A method for resource utilization of vanadium pentoxide vanadium tailings

Abstract

The present invention relates to the technical field of vanadium-containing tailings treatment, and in particular to a method for resource utilization of vanadium pentoxide vanadium tailings. The method provided by the present invention comprises the following steps: (1) pretreatment of vanadium-extracting tailings; (2) taking pretreated raw materials and preparing them into agglomerates; (3) sintering the result of step (2) at high temperature for solidification; (4) melting the sintered agglomerates in an ore-fired furnace; (5) after high-temperature melting in the ore-fired furnace, obtaining an alloy containing 4wt%-5wt% vanadium and a high-temperature molten slag; (6) cold-forming the vanadium-containing alloy for steelmaking and vanadium addition; (7) cooling the high-temperature molten slag to prepare fine powder. After the vanadium-extracting tailings are treated by the method of the present invention, 95wt% of metals such as iron, vanadium, chromium, manganese, etc. in the waste slag can be recovered, and the treated waste slag can be used to make fine powder for cement concrete or building materials.

Description

Technical Field

[0001] The present invention relates to the technical field of tailings recycling, and in particular to a method for resource utilization of vanadium pentoxide-extracted tailings. Background Art

[0002] Vanadium extraction tailings, also known as vanadium leaching residue, are the residue left after sodium roasting and water leaching. Vanadium production enterprises in my country discharge hundreds of thousands of tons of vanadium extraction tailings annually. This massive discharge not only causes severe environmental pollution but also results in a significant waste of vanadium resources.

[0003] Vanadium, known as a "universal alloy," refines the structure and grain size of steel, increasing its hardness and wear resistance, and improving its tensile strength and heat resistance. Adding a small amount of vanadium to steel significantly increases its elasticity and strength, while also providing excellent resistance to wear and cracking. Consequently, it is widely used in the steel industry. Vanadium extraction tailings contain a significant amount of vanadium and other valuable metals. Recycling these tailings would significantly reduce the waste of precious metal resources and minimize environmental pollution. However, the current utilization rate of vanadium extraction tailings is low, and there is no effective method for efficiently recovering the metal elements from them.

[0004] Vanadium pentoxide vanadium extraction tailings are a solid waste that is currently difficult to recycle due to its physical state and chemical composition. Due to the large amount of vanadium extraction tailings discharged, the massive waste of vanadium resources needs to be addressed urgently. Therefore, researchers have conducted research on vanadium extraction processes from vanadium extraction tailings. There are two main approaches to vanadium extraction: one is to return the vanadium extraction tailings to ironmaking to enrich vanadium, producing high-vanadium slag, which is then further extracted. The other method for treating the vanadium extraction tailings is direct vanadium extraction, which includes sodium roasting, calcium roasting, calcium reduction roasting, and direct acid leaching. These processes generally suffer from low vanadium leaching rates and high costs. Traditional processes generally combine vanadium extraction tailings with vanadium slag for production. However, the tailings obtained from direct vanadium extraction have a high moisture content, making combined roasting with vanadium slag more difficult. Furthermore, the vanadium (V) content in the tailings is relatively low, making vanadium extraction more difficult. Therefore, these methods are difficult to scale up and fail to truly solve the problem of vanadium recovery from vanadium extraction tailings.

[0005] Therefore, how to seek an environmentally friendly, economical, efficient and reasonable method for resource utilization of vanadium pentoxide tailings, so as to efficiently recover various metals in the vanadium tailings, has become a technical problem that needs to be solved urgently in the treatment of vanadium tailings. Summary of the Invention

[0006] The purpose of the present invention is to solve the above-mentioned problems and provide a method for resource utilization of vanadium pentoxide vanadium extraction tailings. The method provided by the present invention can extract vanadium from the vanadium extraction tailings at a rate of more than 98wt%, and can also recover more than 95% of the metals in the waste slag. In addition to recovering vanadium, the method of the present invention can also efficiently recover valuable metals including iron, chromium, manganese, etc., and its impurity content is low. The treated waste slag can be used to make micropowder for use in cement concrete or building materials, etc., and the resource utilization efficiency of vanadium pentoxide vanadium extraction tailings is extremely good.

[0007] The present invention provides a method for resource utilization of vanadium pentoxide vanadium tailings, the method comprising the following steps:

[0008] (1) The vanadium-extraction tailings are ball-milled into vanadium-rich slag with a particle size of 20-30 μm, and 90-95 parts of the vanadium-rich slag, 1-4 parts of an additive, and 2.5-5 parts of a binder are uniformly mixed to form pellets; wherein the additive is a mixture of potassium sulfate, calcium chloride, and iron powder in a mass ratio of 1:2:1; and the binder is a mixture of dolomite, clay, and water glass in a mass ratio of 2:2:1;

[0009] (2) sintering the pellets obtained in step (1) at a high temperature of 1000-1050° C.;

[0010] (3) melting the sintered agglomerates in step (2) in an electric arc furnace at a temperature of 1100-1240° C. for 2-3 hours to obtain a vanadium-containing alloy having a vanadium content of 4 wt%-5 wt% and a high-temperature molten slag;

[0011] (4) The vanadium-containing alloy obtained in step (3) is cooled and shaped, and used for steelmaking and adding vanadium; the high-temperature molten slag is cooled and prepared into fine powder, which is used for building materials.

[0012] The method for resource utilization of vanadium pentoxide tailings provided by the present invention is the result of years of research and exploration by the inventors. The inventors have found that by refining the vanadium-containing tailings to obtain vanadium-rich slag, and then combining it with the additives and binder formula selected by the present invention, it is possible to effectively achieve the effect of stably preparing vanadium-containing alloys. The resulting agglomerates have stable performance during subsequent sintering and solidification. Further treatment by smelting in a submerged arc furnace can effectively recover multiple metals, and more than 95wt% of the metal elements in the vanadium-containing tailings can be recovered. The vanadium content in the prepared vanadium-containing alloy can reach 4-5wt%, and the recovery and extraction rate of vanadium reaches more than 98wt%. The recovery and extraction rates of elements such as Fe, Cr, and Mn also reach more than 95wt%.

[0013] The inventors conducted a large number of experimental studies on each process and ultimately determined that only when the raw material particle size is 20-30 μm and the additives and adhesives of the present invention are added to prepare pellets can the present invention achieve such excellent technical effects. If the process parameters are modified or the additives and adhesive formulas of the present invention are changed, it will be difficult to achieve the technical effects of the present invention.

[0014] The inventors conducted a large number of experiments on the specific selection of each process. Regarding the selection of raw material particle size, the inventors found that when finer-particle raw materials are used to prepare pellets, the technical effect of improving the V content can be achieved. However, combined with actual production, the mechanical equipment required to reduce the raw material particle size is extremely sophisticated, which greatly increases the preparation cost. The inventors hope to provide a more economical and efficient tailings recycling method. Therefore, the inventors conducted multiple attempts and found that after multiple experiments, sintering at 1000-1050°C and then melting at 1100-1240°C can effectively shorten the time required for the entire process, ensure the quality of the extracted vanadium-containing alloy, and greatly reduce production energy consumption.

[0015] Furthermore, the diameter of the pellets in step (1) is 5-9 mm.

[0016] Furthermore, the vanadium-rich slag in step (1) is 92 parts, the additive is 2 parts, and the binder is 3.75 parts.

[0017] Furthermore, the sintering temperature in step (2) is 1030°C.

[0018] Furthermore, the sintering time in step (2) is 90-120 minutes.

[0019] Furthermore, the sintering time in step (2) is 100 minutes.

[0020] Furthermore, the melting temperature in step (3) is 1190° C., and the melting time is 2.5 hours.

[0021] Furthermore, the vanadium-containing alloy in step (3) includes vanadium, iron, chromium and manganese.

[0022] Furthermore, the vanadium addition in the steelmaking in step (4) is to use a vanadium-containing alloy to replace 50 vanadium iron.

[0023] The beneficial effects of the present invention are as follows:

[0024] (1) The present invention provides a method for resource utilization of vanadium pentoxide tailings, wherein the method achieves a vanadium recovery rate of over 98 wt% in the vanadium tailings, and the recovery rates of iron, manganese, and chromium in the obtained vanadium-containing alloy all reach over 95 wt%. At the same time, the content of impurities such as P and S in the vanadium-containing alloy is low, and the effect after recovery and extraction is extremely excellent;

[0025] (2) The method for resource utilization of vanadium pentoxide tailings provided by the present invention has the advantages of simple operation, low processing cost, and can efficiently recover most of the metal elements in the vanadium tailings, with significant economic benefits;

[0026] (3) The method for recycling and reusing vanadium-containing tailings of the present invention is green and environmentally friendly. DETAILED DESCRIPTION

[0027] The present invention will be further described in detail below with reference to specific embodiments. It should be noted that the embodiments of the present invention are merely examples for illustrating the present invention and are not intended to limit the scope of the present invention. Any obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

[0028] Example 1

[0029] A method for resource utilization of vanadium pentoxide vanadium extraction tailings, wherein the vanadium extraction tailings contain 8.75 wt% MnO, 34.14 wt% TFe, 2.12 wt% V2O5, and 3.11 wt% Cr2O3. The recycling method is as follows:

[0030] (1) Using a high-efficiency ball mill, the vanadium pentoxide vanadium extraction tailings were prepared into vanadium-rich slag with a particle size of 20 μm. 90 parts of the treated vanadium-rich slag, 0.25 parts of potassium sulfate, 0.5 parts of calcium chloride, 0.25 parts of iron powder, 1 part of dolomite, 0.5 parts of water glass, and 1 part of clay were evenly mixed to form pellets with a diameter of 5 mm;

[0031] (2) sintering the pellets obtained in step (1) at 1000° C. for 90 minutes;

[0032] (3) The sintered pellets were melted in a submerged arc furnace at a temperature of 1100° C. for 2 hours to obtain a vanadium-containing alloy with a vanadium content of 4.17 wt% and a high-temperature molten slag;

[0033] (4) The vanadium-containing alloy obtained in step (3) is cooled and shaped, and used for steelmaking and adding vanadium; the high-temperature molten slag is cooled and prepared into fine powder, which is used for building materials.

[0034] Example 2

[0035] A method for resource utilization of vanadium pentoxide vanadium extraction tailings, wherein the vanadium extraction tailings contain 8.69wt% MnO, 34.53wt% TFe, 2.65wt% V2O5, and 3.16wt% Cr2O3. The recycling method is as follows:

[0036] (1) Using a high-efficiency ball mill, the vanadium pentoxide vanadium extraction tailings were prepared into vanadium-rich slag with a particle size of 30 μm. 95 parts of the treated vanadium-rich slag, 1 part of potassium sulfate, 2 parts of calcium chloride, 1 part of iron powder, 2 parts of dolomite, 2 parts of water glass, and 1 part of clay were evenly mixed to form pellets with a diameter of 9 mm;

[0037] (2) sintering the pellets obtained in step (1) at 1050° C. for 120 min;

[0038] (3) The sintered pellets were melted in a submerged arc furnace at a temperature of 1240° C. for 3 hours to obtain a vanadium-containing alloy with a vanadium content of 5.21 wt% and a high-temperature molten slag;

[0039] (4) The vanadium-containing alloy obtained in step (3) is cooled and shaped, and used for steelmaking and adding vanadium; the high-temperature molten slag is cooled and prepared into fine powder, which is used for building materials.

[0040] Example 3

[0041] A method for resource utilization of vanadium pentoxide vanadium tailings, wherein the vanadium tailings contain 8.95 wt% MnO, 38.71 wt% TFe, 2.87 wt% V2O5, and 3.62 wt% Cr2O3. The recycling method is as follows:

[0042] (1) using a high-efficiency ball mill to prepare the vanadium pentoxide vanadium extraction tailings into vanadium-rich slag with a particle size of 25 μm, taking 92 parts of the treated vanadium-rich slag, 0.5 parts of potassium sulfate, 1 part of calcium chloride, 0.5 parts of iron powder, 1.5 parts of dolomite, 0.75 parts of water glass, and 1.5 parts of clay, and evenly mixing them to form pellets with a diameter of 7 mm;

[0043] (2) sintering the pellets obtained in step (1) at 1030° C. for 100 min;

[0044] (3) The sintered pellets were melted in a submerged arc furnace at a temperature of 1190° C. for 2.5 hours to obtain a vanadium-containing alloy with a vanadium content of 5.68 wt% and a high-temperature molten slag;

[0045] (4) The vanadium-containing alloy obtained in step (3) is cooled and shaped, and used for steelmaking and adding vanadium; the high-temperature molten slag is cooled and prepared into fine powder, which is used for building materials.

[0046] Comparative Example 1

[0047] The method of Example 1 is followed, except that the potassium sulfate component is removed.

[0048] Comparative Example 2

[0049] The method of Example 2 is followed, except that the water glass component is removed.

[0050] Comparative Example 3

[0051] The method of Example 3 was followed, except that the calcium chloride was replaced by sodium chloride.

[0052] Comparative Example 4

[0053] The method of Example 1 is followed, except that the vanadium pentoxide vanadium extraction tailings are prepared into vanadium-rich slag with a particle size of 50 μm, and then corresponding additives and binders are added, and the sintering is carried out at 1100° C. for 60 min.

[0054] Comparative Example 5

[0055] The method of Example 2 is followed, except that the vanadium pentoxide vanadium extraction tailings are prepared into vanadium-rich slag with a particle size of 10 μm, and then corresponding additives and binders are added. 95 parts of vanadium-rich slag, 6 parts of additives, and 8 parts of binder are taken, wherein the additives are 2 parts of potassium sulfate, 2 parts of calcium chloride, and 2 parts of iron powder, and the binder is 4 parts of dolomite, 2 parts of water glass, and 2 parts of clay.

[0056] Experimental example:

[0057] The vanadium, iron, chromium, and manganese content, as well as impurity levels, of the vanadium-containing alloys obtained in Examples 1-3 and Comparative Examples 1-5 were tested. Element recovery was calculated as the percentage of the weight of the enriched element to the total weight of the element in the vanadium extraction tailings. The test results are shown in Table 1.

[0058] Table 1

[0059]

[0060] As shown in Table 1, the method for resource utilization of vanadium tailings provided in the embodiment of the present invention can obtain a high-quality vanadium-containing alloy with a high vanadium content and a high recovery rate. The recovery rates of other metal elements Fe, Mn, and Cr are also high. The main impurities CaO+MgO are reduced to 0.02% to 0.05wt%, and the impurity S content is low. However, the quality of the vanadium-containing alloy obtained in the comparative example is poor and cannot achieve the above effects.

Claims

1. A method for resource utilization of vanadium pentoxide tailings, characterized in that: The method comprises the following steps: (1) The vanadium-extraction tailings are ball-milled into vanadium-rich slag with a particle size of 20-30 μm, and 90-95 parts of the vanadium-rich slag, 1-4 parts of an additive, and 2.5-5 parts of a binder are uniformly mixed to form pellets; wherein the additive is a mixture of potassium sulfate, calcium chloride, and iron powder in a mass ratio of 1:2:1; and the binder is a mixture of dolomite, clay, and water glass in a mass ratio of 2:2:1; (2) sintering the pellets obtained in step (1) at a high temperature of 1000-1050° C.; (3) melting the sintered agglomerates in step (2) in an electric arc furnace at a temperature of 1100-1240° C. for 2-3 hours to obtain a vanadium-containing alloy having a vanadium content of 4 wt%-5 wt% and a high-temperature molten slag; (4) The vanadium-containing alloy obtained in step (3) is cooled and shaped, and used for steelmaking and adding vanadium; the high-temperature molten slag is cooled and prepared into fine powder, which is used for building materials.

2. The method according to claim 1, characterized in that The diameter of the pellets in step (1) is 5-9 mm.

3. The method according to claim 1, characterized in that 92 parts of the vanadium-rich slag described in step (1), 2 parts of additives, and 3.75 parts of adhesives.

4. The method according to claim 1, wherein The sintering temperature in step (2) is 1030°C.

5. The method according to claim 1, wherein The sintering time in step (2) is 90-120 minutes.

6. The method according to claim 1, wherein The sintering time in step (2) is 100 minutes.

7. The method according to claim 1, characterized in that The melting temperature in step (3) is 1190°C.

8. The method according to claim 1, characterized in that The melting time in step (3) is 2.5 hours.

9. The method according to claim 1, characterized in that The vanadium-containing alloy in step (3) includes vanadium, iron, chromium and manganese.

10. The method according to claim 1, characterized in that The vanadium addition in steelmaking in step (4) is to use a vanadium-containing alloy to replace 50 vanadium iron.

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