TW202111132A - Method for producing titanium concentrate - Google Patents

Abstract

Provided is a method for removing iron, silica, and other impurities from a titanium-containing iron ore or an analogue thereof by an industrially advantageous method to produce a high-quality titanium concentrate. In the present invention, a ground product obtained by grinding a titanium-containing iron ore or an analogue thereof to a particle diameter that passes through a 330 mesh sieve is subjected to a preliminary leaching at a reaction temperature of 80 DEG C or below at a hydrochloric acid initial concentration of 1-20% by mass, and then subjected to a main leaching at a reaction temperature of 90 DEG C or above at a hydrochloric acid initial concentration of 15-20% by mass in the presence of a soluble reducing substance. After the main leaching, the leachate obtained by solid-liquid separation is then washed and granulated/dried to produce a titanium concentrate including titanium oxide having a rutile structure.

Description

Manufacturing method of titanium concentrate

The present invention relates to a method for manufacturing high-grade titanium concentrates by removing impurities such as iron components and silicon oxide components from ilmenite-containing iron ore or the like.

The titanium concentrate is used as a raw material for the production of titanium tetrachloride, which is used for the production of titanium dioxide pigments and the production of metallic titanium by the chlorine method. Since titanium tetrachloride is usually produced by chlorinating titanium concentrate with chlorine gas by fluidization method (ie fluid chlorination), it is high-grade and does not contain fine powder, and is easily chlorinated in fluidization method. Concentrate is a must. The reason is that if the titanium concentrate contains a lot of fine powder, the fine powder will scatter outside the fluid chlorination furnace, so the yield of titanium tetrachloride will be low. In addition, when the titanium concentrate contains a lot of impurities such as iron components, the utilization efficiency of chlorine gas is deteriorated due to the production of ferric chloride and the like during fluid chlorination. Here, the so-called fluid chlorination is a method in which the titanium component raw material and the carbonaceous reducing agent are brought into a uniform fluidized state by a chlorinated gas and finally react while maintaining a floating and dispersed state.

As these titanium concentrates, high-grade titanium concentrates with iron content removed from natural rutile, ilmenite, or ilmenite, hematite, etc. containing ilmenite are used. These titanium concentrates are known to be leached with sulfuric acid in the presence of seed crystals for promoting hydrolysis of titanium salt or titanium (III) salt by, for example, reducing ilmenite-containing iron ore, etc., to make the iron component into a ferrous state. After ferrous iron, it is manufactured by firing (Patent Document 1 and Patent Document 2). In these methods, due to the high degree of metamorphism (that is, the degree of metamorphism) depending on the pressure and temperature that the titanium-containing iron ore is subjected to before being excavated, the titanium component is easy to be easily concentrated, so the titanium-containing iron can be used Ores, etc. are used as raw materials, but when using massive ore deposits that freely contain a large amount of impurities represented by silicon oxide, ilmenite with low metamorphism is used as raw materials, the methods of Patent Documents 1 and 2 cannot be used. Manufacturing high-grade titanium concentrates.

Therefore, as a method for producing high-grade titanium concentrates using ilmenite with low metamorphism produced from massive deposits, etc., methods have been proposed in Patent Documents 3, 4, 5, and 6. Patent Document 3 describes that 80% by mass or more of ilmenite produced from a massive ore deposit is crushed like a 200-mesh (mesh opening 75μm) sieve, and then leached with mineral acid to remove iron components. A method to obtain a _{powdered titanium concentrate with a TiO 2} grade (ie, TiO ₂ content) of more than 90% by mass, and granulate it into a size that substantially passes through a 10-150 mesh (mesh opening 1.70mm-100μm) .

Patent Document 4 describes that titanium oxide slag containing at least one selected from the group consisting of iron oxide, manganese oxide, chromium oxide, vanadium oxide, aluminum oxide, silicon oxide, and alkaline earth metal oxides is sized to 75 to 850 μm. , The method of manufacturing high-grade titanium concentrate through the various steps of oxidation, reduction, hydrochloric acid leaching, washing, and firing.

Patent Document 5 describes a method of producing pigment-grade titanium oxide by a hydrometallurgical method including a production step of leaching high-magnesium ilmenite ore with concentrated hydrochloric acid in two stages.

Patent Document 6 describes the solids obtained by leaching low-grade titanium ore with 35-40% hydrochloric acid at a reaction temperature of 60-70°C, and then using 35-40% hydrochloric acid at a reaction temperature of 75-80°C. Under leaching, and manufacturing high-grade synthetic rutile method. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Publication No. 49-18330 [Patent Document 2] Japanese Patent Publication No. 49-37484 [Patent Document 3] Japanese Patent Application Laid-Open No. 57-51128 [Patent Document 4] Specification of US Patent No. 5830420 [Patent Document 5] International Publication No. 96/24555 [Patent Document 6] Specification of U.S. Patent Publication No. 2015/0252448

[The problem to be solved by the invention]

The method described in the aforementioned Patent Document 3 prevents the titanium concentrate caused by granulation from being scattered outside the flow chlorination furnace. However, since a large amount of silicon oxide remains in the titanium concentrate, the silicon oxide component is used as fine particles during flow chlorination. The reaction residue stays outside the chlorination furnace and adheres to the piping, so there is a problem that frequent cleaning is required in order to remove it. On the other hand, the method described in Patent Document 4 uses titanium oxide slag of 75 to 850 μm as a starting material to prevent the micronization of the titanium concentrate and undergo oxidation, reduction, hydrochloric acid leaching, washing, and firing. In each step, impurities such as silicon oxide components are removed, but there is a problem that the steps are very long and cumbersome. For these reasons, it is a problem to use a simple method to produce high-grade titanium concentrates without adversely affecting production equipment during fluid chlorination. The methods described in the aforementioned Patent Documents 5 and 6 all include a two-stage leaching step using concentrated hydrochloric acid. Therefore, there are problems with safety and the durability of the reaction vessel, and cannot be said to be an industrially advantageous production method. [Means to solve the problem]

In order to solve the above-mentioned problems, the inventors have made active research and obtained the insight that after pulverizing ilmenite-containing iron ore to be finer than before, the initial concentration of hydrochloric acid at a reaction temperature of 80°C or less is 1-20% by mass. After pre-leaching, in the presence of soluble reducing substances, the reaction temperature is above 90℃ and the initial concentration of hydrochloric acid is 15-20% by mass. The impurities such as iron and silicon oxide can be removed by a simple method to obtain high-grade Titanium concentrate, thus completing the present invention. In addition, the obtained knowledge is that if the obtained titanium concentrate is granulated and dried at the same time, the titanium concentrate can have a particle size and hardness suitable for flow chlorination, and it can prevent the titanium concentrate from containing fine powder. The fine powder is scattered to the outside of the furnace, so that it will not have an adverse effect on the production equipment and can effectively carry out fluid chlorination, thus completing the present invention.

That is, the present invention for solving the above-mentioned problems is as follows. [1] A manufacturing method of titanium concentrate, which comprises: The ilmenite-containing iron ore or the like is pulverized into a pulverized product that can pass through a 330-mesh sieve. After pre-leaching at a reaction temperature below 80°C with an initial concentration of 1-20% by mass of hydrochloric acid, In the presence of soluble reducing substances, formal leaching is performed at a reaction temperature above 90°C with an initial concentration of 15-20% by mass of hydrochloric acid. [2] The manufacturing method of titanium concentrate as in [1], in which the initial concentration of hydrochloric acid of 1 to 15% by mass is used for pre-leaching. [3] The method for producing a titanium concentrate as in [1] or [2], which includes, after performing the aforementioned formal leaching, washing the leaching material obtained by solid-liquid separation and drying. [4] The manufacturing method of titanium concentrate as in [3], wherein the drying is granulation and drying. [5] The method for producing a titanium concentrate such as [3] or [4], wherein the dried product obtained by drying is fired at a temperature of 600~1000°C. [6] The method for producing a titanium concentrate according to any one of [1] to [5], wherein the formal leaching is performed at a temperature below the boiling point of the leaching solution. [7] The method for producing a titanium concentrate according to any one of [1] to [6], wherein pre-leaching is performed in the presence of a fluorine-based additive. [8] The method for producing a titanium concentrate as described in any one of [1] to [7], which includes pre-leaching in the presence of a soluble reducing substance. [9] The method for producing a titanium concentrate according to any one of [1] to [8], wherein the step of adding a fluorine-based additive is performed after the above-mentioned main leaching is performed. [10] The method for producing a titanium concentrate according to any one of [1] to [9], wherein the titanium concentrate contains titanium oxide having a rutile structure. [11] The method for producing a titanium concentrate according to [3] or [4], wherein the aforementioned drying is performed to produce a titanium concentrate containing titanium oxide having a rutile structure. [12] The method for producing a titanium concentrate according to any one of [1] to [11], wherein the soluble reducing substance is metallic iron and/or soluble titanium salt. [13] The method for producing a titanium concentrate as in [12], wherein the soluble reducing substance is a titanium (III) salt. [Effects of the invention]

According to the manufacturing method of the titanium concentrate of the present invention, even if the ilmenite containing a large amount of iron and silicon oxide and other impurities are used as the starting material, it is simple and safe, and it is convenient and safe for the reaction vessel. It is an industrially advantageous method with less load, so it can effectively produce high-grade titanium concentrates. Moreover, by performing the granulation and drying of the titanium concentrate at the same time, the titanium concentrate can be made into an appropriate particle size and hardness, and the titanium concentrate can be prevented from containing fine powder, which can prevent the fine powder from flying out of the flow chlorination furnace, which can achieve high yield Obtain titanium tetrachloride.

The following is a detailed description of the embodiments of the present invention. However, the present invention is not limited to these, and various changes can be made within the stated scope, and embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

The ilmenite-containing ore or its analogues applicable to the production method of the present invention are ilmenite, ilmenite-containing metamorphic substances, such as ilmenite, hematite, and other ilmenite-containing ore. Those who implement pretreatment or analogs with similar composition and properties. Titanium-containing iron ore with a high degree of metamorphism or a low degree of metamorphism can be applied, and ilmenite-containing ore with a low degree of metamorphism or the like containing a large amount of impurities such as silicon oxide components can also be preferably used. Moreover, so-called titanium slag, which is a by-product of iron smelting, can also be used. The particle size of these ilmenite-containing iron ore or the like is usually 50 to 500 μm, and those with a particle size larger than that can be appropriately pulverized in advance for use. Such ilmenite-containing iron ore or the like, in addition to the iron component and the silicon oxide component, may also contain selected from Al, Ca, Co, Cr, Cu, Ga, Ge, Mg, Mn, Mo, Nb, Impurities formed by oxides of at least one element of the group consisting of Ni, Pd, Ru, Sn, Ta, V, W, and Zr. The content of silicon oxide in titanium-containing iron ore or the like is usually 0.5 to 35% by mass _{in terms of SiO 2.}

In the manufacturing method of the present invention, the ilmenite-containing iron ore or the like is crushed to a particle size that can pass through a 330 mesh (mesh opening 45 μm) sieve. The pulverization is dry pulverization, or wet pulverization in a solvent. Common pulverization methods such as ball mills, tube mills, vibratory ball mills, sand mills, disc mills, media mills, and no media can be used. Mill, roll mill, etc. The pulverization is preferably performed after dry pulverization and then wet pulverization. In the case of wet pulverization, the solvent and the pulverized product are separated into solid and liquid after pulverization. The solid-liquid separation can be carried out by decantation, sedimentation separation, centrifugal separation, filtration, membrane separation, etc., but it is desirable to carry out by decantation. The obtained pulverized product is not pulverized, or the pulverization is not sufficiently pulverized to a specific particle size, and impurities such as silicon oxide components in the titanium concentrate cannot be sufficiently removed, and a high TiO ₂ grade titanium concentrate cannot be obtained. Moreover, it also has the disadvantage of not being able to effectively perform the pre-leaching or formal leaching steps. Therefore, it is important to be crushed to a particle size that can pass through a 330 mesh (mesh opening of 45 μm), preferably a particle size that can pass through a 440 mesh (mesh opening of 32 μm), and more preferably a particle size that can pass through 635. The size of the sieve of the mesh (mesh opening 20μm). After pulverization, it is better to carry out sizing. The difference in the sedimentation speed of the particles can be used to remove extremely fine powder.

After pre-leaching the resulting pulverized product at a reaction temperature below 80°C with an initial concentration of 1-20% by mass of hydrochloric acid, in the presence of soluble reducing substances, at a reaction temperature above 90°C with an initial concentration of 15-20% by mass of hydrochloric acid Perform formal leaching to remove impurities such as iron and silicon oxide. The hydrochloric acid used is expressed by the initial concentration, which is the concentration of hydrochloric acid at the beginning of leaching. In the pre-leaching, the initial concentration of hydrochloric acid is desirably 1 to 15% by mass in order to remove the silicon oxide component more efficiently. On the other hand, if the initial concentration of hydrochloric acid is set to 15-20% by mass, the iron component can be removed more efficiently. Both the leaching container for pre-leaching and the leaching container for formal leaching use leaching containers made of materials that are not corroded by hydrochloric acid. They can be open containers or closed containers like autoclaves. In addition, in order to sufficiently remove the iron component and the silicon oxide component, the aforementioned pre-leaching may be performed multiple times, and the main leaching may be performed multiple times.

The amount of hydrochloric acid used in the pre-leaching (V), relative to the mass (W) of the pulverized product, preferably V/W is 1.5-20, more preferably 5-15, and even more preferably 7-12. Moreover, the pre-leaching is preferably performed at a temperature below 80°C, and more preferably performed at a temperature below 60°C. The time can be set appropriately, preferably 1 to 15 hours. Furthermore, if the pre-leaching is performed in the presence of a fluorine-based additive, the silicon oxide component can be dissolved, so it is efficient. As the fluorine-based additive, sodium fluoride, potassium fluoride, calcium fluoride, hydrofluoric acid, etc. can be used. The amount of fluorine-based additives added can be appropriately set. The pre-leaching is also the same as the formal leaching. In order to increase the dissolution rate and the dissolution amount of the iron component, a soluble reducing substance described later may also be present. The leaching material after pre-leaching can be directly supplied to the subsequent formal leaching step, or the pre-leaching container can be added with hydrochloric acid and soluble reducing substances for continuous formal leaching. On the other hand, after pre-leaching, decantation, sedimentation separation, centrifugal separation, filtration, membrane separation, etc. can also be used to separate the pre-leached extract from solid-liquid, and then concentrate it in the form of wet cake or slurry. After the formal leaching step. Furthermore, after the solid-liquid separation of the extract, it may be washed with water, and the coexisting ions remaining in the extract may be desalinated. In this case, the extract is separated in the form of a wet cake and used for the subsequent formal leaching step.

The amount of hydrochloric acid used in the formal leaching (V), relative to the mass (W) of the extract after pre-leaching, preferably V/W is 1-10, more preferably 2-8. The formal leaching is carried out at a reaction temperature above 90°C, and is more preferably carried out at a temperature below the boiling point of the leaching solution. The time can be set appropriately, preferably for 2-20 hours. When using an open type leaching vessel, it is better to perform leaching at 90~110℃ (below the boiling point) for 5-20 hours. When using a closed type leaching vessel, the temperature and time can be set appropriately according to the pressurization conditions, preferably 110~ Leach at 160°C for 2-18 hours.

During pre-leaching or formal leaching, due to the presence of soluble reducing substances in the leaching solution (also referred to as "soluble reducing substances" in this application), the dissolution rate or amount of iron components can be increased, and the yield of titanium can also be increased. rate. Examples of the soluble reducing substance include metallic iron and/or soluble titanium salt. When metallic iron enters the leachate, it dissolves and becomes iron ions. As the soluble titanium salt, there are exemplified titanium (III) salt, titanium (IV) salt, etc., but titanium (III) salt is preferable. Moreover, as a method for making the titanium(III) salt exist in the system, in addition to the method of adding the titanium(III) salt solution, the addition of metal iron powder to the leaching solution can also reduce the titanium(IV) salt in the system to Titanium(III) salt, therefore, it is preferable to combine metallic iron and soluble titanium salt as a soluble reducing substance. The addition amount of the soluble titanium salt can be appropriately set, and is preferably 0.8 to 1.5 times the amount, more preferably 0.9 to 1.2 times the amount for reducing the trivalent iron component to divalent (reduction equivalent).

In addition, in the main leaching, the seed crystals for promoting hydrolysis of titanium salt may be used in combination. It is the seed crystal used to hydrolyze the titanium salt solution and precipitate the titanium component in the general method of producing titanium dioxide pigment by the sulfuric acid method. It is an acidic solution such as titanium salt that neutralizes titanium oxysulfate to precipitate The colloidal titanium compound is matured. When the titanium salt hydrolysis promotion seed crystal is used together, its addition amount is relative to the extract after pre-leaching. The titanium component in the titanium salt hydrolysis promotion seed crystal is _{calculated as TiO 2} , preferably about 0.05-2 mass%, usually It is 0.1 to 1% by mass.

If fluorine-based additives are added to the leaching solution after the formal leaching, or the leaching solution is made into a slurry after solid-liquid separation by decantation, sedimentation separation, centrifugal separation, filtration, membrane separation, etc., the leaching can be removed The remaining silicon oxide component in the substance is preferred. This step is called deoxidation treatment, and as the fluorine-based additives, the aforementioned sodium fluoride, potassium fluoride, calcium fluoride, hydrofluoric acid, etc. can be used. The amount of fluorine-based additives added can be appropriately set. The temperature of the deoxidation treatment is preferably performed at a temperature below the boiling point of the leachate, and more preferably at a temperature of 20 to 90°C. The time of deoxidation treatment can be set appropriately, preferably 0.5~10 hours.

Pre-leaching and formal leaching are followed by deoxidation treatment to remove iron and silica components and other impurities (ie titanium concentrate) by decantation, sedimentation separation, centrifugal separation, filtration, membrane separation, etc. And solid-liquid separation. Subsequently, it is better to wash and perform desalination treatment of the coexisting ions remaining in the extract. The desalination treatment is preferably washed until the conductivity becomes 0.1 S/m or less. Subsequently, the extract is usually dried for powder. The drying temperature can be set appropriately. Furthermore, after drying, pulverization and granulation may be carried out as needed. The more concentrated the titanium-based composition for producing a high grade of TiO _2, preferably less than 95% by mass.

When the granulation is performed at the same time during the drying, it is preferable to have a particle size and hardness suitable for flow chlorination. Such granulation drying can use a usual granulation dryer, more preferably a fluidized bed granulation dryer or a spray dryer. In the case of granulation and drying by a spray dryer, it is preferable to prepare the aforementioned wet cake into a slurry, perform wet pulverization as necessary, and then perform spray drying. By granulating and drying, the titanium concentrate can be granulated to a particle size of 30~300μm, and it can have a moderate hardness.

The manufacturing method of the titanium concentrate of the present invention is carried out after the pre-leaching and the formal leaching, and then the solid-liquid separation obtained after the formal leaching (preferably the leaching after deoxidized silicon treatment) is cleaned Drying, especially granulating drying, can produce a titanium concentrate containing titanium oxide with a rutile structure. Even if the method of the present invention is not fired at a high temperature, if it is dried, it is possible to produce a titanium concentrate containing only titanium oxide having a rutile structure. Titanium oxide having a rutile structure is efficiently chlorinated due to its good reactivity with chlorine gas. The obtained titanium concentrate containing titanium oxide with a rutile structure can be fired at a temperature of 600~1000°C according to need in order to improve the hardness and purity. [Example]

Next, the present invention will be specifically described based on examples and comparative examples, but the present invention is not limited to the following examples and comparative examples at all.

The main component composition of the raw material ilmenite ore is shown in Table 1, and the particle size distribution is shown in Figure 1. In addition, the total TiO _{2 in} each table represents the value of the Ti content in the composition in terms of TiO _2. The composition is analyzed by volume analysis (Ti composition and Fe composition) and ICP emission spectroscopy analysis. The particle size distribution was measured with a laser diffraction/scattering particle size distribution measuring device LA-950 (manufactured by Horiba Manufacturing Co., Ltd.).

Example 1 The aforementioned ilmenite ore was pulverized with a ball mill, and it was confirmed that it can pass through a 330-mesh (44 μm) sieve. The particle size distribution of the crushed product is shown in FIG. 2. The obtained pulverized product and 10% by mass hydrochloric acid were put into a reaction vessel with a stirrer and mixed so that V/W=10, and the pre-leaching was performed while stirring at 30°C for 2 hours. Then the solid-liquid separation is carried out by filtration and washing with water. The wet cake obtained is transferred to a reaction tank with a condenser and mixed with 19% by mass hydrochloric acid in a manner of V/W=3.77. The trivalent iron component was reduced to the divalent amount (reduction equivalent) of TiCl ₃ together at 108°C (boiling point) for 10 hours. After completion of the reaction, solid-liquid separation was performed by filtration and washing with water, and after the slurry was made, it was spray-dried with a spray dryer to obtain a titanium concentrate. As the titanium concentrate, by replacing the nozzle of the spray dryer, two kinds of granular dried products with an average particle size of 40μm and 200μm particles can be obtained. The main component composition of the obtained titanium concentrate is shown in Table 2. The total _{amount of TiO 2} is titanium oxide with rutile structure, and does not contain anatase structure titanium oxide or amorphous titanium oxide. The total Fe in the table represents _{the total amount of FeO and Fe 2} O ₃ analyzed in terms of Fe.

Example 2 The pulverized product obtained in the same manner as in Example 1 and 19% by mass hydrochloric acid were put into a reaction vessel with a stirrer so that V/W=3.25. Pre-leaching is carried out in the presence of Fe(0) (ie, metallic iron) equivalent to 1 times the reduction equivalent of TiCl _3. Then it was transferred to a reaction tank with a condenser, and 19% by mass hydrochloric acid was additionally mixed so that V/W=3.50, and the titanium (III) salt reduced by the aforementioned Fe(0) was added at 108°C (boiling point). Formally leaches for 10 hours in the presence of water. After the reaction, the solid-liquid separation is performed by filtration and washing with water. Next, after the slurry is made, it is mixed with a 3% hydrofluoric acid solution (hydrofluoric acid aqueous solution) and stirred at 70° C. for 2 hours to perform deoxidation treatment. After the silica removal treatment is completed, solid-liquid separation is performed by filtration and washing with water, and after the slurry is made, it is spray-dried with a spray dryer to obtain a titanium concentrate. As a titanium concentrate, by replacing the nozzle of the spray dryer, two kinds of granular dried products with an average particle size of 40μm and a granular dried product with an average particle size of 200μm can be obtained. The main components of the titanium concentrate are shown in Table 3. The total _{amount of TiO 2} is titanium oxide with rutile structure, and does not contain anatase structure titanium oxide or amorphous titanium oxide. The total Fe in the table means the total amount of FeO and Fe ₂ O ₃ analyzed in terms of Fe.

Comparative Example 1 The ilmenite ore before pulverization used in Example 1 and 19% by mass hydrochloric acid were put into a reaction tank with a condenser so that V/W=3.77, together with 1 reduction equivalent of TiCl ₃ Leach at 108°C (boiling point) for 10 hours. After the reaction, solid-liquid separation was performed by filtration and washing with water to obtain a titanium concentrate. The main component composition of the dried titanium concentrate at this time is shown in Table 4.

When comparing the titanium concentrates of Example 1 and Example 2 and Comparative Example 1, it can be seen that the TiO ₂ grade of Example 1 and Example 2 is higher than that of Comparative Example 1, and the content of silicon oxide and iron is also lower. And it can be seen that after the titanium concentrates of Example 1 and Example 2 are used for fluid chlorination, since they are not scattered outside the furnace, they have no adverse effects on the production equipment, and the fluid chlorination can be effectively performed, which can achieve high yields. Rate manufacturing titanium tetrachloride. [Industrial availability]

The manufacturing method of the titanium concentrate of the present invention can efficiently manufacture high-grade titanium by a simple method, even if the ilmenite containing a large amount of iron and silicon oxide and other impurities are used as the starting material. The concentrate can obtain titanium tetrachloride and the like in a high yield and is an industrially useful technology.

[Figure 1] The particle size distribution diagram of the raw material ilmenite ore. [Figure 2] is the particle size distribution diagram of the crushed ilmenite ore used in the examples.

Claims (13)

A manufacturing method of titanium concentrate, which comprises: The ilmenite-containing iron ore or the like is pulverized into a pulverized product that can pass through a 330-mesh sieve. After pre-leaching at a reaction temperature below 80°C with an initial concentration of 1-20% by mass of hydrochloric acid, In the presence of soluble reducing substances, formal leaching is performed at a reaction temperature above 90°C with an initial concentration of 15-20% by mass of hydrochloric acid. Such as the manufacturing method of the titanium concentrate of claim 1, wherein the initial concentration of hydrochloric acid of 1 to 15% by mass is pre-leached. The method for manufacturing a titanium concentrate according to claim 1 or 2, which includes, after performing the aforementioned formal leaching, washing and drying the leached product obtained by solid-liquid separation. Such as the method of manufacturing a titanium concentrate of claim 3, wherein the drying is granulation and drying. Such as claim 3 or 4 of the manufacturing method of titanium concentrate, wherein the dried product obtained by drying is fired at a temperature of 600-1000°C. The method for producing a titanium concentrate according to any one of claims 1 to 5, wherein the formal leaching is performed at a temperature below the boiling point of the leaching solution. The method for producing a titanium concentrate according to any one of claims 1 to 6, wherein the pre-leaching is performed in the presence of a fluorine-based additive. The method for manufacturing a titanium concentrate according to any one of claims 1 to 7, which includes pre-leaching in the presence of a soluble reducing substance. The method for producing a titanium concentrate according to any one of claims 1 to 8, wherein after the aforementioned formal leaching is performed, the step of adding a fluorine-based additive is performed. The method for producing a titanium concentrate according to any one of claims 1 to 9, wherein the titanium concentrate comprises titanium oxide having a rutile structure. The method for producing a titanium concentrate according to claim 3 or 4, wherein the aforementioned drying is performed to produce a titanium concentrate containing titanium oxide having a rutile structure. The method for manufacturing a titanium concentrate according to any one of claims 1 to 11, wherein the soluble reducing substance is metallic iron and/or soluble titanium salt. For example, the method for manufacturing a titanium concentrate of claim 12, wherein the soluble reducing substance is a titanium (III) salt.

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