Method for effectively extracting iron, vanadium and titanium from vanadium titano-magnetite

Abstract

The invention discloses a method for effectively extracting iron, vanadium and titanium from vanadium titano-magnetite, belongs to the technical field of chemical metallurgy, and particularly relates to a method for gradually separating titanium, iron and titanium products by adopting technologies such as hydrochloric acid ore dissolution, solid-liquid separation, extraction and pyrolysis. By means of the method, the ore dissolving efficiency can be effectively improved, the technological process is shortened, traditional vanadium precipitation wastewater and treatment cost are avoided, titanium, iron and vanadium can be effectively separated and recycled, and value maximization of the South African vanadium titano-magnetite is effectively achieved.

Description

Technical Field

[0001] The invention relates to the technical field of vanadium chemical metallurgy, and in particular to a method for effectively extracting iron, vanadium and titanium from vanadium-titanium magnetite. Background Art

[0002] Vanadium-titanium magnetite is a low-grade multi-metallic mineral with great utilization value. It contains key elements such as iron, titanium, and vanadium, and is also associated with a variety of metal elements such as chromium, cobalt, nickel, copper, and gallium. Globally, South Africa's vanadium-titanium magnetite resources are particularly eye-catching. With its abundant reserves, it accounts for 31% of the world's total vanadium reserves, showing a unique advantage in resource reserves. At present, the processing of South African vanadium-titanium magnetite has many disadvantages in traditional processing methods. The processing process usually involves beneficiation and enrichment of the original ore to separate the vanadium-titanium magnetite concentrate, and then the concentrate enters the iron-making blast furnace process, focusing on the extraction of iron and vanadium elements. In this process, titanium is mostly treated as slag. Due to the close symbiosis of titanium and iron, coupled with the limitations of the existing process level, the high content of titanium in the ore cannot be effectively utilized, resulting in a huge waste of resources.

[0003] At present, the existing conventional technical means have two shortcomings. On the one hand, the comprehensive utilization rate of vanadium is greatly reduced, and a large amount of potential value has not been tapped; on the other hand, it has also produced many negative impacts on the environment. In the vanadium extraction process, a large amount of high-salt and high-ammonia nitrogen wastewater will be continuously produced, which is extremely difficult to treat. Furthermore, even if methods such as high-temperature oxidation / sodium treatment are used to extract vanadium, although vanadium can be extracted, the problems of vanadium extraction wastewater pollution and low titanium recovery rate cannot be avoided. Therefore, it is of great value and significance to develop a comprehensive extraction method that can simultaneously and efficiently separate and recover iron, vanadium and titanium. This not only helps to improve the utilization rate of resources, but also reduces environmental pollution and promotes the sustainable development of vanadium-titanium magnetite resources.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] In order to achieve efficient separation of vanadium from vanadium-titanium magnetite and maximize the value of mineral resources, the present invention proposes an efficient, energy-saving, green and environmentally friendly extraction and separation technology, which provides a new approach and method for the fine processing of vanadium-titanium magnetite. The key technology is to use efficient ore dissolution technology to obtain ferrovanadium acid solution and separate it to obtain high-titanium slag, and combine it with mature iron extraction technology to separate ferric chloride, and finally obtain a solution of vanadium oxychloride, and then prepare vanadium pentoxide.

[0006] The present invention is achieved in that:

[0007] The present invention provides a method for effectively extracting vanadium from vanadium-titanium magnetite, which comprises the following steps: mixing hydrochloric acid and vanadium-titanium magnetite for reaction, then introducing hydrogen chloride gas into the system, ensuring that the temperature and pressure of the system are maintained at set values ​​during the reaction, cooling the reaction mixture after the reaction is completed, then adding an oxidant, and performing solid-liquid separation after the oxidation reaction is completed to obtain high-titanium slag and a hydrochloric acid solution containing vanadium-iron ions;

[0008] The hydrochloric acid solution containing vanadium and iron ions is subjected to multi-stage extraction using an iron extractant, and the organic phases extracted at each stage are combined to obtain an iron-rich organic extraction phase and a vanadium-containing solution, and the iron-rich extraction organic phase is stripped of iron ions using an iron stripping agent to obtain an organic phase and a ferric chloride solution;

[0009] Finally, the vanadium-containing solution is subjected to vanadium precipitation and vanadium pentoxide is obtained through post-treatment.

[0010] In some preferred embodiments, the mass ratio of the vanadium-titanium magnetite to the hydrochloric acid is 1:2-10.

[0011] In some preferred embodiments, the vanadium-titanium magnetite is vanadium-titanium magnetite from South Africa, wherein the titanium dioxide content is 12%-15%, the iron oxide content is 60%-70%, and the vanadium pentoxide content is 1.0%-1.4%.

[0012] In some preferred embodiments, the mass percentage concentration of the hydrochloric acid is 15%-30%.

[0013] In some preferred embodiments, the temperature setting value is 25-100° C., and the pressure setting value is 0.101 MPa-1.0 MPa.

[0014] In some preferred embodiments, the oxidant is selected from one or more of potassium chlorate, sodium chlorate, hydrogen peroxide, sodium peroxide, potassium peroxide, sodium percarbonate, potassium percarbonate, oxygen or air;

[0015] Preferred are one or more of potassium chlorate, sodium chlorate or air.

[0016] In some preferred embodiments, the vanadium is precipitated by maintaining the reaction temperature at 90-102° C. and adding a hydrogen peroxide solution to the system for precipitation treatment.

[0017] In some preferred embodiments, the titanium dioxide content of the high titanium slag is 68-75%, and the titanium recovery rate is 98-99%.

[0018] In some preferred embodiments, the mass fraction of the titanium trichloride solution is 30-38%, and after acid washing, it is used as an iron stripping agent or returned to the iron extracting agent, and the iron recovery rate is 95-99%.

[0019] In some preferred embodiments, the content of vanadium pentoxide is 99%, and the recovery rate of vanadium is 90-95%.

[0020] The present invention has the following beneficial effects:

[0021] 1. The present invention adopts a hydrochloric acid acid dissolution method to effectively separate titanium, iron and vanadium from vanadium-titanium magnetite, thereby efficiently recovering iron, vanadium and titanium.

[0022] 2. The technical means proposed in the present invention effectively avoids the high-temperature oxidation calcination process, as well as the high-salt and high-ammonia nitrogen wastewater produced as a by-product in the vanadium extraction process of the existing vanadium precipitation industry, greatly reducing production costs and improving the application value of vanadium-titanium magnetite. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 This is a production flow chart of Example 1 of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be described clearly and completely below. If the specific conditions are not specified in the embodiments, they are carried out according to conventional conditions or conditions recommended by the manufacturer. If the manufacturer of the reagents or instruments used is not specified, they are all conventional products that can be purchased commercially.

[0026] In order to achieve efficient separation of vanadium from vanadium-titanium magnetite and maximize the value of mineral resources, the present invention provides a method for effectively extracting vanadium from vanadium-titanium magnetite, which comprises the following steps: mixing hydrochloric acid and vanadium-titanium magnetite for reaction, then introducing hydrogen chloride gas into the system, ensuring that the temperature and pressure of the system are maintained at set values ​​during the reaction, cooling the reaction mixture after the reaction, and then adding an oxidant, performing solid-liquid separation after the oxidation reaction, and obtaining high-titanium slag and a hydrochloric acid solution containing vanadium-iron ions;

[0027] The hydrochloric acid solution containing vanadium and iron ions is subjected to multi-stage extraction using an iron extractant, and the organic phases extracted at each stage are combined to obtain an iron-rich organic extraction phase and a vanadium-containing solution, and the iron-rich extraction organic phase is stripped of iron ions using an iron stripping agent to obtain an organic phase and a ferric chloride solution;

[0028] In the embodiment of the present invention, the vanadium-titanium magnetite selected is the vanadium-titanium magnetite from South Africa, wherein the titanium dioxide content is 12%-15%, the iron oxide content is 60%-70%, and the vanadium pentoxide content is 1.0%-1.4%. South African vanadium-titanium magnetite has significant advantages in extracting iron, vanadium and titanium. First, its iron content is high, and the iron content of some ores can reach 58.5%, which enables a large amount of molten iron to be produced during the smelting process, and the iron recovery rate is high. For the extraction of vanadium, the vanadium content in South African ores is high, for example, it can be purified into a concentrated ore with a vanadium pentoxide content of 2.0-2.2%, providing a rich resource base for the extraction of vanadium. In terms of titanium extraction, the vanadium resources in South Africa's vanadium-titanium magnetite are rich, providing sufficient raw materials for the production of titanium products such as titanium alloys and titanium dioxide.

[0029] In some preferred embodiments, the mass ratio of the vanadium-titanium magnetite to the hydrochloric acid is 1:2-10, wherein the mass percentage concentration of the hydrochloric acid is 15%-30%.

[0030] In order to improve the leaching efficiency of vanadium, hydrogen chloride gas is introduced into the mixed system of hydrochloric acid and vanadium-titanium magnetite to ensure that the pressure setting value during the reaction is 0.101MPa-1.0MPa and the setting temperature of the overall system is 25℃-100℃. This method can more effectively destroy the ore structure and increase the extractability of vanadium.

[0031] In some preferred embodiments, the oxidant is selected from one or more of potassium chlorate, sodium chlorate, hydrogen peroxide, sodium peroxide, potassium peroxide, sodium percarbonate, potassium percarbonate, oxygen or air;

[0032] Preferred are one or more of potassium chlorate, sodium chlorate or air.

[0033] Among them, the process of oxidizing vanadium using oxidants such as potassium chlorate, sodium chlorate, hydrogen peroxide, sodium peroxide, potassium peroxide, sodium percarbonate, potassium percarbonate, oxygen or air can improve the leaching rate and recovery rate of vanadium, while having a better impact on the environment and helping to reduce the burden of industrial wastewater treatment; and compared with strong oxidants, the operation is safer; the above-mentioned oxidants are cheap and readily available, which can reduce production costs; they can react under different temperature and pressure conditions, so the reaction conditions can be adjusted according to needs to optimize the oxidation process; the use of the above-mentioned oxidants can improve the purity and quality of the vanadium oxide product; reduce side reactions and other advantages, these characteristics make these oxidants an effective choice for improving vanadium extraction efficiency and reducing production costs.

[0034] In some preferred embodiments, the precipitation of vanadium is carried out by raising the reaction temperature to 90-102° C. and adding a hydrogen peroxide solution to the system for precipitation treatment.

[0035] In some preferred embodiments, the titanium dioxide content of the high titanium slag is 68-75%, and the titanium recovery rate is 98-99%.

[0036] In some preferred embodiments, the mass fraction of the titanium trichloride solution is 30-38%, and after acid washing, it is used as an iron stripping agent or returned to the iron extracting agent, and the iron recovery rate is 95-99%.

[0037] The mass fraction of the titanium trichloride solution obtained is 30-38%, and the iron recovery rate is 95-99%. It not only improves the resource utilization rate and reduces the raw material cost, but also realizes the recycling of resources and reduces waste generation and environmental impact by recycling the ferric chloride solution as an iron stripping agent or returning it to the iron extracting agent, thereby enhancing the environmental protection and economic sustainability of the entire process.

[0038] In some preferred embodiments, the content of vanadium pentoxide is 99%, and the recovery rate of vanadium is 90-95%.

[0039] Among them, after the vanadium precipitate is prepared, vanadium pentoxide is obtained through post-treatment, and the post-treatment steps include: washing the vanadium-containing precipitate with ammonium bicarbonate solution to remove impurities, then oxidizing and calcining it at a specific temperature to convert it into vanadium pentoxide, and achieving solid-liquid separation through filtration or centrifugation, and adjusting the pH value of the solution to promote the precipitation or dissolution of vanadium. Finally, the supernatant of the vanadium precipitation can be recycled as a leaching agent. This series of post-treatment operations is aimed at improving the purity of vanadium pentoxide, ensuring product quality, while reducing the generation of waste and improving the environmental protection and economic benefits of the process. The high recovery rate of vanadium in the end reflects the excellent performance of the process, which not only ensures the high market value of the product, but also significantly improves the utilization efficiency of resources and environmental sustainability, reduces resource waste, and reduces production costs, providing effective technical support for the recycling of vanadium resources and environmental protection.

[0040] The features and performance of the present invention are further described in detail below in conjunction with the embodiments.

[0041] Example 1

[0042] like Figure 1 As shown, this embodiment provides a method for effectively extracting vanadium from vanadium-titanium magnetite, which specifically includes the following steps:

[0043] (1) Take 500 g of vanadium-titanium magnetite, add 1500 g of 30% concentrated hydrochloric acid, stir, and continuously introduce hydrogen chloride gas into the system to maintain the acid value of the system unchanged and keep the pressure of the system at 0.1 MPa. Stop the reaction after 10 hours, add 50 g of NaClO3 after cooling to room temperature, continue stirring and reacting for 1 hour, filter by pressure, wash the filter residue until it is neutral, and collect the high-titanium slag;

[0044] (2) At 30°C, TBP / MIBK (wt) = 1:1 was used as the extractant, the oil phase to water phase ratio O / A = 4:1, and after two-stage extraction, the oil phase was the iron extraction phase and the water phase was the vanadium-containing residual phase;

[0045] (3) The iron extraction phase is stripped with deionized water at an O / A ratio of 1:12, and the oil phase extractant is returned to the Fe extractor. After that, part of the water in the iron-containing aqueous phase is evaporated and concentrated to a concentration of 250 g / L of iron;

[0046] (4) The vanadium-containing aqueous phase is directly introduced into a vanadium pentoxide synthesis reactor, the temperature is raised to 90-102°, a small amount of 20% hydrogen peroxide aqueous solution is added to the system to prepare a vanadium precipitate, and finally the vanadium-containing precipitate is washed with an ammonium bicarbonate solution to remove impurities, and then oxidized and calcined at a specific temperature to convert it into vanadium pentoxide, and solid-liquid separation is achieved by filtration or centrifugation.

[0047] The components of the South African vanadium-titanium magnetite and the obtained high-titanium slag used in Example 1 were tested by XRF as shown in Table 1. The ferric chloride solution was further distilled and crystallized to prepare crystalline ferric chloride, which was tested according to national standards as shown in Table 2. The vanadium pentoxide was tested according to national standards as shown in Table 3.

[0048] Table 1. Composition of vanadium-titanium magnetite and high-titanium slag

[0049]

[0050] Note: “ / ” means not detected.

[0051] Table 2. Composition of ferric chloride

[0052]

[0053] Note: The ferric chloride solution in Example 1 was further distilled to prepare hydrated ferric chloride solid for testing and compared with the national standard; “ / ” means not detected.

[0054] Table 3. Composition of vanadium pentoxide

[0055]

[0056] Note: “ / ” means not detected.

[0057] According to the results shown above, it can be seen from Table 1 that the contents of titanium (TiO2) and iron (FeO) in vanadium-titanium magnetite are relatively high, 13.77% and 65.33% respectively. In the high-titanium slag obtained after extracting vanadium, the content of titanium significantly increases to 80.11%, while the content of iron significantly decreases to 1.27%. This shows that the method effectively separates iron from vanadium-titanium magnetite. It can be seen from Table 2 that the ferric chloride solution obtained in Example 1 is further distilled and crystallized, and the FeCl3·6H2O content in the ferric chloride finally obtained is 99.1%, which is higher than the requirement of the national standard reagent grade (≥99%), and the water-insoluble content is 0.01%, which is lower than the national standard requirement of ≤0.05%. This shows that the ferric chloride prepared by distillation and crystallization is of high purity and better quality than the national standard reagent grade. As can be seen from Table 3, the vanadium pentoxide (V2O5) content of the prepared vanadium pentoxide Example 1 is 98%, which is higher than the national standard requirement of ≥97%. At the same time, the contents of other impurities such as silicon (Si), phosphorus (P), sulfur (S), arsenic (As) and sodium potassium (NaO+K2O) are far lower than the national standard limit, which shows that the purity of vanadium pentoxide is very high and has met the national standard limit.

[0058] In summary, the embodiment of the present invention uses South African vanadium-titanium magnetite as a raw material, mixes hydrochloric acid and vanadium-titanium magnetite for reaction, and then introduces hydrogen chloride gas into the system to ensure that the temperature and pressure of the system during the reaction are maintained at a set value, and the reaction mixture is cooled after the reaction is completed, and then an oxidant is added, and solid-liquid separation is performed after the oxidation is completed to obtain a hydrochloric acid solution containing high-titanium slag and vanadium-iron examples; the hydrochloric acid solution containing vanadium-iron ions is subjected to multi-stage extraction using an iron extractant, and the organic phases of the extractions at each stage are combined to obtain an iron-rich organic extraction phase and a vanadium-containing solution, and the iron-rich extraction organic phase is stripped of iron ions with an iron stripping agent to obtain an organic phase and a ferric chloride solution, and then the vanadium-containing solution is subjected to vanadium precipitation preparation, and finally vanadium pentoxide is obtained after post-treatment. The method achieves efficient extraction of iron, vanadium, and titanium by precisely controlling the conditions for the reaction of vanadium-titanium magnetite with hydrochloric acid, including temperature and pressure, as well as selective oxidation and solid-liquid separation technology. The multi-stage extraction process further improves the recovery rate of vanadium, while achieving effective separation of iron, and after extraction with an iron stripping agent, a ferric chloride solution is obtained. Finally, high-purity vanadium pentoxide was obtained through precipitation preparation and post-treatment. This method not only improves resource utilization and reduces production costs, but also reduces waste emissions, is environmentally friendly, has high economic and environmental benefits, and its process flexibility and technical maturity are also conducive to its industrial application.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for effectively extracting iron, vanadium and titanium from vanadium-titanium magnetite, characterized in that: It includes the following steps: The hydrochloric acid and vanadium-titanium magnetite are mixed for reaction, and then hydrogen chloride gas is introduced into the system to ensure that the temperature and pressure of the system are maintained at set values ​​during the reaction. After the reaction is completed, the reaction mixture is cooled, and then an oxidant is added. After the oxidation reaction is completed, solid-liquid separation is performed to obtain high-titanium slag and a hydrochloric acid solution containing vanadium-iron ions; The hydrochloric acid solution containing vanadium and iron ions is subjected to multi-stage extraction using an iron extractant, and the organic phases extracted at each stage are combined to obtain an iron-rich organic extraction phase and a vanadium-containing solution, and the iron-rich extraction organic phase is stripped of iron ions using an iron stripping agent to obtain an organic phase and a ferric chloride solution; Finally, the vanadium-containing solution is subjected to vanadium precipitation preparation, and vanadium pentoxide is obtained through post-treatment.

2. A method for effectively extracting iron, vanadium and titanium from vanadium-titanium magnetite according to claim 1, characterized in that: The mass ratio of the vanadium-titanium magnetite to the hydrochloric acid is 1:2-10.

3. A method for effectively extracting iron, vanadium and titanium from vanadium-titanium magnetite according to claim 1, characterized in that: The vanadium-titanium magnetite is from South Africa, wherein the titanium dioxide content is 12%-15%, the iron oxide content is 60%-70%, and the vanadium pentoxide content is 1.0%-1.4%.

4. A method for effectively extracting iron, vanadium and titanium from vanadium-titanium magnetite according to claim 1, characterized in that: The mass percentage concentration of the hydrochloric acid is 15%-30%.

5. A method for effectively extracting iron, vanadium and titanium from vanadium-titanium magnetite according to claim 1, characterized in that: The temperature setting value is 25-100° C., and the pressure setting value is 0.101 MPa-1.0 MPa.

6. A method for effectively extracting iron, vanadium and titanium from vanadium-titanium magnetite according to claim 1, characterized in that: The oxidant is one or more selected from potassium chlorate, sodium chlorate, hydrogen peroxide, sodium peroxide, potassium peroxide, sodium percarbonate, potassium percarbonate, oxygen or air; Preferred are one or more of potassium chlorate, sodium chlorate or air.

7. A method for effectively extracting iron, vanadium and titanium from vanadium-titanium magnetite according to claim 1, characterized in that: The vanadium precipitation is carried out by maintaining the reaction temperature at 90-102° C. and adding a hydrogen peroxide solution into the system for precipitation treatment.

8. A method for effectively extracting iron, vanadium and titanium from vanadium-titanium magnetite according to claim 1, characterized in that: The titanium dioxide content of the high-titanium slag is 68-75%, and the titanium recovery rate is 98-99%.

9. A method for effectively extracting iron, vanadium and titanium from vanadium-titanium magnetite according to claim 1, characterized in that: The mass fraction of the ferric chloride solution is 30-38%. After acid washing, it is used as an iron stripping agent or returned to the iron extracting agent, and the iron recovery rate is 95-99%.

10. A method for effectively extracting iron, vanadium and titanium from vanadium-titanium magnetite according to claim 1, characterized in that: The content of vanadium pentoxide is 99%, and the recovery rate of vanadium is 90-95%.

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