.5 to 12.0 mol/L, More preferably, the concentration is 2.7 to 12.0 mol/L.

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

In the acid treatment, the contact time between the titanium hydroxide agglomerates obtained by the titanium hydroxide aggregating treatment step and hydrochloric acid or titanium chloride is preferably 10 minutes or longer, more preferably 20 minutes or longer, and even more preferably 30 minutes or longer. , more preferably 60 minutes or longer.

In the method for recovering the titanium component of the present invention, the acid treatment step may be performed by any method as long as the titanium hydroxide agglomerate and hydrochloric acid are brought into contact with each other. Examples of the acid treatment step include the following forms.

In the method for recovering a titanium component according to the first aspect of the present invention, the titanium hydroxide aggregating step is performed to obtain a concentrate of the titanium hydroxide agglomerate, followed by separating the concentrate of the titanium hydroxide agglomerate. This embodiment has an acid treatment step (A) in which a concentrated titanium hydroxide agglomerate is brought into contact with hydrochloric acid to acid-treat the agglomerate of titanium hydroxide to obtain an acid-treated product of the agglomerate of titanium hydroxide.

An embodiment having a titanium hydroxide aggregating step and an acid treatment step (A) according to the method for recovering a titanium component according to the first aspect of the present invention will be described with reference to FIG. FIG. 5 is a flow diagram of an example of a titanium hydroxide aggregating step and an acid treatment step (A) according to the method for recovering a titanium component according to the first embodiment of the present invention. Here, too, an embodiment in which calcium hydroxide is applied as a neutralizing agent will be described as an example. effect is obtained. In FIG. 5, a waste liquid 10 containing a titanium compound is transferred to a water receiving tank 1, water 11 is supplied into the water receiving tank 1, and the water 11 and the waste liquid 10 containing a titanium compound are mixed to perform a hydrolysis treatment. Apply. Next, the hydrolyzed treated liquid is transferred to the primary neutralization tank 2, the calcium hydroxide suspension 12 is supplied to the primary neutralization tank 2, and the treated liquid in the primary neutralization tank 2 is A primary neutralization treatment is performed so that the pH of the solution becomes 1.5 or more and less than 2.5. Next, the treated 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 is A secondary neutralization treatment is performed so that the pH of the treatment liquid in 3 becomes 2.5 or more and 7.5 or less. Next, the treated liquid subjected to the secondary neutralization treatment is transferred to the flocculation tank 4, and a flocculating agent is added to the flocculation tank 4 to flocculate the titanium hydroxide to form a titanium hydroxide agglomerate. . Next, the resulting coagulation treatment liquid containing the titanium hydroxide aggregates is transferred to the sedimentation tank 5, where the titanium hydroxide aggregates are allowed to settle. Extract the sediment of titanium agglomerates. Next, the sediment of titanium hydroxide agglomerates extracted from the sedimentation tank 5 is transferred to the sediment storage tank 6 . Next, the sediment of the titanium hydroxide agglomerate is filtered using a filter press device 81 to remove the liquid phase from the sediment of the titanium hydroxide agglomerate, filter out the titanium hydroxide agglomerate, and A press cake of titanium agglomerates is obtained. Next, the press cake of titanium hydroxide agglomerates is transferred to an acid treatment tank 7, and hydrochloric acid 14 is supplied to the acid treatment tank 7, and the titanium hydroxide agglomerates and hydrochloric acid 14 are mixed and acid treated. Next, the suspension containing the acid-treated titanium hydroxide agglomerates is subjected to a primary pressing step, a penetration washing step and a secondary pressing step using a filter press device 82 to acid-treat the titanium hydroxide agglomerates. The substance is washed and the liquid phase is removed, and the acid-treated titanium hydroxide agglomerate is filtered to obtain a press cake 21 of the acid-treated titanium hydroxide agglomerate.

A method for recovering a titanium component according to the first aspect of the present invention includes a titanium hydroxide aggregation treatment step and an acid treatment step (A). The neutralization treatment, the primary neutralization treatment, the secondary neutralization treatment and the aggregation treatment of the titanium hydroxide coagulation treatment step according to the method for recovering the titanium component of the first embodiment of the present invention are the same as the method for recovering the titanium compound of the present invention. The details are the same as those of the method for recovering the titanium component of the present invention.

In the acid treatment step (A) according to the method for recovering a titanium component according to the first aspect of the present invention, after obtaining a concentrate of titanium hydroxide agglomerates produced by performing the titanium hydroxide agglomeration treatment step, A concentrate of titanium agglomerates is separated from the agglomeration treatment liquid.

In the acid treatment step (A), the method for obtaining a concentrate of titanium hydroxide agglomerates from the aggregating treatment liquid containing the titanium hydroxide agglomerates after the titanium hydroxide aggregating treatment step is not particularly limited. For example, first, the aggregating treatment liquid containing the titanium hydroxide agglomerates after the (i) titanium hydroxide aggregating treatment step is carried out is transferred to a sedimentation tank, and the titanium hydroxide agglomerates are allowed to settle in the sedimentation tank. Next, (ii) the sediment of the titanium hydroxide agglomerate is extracted from the bottom or bottom of the sedimentation tank, the sediment of the titanium hydroxide agglomerate is separated from the flocculation treatment liquid, and the titanium hydroxide agglomerate extracted from the sedimentation tank. The sediment of matter is transferred to a sediment reservoir to obtain a sediment of titanium hydroxide agglomerates, ie, a concentrate of titanium hydroxide agglomerates.

In addition, in the acid treatment step (A), there are other methods for obtaining a concentrate of titanium hydroxide agglomerates from the flocculation treatment liquid containing the titanium hydroxide agglomerates after the titanium hydroxide agglomeration treatment step has been performed. For example, the aggregating treatment liquid containing titanium hydroxide agglomerates after the titanium hydroxide aggregating treatment step is treated with a liquid cyclone, a screw decanter, or the like to separate the aqueous phase from the aggregating treatment liquid, and titanium hydroxide A method for obtaining agglomerate concentrates is included.

Further, in the acid treatment step (A), as a method for obtaining a concentrate of titanium hydroxide agglomerates from a flocculation treatment liquid containing titanium hydroxide agglomerates after performing the titanium hydroxide flocculation treatment step, first, water After the titanium oxide agglomeration treatment is performed to settle the resulting titanium hydroxide agglomerate, the sediment of the titanium hydroxide agglomerate is separated from the aggregating treatment liquid, and then the liquid phase is removed from the sediment of the titanium hydroxide agglomerate. dehydration treatment to obtain a dehydrated titanium hydroxide agglomerate, that is, a method for obtaining a dehydrated titanium hydroxide agglomerate concentrate. Examples of the dehydration method include a method of filtering using a solid-liquid separation device such as a filter press device, a centrifugal separator, or a liquid cyclone device.

In the acid treatment step (A), the concentrated titanium hydroxide agglomerate is then brought into contact with hydrochloric acid or titanium chloride to acid-treat the agglomerate of titanium hydroxide.

In the acid treatment in the acid treatment step (A), the dehydrated titanium hydroxide aggregate is brought into contact with hydrochloric acid or titanium chloride. Hydrochloric acid is brought into contact so that it becomes 0 or more and 5.5 or less, more preferably 3.5 or more and 5.0 or less. When the pH of the liquid phase during the acid treatment is within the above range, the calcium content in the titanium hydroxide aggregates can be reduced. On the other hand, when 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 titanium hydroxide aggregates.

The acid used for the acid treatment in the acid treatment step (A) is hydrochloric acid or titanium chloride.

The concentration of hydrochloric acid used for acid treatment in the acid treatment step (A) is not particularly limited, but is preferably 1.0 to 13.0 mol/L, more preferably 1.5 to 12.0 mol/L. It is preferably 2.7 to 12.0 mol/L, and more preferably 2.7 to 12.0 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 the 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 below the above range, it becomes difficult to carry out the acid treatment smoothly.

The concentration of titanium chloride used in the acid treatment step (A) is not particularly limited, but the concentration of hydrochloric acid produced by hydrolysis is preferably 1.0 to 13.0 mol/L, more preferably 1.5 to 12.0 mol/L. The concentration is 0 mol/L, more preferably 2.7 to 12.0 mol/L.

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

In the acid treatment in the acid treatment step (A), the contact time between the concentrated titanium hydroxide aggregate and hydrochloric acid is appropriately selected, but is preferably 10 minutes or longer, more preferably 20 minutes or longer, and 30 minutes or longer. is more preferred.

In the acid treatment step (A), the acid treatment is preferably carried out by bringing the concentrate of titanium hydroxide agglomerate into contact with hydrochloric acid or titanium chloride in an acid treatment tank.

Then, by performing the acid treatment step (A), a suspension of the acid-treated titanium hydroxide aggregate is obtained.

In the titanium hydroxide flocculation treatment step and the acid treatment step (A) according to the method for recovering a titanium component according to the first embodiment of the present invention, waste water containing a titanium compound is subjected to hydrolysis treatment, followed by calcium hydroxide or oxidation Using calcium as a neutralizing agent, primary neutralization treatment, secondary neutralization treatment, and aggregation treatment are sequentially performed at a specific pH to generate titanium hydroxide aggregates, and then the aqueous phase is separated to obtain This is because the calcium content in the titanium hydroxide agglomerate obtained by the acid treatment can be reduced by subjecting the concentrate of the agglomerate of titanium hydroxide to an acid treatment step of contacting with hydrochloric acid or titanium chloride. , titanium hydroxide with low calcium content can be recovered. In the method for recovering a titanium component according to the first aspect of the present invention, the concentrated titanium hydroxide agglomerate generated in the titanium hydroxide agglomeration treatment step is subjected to an acid treatment, whereby the acid treatment of the titanium hydroxide agglomerate is performed. By doing so, the calcium hydroxide remaining in the titanium hydroxide agglomerate and other unreacted substances with poor water solubility such as calcium hydroxide are dissolved, so that the calcium content in the titanium hydroxide agglomerate can be reduced. From the above, it is considered that the titanium component recovery method of the first embodiment of the present invention can recover titanium hydroxide having a low calcium content.

In the method for recovering a titanium component according to the second aspect of the present invention, the titanium hydroxide agglomeration treatment step is performed to precipitate the resulting titanium hydroxide agglomerate, and then hydrochloric acid or titanium chloride is added to the sediment of the titanium hydroxide agglomerate. It is a form having an acid treatment step (B) in which the titanium hydroxide agglomerates are brought into contact with each other to acid-treat the titanium hydroxide agglomerates to obtain an acid-treated product of the titanium hydroxide agglomerates.

An embodiment having a titanium hydroxide aggregation treatment step and an acid treatment step (B) according to the second embodiment of the method for recovering a titanium component of the present invention will be described with reference to FIG. FIG. 6 is a flow diagram of an example of a titanium hydroxide aggregation treatment step and an acid treatment step (B) according to the second embodiment of the titanium component recovery method of the present invention. Here, too, an embodiment in which calcium hydroxide is applied as a neutralizing agent will be described as an example. effect is obtained. In FIG. 6, a waste liquid 10 containing a titanium compound is transferred to a water receiving tank 1, water 11 is supplied into the water receiving tank 1, the waste liquid 10 containing a titanium compound and water 11 are mixed, and hydrolysis treatment is performed. Apply. Next, the hydrolyzed treated liquid is transferred to the primary neutralization tank 2, the calcium hydroxide suspension 12 is supplied to the primary neutralization tank 2, and the treated liquid in the primary neutralization tank 2 is A primary neutralization treatment is performed so that the pH of the solution becomes 1.5 or more and less than 2.5. Next, the treated 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 is A secondary neutralization treatment is performed so that the pH of the treatment liquid in 3 becomes 2.5 or more and 7.5 or less. Next, the treated liquid subjected to the secondary neutralization treatment is transferred to the flocculation tank 4, and a flocculating agent is added to the flocculation tank 4 to flocculate the titanium hydroxide to form a titanium hydroxide agglomerate. . Next, the resulting coagulation treatment liquid containing the titanium hydroxide aggregates is transferred to the sedimentation tank 5, where the titanium hydroxide aggregates are allowed to settle. Extract the sediment of titanium agglomerates. Next, the sediment of the titanium hydroxide agglomerate extracted from the sedimentation tank 5 is transferred to the acid treatment tank 7, and hydrochloric acid 14 is supplied to the acid treatment tank 7 to separate the sediment of the titanium hydroxide agglomerate and the hydrochloric acid 14. Mix and acid treat. Next, the acid-treated titanium hydroxide agglomerate is subjected to a primary pressing step, a penetration washing step and a secondary pressing step using a filter press device 83 to wash and liquid the acid-treated titanium hydroxide agglomerate. The phase is removed, and the acid-treated titanium hydroxide agglomerate is filtered to obtain a press cake 24 of the acid-treated titanium hydroxide agglomerate.

A method for recovering a titanium component according to a second aspect of the present invention includes a titanium hydroxide aggregation treatment step and an acid treatment step (B). The neutralization treatment, the primary neutralization treatment, the secondary neutralization treatment and the aggregation treatment of the titanium hydroxide aggregation treatment process according to the second embodiment of the method for recovering a titanium component of the present invention are the same as the method for recovering a titanium compound of the present invention. The details are the same as those of the method for recovering the titanium component of the present invention.

In the acid treatment step (B) according to the second aspect of the method for recovering a titanium component of the present invention, the titanium hydroxide agglomerates obtained after the titanium hydroxide agglomeration treatment step is carried out and the resulting titanium hydroxide agglomerates are allowed to settle. The precipitate is brought into contact with hydrochloric acid or titanium chloride to acid-treat the titanium hydroxide agglomerate to obtain an acid-treated titanium hydroxide agglomerate.

In the acid treatment step (B), the method for obtaining the precipitate of the titanium hydroxide agglomerate from the aggregating treatment liquid containing the titanium hydroxide aggregating treatment after the titanium hydroxide aggregating treatment step is not particularly limited. For example, first, (i) the aggregating treatment liquid containing titanium hydroxide agglomerates after the titanium hydroxide aggregating treatment is transferred to a sedimentation tank, and the titanium hydroxide agglomerates are allowed to settle in the sedimentation tank. Next, (ii) a method of withdrawing the sediment of the titanium hydroxide agglomerate from the bottom or bottom of the sedimentation tank and transferring the sediment of the titanium hydroxide agglomerate withdrawn from the sedimentation tank to the acid treatment tank.

Further, in the acid treatment step (B), a method for obtaining a sediment of titanium hydroxide agglomerates from a flocculation treatment solution containing titanium hydroxide agglomerates after performing the titanium hydroxide flocculation treatment step includes titanium hydroxide After the coagulation treatment, the coagulation treatment liquid containing the titanium hydroxide agglomerates is treated with a thickener, a liquid cyclone, a screw decanter, or the like to separate the water phase from the agglomeration treatment liquid, thereby obtaining a sediment of the titanium hydroxide agglomerates. is obtained.

In the acid treatment step (B), the sediment of the titanium hydroxide agglomerate is then brought into contact with hydrochloric acid or titanium chloride to acid-treat the titanium hydroxide agglomerate, resulting in an acid-treated titanium hydroxide agglomerate. to obtain a suspension of

In the acid treatment in the acid treatment step (B), the sediment of titanium hydroxide aggregates is brought into contact with hydrochloric acid or titanium chloride. At this time, the pH of the liquid phase is 5.0 or less, preferably 2.5. Hydrochloric acid or titanium chloride is brought into contact so that the viscosity is 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 within the above range, the calcium content in the titanium hydroxide aggregates can be reduced. On the other hand, when 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 titanium hydroxide aggregates.

The acid used for the acid treatment in the acid treatment step (B) is hydrochloric acid or titanium chloride.

The concentration of hydrochloric acid used for the acid treatment in the acid treatment step (B) is not particularly limited, but is preferably 1.0 to 13.0 mol/L, more preferably 1.5 to 12.0 mol/L. It is preferably 2.7 to 12.0 mol/L, more preferably. 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 the 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 below the above range, it becomes difficult to carry out the acid treatment smoothly.

The concentration of titanium chloride used in the acid treatment step (B) is not particularly limited, but the concentration of hydrochloric acid produced by hydrolysis is preferably 1.0 to 13.0 mol/L, more preferably 1.5 to 12.0 mol/L. The concentration is 0 mol/L, more preferably 2.7 to 12.0 mol/L.

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

In the acid treatment in the acid treatment step (B), the contact time between the sediment of titanium hydroxide aggregates and hydrochloric acid or titanium chloride is appropriately selected, but is preferably 10 minutes or longer, more preferably 20 minutes or longer. , more preferably 30 minutes or longer.

In the acid treatment step (B), the acid treatment is preferably carried out by contacting the sediment of titanium hydroxide aggregates with hydrochloric acid or titanium chloride in an acid treatment tank.

Then, by performing the acid treatment step (B), a suspension of the acid-treated titanium hydroxide aggregate is obtained.

In the titanium hydroxide flocculation treatment step and the acid treatment step (B) according to the method for recovering the titanium component of the second embodiment of the present invention, the wastewater containing the titanium compound is hydrolyzed, and then the calcium hydroxide is neutralized. As an agent, a primary neutralization treatment, a secondary neutralization treatment, and an aggregation treatment are sequentially performed at a specific pH to cause titanium hydroxide agglomerates to settle. Since the calcium content in the titanium hydroxide agglomerate obtained by the acid treatment can be reduced by subjecting it to acid treatment in which it is brought into contact with hydrochloric acid or titanium chloride, titanium hydroxide with a low calcium content can be recovered. can do. In the titanium hydroxide aggregation treatment step and the acid treatment step (B) according to the method for recovering the titanium component of the second embodiment of the present invention, sediment obtained by settling the titanium hydroxide aggregation produced in the titanium hydroxide aggregation treatment step On the other hand, the acid treatment process dissolves the poorly water-soluble unreacted substances such as calcium hydroxide remaining in the titanium hydroxide agglomerates, so that the calcium content in the titanium hydroxide agglomerates can be reduced. can. From the above, it is considered that titanium hydroxide having a low calcium content can be recovered in the method for recovering a titanium component according to the second aspect of the present invention.

In the method for recovering a titanium component of the present invention, the titanium hydroxide obtained by performing the secondary pressing step 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 waste liquid containing the titanium compound in the form of aggregates of titanium hydroxide. The recovered titanium hydroxide agglomerate (acid-treated product) is dried and calcined, and then converted to titanium oxide, which is used as a raw material for producing various titanium compounds.

In this manner, in the method for recovering a titanium component of the present invention, the waste liquid containing a titanium compound, preferably the waste containing a titanium compound generated during the preparation of a solid catalyst component for olefin polymerization or a catalyst for olefin polymerization, is used. The titanium compound in the liquid can be recovered as titanium hydroxide, and titanium hydroxide having a low content of calcium and chlorine can be easily recovered at a high yield.

According to the present invention, the following can be said. The present invention is a filter press device having a pressurized filtration chamber and a compression portion provided inside the pressurized filtration chamber, having a filtration membrane, and filled with a substance to be filtered. A suspension containing an acid-treated titanium oxide agglomerate is fed, the compression part is filled with the suspension containing an acid-treated titanium hydroxide agglomerate, and then the compression part and the suspension are separated by a pressurized filtration chamber. A primary compression step of compressing the liquid at 0.10 to 1.00 MPa to remove water from the suspension to obtain a primary compression of titanium hydroxide aggregates, and a compression section inside the pressurized filtration chamber. The washing water is supplied to the outside of the, and the washing liquid is flowed so as to penetrate the compression part and the primary pressed product of the acid-treated titanium hydroxide agglomerate inside it, and the acid-treated titanium hydroxide agglomerate a through-washing step of through-washing the primary compressed material to obtain an acid-treated titanium hydroxide agglomerate through-washing; and a secondary pressing step for squeezing the material to remove moisture from the through-washed matter of the acid-treated titanium hydroxide agglomerate to obtain a cake of the acid-treated titanium hydroxide agglomerate. This is a method for recovering titanium components.

The present inventors prefer positive washing, in which washing water is sent from the same feed port as the feed port that sends the suspension containing the acid-treated titanium hydroxide aggregate, to wash the suspension, rather than the primary pressing step. If this is done before, cracks will form in the suspension or cake containing the acid-treated titanium hydroxide agglomerates. It was found that the cleaning efficiency as a whole was significantly reduced. Therefore, the present inventors performed the primary pressing step without performing forward washing, and then washed the suspension (cake) containing the acid-treated titanium hydroxide agglomerate by penetrating washing. , the suspension (cake) can be prevented from cracking, and the cleaning efficiency of the cake can be improved. As a result, the method for recovering the titanium component of the present invention can improve the cleaning efficiency and significantly reduce the chlorine content remaining in the cake of titanium hydroxide aggregates compared to the case of carrying out forward cleaning. .

Further, an embodiment of the present invention is a method for recovering a titanium component, characterized in that the insertion pressure of the cleaning water in the penetration cleaning step is 0.10 to 0.60 MPa, and the cleaning time is 17 to 60 minutes. be. According to this configuration, a sufficient cake cleaning effect can be obtained in the penetration cleaning step.

Further, the embodiment of the present invention is characterized in that the pressing pressure in the secondary pressing step is 0.10 to 1.00 MPa. According to this configuration, sufficient pressing and dehydration can be performed in the secondary pressing step.

Further, an embodiment of the present invention is a method for recovering a titanium component, wherein the pressing time in the secondary pressing step is longer than the pressing time in the primary pressing step. According to this configuration, sufficient pressing and dehydration can be performed in the secondary pressing step.

Further, an embodiment of the present invention is a method for recovering a titanium component, wherein the pressure of washing water in the through washing step is 0.10 to 0.60 MPa. According to this configuration, it is possible to prevent the cake from cracking, improve the cleaning efficiency, and significantly reduce the content of chlorine remaining in the cake of titanium hydroxide aggregates.

Next, a method for producing titanium oxide according to 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 waste liquid containing a titanium compound,
The waste liquid containing the titanium compound is subjected to at least hydrolysis, primary neutralization using calcium hydroxide or calcium oxide as a neutralizing agent, and secondary neutralization using calcium hydroxide or calcium oxide as a neutralizing agent. a titanium hydroxide aggregation treatment step for obtaining a titanium hydroxide aggregate by performing a treatment and an aggregation treatment for aggregating titanium hydroxide;
After the titanium hydroxide agglomeration treatment step, the titanium hydroxide agglomerate is subjected to an acid treatment in which hydrochloric acid or titanium chloride is brought into contact with the acid treatment step to obtain a suspension containing the acid-treated titanium hydroxide agglomerate. and,
The space in the compression section of a filter press device having a pressurization type filtration chamber and a compression section provided inside the pressure type filtration chamber, having a filtration membrane, and filled with a substance to be filtered, is filled with the water. A suspension containing an acid-treated titanium oxide agglomerate is sent, the compression part is filled with a suspension containing an acid-treated titanium hydroxide agglomerate, and then the pressurized filtration chamber is used for the compression. a primary pressing step of pressing the part and the suspension at 0.10 to 1.00 MPa to remove moisture from the suspension to obtain a primary pressed product of the acid-treated titanium hydroxide agglomerate;
Washing water is supplied to the inside of the pressurized filtration chamber and the outside of the compression section so that the washing liquid penetrates the compression section and the primary compressed product of the acid-treated titanium hydroxide agglomerate therein. a penetration cleaning step of penetrating and cleaning the primary pressed product of the acid-treated titanium hydroxide agglomerate to obtain a penetration-washed product of the acid-treated titanium hydroxide agglomerate;
The pressurized filtration chamber squeezes the compressed portion and the acid-treated titanium hydroxide agglomerate through-washed material to remove water from the acid-treated titanium hydroxide agglomerate-through-washed material. a secondary pressing step for obtaining a cake of an acid-treated titanium oxide aggregate;
a calcination step of obtaining titanium oxide by calcining the acid-treated titanium hydroxide aggregate after the secondary pressing step;
characterized by having

The method for producing titanium oxide of the present invention comprises a step of firing an acid-treated titanium hydroxide aggregate to obtain titanium oxide, and a step of aggregating titanium hydroxide, an acid treatment step, and a primary pressing step. The steps, the penetration washing step, the secondary pressing step, and the like are the same as those of the titanium compound recovery method of the present invention.

The calcination step in the method for producing titanium oxide of the present invention is a step of obtaining titanium oxide by calcining an acid-treated titanium hydroxide agglomerate.

The firing conditions in the firing step are not particularly limited as long as they are conditions under which titanium hydroxide is converted to titanium oxide. For example, the firing temperature in the firing step is preferably 60 to 1300°C. Also, the firing time is appropriately selected. The firing atmosphere is an oxidizing atmosphere such as an air atmosphere or an oxygen gas atmosphere. In the firing step, the firing may be performed only once, or the firing may be performed two or more times at the same temperature or different temperatures.

In the method for producing titanium oxide of the present invention, the titanium hydroxide agglomerate obtained by the titanium hydroxide flocculation treatment step is subjected to the acid treatment step. When obtaining titanium, even if calcium hydroxide is used as a neutralizing agent, titanium hydroxide with a low calcium content can be obtained, so titanium oxide with 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 reduced by further performing the primary pressing step, the penetration cleaning step and the secondary pressing step.

In this way, in the method for producing titanium oxide of the present invention, the titanium compound in the waste liquid containing the titanium compound can be recovered as titanium oxide, and an oxidized titanium oxide having a low calcium content and a low chlorine content is obtained. Titanium can be easily recovered. Also, the amount of calcium hydroxide and/or calcium oxide used as a neutralizing agent can be reduced.

Next, the method for producing the alkali titanate of the present invention will be described.
The method for producing an alkali titanate of the present invention includes titanium hydroxide recovered by the method for recovering a titanium component of the present invention (acid-treated cake of titanium hydroxide agglomerates obtained by the secondary pressing step), or It is characterized by using titanium oxide obtained by the method for producing titanium oxide of the present invention as a raw material.

The method for producing an alkali titanate of the present invention uses, as a raw material, titanium hydroxide recovered by the method for recovering a titanium component of the present invention (a cake of an acid-treated titanium hydroxide agglomerate obtained by performing a secondary pressing step). ) or titanium oxide obtained by the method for producing titanium oxide of the present invention is used as a raw material, a known method can be adopted.

For example, when titanium hydroxide recovered by the method for recovering titanium components of the present invention (acid-treated cake of titanium hydroxide agglomerates obtained by performing the secondary pressing step) is used as the titanium raw material, an appropriate oxidizing titanium hydroxide (a cake of an acid-treated titanium hydroxide agglomerate obtained by the secondary pressing step) to convert it into titanium oxide, and then using the resulting titanium oxide as a raw material for titanium. At the same time, a potassium compound is used as an alkali raw material, and an alkali titanate can be produced by firing and pulverizing a raw material mixture containing both. Further, when titanium oxide obtained by the method for producing titanium oxide of the present invention is used as the titanium raw material, the titanium oxide obtained by the method for producing titanium oxide of the present invention is used as the titanium raw material, and an alkali An alkali titanate can be produced by using a potassium compound as a raw material and firing and pulverizing a raw material mixture containing both.
In addition to potassium compounds, alkaline raw materials include compounds containing alkali metals such as lithium compounds, sodium compounds, rubidium compounds, cesium compounds, and francium compounds, and alkaline earth metals such as magnesium compounds, barium compounds, and calcium compounds. It is also possible to apply compounds comprising

The resulting alkali titanate is suitably used as a friction material for friction sliding members such as brake linings, disc pads, and clutch fadings, which constitute braking devices in automobiles, railway vehicles, aircraft, industrial machinery, and the like. be done.

For example, when the alkali titanate obtained by the method for producing an alkali titanate of the present invention is used as a material for a brake friction material, the alkali titanate is 15 to 25% by mass, the phenol resin is 9 to 11% by mass, and graphite ( artificial graphite) 7-9% by mass, barium sulfate (barite) 25-30% by mass, zirconium silicate 6-8% by mass, antimony trisulfide 2-4% by mass, copper fiber and powder 0-9% by mass %, cashew dust 4-6% by mass, rubber powder 1-3% by mass, aramid fiber 3-5% by mass, mica 4-6% by mass, chromite (chromite) 0-2% by mass % is molded into the shape of a brake friction material and pressurized at a surface pressure of 10 to 400 kgf/cm ² and a thermoforming temperature of 70 to 250° C. to obtain a brake friction material.

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

Metallic titanium is obtained through the following steps. Titanium tetrachloride is produced by chlorinating titanium oxide in a chlorination furnace using natural rutile, synthetic rutile, and highly purified slag, which are titanium oxide raw materials with high purity, as raw materials. Next, titanium tetrachloride is reduced with metallic magnesium in a closed container to produce a sponge titanium mass. The titanium sponge mass is pushed out from the container using a high-pressure cylinder, cut into pieces according to the quality of the parts of the mass, and crushed to obtain crushed sponge titanium materials. In order to use titanium for various metal materials, it is necessary to melt and roll crushed sponge titanium to refine ingots of 1 to 15 tons depending on the application.
Thus, titanium oxide becomes, for example, titanium tetrachloride raw material. That is, titanium oxide is a raw material for producing titanium tetrachloride by chlorinating titanium oxide.

The titanium hydroxide obtained by the method for recovering the titanium component of the present invention (the cake of the acid-treated titanium hydroxide agglomerate obtained by the secondary pressing step) is baked at a predetermined temperature to obtain an appropriate hardness. The titanium oxide can be used as a raw material for the production of titanium tetrachloride. The firing temperature for firing the titanium hydroxide aggregate is 1100° C. or higher, preferably 1200° C. or higher. Although the upper limit of the firing temperature is not particularly limited, it is appropriately selected in the range of, for example, 1200 to 1300°C, and the firing temperature is, for example, 1300°C or less. If the firing temperature is less than 1100° C., it is not preferable because the titanium oxide does not have an appropriate hardness. Here, the hardness of titanium oxide refers to the degree of hardness that can remain in the fluidized bed after the titanium tetrachloride raw material (approximately 2 tons) is put into the chlorination furnace (fluidized bed) and maintain a particle size that allows chlorination. means Specifically, the hardness of titanium oxide is 10.0 N/mm ² (1000 gf/mm ² ) or more, preferably 20.0 N/mm ² (2000 gf/mm ² ) or more. Although the upper limit of the hardness of the titanium oxide is not particularly limited, it can be, for example, 20.0 N/mm ² (2000 gf/mm ² ) or more and 50.0 N/mm ² (5000 gf/mm ² ) or less. When the hardness of titanium oxide is less than 10.0 N/mm ² (1000 gf/mm ² ), it is not preferable because it remains in the fluidized bed and cannot maintain a particle size that allows chlorination treatment.
In the present invention, the firing atmosphere is not particularly limited, but firing may be performed in an oxidizing atmosphere such as an air atmosphere or an oxygen gas atmosphere. Also, the firing may be performed only once, or the firing may be performed two or more times at the same or different temperatures.

That is, the method for producing a raw material for titanium tetrachloride of the present invention includes titanium hydroxide recovered by the method for recovering a titanium component of the present invention (a cake of an acid-treated titanium hydroxide agglomerate obtained by the secondary pressing step). ) as a raw material to obtain titanium oxide as a raw material for the production of titanium tetrachloride. A cake of an acid-treated titanium agglomerate) is calcined at 1100° C. or higher in an oxidizing atmosphere to obtain titanium oxide as a raw material for producing titanium tetrachloride. The firing temperature for firing the titanium hydroxide recovered by the method for recovering the titanium component of the present invention is preferably 1200° C. or higher. Although the upper limit of the sintering temperature is not particularly limited, it is appropriately selected in the range of, for example, 1200 to 1300° C. The sintering temperature is, for example, 1300° C. or lower.

EXAMPLES 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.

The titanium component was recovered according to the flow charts shown in FIGS. As a filter press device for carrying out the flow of FIG. 2, Kurita type HJMF-2B-A type manufactured by Kurita Machinery Co., Ltd. was used.

(Production example 1)
<Preparation of suspension of acid-treated titanium hydroxide aggregate>
Wastewater containing titanium tetrachloride, diethoxymagnesium, toluene, and heptane at a temperature of 25°C, which is generated when solid catalyst components for olefin polymerization are prepared in a Ziegler-Natta catalyst manufacturing plant, is treated. The liquids were mixed by feeding into a water receiving tank 1 having a capacity of 250 m ³ and hydrolyzed. At this time, water 11 for hydrolysis was fed into the water receiving tank so that the pH of the waste liquid in the water receiving tank became 1.
The hydrolyzed treatment liquid is fed into the primary neutralization treatment tank 2 with a capacity of 10 m ³ at a rate of 10 m ³ /h, and a 12.5 mol / L calcium hydroxide aqueous solution at a liquid temperature of 25 ° C. is used to The primary neutralization treatment was carried out so that the pH of the treatment liquid fed into the primary neutralization treatment tank 2 was 2.0.
Next, the treated liquid subjected to the primary neutralization treatment is 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 at a liquid temperature of 25 ° C. A secondary neutralization treatment was performed using an aqueous solution so that the pH of the treatment liquid sent into the secondary neutralization treatment tank 3 was 7.2.
The liquid temperature of 25°C that has been subjected to the secondary neutralization treatment is fed into a coagulation tank 4 with a capacity of 10 m ³ at a rate of 10 m ³ /h, and a flocculant (Kurita Chemical Hokuriku Co., Ltd. Clifarm PA -833) to obtain a flocculation treatment liquid, the flocculation treatment liquid was transferred to the sedimentation tank 5 and allowed to settle in the sedimentation tank 5, and the sediment was extracted from the sedimentation tank 5. The sediment extracted from the sedimentation tank 5 was then transferred to the sediment storage tank 6 .
Next, the sediment is fed into the acid treatment tank 7, diluted with ion-exchanged water, and then hydrochloric acid 14 is supplied to the acid treatment tank 7 so that the resulting liquid phase has a pH of 5.0, Titanium hydroxide aggregates and hydrochloric acid 14 were mixed and acid-treated to obtain a suspension of acid-treated titanium hydroxide aggregates.

(Example 1)
According to the process flow shown in FIG. 1, the space in the compression section of the filter press was filled with the acid-treated suspension of titanium hydroxide agglomerates sent from the acid treatment tank 7 . In Example 1, the suspension of the acid-treated titanium hydroxide agglomerate was not subjected to forward washing, but the diaphragm was driven to advance the compressed membrane toward the compression section, thereby A suspension of acid-treated titanium hydroxide agglomerates was subjected to primary pressing. The primary pressing was performed at a pressure of 0.68 MPa for a pressing time of 3 minutes. Next, after the primary compression was released, the primary compression material in the compressed portion that had been compressed in the primary compression was penetrated and washed using washing water composed of water. Penetration cleaning was carried out for 22 minutes by injecting cleaning water at a pressure of 0.36 MPa. Next, the diaphragm was driven to advance the compression membrane toward the compression section, thereby secondary compression of the wash-through material in the compression section. Secondary pressing was performed at a pressure of 0.68 MPa for a pressing time of 10 minutes. After the secondary pressing was released, the press cake was obtained as an acid-treated titanium hydroxide agglomerate by removing it from the compression section.

The content of Cl in the press cake was analyzed by elemental determination by the FP method using a fluorescent X-ray analyzer (EDXL300 manufactured by Rigaku Corporation). The content of Cl remaining in the press cake in terms of atoms was 0.10% by mass or less. The analysis results are shown below.

(Example 2)
According to the process flow shown in FIG. 1, the space in the compression section of the filter press was filled with the acid-treated suspension of titanium hydroxide agglomerates sent from the acid treatment tank 7 . In Example 2, the suspension of the acid-treated titanium hydroxide agglomerates was not subjected to forward washing, but the diaphragm was driven to advance the compressed membrane toward the compression section, thereby A suspension of acid-treated titanium hydroxide agglomerates was subjected to primary pressing. The primary pressing was performed at a pressure of 0.68 MPa for a pressing time of 3 minutes. Next, after the primary compression was released, the primary compression material in the compressed portion that had been compressed in the primary compression was penetrated and washed using washing water composed of water. Penetration cleaning was carried out for 25 minutes by injecting cleaning water at a pressure of 0.36 MPa. Next, the diaphragm was driven to advance the compression membrane toward the compression section, thereby secondary compression of the wash-through material in the compression section. Secondary pressing was performed at a pressure of 0.68 MPa for a pressing time of 7 minutes. After the secondary pressing was released, the press cake was obtained as an acid-treated titanium hydroxide agglomerate by removing it from the compression section.

The content of Cl in the presscake was analyzed. The content of Cl remaining in the press cake in terms of atoms was 0.10% by mass or less.

(Example 3)
According to the process flow shown in FIG. 1, the space in the compression section of the filter press was filled with the acid-treated suspension of titanium hydroxide agglomerates sent from the acid treatment tank 7 . In Example 3, the suspension of the acid-treated titanium hydroxide agglomerate was not subjected to forward washing, but the diaphragm was driven to advance the compressed membrane toward the compression section, thereby A suspension of acid-treated titanium hydroxide agglomerates was subjected to primary pressing. The primary pressing was performed at a pressure of 0.68 MPa for a pressing time of 3 minutes. Next, after the primary compression was released, the primary compression material in the compressed portion that had been compressed in the primary compression was penetrated and washed using washing water composed of water. Penetration cleaning was carried out for 20 minutes by injecting cleaning water at a pressure of 0.36 MPa. Next, the diaphragm was driven to advance the compression membrane toward the compression section, thereby secondary compression of the wash-through material in the compression section. Secondary pressing was performed at a pressure of 0.68 MPa for a pressing time of 10 minutes. After the secondary pressing was released, the press cake was obtained as an acid-treated titanium hydroxide agglomerate by removing it from the compression section.

The content of Cl in the presscake was analyzed. The content of Cl remaining in the press cake in terms of atoms was 0.10% by mass.

(Comparative example 1)
According to the process flow shown in FIG. 1, the space in the compression section of the filter press was filled with the acid-treated suspension of titanium hydroxide agglomerates sent from the acid treatment tank 7 . In Comparative Example 1, the acid-treated suspension of titanium hydroxide aggregates was subjected to forward washing. Forward washing was performed by injecting washing water at a pressure of 0.36 MPa for 10 minutes. Next, the diaphragm was driven to advance the compression membrane toward the compression section, and the suspension of the acid-treated titanium hydroxide agglomerates in the compression section was primarily compressed. The primary pressing was performed at a pressure of 0.68 MPa for a pressing time of 5 minutes. Next, after the primary compression was released, the primary compression material in the compressed portion that had been compressed in the primary compression was penetrated and washed using washing water composed of water. Penetration cleaning was carried out for 5 minutes by injecting cleaning water at a pressure of 0.36 MPa. Next, the diaphragm was driven to advance the compression membrane toward the compression section, thereby secondary compression of the wash-through material in the compression section. Secondary pressing was performed at a pressure of 0.68 MPa for a pressing time of 15 minutes. After the secondary pressing was released, the press cake was obtained as an acid-treated titanium hydroxide agglomerate by removing it from the compression section.

The content of Cl in the presscake was analyzed. The atomically converted Cl content remaining in the press cake was 0.50% by mass.

(Comparative example 2)
According to the process flow shown in FIG. 1, the space in the compression section of the filter press was filled with the acid-treated suspension of titanium hydroxide agglomerates sent from the acid treatment tank 7 . In Comparative Example 2, the acid-treated suspension of titanium hydroxide aggregates was subjected to forward washing. Forward washing was performed by injecting washing water at a pressure of 0.36 MPa for 5 minutes. Next, the diaphragm was driven to advance the compression membrane toward the compression section, and the suspension of the acid-treated titanium hydroxide agglomerates in the compression section was primarily compressed. The primary pressing was performed at a pressure of 0.68 MPa for a pressing time of 5 minutes. Next, after the primary compression was released, the primary compression material in the compressed portion that had been compressed in the primary compression was penetrated and washed using washing water composed of water. Penetration cleaning was carried out for 10 minutes by injecting cleaning water at a pressure of 0.36 MPa. Next, the diaphragm was driven to advance the compression membrane toward the compression section, thereby secondary compression of the wash-through material in the compression section. Secondary pressing was performed at a pressure of 0.68 MPa for a pressing time of 15 minutes. After the secondary pressing was released, the press cake was obtained as an acid-treated titanium hydroxide agglomerate by removing it from the compression section.

The content of Cl in the presscake was analyzed. The atomically converted Cl content remaining in the press cake was 0.60% by mass.

(Comparative Example 3)
According to the process flow shown in FIG. 1, the space in the compression section of the filter press was filled with the acid-treated suspension of titanium hydroxide agglomerates sent from the acid treatment tank 7 . In Comparative Example 3, the acid-treated suspension of titanium hydroxide aggregates was subjected to forward washing. Forward washing was carried out for 1 minute by injecting washing water at a pressure of 0.36 MPa. Next, the diaphragm was driven to advance the compression membrane toward the compression section, and the suspension of the acid-treated titanium hydroxide agglomerates in the compression section was primarily compressed. The primary pressing was performed at a pressure of 0.68 MPa for a pressing time of 3 minutes. Next, after the primary compression was released, the primary compression material in the compressed portion that had been compressed in the primary compression was penetrated and washed using washing water composed of water. Penetration cleaning was carried out for 16 minutes by injecting cleaning water at a pressure of 0.36 MPa. Next, the diaphragm was driven to advance the compression membrane toward the compression section, thereby secondary compression of the wash-through material in the compression section. Secondary pressing was performed at a pressure of 0.68 MPa for a pressing time of 15 minutes. After the secondary pressing was released, the press cake was obtained as an acid-treated titanium hydroxide agglomerate by removing it from the compression section.

The content of Cl in the presscake was analyzed. The atomically converted Cl content remaining in the press cake was 0.60% by mass.

(Comparative Example 4)
According to the process flow shown in FIG. 1, the space in the compression section of the filter press was filled with the acid-treated suspension of titanium hydroxide agglomerates sent from the acid treatment tank 7 . In Comparative Example 4, the acid-treated suspension of titanium hydroxide aggregates was subjected to forward washing. Forward washing was carried out for 1 minute by injecting washing water at a pressure of 0.36 MPa. Next, the diaphragm was driven to advance the compression membrane toward the compression section, and the suspension of the acid-treated titanium hydroxide agglomerates in the compression section was primarily compressed. The primary pressing was performed at a pressure of 0.68 MPa for a pressing time of 5 minutes. Next, after the primary compression was released, the primary compression material in the compressed portion that had been compressed in the primary compression was penetrated and washed using washing water composed of water. Penetration cleaning was carried out for 1 minute by injecting cleaning water at a pressure of 0.36 MPa. Next, the diaphragm was driven to advance the compression membrane toward the compression section, thereby secondary compression of the wash-through material in the compression section. Secondary pressing was performed at a pressure of 0.68 MPa for a pressing time of 15 minutes. After the secondary pressing was released, the press cake was obtained as an acid-treated titanium hydroxide agglomerate by removing it from the compression section.

The content of Cl in the presscake was analyzed. The original Cl content remaining in the press cake was 1.2% by mass.

(Comparative Example 5)
According to the process flow shown in FIG. 1, the space in the compression section of the filter press was filled with the acid-treated suspension of titanium hydroxide agglomerates sent from the acid treatment tank 7 . In Comparative Example 5, the acid-treated suspension of titanium hydroxide aggregates was subjected to forward washing. Forward washing was performed for 2 minutes by injecting washing water at a pressure of 0.36 MPa. Next, the diaphragm was driven to advance the compression membrane toward the compression section, and the suspension of the acid-treated titanium hydroxide agglomerates in the compression section was primarily compressed. The primary pressing was performed at a pressure of 0.68 MPa for a pressing time of 1 minute. Next, after the primary compression was released, the primary compression material in the compressed portion that had been compressed in the primary compression was penetrated and washed using washing water composed of water. Penetration cleaning was carried out for 20 minutes by injecting cleaning water at a pressure of 0.36 MPa. Next, the diaphragm was driven to advance the compression membrane toward the compression section, thereby secondary compression of the wash-through material in the compression section. Secondary pressing was performed at a pressure of 0.68 MPa for a pressing time of 12 minutes. After the secondary pressing was released, the press cake was obtained as an acid-treated titanium hydroxide agglomerate by removing it from the compression section.

The content of Cl in the presscake was analyzed. The content of Cl remaining in the press cake in terms of atoms was 1.0% by mass.

In Examples 1 to 3, since the through washing process was performed after the primary pressing process without performing the forward washing, the suspension (cake) of the acid-treated titanium hydroxide aggregate was previously aggregated and It is surmised that it could be compression molded so that the acid treated suspension (cake) of titanium hydroxide agglomerates did not crack during penetration cleaning. As a result, it is presumed that the cleaning efficiency of the cake as a whole was improved in through-cleaning, and the Cl concentration in the press cake was remarkably lowered. On the other hand, in Comparative Examples 1 to 5, since the positive washing was performed before the primary pressing process, it is possible that the suspension (cake) of the acid-treated titanium hydroxide aggregates cracked during the positive washing. It is presumed that the cleaning efficiency of the cake as a whole decreased due to the fact that the cleaning water concentratedly flowed into the cracked portions during penetration cleaning. As a result, in Comparative Examples 1 to 5, it is presumed that the Cl content in the press cake was not sufficiently lowered.

(Example 4)
The press cake of the acid-treated titanium hydroxide agglomerate obtained in Example 1 was heat-treated in an air atmosphere at 850°C for 2 hours using a shuttle kiln, and then further heat-treated at 950°C for 2 hours. was applied to obtain the desired titanium oxide.
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 PANalytical), the obtained titanium hydroxide contained a small amount of rutile. Although it contains titanium oxide, it was confirmed that the main crystal system was amorphous, whereas titanium oxide was of the rutile type.

(Example 5)
52.16 kg of titanium oxide obtained in Example 4, 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 (Chuo Kakoki Co., Ltd.). Co., Ltd.), 0.6 kg of lower alcohol was further added thereto, and the material mixture was obtained by processing for 15 minutes at an amplitude of 5 mm.
Approximately 140 kg of the above raw material mixture was supplied to a rotary kiln at a temperature of 1200° C. at a flow rate of 17.5 kg/hr. A synthesis reaction to potassium titanate occurred in this rotary kiln, and the fired product was discharged from the rotary kiln. The fired product discharged was rapidly cooled to room temperature.
After that, the cooled baked product is pulverized with a vibrating rod mill (manufactured by Chuo Kakoki Co., Ltd.), and then pulverized with an impact type pulverizer (manufactured by Hosokawa Micron Co., Ltd., ACM Pulverizer) with a built-in classifier to obtain potassium titanate particles. rice field. Table 2 shows the physical properties of the obtained potassium titanate particles. FIG. 7 shows XRD measurement results, and FIG. 8 shows SEM observation results.
For comparison, Table 2 also shows physical properties of commercially available potassium titanate particles (TOFIX-SNR-S manufactured by Toho Titanium Co., Ltd.). SEM observation results are shown in FIG.
The measuring devices and measuring methods used for measuring each physical property are as follows.
≪Measuring device≫
XRD: X'PERT-PRO-MPD multipurpose X-ray diffractometer (manufactured by PANalytical)
SEM: Scanning electron microscope, JSM-7800 (manufactured by JEOL Ltd.)
Specific surface area: specific surface area meter, monosorb (manufactured by Quantachrome)

As shown in Table 2, it was confirmed that the potassium titanate particles of Example 5 had the same phase structure and powder shape as those of the commercially available product. The specific surface area was also within the standard value for commercial products (standard value: 2.0 to 3.0 m ² /g).

(Example 6)
52.16 kg of titanium oxide obtained in Example 4, 52.23 kg of titanium ore, 24.65 kg of sodium carbonate powder, 2.87 kg of titanium powder, and 5.70 kg of wood chips (wood pellets) were placed in a vibrating rod mill (Chuo Kakoki Co., Ltd.). Co., Ltd.), 0.6 kg of lower alcohol was added thereto, and the raw material mixture was obtained by processing for 15 minutes at an amplitude of 5 mm. Sodium titanate particles were obtained in the same manner as in Example 5, except that the powder was supplied to a rotary kiln at 1200°C at a flow rate of 17.5 kg/hr. Table 3 shows the physical properties of the obtained sodium titanate particles. Moreover, the XRD measurement result is shown in FIG.
For comparison, Table 3 also shows physical properties of commercially available sodium titanate particles (TOFIX-NTO manufactured by Toho Titanium Co., Ltd.).
The measuring device or measuring method used for measuring each physical property is the same as in Example 5.

As shown in Table 3, it was confirmed that the sodium titanate particles of Example 6 had the same phase structure and powder shape as those of the commercially available product. Also, the specific surface area was within the standard value for commercial products (standard value: 2.5 to 4.5 m ² /g).

(Example 7)
52.16 kg of titanium oxide obtained in Example 4, 52.23 kg of titanium ore, 275.40 kg of barium carbonate powder, 2.87 kg of titanium powder, and 5.70 kg of wood chips (wood pellets) were placed in a vibrating rod mill (Chuo Kakoki Co., Ltd.). Co., Ltd.), 0.6 kg of a lower alcohol is added thereto, and the mixture is treated for 15 minutes at an amplitude of 5 mm to obtain a raw material mixture. Barium titanate particles were obtained in the same manner as in Example 5 except that the powder was supplied to a rotary kiln at 1200° C. at a flow rate of 17.5 kg/hr. Table 4 shows the physical properties of the obtained barium titanate particles. Moreover, the XRD measurement result is shown in FIG.
The measuring device or measuring method used for measuring each physical property is the same as in Example 5.

(Example 8)
52.16 kg of titanium oxide obtained in Example 4, 52.23 kg of titanium ore, 139.68 kg of calcium carbonate powder, 2.87 kg of titanium powder, and 5.70 kg of wood chips (wood pellets) were placed in a vibrating rod mill (Chuo Kakoki Co., Ltd.). Co., Ltd.), 0.6 kg of lower alcohol was added thereto, and the raw material mixture was obtained by processing for 15 minutes with an amplitude of 5 mm. Calcium titanate particles were obtained in the same manner as in Example 5, except that the powder was supplied to a rotary kiln at 1200° C. at a flow rate of 17.5 kg/hr. Table 4 shows the physical properties of the obtained calcium titanate particles. Moreover, the XRD measurement result is shown in FIG.
The measuring device or measuring method used for measuring each physical property is the same as in Example 5.

(Example 9)
A friction material was produced using the alkali titanate (potassium hexatitanate; 6KTO) obtained in Example 5.
As friction material raw materials, together with alkali titanate prepared in Example 5, phenol resin, artificial graphite, barium sulfate, zirconium silicate, antimony trisulfide, copper fiber, copper powder, cashew dust, rubber powder, aramid fiber, mica (mica ) and chromite at the mixing ratio shown in Table 5 to obtain a raw friction material mixed powder.
The obtained friction material raw material mixed powder was preformed at 200 kgf/cm ² , and the obtained preform was preheated at 70°C for 2 hours, then thermoformed at 180°C and 400 kgf/cm ² . A molded body was obtained by heat treatment at 10 kgf/cm ² for 3 hours at °C, and a friction material having a length of 10 mm, a width of 50 mm, and a thickness of 10 mm was obtained.

<Brake test>
The coefficient of friction of the friction material obtained in Example 9 was measured according to JASO-C406, a standard of the Japan Society of Automotive Engineers of Japan. The average value of the coefficient of friction in the second fade test of the second fade recovery test was 0.36.

(Comparative Example 6, Examples 10 to 12)
The press cake of the acid-treated titanium hydroxide aggregate obtained in Example 1 was dried at 120° C. for 16 hours in an air atmosphere using a constant temperature dryer (DX602, manufactured by Yamato Scientific Co., Ltd.). After that, it is lightly pulverized, subjected to heat treatment for 10 minutes at the firing temperature shown in Table 6 in an air atmosphere using an MS electric furnace (Motoyama Co., Ltd., SC-2035D-SP), and sieved (500 to 710 μm opening). Then, the desired titanium oxide was obtained.
The hardness of the obtained titanium oxide was measured using a fully automatic particle hardness tester "Better Hardness Tester" (manufactured by Seishin Enterprise Co., Ltd., BHT-500). Table 6 shows the results. Note that the oil coke in Table 6 has the lowest hardness among raw materials put into a fluidized bed in the general production of titanium chloride, and is listed so that this hardness is used as a reference value. From the hardness of oil coke, the suitable hardness of the titanium oxide of the present invention is 10.0 N/mm ² (1000 gf/mm ² ) or more, preferably 20.0 N/mm ² (2000 gf/mm ² ) or more. Conceivable. "⊚: 20.0 Nmm ² or more, suitable, good hardness", "◯: 10.0 Nmm ² or more and less than 20.0 Nmm ² , suitable", "X: less than 10.0 Nmm ² , unsuitable".

1 Receiving tank 2 Primary neutralization tank 3 Secondary neutralization tank 4 Coagulation tank 5 Sedimentation tank 6 Sediment storage tank 7 Acid treatment tank 8, 81, 82, 83 Filter press device 10 Waste liquid containing titanium compound 11 Water 12, 13 Calcium hydroxide suspension 14 Hydrochloric acid 20, 21, 24 Press cake 31 of acid-treated titanium hydroxide aggregate Filtration chamber 32 Filtration membrane 33 Filtration plate 34 Compression membrane 36 Compression part

Claims (9)

A method for recovering a titanium component from a waste liquid containing a titanium compound, comprising:
The waste liquid containing the titanium compound is subjected to at least hydrolysis, primary neutralization using calcium hydroxide or calcium oxide as a neutralizing agent, and secondary neutralization using calcium hydroxide or calcium oxide as a neutralizing agent. a titanium hydroxide aggregation treatment step for obtaining a titanium hydroxide aggregate by performing a treatment and an aggregation treatment for aggregating titanium hydroxide;
After the titanium hydroxide agglomeration treatment step, the titanium hydroxide agglomerate is subjected to an acid treatment in which hydrochloric acid or titanium chloride is brought into contact with the acid treatment step to obtain a suspension containing the acid-treated titanium hydroxide agglomerate. and,
In a space in the compression section of a filter press device having a pressurization-type filtration chamber and a compression section provided inside the pressurization-type filtration chamber, having a filtration membrane, and filled with a substance to be filtered, the A suspension containing an acid-treated titanium hydroxide agglomerate is sent, the compression section is filled with the suspension containing an acid-treated titanium hydroxide agglomerate, and then the pressurized filtration chamber passes through the pressurized filter chamber. a primary pressing step of compressing the compressed portion and the suspension at 0.10 to 1.00 MPa to remove moisture from the suspension to obtain a primary pressed product of the acid-treated titanium hydroxide agglomerate; ,
Washing water is supplied to the inside of the pressurized filtration chamber and the outside of the compression section so that the washing liquid penetrates the compression section and the primary compressed product of the acid-treated titanium hydroxide agglomerate therein. a penetration cleaning step of penetrating and cleaning the primary pressed product of the acid-treated titanium hydroxide agglomerate to obtain a penetration-washed product of the acid-treated titanium hydroxide agglomerate;
The pressurized filtration chamber squeezes the compressed portion and the acid-treated titanium hydroxide agglomerate through-washed material to remove water from the acid-treated titanium hydroxide agglomerate-through-washed material. a secondary pressing step for obtaining a cake of an acid-treated titanium oxide aggregate;
A method for recovering a titanium component, comprising: 2. The method for recovering a titanium component according to claim 1, wherein in said penetration cleaning step, the cleaning water is inserted at a pressure of 0.10 to 0.60 MPa, and the cleaning time is 17 to 60 minutes. 3. The method for recovering a titanium component according to claim 1, wherein the pressing pressure in the secondary pressing step is 0.10 to 1.00 MPa. The method for recovering a titanium component according to any one of claims 1 to 3, wherein the pressing time in the secondary pressing step is longer than the pressing time in the primary pressing step. The method for recovering a titanium component according to any one of claims 1 to 4, wherein the pressure of said washing water in said through washing step is 0.10 to 0.60 MPa. A method for producing titanium oxide by producing titanium oxide from a waste liquid containing a titanium compound,
The waste liquid containing the titanium compound is subjected to at least hydrolysis, primary neutralization using calcium hydroxide or calcium oxide as a neutralizing agent, and secondary neutralization using calcium hydroxide or calcium oxide as a neutralizing agent. a titanium hydroxide aggregation treatment step for obtaining a titanium hydroxide aggregate by performing a treatment and an aggregation treatment for aggregating titanium hydroxide;
After the titanium hydroxide agglomeration treatment step, the titanium hydroxide agglomerate is subjected to an acid treatment in which hydrochloric acid or titanium chloride is brought into contact with the acid treatment step to obtain a suspension containing the acid-treated titanium hydroxide agglomerate. and,
The space in the compression section of a filter press device having a pressurization type filtration chamber and a compression section provided inside the pressure type filtration chamber, having a filtration membrane, and filled with a substance to be filtered, is filled with the water. A suspension containing an acid-treated titanium oxide agglomerate is sent, the compression part is filled with a suspension containing an acid-treated titanium hydroxide agglomerate, and then the pressurized filtration chamber is used for the compression. a primary pressing step of pressing the part and the suspension at 0.10 to 1.00 MPa to remove moisture from the suspension to obtain a primary pressed product of the acid-treated titanium hydroxide agglomerate;
Washing water is supplied to the inside of the pressurized filtration chamber and the outside of the compression section so that the washing liquid penetrates the compression section and the primary compressed product of the acid-treated titanium hydroxide agglomerate therein. a penetration cleaning step of penetrating and cleaning the primary pressed product of the acid-treated titanium hydroxide agglomerate to obtain a penetration-washed product of the acid-treated titanium hydroxide agglomerate;
The pressurized filtration chamber squeezes the compressed portion and the acid-treated titanium hydroxide agglomerate through-washed material to remove water from the acid-treated titanium hydroxide agglomerate-through-washed material. a secondary pressing step for obtaining a cake of an acid-treated titanium oxide aggregate;
a calcination step of obtaining titanium oxide by calcining the acid-treated titanium hydroxide aggregate after the secondary pressing step;
A method for producing titanium oxide, comprising: Titanium hydroxide recovered by the method for recovering a titanium component according to any one of claims 1 to 5 or titanium oxide obtained by the method for producing titanium oxide according to claim 6 is used as a raw material. A method for producing an alkali titanate. A method for producing a friction material, wherein the alkali titanate obtained by the method for producing an alkali titanate according to claim 7 is used as a raw material. A method for producing a raw material for titanium tetrachloride, wherein the titanium hydroxide recovered by the method for recovering a titanium component according to any one of claims 1 to 5 is used as a raw material.

Images