Method for extracting vanadium from stone coal based on sintering-blast furnace-converter process

Abstract

The invention discloses a method for extracting vanadium from stone coal based on a sintering-blast furnace-converter process, which comprises the following steps of: (1) crushing vanadium-containing stone coal mine to obtain crushed vanadium-containing stone coal powder, and screening by using a 100-mesh sieve to obtain the particle size lt; 100-mesh fine-fraction stone coal powder and stone coal powder with the particle size larger than or equal to 100 meshes; (2) in the sintering procedure, the vanadium-containing stone coal powder with the particle size larger than or equal to 100 meshes is mixed into the vanadium titano-magnetite sintering mixture according to the set proportion, and vanadium-containing sintered ore is obtained after sintering; (3) feeding the vanadium-containing sintered ore into a blast furnace for smelting, and reducing the granularity to be 1t; 100-mesh vanadium-containing stone coal powder is mixed into coal powder sprayed by a blast furnace according to a preset proportion, the coal powder added with the vanadium-containing stone coal is sprayed into the blast furnace through a spray gun, meanwhile, hydrogen-rich gas is sprayed, vanadium-containing molten iron is obtained after blast furnace smelting, and vanadium is recycled from the obtained vanadium-containing molten iron through a converter vanadium extraction process. The sintering-blast furnace-converter process is utilized, the stone coal powder containing vanadium is added in the sintering procedure and the blast furnace procedure, hydrogen is sprayed in the blast furnace smelting process, the recovery rate of vanadium is further increased, recycling of vanadium is achieved, a new production line does not need to be additionally built, and the method has the advantages of being low in cost, large in treatment scale, high in vanadium recovery rate and the like.

Description

Technical Field

[0001] The invention belongs to the field of mineral processing and relates to a method for extracting vanadium from stone coal based on a sintering-blast furnace-converter process. Background Art

[0002] Stone coal is a low-quality "coal" with a far greater proportion of inorganic components than organic components. Its main characteristics are high ash content, low calorific value, and a wide variety of associated elements. Therefore, stone coal is often extracted and utilized as a low-grade polymetallic ore containing valuable elements. Total proven reserves exceed 60 billion tons. Vanadium is a common feature of Chinese stone coal, with V2O5 grades ranging from 0.3% to 1.2%. Total V2O5 reserves are 6.7 times the V2O5 reserves of vanadium-titanium magnetite in my country and exceed the total vanadium reserves of the rest of the world combined. Stone coal with a V2O5 content greater than 0.8% can be utilized as a vanadium ore resource.

[0003] Currently, the conventional process for extracting vanadium from stone coal involves roasting followed by leaching. This involves first destroying the mineral structure of the stone coal and oxidizing the vanadium into soluble vanadates. Leaching then converts the solid phase into a liquid phase, and extracting the refined vanadium from the solution. The traditional sodium roasting and water leaching process involves high-temperature reaction to produce water-soluble sodium vanadates. This process presents challenges such as severe exhaust gas pollution, low recovery rates, and complex wastewater ions.

[0004] In addition, new vanadium extraction processes such as blank oxidation roasting-leaching process, calcification roasting-carbonate leaching process, direct acid leaching process and double-circulation high-efficiency oxidation process are constantly emerging. However, due to factors such as the complex mineral composition of stone coal, low vanadium grade and diverse occurrence states, the current stone coal vanadium extraction process generally has the following problems: (1) The ore dressing ratio is high, and the equipment investment and production cost of building a large stone coal vanadium extraction enterprise are large. (2) The acid consumption is high, and the leaching residual liquid has a great impact on the environment. Since the content of acid-consuming gangue minerals such as calcite and hematite in stone coal is generally high, the acid consumption is large and the production cost is high during the stone coal vanadium extraction acid leaching process. (3) The mineral composition of stone coal is complex, the occurrence state of vanadium is diverse, and the vanadium leaching rate is low, mainly the difficult-to-leach V 3+ With the increasing requirements for environmental protection, it is imperative to find a vanadium extraction process that can avoid the above problems. Summary of the Invention

[0005] In response to the problems of high acid consumption, serious environmental pollution and high extraction cost in the existing stone coal vanadium extraction technology, the purpose of the present invention is to provide a method for extracting vanadium from stone coal based on the sintering-blast furnace-converter process. Utilizing the sintering-blast furnace-converter vanadium extraction process, vanadium-containing stone coal powder is added to the sintering process and the blast furnace process respectively, and hydrogen is sprayed during the blast furnace smelting process to further improve the vanadium recovery rate. No additional new production line needs to be built, and the method has the advantages of low cost, low pollution and high efficiency.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A method for extracting vanadium from stone coal based on a sintering-blast furnace-converter process comprises the following steps:

[0008] (1) crushing vanadium-containing stone coal ore to obtain crushed vanadium-containing stone coal powder, and sieving it with a 100-mesh sieve to obtain fine-grained stone coal powder with a particle size of less than 100 mesh and stone coal powder with a particle size of ≥100 mesh;

[0009] (2) In the sintering process, the vanadium-containing stone coal powder with a particle size of ≥100 mesh obtained in step (1) is added to the vanadium-titanium magnetite sintering mixture according to a set ratio, and vanadium-containing sintered ore is obtained after sintering;

[0010] (3) The vanadium-containing sintered ore obtained in step (2) is fed into a blast furnace for smelting, and the vanadium-containing stone coal powder with a particle size of less than 100 mesh obtained in step (1) is mixed into the coal powder sprayed into the blast furnace according to a predetermined ratio. The coal powder mixed with the vanadium-containing stone coal is sprayed into the blast furnace by a spray gun, and hydrogen-rich gas is sprayed into the blast furnace at the same time. After smelting in the blast furnace, vanadium-containing molten iron is obtained, and the obtained vanadium-containing molten iron is subjected to a converter vanadium extraction process to recover vanadium.

[0011] Furthermore, in step (1), the vanadium-containing coal ore is crushed to a particle size of -3 mm greater than 90%.

[0012] Furthermore, in step (1), the V2O5 content in the vanadium-containing stone coal is above 0.8%.

[0013] Furthermore, in step (1), the C content in the vanadium-containing stone coal is above 8.0%.

[0014] Furthermore, in step (2), the proportion of the vanadium-containing stone coal powder in the sintering mixture is 2% to 5%.

[0015] Furthermore, the vanadium-containing sintered ore includes: TFe=45-60%, V2O5=0.5-3%, SiO2=4-8%, CaO=8-20%, MgO=1-8%, Al2O3=1-8%, and TiO2=2-20%.

[0016] Furthermore, in step (3), the mass ratio of the vanadium-containing stone coal powder to ordinary coal powder is 20-50:80-50; the injection amount of hydrogen-rich gas accounts for 5-15% of the injection amount of hot air; and the hydrogen-rich gas includes one or more of hydrogen, coke oven gas, and natural gas.

[0017] Furthermore, in step (3), the proportion of vanadium-containing sintered ore in the blast furnace charge structure is greater than 70%.

[0018] Furthermore, the V content in the vanadium-containing molten iron is greater than 0.5%.

[0019] Furthermore, in step (3), the converter vanadium extraction process is specifically as follows: after charging vanadium-containing molten iron into the furnace, oxygen is introduced, the molten pool temperature is controlled to be 1300-1450°C, and oxygen is blown for 5-15 minutes. After the blowing is completed, the converter is tilted to first release the semi-steel and then pour out the vanadium slag for recovery.

[0020] Furthermore, the lance includes a coal conveying pipe, a mixer, a distributor, a straight blowing pipe and a coal injection port;

[0021] The mixer is provided with a feeding port for mixing vanadium-containing stone coal powder into coal powder;

[0022] The mixer and the distributor are connected through a coal conveying pipe, and the output end of the distributor is connected to the input end of the direct blowing pipe; the direct blowing pipe is provided with a heating chamber, a coal injection pipe and a high-pressure hot air pipe;

[0023] The heating chamber is provided inside the side wall of the direct blowing pipe and is used to heat the pulverized coal. The number of the coal injection pipes is several, the input end of the coal injection pipe is connected to the output end of the distributor, and the output end of the coal injection pipe is connected to the coal injection port.

[0024] The high-pressure hot air pipe is arranged at the output end of the direct blowing pipe and is located at the center of the direct blowing pipe.

[0025] The mixer is provided with a vibrator or an ultrasonic device to facilitate uniform mixing of vanadium-containing stone coal powder and ordinary coal powder.

[0026] The number of the coal injection pipes is four and they are symmetrically arranged inside the direct blowing pipe.

[0027] A gas inlet is provided on the top of the distributor.

[0028] The heating chamber is provided with a heating medium inlet and a heating medium outlet.

[0029] The advantages of the present invention are:

[0030] The present invention utilizes the sintering-blast furnace-converter process, adds vanadium-containing stone coal powder into the sintering process and the blast furnace process respectively, and injects hydrogen-rich gas into the blast furnace smelting process, thereby further improving the vanadium recovery rate, reducing carbon emissions, and realizing the recycling and utilization of vanadium. It does not require the construction of new production lines, and has the advantages of low cost, large processing scale, and high vanadium recovery rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a process flow chart of the present invention.

[0032] Figure 2 It is a structural schematic diagram of the blast furnace coal powder injection gun of the present invention.

[0033] Figure 3 for Figure 2Sectional view at the AB position.

[0034] Figure 4 for Figure 2 Another cross-sectional view at the AB position.

[0035] In the figure, 1-coal conveying pipe; 2-mixer; 201-vibrator; 202-feeding port; 3-distributor; 301-gas adding port; 4-direct blowing pipe; 401-heating chamber; 402-coal injection pipe; 403-high-pressure hot air pipe; 5-coal injection port. DETAILED DESCRIPTION

[0036] The specific embodiments of the present invention are further described below by way of examples, but the specific embodiments of the present invention are not limited to the following examples.

[0037] Example 1

[0038] A method for extracting vanadium from stone coal based on a sintering-blast furnace-converter process comprises the following steps:

[0039] (1) Stone coal containing 0.98% V2O5 and 14.86% C was taken from a certain place, and the vanadium-containing stone coal ore was crushed to a particle size of more than 90% of -3 mm, and sieved with a 100-mesh sieve to obtain fine-grained stone coal powder with a particle size of <100 mesh and stone coal powder with a particle size of ≥100 mesh;

[0040] (2) adding vanadium-containing stone coal powder with a particle size of ≥100 mesh into the vanadium-titanium magnetite sintering mixture according to a set ratio, wherein the proportion of vanadium-containing stone coal powder in the sintering mixture is 3%, and obtaining vanadium-containing sintered ore after sintering;

[0041] (3) The vanadium-containing sintered ore is fed into a blast furnace for smelting. Vanadium-containing stone coal powder with a particle size of less than 100 mesh is mixed with ordinary coal powder in a ratio of 50:50, and then sprayed into the blast furnace through a spray gun from the coal injection port. Hydrogen is also sprayed at the same time. The injection amount of hydrogen is 10% of the hot air volume. The sintered ore accounts for 75% of the blast furnace charge structure, and the rest is pellets and lump ore. After smelting in the blast furnace, vanadium-containing molten iron with a V content of 0.65% is obtained. The vanadium-containing molten iron is subjected to a converter to extract vanadium. The recovery rate calculated based on the vanadium entering the vanadium-containing molten iron is 90.02%. The process flow is as follows: Figure 1 shown.

[0042] The spray gun includes a coal conveying pipe 1, a mixer 2, a distributor 3, a straight blowing pipe 4 and a coal injection port 5;

[0043] The mixer 2 is provided with a feed port 202 for mixing vanadium-containing stone coal powder into the coal powder;

[0044] A gas inlet 301 is provided at the top of the distributor 3;

[0045] The mixer 2 and the distributor 3 are connected via a coal conveying pipe 1. The output end of the distributor 3 is connected to the input end of a direct blowing pipe 4. The direct blowing pipe 4 is provided with a heating chamber 401, a coal injection pipe 402 and a high-pressure hot air pipe 403.

[0046] The heating chamber 401 is provided inside the side wall of the direct blowing pipe 4 for heating the pulverized coal; a plurality of coal injection pipes 402 are provided, the input end of the coal injection pipe 402 is connected to the output end of the distributor 3, and the output end of the coal injection pipe 402 is connected to the coal injection port 5;

[0047] The high-pressure hot air pipe 403 is provided at the output end of the direct blowing pipe 4 and is located at the center of the direct blowing pipe 4 .

[0048] A vibrator 201 is provided in the mixer 2. Figure 2 shown.

[0049] There are four coal injection pipes 402, which are symmetrically arranged inside the direct blowing pipe 4. Figure 3 shown.

[0050] Furthermore, the number of the coal injection pipe 402 is one, and the coal injection pipe 402 and the inner wall of the direct blowing pipe 4 form a second cavity for conveying coal powder, such as Figure 4 shown.

[0051] Furthermore, the heating chamber 401 is provided with a heating medium inlet and a heating medium outlet. High-temperature steam enters from the heating medium inlet and fills the heating chamber 401 , and the high-temperature steam is used to preheat the pulverized coal in the coal injection pipe 402 .

[0052] Furthermore, the high-pressure hot air pipe 403 is connected to the high-pressure hot air inlet to achieve further mixing and pressurization of the mixed powder before blowing it into the furnace.

[0053] The working principle of the spray gun is as follows: coal powder is transported to the coal conveying pipe 1, and the coal powder in the coal conveying pipe 1 first passes through the mixer 2; vanadium-containing coal powder is added to the mixer 2 through the feeding port 202, and the vibrator 201 in the mixer 2 is used to evenly mix the vanadium-containing coal powder and coal powder; the mixed powder is added to the distributor 3 through the coal conveying pipe 1, and the distributor 3 transports the mixed powder to the coal injection pipe 402, and the mixed powder enters the coal injection port 5 from different angles; at the same time, hydrogen enters the distributor 3 through the gas feeding port 301, and then enters the coal injection port 5 through the coal injection pipe 402; the high-pressure hot air from the direct blowing pipe 4 further mixes and pressurizes the mixed powder, so that the hydrogen and the mixed powder are completely mixed, and the mixed coal powder is blown into the blast furnace for combustion.

[0054] Example 2

[0055] A method for extracting vanadium from stone coal based on a sintering-blast furnace-converter process comprises the following steps:

[0056] (1) Stone coal containing 1.08% V2O5 and 16.56% C was taken from a certain place, and the vanadium-containing stone coal ore was crushed to a particle size of more than 90% of -3 mm, and sieved with a 100-mesh sieve to obtain fine-grained stone coal powder with a particle size of <100 mesh and stone coal powder with a particle size of ≥100 mesh;

[0057] (2) adding vanadium-containing stone coal powder with a particle size of ≥100 mesh into the vanadium-titanium magnetite sintering mixture according to a set ratio, wherein the proportion of vanadium-containing stone coal powder in the sintering mixture is 2%, and vanadium-containing sintered ore is obtained after sintering;

[0058] (3) The vanadium-containing sintered ore is fed into a blast furnace for smelting. Vanadium-containing stone coal powder with a particle size of less than 100 mesh is mixed with ordinary coal powder in a ratio of 30:70, and then sprayed into the blast furnace through a spray gun from a coal injection port. At the same time, coke oven gas is sprayed into the blast furnace, and the injection amount accounts for 15% of the hot air volume. The sintered ore accounts for 75% of the blast furnace charge structure. After smelting in the blast furnace, vanadium-containing molten iron with a V content of 0.76% is obtained. The vanadium-containing molten iron is subjected to a converter to extract vanadium. The recovery rate calculated based on the vanadium entering the vanadium-containing molten iron is 92.02%.

[0059] Example 3

[0060] A method for extracting vanadium from stone coal based on a sintering-blast furnace-converter process comprises the following steps:

[0061] (1) Stone coal containing 0.96% V2O5 and 15.28% C was taken from a certain place, and the vanadium-containing stone coal ore was crushed to a particle size of more than 90% of -3 mm, and sieved with a 100-mesh sieve to obtain fine-grained stone coal powder with a particle size of <100 mesh and stone coal powder with a particle size of ≥100 mesh;

[0062] (2) adding vanadium-containing stone coal powder with a particle size of ≥100 mesh into the sintered ore according to a set ratio, wherein the proportion of the vanadium-containing stone coal powder in the sintering ingredients is 5%, thereby obtaining vanadium-containing sintered ore;

[0063] (3) The vanadium-containing sintered ore is fed into a blast furnace for smelting. Vanadium-containing stone coal powder with a particle size of less than 100 mesh is mixed with ordinary coal powder in a ratio of 40:60, and then sprayed into the blast furnace from the coal injection port through a spray gun. Natural gas is also sprayed at the same time. The amount of natural gas injected accounts for 5% of the hot air volume. The sintered ore accounts for 75% of the blast furnace charge structure. After smelting in the blast furnace, vanadium-containing molten iron with a V content of 0.85% is obtained. The vanadium-containing molten iron is subjected to a converter to extract vanadium. The recovery rate calculated based on the vanadium entering the vanadium-containing molten iron is 91.02%.

[0064] Example 4

[0065] A method for extracting vanadium from stone coal based on a sintering-blast furnace-converter process comprises the following steps:

[0066] (1) Stone coal containing 1.12% V2O5 and 12.32% C was taken from a certain place, and the vanadium-containing stone coal ore was crushed to a particle size of more than 90% of -3 mm, and sieved with a 100-mesh sieve to obtain fine-grained stone coal powder with a particle size of <100 mesh and stone coal powder with a particle size of ≥100 mesh;

[0067] (2) adding vanadium-containing stone coal powder with a particle size of ≥100 mesh into the sintered ore according to a set ratio, wherein the proportion of the vanadium-containing stone coal powder in the sintering ingredients is 3%, thereby obtaining vanadium-containing sintered ore;

[0068] (3) The vanadium-containing sintered ore is fed into a blast furnace for smelting. Vanadium-containing stone coal powder with a particle size of less than 100 mesh and ordinary coal powder are mixed in a ratio of 20:80, and then sprayed into the blast furnace through a spray gun from a coal injection port. Hydrogen is also sprayed at the same time. The hydrogen accounts for 8% of the hot air volume. The sintered ore accounts for 80% of the blast furnace charge structure. After smelting in the blast furnace, vanadium-containing molten iron with a V content of 0.78% is obtained. The vanadium-containing molten iron is subjected to a converter to extract vanadium. The recovery rate calculated based on the vanadium entering the vanadium-containing molten iron is 93.12%.

[0069] Comparative Example 1

[0070] A method for recovering vanadium from stone coal comprises the following steps:

[0071] (1) Take stone coal containing 0.8% V2O5 and 12.86% C from a certain place, crush the vanadium-containing stone coal ore to a particle size of -3mm greater than 90%;

[0072] (2) adding the crushed vanadium-containing stone coal powder to the sintered ore according to a set ratio, wherein the ratio of the vanadium-containing stone coal powder in the sintering ingredients is 3%, thereby obtaining a vanadium-containing sintered ore;

[0073] (3) The vanadium-containing sintered ore is fed into a blast furnace for smelting. The sintered ore accounts for 75% of the blast furnace charge structure. After smelting in the blast furnace, vanadium-containing molten iron with a V content of 0.36% is obtained. The vanadium-containing molten iron is extracted through a converter. The recovery rate calculated based on the vanadium entering the vanadium-containing molten iron is 70.26%.

[0074] Comparative Example 2

[0075] Other conditions were the same as those in Example 1, except that hydrogen was not injected during blast furnace smelting. After blast furnace smelting, vanadium-containing molten iron with a V content of 0.54% was obtained, and the vanadium recovery rate was 79.65%.

[0076] Comparative Example 3

[0077] Other conditions were the same as those in Example 1, except that no vanadium-containing stone coal powder was sprayed into the blast furnace. After smelting in the blast furnace, vanadium-containing molten iron with a V content of 0.45% was obtained, and the vanadium recovery rate was 78.25%.

[0078] The above is only a preferred embodiment of the present invention, and the scope of protection of the present invention is not limited to the above embodiment. For those skilled in the art, improvements and modifications obtained without departing from the technical concept of the present invention should also be considered as the scope of protection of the present invention.

Claims

1. A method for extracting vanadium from stone coal based on a sintering-blast furnace-converter process, characterized in that: The following steps are involved: (1) crushing vanadium-containing stone coal ore to obtain crushed vanadium-containing stone coal powder, and sieving it with a 100-mesh sieve to obtain fine-grained stone coal powder with a particle size of less than 100 mesh and stone coal powder with a particle size of ≥100 mesh; (2) In the sintering process, the vanadium-containing stone coal powder with a particle size of ≥100 mesh obtained in step (1) is added to the vanadium-titanium magnetite sintering mixture according to a set ratio, and vanadium-containing sintered ore is obtained after sintering; (3) The vanadium-containing sintered ore obtained in step (2) is fed into a blast furnace for smelting, and the vanadium-containing stone coal powder with a particle size of less than 100 mesh obtained in step (1) is mixed into the coal powder sprayed into the blast furnace according to a predetermined ratio. The coal powder mixed with the vanadium-containing stone coal is sprayed into the blast furnace by a spray gun, and hydrogen-rich gas is sprayed into the blast furnace at the same time. After smelting in the blast furnace, vanadium-containing molten iron is obtained, and the obtained vanadium-containing molten iron is subjected to a converter vanadium extraction process to recover vanadium.

2. The method for extracting vanadium from stone coal based on the sintering-blast furnace-converter process according to claim 1, characterized in that: In step (1), the vanadium-containing coal ore is crushed to a particle size of -3 mm greater than 90%.

3. The method for extracting vanadium from stone coal based on the sintering-blast furnace-converter process according to claim 1, characterized in that: In step (1), the V2O5 content in the vanadium-containing stone coal is above 0.8%; the C content in the vanadium-containing stone coal is above 8.0%.

4. The method for extracting vanadium from stone coal based on the sintering-blast furnace-converter process according to claim 1, characterized in that: In step (2), the proportion of the vanadium-containing stone coal powder in the sintering mixture is 2% to 5%.

5. The method for extracting vanadium from stone coal based on the sintering-blast furnace-converter process according to claim 1, characterized in that: In step (3), the mass ratio of the vanadium-containing stone coal powder to ordinary coal powder is 20-50:80-50; the injection amount of hydrogen-rich gas accounts for 5-15% of the injection amount of hot air; the hydrogen-rich gas includes one or more of hydrogen, coke oven gas, and natural gas.

6. The method for extracting vanadium from stone coal based on the sintering-blast furnace-converter process according to claim 1, characterized in that: In step (3), the proportion of vanadium-containing sintered ore in the blast furnace charge structure is greater than 70%.

7. The method for extracting vanadium from stone coal based on the sintering-blast furnace-converter process according to claim 1, characterized in that: In step (3), the V content in the vanadium-containing molten iron is greater than 0.5%.

8. The method for extracting vanadium from stone coal based on the sintering-blast furnace-converter process according to claim 1, characterized in that: The spray gun comprises a coal conveying pipe (1), a mixer (2), a distributor (3), a straight blowing pipe (4) and a coal injection port (5); The mixer (2) is provided with a feeding port (202); The top of the distributor (3) is provided with a gas inlet (301); The mixer (2) and the distributor (3) are connected via a coal conveying pipe (1); the output end of the distributor (3) is connected to the input end of a direct blowing pipe (4); a heating chamber (401), a coal injection pipe (402) and a high-pressure hot air pipe (403) are provided in the direct blowing pipe (4); The heating chamber (401) is arranged inside the side wall of the direct blowing pipe (4); the number of the coal injection pipes (402) is several, the input end of the coal injection pipe (402) is connected to the output end of the distributor (3), and the output end of the coal injection pipe (402) is connected to the coal injection port (5); The high-pressure hot air pipe (403) is arranged at the output end of the direct blowing pipe (4) and is located at the center of the direct blowing pipe (4).

9. The method for extracting vanadium from stone coal based on the sintering-blast furnace-converter process according to claim 8, characterized in that: The mixer (2) is provided with a vibrator or an ultrasonic device.

10. The method for extracting vanadium from stone coal based on the sintering-blast furnace-converter process according to claim 8, characterized in that: The number of the coal injection pipes (402) is four, and they are symmetrically arranged inside the direct blowing pipe (4).

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