Method for comprehensive utilization of polymetallic ilmenite

Abstract

The application discloses a comprehensive utilization method of polymetallic ilmenite, and belongs to the technical field of titanium chemical industry or metallurgy. The method comprises the following steps: step one, titanium-containing raw materials are leached by mixed acid to obtain a leaching solution; and step two, the leaching solution is dissolved in a mixed solution of an extraction agent and an organic solvent to perform countercurrent extraction, the obtained organic phase containing titanium, iron, chromium, aluminum and silicon is countercurrently washed by a mixed solution of titanium ions and hydrogen fluoride, then countercurrently washed by a mixed solution of iron ions and hydrogen fluoride solution, then countercurrently washed by hydrogen fluoride solution, then countercurrently washed by pure water, and finally countercurrently washed by sodium hydroxide or sodium carbonate. Therefore, the comprehensive utilization method of polymetallic ilmenite can solve the technical problem that various elements cannot be comprehensively utilized in the prior art.

Description

Technical Field

[0001] This application relates to the fields of titanium chemical and metallurgical technology, specifically to a comprehensive utilization method for polymetallic ilmenite. Background Technology

[0002] Raw materials containing elements such as titanium, iron, chromium, aluminum, and silicon are diverse, including high-titanium slag, titanium concentrate, vanadium-titanium magnetite, slag, and beneficiation tailings. The composition of each element in these raw materials varies, making comprehensive utilization difficult. For high-titanium slag, a chlorination process for producing titanium tetrachloride has been developed, primarily utilizing the titanium element in the raw material. For high-grade ilmenite, the sulfuric acid process is used to produce titanium dioxide, converting titanium and iron into titanium dioxide and ferrous sulfate, while other elements such as aluminum, chromium, and vanadium are stored as waste. Rutile titanium dioxide is prepared from ilmenite for use in the chlorination process, such as the process of preparing synthetic rutile by hydrochloric acid leaching of ilmenite (CN 117800389 A). CN 116287784 A discloses a microwave alkaline roasting method for titanium concentrate followed by ultrasonic sulfuric acid leaching of titanium, primarily aimed at improving the leaching rate of ilmenite and not addressing the comprehensive utilization of multiple elements. CN 110453093 A develops a method for selectively leaching titanium from titanium-containing blast furnace slag. This method achieves pre-removal of silicon from the slag and selective, efficient leaching of titanium, resulting in a low variety and content of impurities in the leached titanium solution, which is beneficial for subsequent removal of impurity elements. Wang Yu, from the State Intellectual Property Office, discussed the utilization of titanium-containing blast furnace slag in her article "Titanium Recovery Technology and Patent Analysis of Titanium-Containing Blast Furnace Slag." The article points out that approximately 4 million tons of titanium-containing blast furnace slag are produced annually in China, with current stockpiles exceeding 80 million tons. For the comprehensive utilization of this massive resource, the extraction of titanium to produce TiO2 remains a key focus for the future. The mainstream technologies are selective leaching separation and titanium extraction, as well as acid leaching and hydrolysis hydrometallurgical titanium extraction. Research directions focus on improving separation, acid leaching, or hydrolysis processes to increase titanium extraction efficiency, reduce acid consumption, and mitigate environmental pollution. CN 117865217 A discloses a method for preparing titanium dioxide using blast furnace slag as raw material and utilizing titanium-rich materials, producing titanium dioxide with a content of approximately 90% from blast furnace slag containing approximately 20% titanium dioxide. Due to the complex mineral composition and difficulty in separating elements, existing methods primarily emphasize the utilization of titanium in minerals, while also comprehensively utilizing elements such as aluminum, silicon, vanadium, and chromium. Addressing this current situation and technical challenge, this invention proposes a method for coordination leaching of titanium, iron, chromium, aluminum, and silicon in a mixed acid medium. The complexes of each element are then separated and purified through solvent extraction, and finally, each element is prepared into a product that meets market demands, achieving the goal of comprehensive utilization of all elements in the raw material. Summary of the Invention

[0003] The purpose of this application is to provide a comprehensive utilization method for polymetallic ilmenite, solving the technical problem that the elements in the prior art cannot be comprehensively utilized.

[0004] To achieve the above object, the application provides a comprehensive utilization method of polymetallic ilmenite, comprising the following steps:

[0005] Step one, leaching the titanium-containing raw material with mixed acid to obtain leaching solution;

[0006] Step two, dissolving the leaching solution in the mixed solution of extractant and organic solvent to perform countercurrent extraction, using the mixed solution of titanium ions and hydrogen fluoride to perform countercurrent washing on the obtained organic phase containing titanium, iron, chromium, aluminum and silicon, then using the mixed solution of iron ions and hydrogen fluoride to perform countercurrent washing, then using hydrogen fluoride solution to perform countercurrent washing on the organic phase, then using pure water to perform countercurrent washing on the organic phase, and finally using sodium hydroxide or sodium carbonate to wash the organic phase.

[0007] Preferably, in step one, the mixed acid is sulfuric acid and hydrochloric acid, or sulfuric acid and chloride such as sodium chloride and magnesium chloride, or the mixed acid is sulfuric acid and HF, or sulfuric acid and fluoride such as sodium fluoride and ammonium fluoride binary mixed acid system, or sulfuric acid containing chlorine and fluoride ions ternary mixed acid system.

[0008] Preferably, in step one, the titanium-containing raw material is leached with mixed acid at a liquid-solid ratio of 0.1-10 to 1 at 10-90℃.

[0009] Preferably, in step two, the substituents R1 and R2 in the extractant are saturated or unsaturated straight-chain or branched-chain alkyl substituents with 1-20 carbon atoms, or saturated or unsaturated straight-chain or branched-chain alkyl-substituted phenyl groups with 1-20 carbon atoms, or saturated or unsaturated straight-chain or branched-chain alkyl-substituted primary or secondary amine groups with 1-20 carbon atoms.

[0010] Preferably, in step two, the organic solvent is saturated or unsaturated straight-chain or branched-chain alkane with 6-20 carbon atoms, or saturated or unsaturated straight-chain or branched-chain alkyl-substituted benzene with 6-20 carbon atoms, or saturated or unsaturated straight-chain or branched-chain alkyl-substituted ether with 6-20 carbon atoms.

[0011] Preferably, in step two, the concentration of chlorine or fluoride ions is 0.1-12 mol / L, and the concentration of iron or titanium ions is 0.1-60 g / L in the mixed solution, the washing phase ratio is 0.1-25 to 1, and the washing temperature is 10-80℃.

[0012] Preferably, the concentration of sodium hydroxide or sodium carbonate washing agent is 0-12 mol / L, the washing phase ratio is 0.1-25 to 1, and the washing temperature is 10-80℃.

[0013] Therefore, the application provides a comprehensive utilization method of polymetallic ilmenite, which has the following beneficial effects: a certain amount of solid mineral containing multiple elements such as titanium and iron is added to a mixed acid solution of a certain volume and a certain complexing agent for leaching. After leaching for a certain period of time, a filtrate is obtained by filtration. The filter residue can be discharged or returned to the leaching process for continuous leaching according to the leaching rate of each element. The leaching solution containing titanium, iron, silicon and aluminum complexes is fully mixed and layered with an organic solvent containing an extractant, and the complexes can be selectively transferred from the leaching solution to the organic solvent, and then single-element solutions are obtained by fractional distillation and washing. These solutions can be prepared into products meeting market demand after post-treatment. DETAILED DESCRIPTION

[0014] The technical solutions of the application are further described below through examples.

[0015] Example 1

[0016] A titanium-containing raw material containing 63.44% titanium dioxide, 10.75% total iron, 0.26% sodium oxide, 3.13% magnesium oxide, 4.85% aluminum oxide, 8.96% silicon dioxide, 3.23% calcium oxide, 0.60% vanadium pentoxide, 1.24% chromium trioxide, and 1.52% manganese oxide is leached with a mixed solution of sulfuric acid and HF at a liquid-solid ratio of 6 to 1 at 70°C for 100 minutes. The total acidity of concentrated sulfuric acid and hydrofluoric acid is 8 mol / L, and the molar ratio of sulfuric acid to hydrofluoric acid is 6 to 4. The leaching rate of titanium is 97.17%, the leaching rate of iron is 98.42%, the leaching rate of aluminum oxide is 96.91%, the leaching rate of vanadium pentoxide is 97.23%, the leaching rate of manganese oxide is greater than 99.9%, and the leaching rate of silicon is 89.32%. The leaching solution is used as a raw material to separate titanium, iron, aluminum, silicon and other elements.

[0017] The above leaching solution is used to dissolve C 10 H 21The organic phase containing titanium, iron, chromium, aluminum and silicon is washed countercurrently with a solution of titanium concentration of 50 g / L and hydrochloric acid concentration of 6 mol / L at a phase ratio of 8:1 for five stages, and the elution rate of chromium is 99.45%; then the organic phase is washed countercurrently with a solution of iron concentration of 42 g / L and hydrochloric acid concentration of 6 mol / L for six stages, and the elution rate of aluminum is 99.27%; then the organic phase is washed countercurrently with a 1 mol / L hydrochloric acid solution at a phase ratio of 2:1 for six stages, and the elution rate of titanium is 99.15%; then the organic phase is washed countercurrently with pure water at a phase ratio of 1:1 for 15 stages, and the washing rate of iron reaches 99.36%; finally, the organic phase is washed with a 1.0 mol / L sodium hydroxide solution at a phase ratio of 6:1 for eight stages, and the elution rate of silicon is 98.78%. The washing solutions are concentrated and crystallized to obtain chloride or chlorine-containing complexes. The organic phase is washed with water and returned to the extraction for continuous use.

[0018] Example 2

[0019] A titanium-containing raw material containing titanium dioxide 66.20%, total iron 8.77%, sodium oxide 0.27%, magnesium oxide 3.22%, aluminum oxide 4.93%, silicon dioxide 9.16%, calcium oxide 3.52%, vanadium pentoxide 0.58%, chromium trioxide 0.96%, and manganese oxide 1.48% is leached with a mixed solution of sulfuric acid and HF at a liquid-solid ratio of 5:1 at 65°C for 120 min. The total acidity of concentrated sulfuric acid and hydrofluoric acid is 12 mol / L, and the molar ratio of sulfuric acid to hydrofluoric acid is 7:3. The leaching rates of titanium, iron, aluminum oxide, vanadium pentoxide, and manganese oxide are 98.23%, 98.58%, 97.25%, 97.34%, and greater than 99.9%, respectively, and the leaching rate of silicon is 92.43%. The leaching solution is used as a raw material to separate titanium, iron, aluminum, and silicon.

[0020] The above leaching solution is extracted with C8H 17 -CO-CO-NH-C8H 17The extraction is carried out with an extractant volume concentration of 45%, an extraction temperature of 50°C, and a phase ratio of 3:1. After 10 stages of countercurrent extraction, the extraction rates of titanium, iron, chromium, aluminum, and silicon are 99.46%, 99.94%, 4.66%, 32.16%, and 99.93%, respectively. The obtained organic phase containing titanium, iron, chromium, aluminum, and silicon is countercurrently washed with a solution having a titanium concentration of 40 g / L and a hydrogen fluoride concentration of 1.5 mol / L according to a phase ratio of 15:1 for five stages, and the elution rate of chromium is 99.83%. Then, the organic phase is countercurrently washed with a solution having an iron concentration of 53 g / L and a hydrogen fluoride concentration of 3 mol / L for 7 stages, and the elution rate of aluminum is 99.43%. Subsequently, the organic phase is countercurrently washed with a 0.5 mol / L hydrogen fluoride solution according to a phase ratio of 3:1 for 8 stages, and the elution rate of titanium is 99.75%. Then, the organic phase is countercurrently washed with pure water according to a phase ratio of 1:1 for 8 stages, and the washing rate of iron reaches 99.44%. Finally, the organic phase is washed with a 1.0 mol / L sodium hydroxide solution according to a phase ratio of 15:1 for 8 stages, and the elution rate of silicon is 98.88%. Each washing liquid is concentrated and crystallized to obtain a complex containing fluoride or fluorine. The organic phase is washed with water and returned to the extraction for continuous use.

[0021] Example 3

[0022] A titanium-containing raw material containing titanium dioxide 23.25%, magnesium oxide 8.01%, aluminum oxide 13.31%, silicon dioxide 25.05%, calcium oxide 26.94%, and vanadium pentoxide 0.28% is leached with a mixed solution of sulfuric acid and HF at a liquid-solid ratio of 4:1 at 75°C for 180 min. The total acidity of concentrated sulfuric acid and hydrogen fluoride is 12 mol / L, and the molar ratio of sulfuric acid to hydrogen fluoride is 1:1. The leaching rates of titanium, iron, aluminum, vanadium pentoxide, manganese oxide, and silicon are 97.34%, 98.63%, 96.38%, 96.32%, greater than 99.9%, and 94.33%, respectively. The leaching solution is used as a raw material to separate titanium, iron, aluminum, and silicon.

[0023] The above leaching solution is extracted with C8H17-CO-CH2-CO--C8H17 dissolved in isopentyl ether, the volume concentration of the extractant is 45%, the extraction temperature is 50°C, and the phase ratio is 3:1; after 15 stages of countercurrent extraction, the extraction rates of titanium, iron, chromium, aluminum and silicon are 98.25%, 98.48%, 27.49%, 66.72% and 98.82%, respectively. The obtained organic phase containing titanium, iron, chromium, aluminum and silicon is countercurrently washed with a solution with a titanium concentration of 40 g / L and a hydrogen fluoride concentration of 1.0 mol / L according to a phase ratio of 15:1 for six stages, and the elution rate of chromium is 98.97%; then the organic phase is countercurrently washed with a solution with an iron concentration of 50 g / L and a hydrogen fluoride concentration of 3 mol / L for 5 stages, and the elution rate of aluminum is 99.64%; then the organic phase is countercurrently washed with a 0.5 mol / L hydrogen fluoride solution according to a phase ratio of 4:1 for 6 stages, and the elution rate of titanium is 98.66%; then the organic phase is countercurrently washed with pure water according to a phase ratio of 2:1 for 10 stages, and the washing rate of iron reaches 99.43%; finally, the organic phase is washed with a 1.0 mol / L sodium hydroxide solution according to a phase ratio of 15:1 for 10 stages, and the elution rate of silicon is 99.78%. Each washing solution is concentrated and crystallized to obtain a complex containing fluoride or fluorine. The organic phase is washed with water and returned to the extraction for continuous use.

[0024] Example 4

[0025] A titanium-containing raw material containing 23.25% of titanium dioxide, 8.01% of magnesium oxide, 13.31% of aluminum oxide, 25.05% of silicon dioxide, 26.94% of calcium oxide and 0.28% of vanadium pentoxide is leached with a mixed solution of sulfuric acid and HF at a liquid-solid ratio of 5:1 at 75°C for 180 min. The total acidity of concentrated sulfuric acid and hydrogen fluoride is 12 mol / L, and the molar ratio of sulfuric acid to hydrogen fluoride is 1:1. The leaching rates of titanium, iron, aluminum, vanadium pentoxide and manganese are 98.46%, 99.71%, 98.49%, 97.45% and more than 99.9%, respectively, and the leaching rate of silicon is 97.58%. The leaching solution is used as a raw material to separate titanium, iron, aluminum and silicon.

[0026] The above leaching solution is extracted with C8H 17 -CO-CH2-CH2-CO-C8H 17The extraction is carried out with the volume concentration of extractant being 38%, the extraction temperature being 50°C, and the phase ratio being 3.5:1. After 20 stages of countercurrent extraction, the extraction rates of titanium, iron, chromium, aluminum and silicon are 97.35%, 99.82%, 6.30%, 33.57% and 97.92%, respectively. The obtained organic phase containing titanium, iron, chromium, aluminum and silicon is countercurrently washed with a solution having a titanium concentration of 25 g / L and a hydrogen fluoride concentration of 2.0 mol / L according to a phase ratio of 15:1 for 3 stages, and the elution rate of chromium is 99.73%. Then, the organic phase is countercurrently washed with a solution having an iron concentration of 55 g / L and a hydrogen fluoride concentration of 2 mol / L for 5 stages, and the elution rate of aluminum is 98.38%. Then, the organic phase is countercurrently washed with a 0.5 mol / L hydrogen fluoride solution according to a phase ratio of 3:1 for 6 stages, and the elution rate of titanium is 99.49%. Then, the organic phase is countercurrently washed with pure water according to a phase ratio of 1.5:1 for 8 stages, and the washing rate of iron reaches 99.56%. Finally, the organic phase is washed with a 1.0 mol / L sodium hydroxide solution according to a phase ratio of 15:1 for 10 stages, and the elution rate of silicon is 99.65%. Each washing liquid is concentrated and crystallized to obtain a complex containing fluoride or fluorine. The organic phase is washed with water and returned to the extraction for continuous use.

[0027] Comparative Example 1

[0028] A titanium-containing raw material containing titanium dioxide 63.44%, total iron 10.75%, sodium oxide 0.26%, magnesium oxide 3.13%, aluminum oxide 4.85%, silicon dioxide 8.96%, calcium oxide 3.23%, vanadium pentoxide 0.60%, chromium trioxide 1.24%, and manganese oxide 1.52% is leached with a sulfuric acid solution at 70°C for 100 min according to a liquid-solid ratio of 6:1. The concentration of the sulfuric acid is 8 mol / L. The leaching rates of titanium, iron, aluminum oxide, vanadium pentoxide, and manganese oxide are 65.43%, 88.15%, 72.33%, 88.26%, and greater than 79.3%, respectively. The leaching rate of silicon is 15.21%. When only sulfuric acid is used for leaching, the leaching rates of the elements in the titanium-containing raw material are low, and the leaching is incomplete.

[0029] Comparative Example 2

[0030] A titanium-containing raw material containing titanium dioxide 23.25%, magnesium oxide 8.01%, aluminum oxide 13.31%, silicon dioxide 25.05%, calcium oxide 26.94%, and vanadium pentoxide 0.28% is leached with a concentrated hydrochloric acid mixed solution at 75°C for 180 min according to a liquid-solid ratio of 4:1. The initial acidity of the hydrochloric acid solution is 12 mol / L. The leaching rates of titanium, iron, aluminum oxide, vanadium pentoxide, and manganese oxide are 35.73%, 78.98%, 32.15%, 72.64%, and 23.92%, respectively. The leaching rate of silicon is 5.02%. Compared with mixed acid leaching, the leaching with a hydrochloric acid solution is incomplete.

[0031] Comparative Example 3

[0032] The leaching solution of Example 1 was extracted with C 10 H 21 -CO-NH-OH dissolved in dodecylbenzene, volume concentration of extractant 30%, extraction temperature 45℃, phase ratio 2.5:1; after 8 stages of countercurrent extraction, the extraction rates of titanium, iron, chromium, aluminum and silicon were 99.32%, 99.92%, 2.5%, 23.24% and 99.88%, respectively. The organic phase containing titanium, iron, chromium, aluminum and silicon was washed countercurrently with a solution of hydrochloric acid with a concentration of 6 mol / L for 1 stage with a phase ratio of 8:1, the elution rate of chromium was 67.23%, and then washed countercurrently with a solution of hydrochloric acid with a concentration of 6 mol / L and a concentration of iron of 42 g / L for 1 stage, the elution rate of chromium was 22.53% (relative to the initial concentration of chromium in the organic phase), the elution rate of aluminum was 62.65%, and the obtained washing solution contained chromium and aluminum, without realizing the separation of chromium and aluminum; the organic phase was washed countercurrently with a solution of 1 mol / L hydrochloric acid for 1 stage with a phase ratio of 2:1, the elution rate of titanium was 88.69%, and the obtained washing solution contained chromium, aluminum and titanium. Then the organic phase was washed countercurrently with pure water for 1 stage with a phase ratio of 1:1, the washing rate of iron reached 55.86%, and the obtained solution contained chromium, aluminum, titanium and iron; finally, the organic phase was washed with 1.0 mol / L sodium hydroxide with a phase ratio of 6:1 for 1 stage, the elution rate of silicon was 59.68%, and serious emulsification occurred, which could not be applied to industrialization.

[0033] Therefore, the application provides a comprehensive utilization method of polymetallic ilmenite, which solves the technical problem that elements cannot be comprehensively utilized in the prior art.

[0034] In the description of the specification, the description referring to the terms "one experimental example", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the experimental example or example are included in at least one experimental example or example of the application. In the specification, the illustrative description of the above terms does not necessarily refer to the same experimental example or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more experimental examples or examples in a suitable manner.

[0035] Finally, it should be noted that: the above experimental examples are only used to illustrate the technical solutions of the application rather than limit them, and although the application has been described in detail with reference to the preferred experimental examples, those skilled in the art should understand that the technical solutions of the application can still be modified or equivalently replaced, and these modifications or equivalent replacements cannot make the modified technical solutions deviate from the spirit and scope of the technical solutions of the application.

Claims

1. A method for the comprehensive utilization of polymetallic ilmenite, characterized in that, Includes the following steps: Step 1: Leach the titanium-containing raw material with a mixed acid to obtain a leachate; Step 2: Dissolve the leachate in a mixed solution of extractant and organic solvent and perform countercurrent extraction. The resulting organic phase containing titanium, iron, chromium, aluminum and silicon is washed countercurrently with a mixed solution of titanium ions and hydrogen fluoride, then with a mixed solution of iron ions and hydrogen fluoride, then with hydrogen fluoride solution, then with pure water, and finally with sodium hydroxide or sodium carbonate. In step two, the substituents R1 and R2 in the extractant are saturated or unsaturated straight-chain or branched alkyl substituents with 1-20 carbon atoms; or saturated or unsaturated straight-chain or branched alkyl substituted phenyl groups with 1-20 carbon atoms; or saturated or unsaturated straight-chain or branched alkyl substituted primary or secondary amine groups with 1-20 carbon atoms.

2. The method for comprehensive utilization of polymetallic ilmenite according to claim 1, characterized in that, In step one, the mixed acid is sulfuric acid and chloride, or sulfuric acid and fluoride; or a ternary mixed acid system containing chloride and fluoride ions.

3. The method for comprehensive utilization of polymetallic ilmenite according to claim 1, characterized in that, In step one, the titanium-containing raw materials are leached with a mixed acid at a liquid-to-solid ratio of 6:1; or at a liquid-to-solid ratio of 5:1; or at a liquid-to-solid ratio of 4:1 at 10–90°C.

4. The method for comprehensive utilization of polymetallic ilmenite according to claim 1, characterized in that, In step two, the organic solvent is a saturated or unsaturated straight-chain alkane, a saturated or unsaturated branched alkane, with 6-20 carbon atoms; or a saturated or unsaturated straight-chain or branched alkyl-substituted benzene, with 6-20 carbon atoms; or a saturated or unsaturated straight-chain or branched alkyl-substituted ether, with 6-20 carbon atoms.

5. The method for comprehensive utilization of polymetallic ilmenite according to claim 1, characterized in that, In step two, a mixed solution with a fluoride ion concentration of 0.1-12 mol / L and an iron or titanium ion concentration of 0.1-60 g / L is countercurrently washed with an organic phase containing titanium, iron, chromium, aluminum and silicon at a washing ratio of 0.1-25:1, and the washing temperature is 10-80℃.

6. The method for comprehensive utilization of polymetallic ilmenite according to claim 1, characterized in that, The concentration range of sodium hydroxide or sodium carbonate detergent is 0-12 mol / L, and not 0. Compared with organic phase detergent containing titanium, iron, chromium, aluminum and silicon, the ratio is 0.1-25:

1. The washing temperature is 10-80℃.