A method for improving the efficiency and purity of producing synthetic rutile from reduced ilmenite rusters

Abstract

The present application relates to the technical field of artificial rutile, and particularly discloses a method for improving the efficiency and purity of artificial rutile produced by reducing ilmenite corrosion, which comprises the following steps: preparing a corrosion solution by mixing hydrochloric acid and industrial water, and then injecting the corrosion solution into a stirring corrosion tank; adding a catalyst into the stirring corrosion tank according to a set proportion; adding reduced ilmenite into the stirring corrosion tank, and simultaneously performing aeration by using a Roots blower to generate a hydration iron oxide and an artificial rutile slurry; and separating the hydration iron oxide and the artificial rutile slurry to obtain the artificial rutile. In the method for improving the efficiency and purity of artificial rutile produced by reducing ilmenite corrosion, the corrosion reaction is quickly and effectively performed by adding the catalyst, the corrosion reaction time is greatly shortened, the production efficiency is improved, and the energy consumption cost is saved; meanwhile, the catalyst, the corrosion solution and the washing solution can be recycled, the chemical reagent cost is saved, and the pollution to the environment is reduced.

Description

Technical Field

[0001] This invention relates to the field of synthetic rutile technology, and in particular to a method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite corrosion. Background Technology

[0002] Rutile's main component is titanium dioxide. It is divided into natural rutile and synthetic rutile. Natural rutile is scarce due to over-exploitation and cannot meet industrial demand. Synthetic rutile has the same composition as natural rutile. However, most titanium ores in nature exist in the form of ilmenite (TiFeO3). To separate titanium dioxide from ilmenite, ilmenite needs to be reduced to reduced ilmenite, and then subjected to a reduced ilmenite corrosion reaction to obtain synthetic rutile.

[0003] The widely used etching method for producing synthetic rutile is the hydrochloric acid etching method. This method involves adding reduced ilmenite to an etching solution containing hydrochloric acid. The iron in the reduced ilmenite reacts with the etching solution to form fine hydrated iron oxide particles, which are then removed from the ore. These hydrated iron oxide particles are extremely small, with most having a diameter of less than 20 micrometers. As the reaction proceeds, more and more iron oxide particles are formed. These hydrated iron oxide particles easily adhere to the surface of the reduced ilmenite, reducing the contact between the reduced ilmenite and oxygen and the etching solution, thus slowing down the etching reaction. This results in an excessively long etching time and high energy consumption costs. Chinese patent application CN114293031A discloses a multi-stage corrosion method for iron-bearing minerals, comprising: detecting the slurry concentration and iron content of the ore body in the reaction tank, and performing multi-stage corrosion treatment on the iron-bearing minerals according to the slurry concentration and iron content of the ore body. Multi-stage corrosion treatment can shorten the corrosion treatment time and improve production efficiency. However, this method requires monitoring the slurry concentration and performing multiple separation and feeding processes, increasing the operation procedures and complexity. To further improve production efficiency and reduce production costs, a method for improving the efficiency and purity of synthetic rutile produced from the corrosion of reduced ilmenite has been developed. Summary of the Invention

[0004] To address the above shortcomings, this invention provides a method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite corrosion. This method overcomes the deficiencies of the hydrochloric acid corrosion method, accelerates the corrosion reaction, significantly shortens the reaction time, and reduces energy costs. Simultaneously, the catalyst is present in the recovery solution and enters the recovery tank, allowing it to participate in the corrosion reaction repeatedly, thus saving catalyst costs. The specific technical solution is as follows:

[0005] A method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite rust includes the following steps:

[0006] (1) Preparation of rust solution: Prepare rust solution with hydrochloric acid and industrial water, and pour it into the stirring rust tank;

[0007] (2) Catalyst preparation: The catalyst is injected into the stirred corrosion tank. The catalyst contains one or two of organic acid solution and fatty alcohol polyoxyethylene ether. The organic acid is one or more of formic acid, acetic acid and propionic acid.

[0008] (3) Add reduced ilmenite to the stirring corrosion tank and ventilate with a Roots blower to carry out the corrosion reaction and generate hydrated iron oxide and artificial rutile slurry.

[0009] (4) Use a hydrocyclone and a high-frequency vibrating screen to separate hydrated iron oxide and artificial rutile slurry into artificial rutile semi-finished product and iron red liquid.

[0010] (5) Wash and dry the artificial rutile semi-finished product to obtain the artificial rutile product.

[0011] The corrosion mechanism of reduced ilmenite is as follows: Reduced ilmenite undergoes an electrochemical reaction in an acidic solution containing chloride ions, as shown in equation (1). Fe is converted to Fe₂O₃·H₂O, thereby removing a large amount of Fe from the reduced ilmenite and generating synthetic rutile with a low Fe content. Titanium originally exists in the mineral particles as titanium oxide; the corrosion reaction simply removes non-titanium impurities, primarily iron, making it synthetic rutile with titanium oxide as the main component.

[0012] Fe-2e - =Fe 2+

[0013] O2+2e - =O 2-

[0014] O2 + 2H2O + 4e - =4OH -

[0015] Fe 2+ +2OH - =Fe(OH)2

[0016] 2Fe(OH)2+1 / 2O2=Fe2O3·H2O+H2O (1)

[0017] The inventors of this invention discovered during their research that adding a catalyst to the rusting system of reduced ilmenite and hydrochloric acid solution can make the rusting reaction proceed rapidly and effectively, greatly shortening the rusting reaction time. The reason for this is that adding a catalyst to the rusting reaction system generates a large number of bubbles. The large number of fine hydrated iron oxide particles produced by the reaction adhere to the surface of the bubbles, thereby reducing the probability of contact between the fine hydrated iron oxide and the surface of reduced ilmenite, promoting the continuous and efficient reaction of reduced ilmenite, thus shortening the reaction time, improving production efficiency, and saving energy costs.

[0018] Preferably, in the above-mentioned method for improving the efficiency and purity of synthetic rutile production by rusting reduced ilmenite, the HCl mass percentage concentration in the rusting solution is 0.3% to 2%, and the mass ratio of the rusting solution to reduced ilmenite is 1.5 to 3:1.

[0019] Preferably, in the above-mentioned method for improving the efficiency and purity of producing synthetic rutile from reduced ilmenite corrosion, the organic acid solution has a mass percentage concentration of 36% to 99.9%, the amount of organic acid solution used is 0.35% to 1.00% of the mass of reduced ilmenite, and the amount of fatty alcohol polyoxyethylene ether used is 0.03% to 0.08% of the mass of reduced ilmenite.

[0020] Preferably, in the above-described method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite corrosion, the catalyst is an acetic acid solution and a fatty alcohol polyoxyethylene ether. The amount of acetic acid solution used is 0.15–0.3% of the mass of the reduced ilmenite, and the amount of fatty alcohol polyoxyethylene ether used is 0.005–0.02% of the mass of the reduced ilmenite. The combined action of fatty alcohol polyoxyethylene ether and acetic acid can enhance the catalytic effect, further shorten the corrosion reaction time, and improve the corrosion efficiency.

[0021] Preferably, in the above-mentioned method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite rusting, in step (3), the rusting temperature is 40℃~90℃, and air is introduced at a flow rate of 1200m³. 3 / h~1800m 3 / h, stirring speed is 70r / min~145r / min.

[0022] Preferably, in the above-mentioned method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite corrosion, the fatty alcohol polyoxyethylene ether is AEO-9, AEO-10, or AEO-12.

[0023] Preferably, in the above-mentioned method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite corrosion, the synthetic rutile obtained in step (5) is subjected to impurity removal, and the impurity removal method includes the following steps:

[0024] S1. Add the artificial rutile semi-finished product obtained in step (5) into an acid leaching tank, add an activator, the solid-liquid ratio is 1:4-6, and then activate it at 110-130℃ for 30-40 minutes;

[0025] S2. Mix the activated synthetic rutile obtained in step S1 with the mixed acid solution at a solid-liquid ratio of 1:4 to 6, and stir at 90 to 100°C for 30 to 40 minutes.

[0026] S3. The synthetic rutile obtained in step S2 is mixed with a mixed solution of hydrogen peroxide and sulfuric acid at a solid-liquid ratio of 1:4-6. The mixture is stirred at 70-80℃ for 30-40 minutes, then filtered, washed, and dried to obtain a high-purity synthetic rutile product. By using the above impurity removal method and optimizing the impurity removal steps and process parameters, the purity of synthetic rutile can be increased to over 92%.

[0027] The washing liquid generated during the impurity removal process can be recycled, but recycling will stop when the artificial rutile product is substandard. At this time, the washing liquid needs to be regenerated. The acid leaching washing liquid is neutralized with lime milk to a pH of 7-8, and Fe(OH)3 and Al(OH)3 can be recovered and used as building material raw materials.

[0028] Preferably, in the above-mentioned method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite corrosion, in step S1, the activator is sulfuric acid or sodium hydroxide solution, wherein the mass percentage concentration of sulfuric acid is 40-80% and the mass percentage concentration of sodium hydroxide is 30-40%.

[0029] Preferably, in the above-mentioned method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite corrosion, in step S2, the mixed acid solution is a mixed solution of sulfuric acid and nitric acid, wherein the mass percentage concentration of sulfuric acid is 15% and the mass percentage concentration of nitric acid is 3-5%.

[0030] Preferably, in the above-mentioned method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite corrosion, in step S3, the mass percentage concentration of hydrogen peroxide in the hydrogen peroxide and sulfuric acid mixed solution is 3%, and the mass percentage concentration of sulfuric acid is 5%.

[0031] Preferably, the above-mentioned method for improving the efficiency and purity of artificial rutile production by reducing ilmenite rust further includes pressing and filtering the iron red liquid in step (4) and the washing liquid obtained in step (5) to obtain iron red filter cake and rust recovery liquid, and collecting the rust recovery liquid in the rust recovery liquid pool for rust reaction recycling.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] 1. In the method of improving the efficiency and purity of synthetic rutile production by reducing ilmenite corrosion according to the present invention, a catalyst is added to enable the hydrochloric acid corrosion reaction to proceed rapidly and effectively, greatly shortening the corrosion reaction time, improving production efficiency and saving energy costs; at the same time, the catalyst and corrosion solution of the present invention can be recycled, saving the cost of chemical reaction reagents and reducing environmental pollution.

[0034] 2. In the method of improving the efficiency and purity of synthetic rutile production from reduced ilmenite corrosion of the present invention, further impurities are removed from the synthetic rutile semi-finished product by adding sulfuric acid or sodium hydroxide solution to activate it, by acid leaching with mixed acid, and by oxidation with hydrogen peroxide. The impurity removal steps and process parameters are optimized, which can improve the purity of the synthetic rutile product to over 92%. Attached Figure Description

[0035] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 The present invention provides a process flow diagram for improving the efficiency of producing synthetic rutile from reduced ilmenite corrosion.

[0037] Figure 2 The flowchart of the impurity removal process in the method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite corrosion according to the present invention. Detailed Implementation

[0038] The specific embodiments of the present invention are described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments. Unless otherwise defined, all technical terms used below have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing specific embodiments only and are not intended to limit the scope of protection of the present invention. Unless otherwise specifically stated, all raw materials, reagents, instruments, and equipment used in the present invention are commercially available or can be prepared by existing methods.

[0039] In the following examples and comparative examples, the reduced ilmenite was obtained from the ilmenite reduction process, and its main components (mass percentage) included: titanium dioxide (TiO2) 61.25% and total iron (TFe) 31.56%.

[0040] Example 1

[0041] A method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite rust, such as... Figure 1 As shown, it includes the following steps:

[0042] (1) Preparation of rust solution: Take hydrochloric acid and industrial water to prepare 2% HCl rust solution by mass percentage, and inject 2 times the mass of reduced ilmenite rust solution into the stirring rust tank;

[0043] (2) Preparation of catalyst: Take an acetic acid solution with a mass percentage concentration of 99.9% as the catalyst. The amount of acetic acid solution used is 0.35% of the mass of reduced ilmenite. Pour the acetic acid aqueous solution into the stirring corrosion tank.

[0044] (3) Add the reduced ilmenite to the agitated corrosion tank, and simultaneously introduce air using a Roots blower at a flow rate of 1800 m³ / h. 3 The stirring speed was 120 r / min and the rusting temperature was 81℃. The rusting reaction was carried out to obtain hydrated iron oxide and artificial rutile slurry.

[0045] (4) Use a hydrocyclone and a high-frequency vibrating screen to separate hydrated iron oxide and artificial rutile slurry into artificial rutile semi-finished product and iron red liquid.

[0046] (5) Wash the artificial rutile semi-finished product with water or washing and recycling liquid, and dry it to obtain the artificial rutile product.

[0047] The iron red liquid in step (4) and the washing liquid obtained from washing in step (5) are filtered by pressure to obtain iron red filter cake and rust recovery liquid. The rust recovery liquid is collected in the rust recovery liquid pool for rust reaction recycling.

[0048] Fourteen tons of reduced ilmenite were placed in an etching tank for etching, and the process was carried out according to the method in Example 1. The etching reaction took 8 hours to complete. The main components (mass percentage) of the resulting synthetic rutile were: TiO2 83.85% and TFe 6.83%. The specific components are shown in Table 1 below.

[0049] Example 2

[0050] A method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite rust includes the following steps:

[0051] (1) Preparation of rust solution: Take hydrochloric acid and industrial water to prepare 2% HCl rust solution by mass percentage, and inject 2 times the mass of reduced ilmenite rust solution into the stirring rust tank;

[0052] (2) Preparation of catalyst: Take an aqueous acetic acid solution with a mass percentage concentration of 36% as the catalyst. The amount of the aqueous acetic acid solution is 1.00% of the mass of the reduced ilmenite and inject it into the stirring corrosion tank.

[0053] (3) Add the reduced ilmenite to the agitated corrosion tank, and simultaneously introduce air using a Roots blower at a flow rate of 1200 m³ / h. 3 The stirring speed was 120 r / min, the rusting temperature was 75℃, and the rusting reaction was carried out to obtain hydrated iron oxide and artificial rutile slurry.

[0054] (4) Use a hydrocyclone and a high-frequency vibrating screen to separate hydrated iron oxide and artificial rutile slurry into artificial rutile semi-finished product and iron red liquid.

[0055] (5) Wash the artificial rutile semi-finished product with water or washing and recycling liquid, and dry it to obtain artificial rutile.

[0056] The iron red liquid in step (4) and the washing liquid obtained from washing in step (5) are filtered by pressure to obtain iron red filter cake and rust recovery liquid. The rust recovery liquid is collected in the rust recovery liquid pool for rust reaction recycling.

[0057] Fourteen tons of reduced ilmenite were placed in an etching tank for etching. The process was carried out according to the method of this embodiment. The etching reaction took 8 hours. The main components (mass percentage) of the resulting synthetic rutile were: TiO2 83.96% and TFe 6.74%.

[0058] Example 3

[0059] A method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite rust includes the following steps:

[0060] (1) Preparation of rust solution: Take hydrochloric acid and industrial water to prepare 2% HCl rust solution by mass percentage, and inject 2 times the mass of reduced ilmenite rust solution into the stirring rust tank;

[0061] (2) Preparation of catalyst: Take fatty alcohol polyoxyethylene ether AEO-10 ​​as catalyst. The amount of fatty alcohol polyoxyethylene ether AEO-10 ​​is 0.05% of the mass of reduced ilmenite and inject it into the stirring corrosion tank.

[0062] (3) Add the reduced ilmenite to the agitated corrosion tank, and simultaneously introduce air using a Roots blower at a flow rate of 1500 m³ / h. 3 The stirring speed was 140 r / min, the rusting temperature was 75℃, and the rusting reaction was carried out to obtain hydrated iron oxide and artificial rutile slurry.

[0063] (4) Use a hydrocyclone and a high-frequency vibrating screen to separate hydrated iron oxide and artificial rutile slurry into artificial rutile semi-finished product and iron red liquid.

[0064] (5) Wash the artificial rutile semi-finished product with water or washing and recycling liquid, and dry it to obtain artificial rutile.

[0065] The iron red liquid in step (4) and the washing liquid obtained from washing in step (5) are filtered by pressure to obtain iron red filter cake and rust recovery liquid. The rust recovery liquid is collected in the rust recovery liquid pool for rust reaction recycling.

[0066] Fourteen tons of reduced ilmenite were placed in an etching tank for etching. The process was carried out according to the method of this embodiment. The etching reaction took 10.5 hours. The main components (mass percentage) of the resulting synthetic rutile were: TiO2 83.27% and TFe 7.49%.

[0067] Example 4

[0068] A method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite rust includes the following steps:

[0069] (1) Preparation of rust solution: Take hydrochloric acid and industrial water to prepare 2% HCl rust solution by mass percentage, and inject 2 times the mass of reduced ilmenite rust solution into the stirring rust tank;

[0070] (2) Preparation of catalyst: Take acetic acid solution with a mass percentage concentration of 99.9% and fatty alcohol polyoxyethylene ether AEO-10 ​​as catalyst. The amount of acetic acid aqueous solution is 0.25% of the mass of reduced ilmenite, and the amount of fatty alcohol polyoxyethylene ether AEO-10 ​​is 0.01% of the mass of reduced ilmenite. The acetic acid aqueous solution and fatty alcohol polyoxyethylene ether AEO-10 ​​are injected into the stirring corrosion tank in sequence.

[0071] (3) Add the reduced ilmenite to the agitated corrosion tank, and simultaneously introduce air using a Roots blower at a flow rate of 1200 m³ / h. 3 The stirring speed was 120 r / min, the rusting temperature was 75℃, and the rusting reaction was carried out to obtain hydrated iron oxide and artificial rutile slurry.

[0072] (4) Use a hydrocyclone and a high-frequency vibrating screen to separate hydrated iron oxide and artificial rutile slurry into artificial rutile and iron red liquid.

[0073] (5) Wash the artificial rutile with water or washing and recycling liquid, and dry it to obtain artificial rutile.

[0074] The iron red liquid in step (4) and the washing liquid obtained from washing in step (5) are filtered by pressure to obtain iron red filter cake and rust recovery liquid. The rust recovery liquid is collected in the rust recovery liquid pool for rust reaction recycling.

[0075] Fourteen tons of reduced ilmenite were placed in a rusting tank for rusting. The production was carried out according to the method of this embodiment. The rusting reaction took 7 hours to complete. The main components (mass percentage) of the obtained synthetic rutile were: TiO2 84.02% and TFe 6.67%.

[0076] Comparative Example 1

[0077] A method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite rust includes the following steps:

[0078] (1) Preparation of rust solution: Take hydrochloric acid and industrial water to prepare 2% HCl rust solution by mass percentage, and inject 2 times the amount of rust solution that reduces ilmenite into the stirring rust tank;

[0079] (3) Add the reduced ilmenite to the agitated corrosion tank, and simultaneously introduce air using a Roots blower at a flow rate of 1800 m³ / h. 3 The stirring speed was 120 r / min and the rusting temperature was 81℃. The rusting reaction was carried out to obtain hydrated iron oxide and artificial rutile slurry.

[0080] (4) Use a hydrocyclone and a high-frequency vibrating screen to separate hydrated iron oxide and artificial rutile slurry into artificial rutile semi-finished product and iron red liquid.

[0081] (5) The artificial rutile semi-finished product is washed with water or washing and recycling liquid to obtain artificial rutile.

[0082] In production, 14 tons of reduced ilmenite were placed in a rusting tank for rusting, and the production was carried out according to the method of Example 1. The rusting reaction took 12 hours to complete. The main components (mass percentage) of the obtained synthetic rutile were: TiO2 82.30% and TFe 8.25%.

[0083] Comparative Example 2

[0084] The difference between this comparative example and Example 1 is that in step (2), the amount of acetic acid solution used is 0.175% of the mass of the reduced ilmenite. Other steps and parameters are the same as in Example 1. The rusting reaction in this comparative example takes 10 hours to complete. The main components (mass percentage) of the obtained synthetic rutile are: TiO2 83.72%, TFe 7.01%.

[0085] Comparative Example 3

[0086] The difference between this comparative example and Example 2 is that in step (2), the amount of acetic acid aqueous solution used is 1.25% of the mass of the reduced ilmenite. Other steps and parameters are the same as in Example 1. The corrosion reaction in this comparative example takes 8 hours to complete. The main components (mass percentage) of the obtained synthetic rutile are: TiO2 83.87%, TFe 6.79%.

[0087] In summary, the catalyst used in this invention can shorten the corrosion reaction time, improve production efficiency, reduce energy consumption costs, and produce synthetic rutile with a purity of over 82%.

[0088] Example 5

[0089] The synthetic rutile prepared in Example 1 was placed in an acid leaching tank and subjected to activation, acid leaching, and oxidation treatments to remove impurities. The impurity removal method included the following steps:

[0090] S1. Add the artificial rutile obtained in step (5) to the acid leaching tank, add the activator sulfuric acid solution, the mass percentage concentration of sulfuric acid is 40%, the solid-liquid ratio is 1:4, then activate at 130℃ for 30 min, and filter.

[0091] S2. Mix the activated synthetic rutile from step S1 with a mixed acid solution (15% by mass of sulfuric acid and 5% by mass of nitric acid) at a solid-liquid ratio of 1:6, stir at 100°C for 0.5 h, and then filter.

[0092] S3. The synthetic rutile obtained in step S2 is mixed with a mixed solution of 3% hydrogen peroxide and 5% sulfuric acid at a solid-liquid ratio of 1:5. The mixture is stirred at 80°C for 0.5 hours, filtered, washed, and dried to obtain a high-purity synthetic rutile product.

[0093] Example 6

[0094] The synthetic rutile prepared in Example 1 was placed in an acid leaching tank and subjected to activation, acid leaching, and oxidation treatments to remove impurities. The impurity removal method included the following steps:

[0095] S1. Add the artificial rutile obtained in step (5) to the acid leaching tank, add the activator sulfuric acid solution, the mass percentage concentration of sulfuric acid is 55%, the solid-liquid ratio is 1:5, then activate at 120℃ for 40 min, and filter.

[0096] S2. Mix the activated synthetic rutile from step S1 with a mixed acid solution (sulfuric acid with a mass percentage concentration of 15% and nitric acid with a mass percentage concentration of 4%), with a solid-liquid ratio of 1:5, stir at 90°C for 40 min, and filter.

[0097] S3. The synthetic rutile obtained in step S2 is mixed with a mixed solution of 3% hydrogen peroxide and 5% sulfuric acid at a solid-liquid ratio of 1:5. The mixture is stirred at 70°C for 30 minutes, filtered, washed, and dried to obtain a high-purity synthetic rutile product.

[0098] Example 7

[0099] The synthetic rutile prepared in Example 1 was placed in an acid leaching tank and subjected to activation, acid leaching, and oxidation treatments to remove impurities. The impurity removal method included the following steps:

[0100] S1. Add the artificial rutile obtained in step (5) to the acid leaching tank, add the activator sodium hydroxide solution, the mass percentage concentration of sodium hydroxide is 35%, the solid-liquid ratio is 1:5, then activate at 120℃ for 30 min, and filter.

[0101] S2. Mix the activated synthetic rutile from step S1 with a mixed acid solution (sulfuric acid mass percentage concentration of 15% and nitric acid mass percentage concentration of 5%), with a solid-liquid ratio of 1:5, stir at 90°C for 40 min, and filter.

[0102] S3. The synthetic rutile obtained in step S2 is mixed with a mixed solution of 3% hydrogen peroxide and 5% sulfuric acid at a solid-liquid ratio of 1:5. The mixture is stirred at 70°C for 30 minutes, filtered, washed, and dried to obtain a high-purity synthetic rutile product.

[0103] The main chemical components (mass percentage) of the high-purity synthetic rutile obtained from the impurity removal processes in Examples 5-7 are shown in Table 1. As can be seen from the table, the present invention can improve the purity of synthetic rutile to over 92% through further impurity removal processes.

[0104] Table 1. Main chemical components of the high-purity synthetic rutile obtained from the purification processes in Examples 5-7.

[0105] Main ingredients Before cleaning Example 5 Example 6 Example 7 <![CDATA[TiO2(%)]]> 83.85 92.66 93.18 92.53 TFe (%) 6.83 1.55 1.36 1.79 CaO (%) 0.23 0.10 0.08 0.12 MgO (%) 0.46 0.18 0.15 0.23 MnO (%) 2.02 0.65 0.62 0.71 <![CDATA[Al2O3(%)]]> 1.20 0.42 0.37 0.40 P(％) 0.02 ＜0.01 ＜0.01 ＜0.01 S(％) 0.02 ＜0.01 ＜0.01 ＜0.01

[0106] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite corrosion, characterized in that, Includes the following steps: (1) Preparation of rust solution: Prepare rust solution with hydrochloric acid and industrial water, and pour it into the stirring rust tank; (2) Preparation of catalyst: The catalyst is injected into the stirred corrosion tank. The catalyst is acetic acid solution and fatty alcohol polyoxyethylene ether. The amount of acetic acid solution is 0.15~0.3% of the mass of reduced ilmenite, and the amount of fatty alcohol polyoxyethylene ether is 0.005~0.02% of the mass of reduced ilmenite. (3) Add reduced ilmenite to the stirring corrosion tank and ventilate with a Roots blower to carry out the corrosion reaction and generate hydrated iron oxide and artificial rutile slurry. (4) Use a hydrocyclone and a high-frequency vibrating screen to separate hydrated iron oxide and artificial rutile slurry into artificial rutile semi-finished product and iron red liquid; (5) Wash and dry the artificial rutile semi-finished product to obtain the artificial rutile product.

2. The method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite corrosion according to claim 1, characterized in that, The HCl concentration in the rusting solution is 0.3% to 2% by mass, and the mass ratio of the rusting solution to reduced ilmenite is 1.5 to 3:

1.

3. The method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite corrosion according to claim 1, characterized in that, The acetic acid solution has a mass percentage concentration of 36% to 99.9%.

4. The method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite corrosion according to claim 1, characterized in that, The fatty alcohol polyoxyethylene ether is AEO-9, AEO-10, or AEO-12.

5. The method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite corrosion according to claim 1, characterized in that, In step (3), the corrosion temperature is 40℃~90℃, and air is introduced at a flow rate of 1200m³. 3 / h~1800m 3 / h, stirring speed is 70r / min~145r / min.

6. The method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite corrosion according to claim 1, characterized in that, The artificial rutile obtained in step (5) is then purified, and the purification method includes the following steps: S1. Add the artificial rutile obtained in step (5) into the acid leaching tank, add an activator, the solid-liquid ratio is 1:4~6, and then activate it at 110~130℃ for 30~40min; S2. Mix the activated synthetic rutile obtained in step S1 with the mixed acid solution at a solid-liquid ratio of 1:4~6, and stir at 90~100℃ for 30~40 min; S3. Mix the synthetic rutile obtained in step S2 with a mixed solution of hydrogen peroxide and sulfuric acid at a solid-liquid ratio of 1:4~6, stir at 70~80℃ for 30~40 minutes, filter, wash, and dry to obtain a high-purity synthetic rutile product.

7. The method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite corrosion according to claim 6, characterized in that, In step S1, the activator is sulfuric acid or sodium hydroxide solution, wherein the mass percentage concentration of sulfuric acid is 40-80% and the mass percentage concentration of sodium hydroxide is 30-40%; in step S2, the mixed acid solution is a mixed solution of sulfuric acid and nitric acid, wherein the mass percentage concentration of sulfuric acid is 15% and the mass percentage concentration of nitric acid is 3-5%.

8. The method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite corrosion according to claim 6, characterized in that, In step S3, the mass percentage concentration of hydrogen peroxide in the mixed solution of hydrogen peroxide and sulfuric acid is 3%, and the mass percentage concentration of sulfuric acid is 5%.

9. The method for improving the efficiency and purity of synthetic rutile production from reduced ilmenite corrosion according to claim 1, characterized in that, It also includes pressing and filtering the iron red liquid in step (4) and the washing liquid obtained in step (5) to obtain iron red filter cake and rust recovery liquid. The rust recovery liquid is collected in the rust recovery liquid pool for rust reaction recycling.

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