Method for efficiently extracting vanadium based on collaborative leaching of nitric acid and high-pressure oxygen

Abstract

The invention discloses a method for efficiently extracting vanadium based on collaborative leaching of nitric acid and high-pressure oxygen, and relates to the technical field of metallurgy. The method comprises the following steps: adding a vanadium-containing raw material into a nitric acid solution, uniformly stirring in a sealed state, then heating, and introducing oxygen for reaction. The method provided by the invention is clean and efficient, can complete leaching in one step, does not need multi-stage treatment, is suitable for various vanadium-containing raw materials, is easy for large-scale production, is short in reaction time, reduces the cost, and effectively solves the problems of low efficiency, high cost of a strong oxidant and serious corrosion of equipment in the traditional vanadium extraction process.

Description

Technical Field

[0001] This invention relates to the field of metallurgical technology, specifically to a method for efficient vanadium extraction based on the synergistic leaching of nitric acid and high-pressure oxygen. Background Technology

[0002] Vanadium-containing raw materials, such as vanadium-bearing steel slag, vanadium-bearing coal ore, vanadium-bearing shale, and vanadium-based waste catalysts, require vanadium extraction through fire-wet or direct wet processes to allow vanadium to enter the solution in ionic or molecular form. Subsequent purification and enrichment are then necessary to produce qualified vanadium-containing products. Therefore, leaching is one of the most important processes in vanadium metallurgy. Direct wet leaching has attracted much attention due to its advantages of low energy consumption and simple operation. Currently, the main industrial vanadium leaching methods are sulfuric acid aging-water leaching and strong oxidant-sulfuric acid leaching. Sulfuric acid aging-water leaching is clean and low-cost, but it also has disadvantages such as long processing time and low vanadium leaching rate. Strong oxidant / sulfuric acid leaching has a high vanadium leaching rate, but strong oxidants are expensive and highly corrosive. Therefore, there is an urgent need to develop a low-cost, high-efficiency leaching process. Summary of the Invention

[0003] To address the aforementioned shortcomings in existing technologies, this invention provides a method for efficient vanadium extraction based on the synergistic leaching of nitric acid and high-pressure oxygen. This method is clean and efficient, effectively solving the problems of low efficiency, high cost of strong oxidants, and severe equipment corrosion in traditional vanadium extraction processes.

[0004] To achieve the above objectives, the technical solution adopted by the present invention to solve its technical problem is: to provide a method for efficient vanadium extraction based on the synergistic leaching of nitric acid and high-pressure oxygen, comprising the following steps: Add vanadium-containing raw materials to nitric acid solution, stir evenly under sealed conditions, then heat, introduce oxygen to carry out the reaction, and maintain constant gas pressure until the reaction is completed.

[0005] Furthermore, the concentration of the nitric acid solution is 0.5-2.5 mol / L.

[0006] Furthermore, the concentration of the nitric acid solution is 1.5 mol / L.

[0007] Furthermore, the vanadium-containing raw material is at least one of vanadium-containing steel slag, vanadium-bearing shale, vanadium-bearing shale, and vanadium-based waste catalyst.

[0008] Furthermore, the volume-to-mass ratio of nitric acid solution to vanadium-containing raw material is 1-15 mL / g.

[0009] Furthermore, the volume-to-mass ratio of nitric acid solution to vanadium-containing raw material is 1 mL / g.

[0010] Further, the mixture is stirred in a high-pressure reactor.

[0011] Furthermore, the stirring speed is 100-500 rpm.

[0012] Furthermore, the stirring speed is 300 rpm.

[0013] Further, heat to a temperature of 80-180℃.

[0014] Further, heat to a temperature of 110°C.

[0015] Further, oxygen is introduced until the pressure is 1.2-3.5 MPa.

[0016] Further, oxygen is introduced until the pressure reaches 2 MPa.

[0017] Furthermore, the reaction time is 0.5-5 h.

[0018] Furthermore, the reaction time is 2.5 h.

[0019] The above-mentioned method for efficient vanadium extraction based on the synergistic leaching of nitric acid and high-pressure oxygen is applied to the leaching of vanadium from vanadium-containing raw materials.

[0020] In summary, the present invention has the following beneficial effects: 1. This invention provides a method for efficient leaching of vanadium-containing raw materials. The process uses nitric acid and high-pressure oxygen as oxidants for oxygen-pressure acid leaching. During the reaction, the nitrogen in the nitric acid is recycled, and the main oxidant consumed is oxygen. The synergistic effect of these two agents increases the vanadium leaching rate to over 80% and shortens the reaction time. The main step of this invention is nitric acid oxygen-pressure leaching. This method is primarily based on the catalytic oxidation of vanadium-containing raw materials by nitric acid. The reaction process mainly involves the reduction of nitric acid (HNO3) to NO, which is then oxidized by oxygen (O2) to NO2. NO2 reacts with H2O to generate HNO3, and this cycle continues until the vanadium-containing raw material is completely leached. During this process, the catalyst nitric acid is almost not consumed through nitrogen recycling, and its concentration does not need to be too high. Compared to sulfuric acid and hydrochloric acid, nitric acid is less corrosive. Furthermore, the main oxidant consumed in the leaching process of this invention is oxygen. Compared to traditional strong oxidants such as potassium permanganate, oxygen is a cleaner and lower-cost oxidant.

[0021] 2. This invention is clean and efficient, completing leaching in one step without the need for multi-stage processing. It is suitable for a variety of vanadium-containing raw materials, easy to scale up, and has a short reaction time, thus reducing costs. Detailed Implementation

[0022] The principles and features of this invention are described below. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer should be followed. Reagents or instruments whose manufacturers are not specified are all commercially available products.

[0023] Example 1 A method for efficient vanadium extraction based on the synergistic leaching of nitric acid and high-pressure oxygen includes the following steps: A 1.5 mol / L nitric acid solution was prepared in a high-pressure reactor, and then vanadium-containing steel slag was added. The volume-to-mass ratio of the nitric acid solution to the vanadium-containing steel slag was 1 mL / g. The reactor was sealed and stirred at 100 rpm until homogeneous. The reactor was then heated to 80 °C, and oxygen was introduced into the reactor until the pressure reached 1.2 MPa. The reaction was maintained at a constant pressure for 5 h until the reaction was complete.

[0024] Example 2 A method for efficient vanadium extraction based on the synergistic leaching of nitric acid and high-pressure oxygen includes the following steps: A 0.5 mol / L nitric acid solution was prepared in a high-pressure reactor, and then vanadium shale was added. The volume-to-mass ratio of the nitric acid solution to the vanadium shale was 15 mL / g. The reactor was sealed and stirred at 300 rpm until homogeneous. The reactor was then heated to 110 °C, and oxygen was introduced into the reactor until the pressure reached 2 MPa. The pressure was maintained constant and the reaction was allowed to proceed for 2.5 h until the reaction was complete.

[0025] Example 3 A method for efficient vanadium extraction based on the synergistic leaching of nitric acid and high-pressure oxygen includes the following steps: A 2.5 mol / L nitric acid solution was prepared in a high-pressure reactor, and then vanadium shale was added. The volume-to-mass ratio of the nitric acid solution to the vanadium shale was 10 mL / g. The reactor was sealed and stirred at 500 rpm until homogeneous. The reactor was then heated to 180 °C, and oxygen was introduced into the reactor until the pressure reached 2.5 MPa. The pressure was maintained constant and the reaction was allowed to proceed for 0.5 h until the reaction was complete.

[0026] Example 4 A method for efficient vanadium extraction based on the synergistic leaching of nitric acid and high-pressure oxygen includes the following steps: A 2.5 mol / L nitric acid solution was prepared in a high-pressure reactor, and then vanadium-containing shale was added. The volume-to-mass ratio of the nitric acid solution to the vanadium-containing shale was 10 mL / g. The reactor was sealed and stirred at 500 rpm until homogeneous. The reactor was then heated to 180 °C, and oxygen was introduced into the reactor until the pressure reached 3.5 MPa. The reaction was maintained at a constant pressure for 3.5 h until the reaction was complete.

[0027] Comparative Example 1 A method for extracting vanadium from vanadium-containing raw materials includes the following steps: A 1.5 mol / L nitric acid solution was prepared in a high-pressure reactor, and then vanadium shale was added. The volume-to-mass ratio of the nitric acid solution to the vanadium shale was 1 mL / g. The reactor was sealed and stirred at 100 rpm until homogeneous. The reactor was then heated to 80 °C and reacted for 0.5 h until the reaction was complete.

[0028] Comparative Example 2 A method for extracting vanadium from vanadium-containing raw materials includes the following steps: A 0.5 mol / L hydrochloric acid solution was prepared in a high-pressure reactor, and then vanadium-containing steel slag was added. The volume-to-mass ratio of the hydrochloric acid solution to the vanadium-containing steel slag was 15 mL / g. The reactor was sealed and stirred at 300 rpm until homogeneous. The reactor was then heated to 110 °C, and oxygen was introduced into the reactor until the pressure reached 2 MPa. The reaction was maintained at a constant pressure for 2.5 h until the reaction was completed.

[0029] Experimental Example 1 Comparing the methods provided in Examples 1-3 and Comparative Examples 1-3, after the reaction was completed and the temperature dropped to room temperature, the autoclave was opened, the leaching material was filtered, the filtrate was collected for subsequent purification and enrichment, the filter residue was dried, weighed, and the vanadium grade was analyzed by ICP and the vanadium leaching rate was calculated. The results are shown in Table 1.

[0030] Table 1 Comparison of Vanadium Leaching Rates

[0031] As shown in Table 1, compared with Example 1, Comparative Example 1 did not introduce oxygen into the autoclave. During the reaction, only nitric acid acted as the oxidant, and the amount of nitric acid was not excessive relative to the material. Even after the nitric acid reaction was complete, some material was still leached, resulting in a lower vanadium leaching rate. Compared with Example 2, Comparative Example 2 used hydrochloric acid instead of nitric acid. During the reaction, hydrochloric acid could not act as the oxidant; only dissolved oxygen did. Since the solubility of oxygen in aqueous solution is very limited, there was no catalytic oxidation by nitric acid, resulting in a lower vanadium leaching rate within the same time frame. Compared with Example 3, Comparative Example 3 used oxygen at a higher pressure. Higher pressure resulted in more dissolved oxygen, a faster reaction rate between oxygen and NO, and a faster rate of nitric acid regeneration. Therefore, within the same time frame, the vanadium leaching rate was better.

[0032] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for efficient vanadium extraction based on the synergistic leaching of nitric acid and high-pressure oxygen, characterized in that, The process includes the following steps: adding vanadium-containing raw materials to a nitric acid solution, stirring evenly under sealed conditions, then heating, introducing oxygen to carry out the reaction, and maintaining a constant pressure until the reaction is complete.

2. The method for efficient vanadium extraction based on the synergistic leaching of nitric acid and high-pressure oxygen as described in claim 1, characterized in that, The concentration of the nitric acid solution is 0.5-2.5 mol / L.

3. The method for efficient vanadium extraction based on the synergistic leaching of nitric acid and high-pressure oxygen as described in claim 1, characterized in that, The vanadium-containing raw material is at least one of vanadium-containing steel slag, vanadium-bearing coal ore, vanadium-bearing shale, and vanadium-based waste catalyst.

4. The method for efficient vanadium extraction based on the synergistic leaching of nitric acid and high-pressure oxygen as described in claim 1, characterized in that, The volume-to-mass ratio of the nitric acid solution to the vanadium-containing raw material is 1-15 mL / g.

5. The method for efficient vanadium extraction based on the synergistic leaching of nitric acid and high-pressure oxygen as described in claim 1, characterized in that, The stirring speed should be 100-500 rpm.

6. The method for efficient vanadium extraction based on the synergistic leaching of nitric acid and high-pressure oxygen as described in claim 1, characterized in that, Heat to a temperature of 80-180℃.

7. The method for efficient vanadium extraction based on the synergistic leaching of nitric acid and high-pressure oxygen as described in claim 1, characterized in that, Fill with oxygen to a pressure of 1.2-3.5 MPa.

8. The method for efficient vanadium extraction based on the synergistic leaching of nitric acid and high-pressure oxygen as described in claim 1, characterized in that, The reaction time is 0.5-5 h.

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