Method for extracting vanadium from vanadium-titanium magnetite concentrate and vanadium-containing stone coal based on blast furnace-converter process

Abstract

The invention discloses a method for extracting vanadium from vanadium-titanium magnetite concentrate and vanadium-containing stone coal based on a blast furnace-converter process, which comprises the following steps: (1) crushing and levigating the vanadium-containing stone coal mine, and sorting to obtain high-vanadium low-carbon stone coal powder and high-carbon stone coal powder; (2) uniformly mixing the high-vanadium low-carbon stone coal powder with the vanadium-titanium magnetite concentrate and a binder for pelletizing, and drying, preheating and roasting to obtain vanadium-containing oxidized pellets; and (3) the vanadium-containing oxidized pellets are fed into a blast furnace to be smelted, high-carbon stone coal powder is mixed into coal powder sprayed by the blast furnace according to a preset proportion, mixed coal powder is obtained, the mixed coal powder 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 technology. According to the method, the synergistic effect between the two minerals is fully exerted, carbon emission is reduced, vanadium recycling 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 recycling 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 vanadium-titanium magnetite concentrate and vanadium-containing stone coal based on a blast furnace-converter process. Background Art

[0002] Vanadium-titanium magnetite is an important polymetallic mineral, and the extraction of vanadium from it has significant economic value. However, existing methods for extracting vanadium from vanadium-titanium magnetite concentrate have several shortcomings, such as low vanadium extraction rates, complex processes, high energy consumption, and significant environmental impact.

[0003] Vanadium-containing 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 stone coal in my country, 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. Currently, the conventional process for extracting vanadium from stone coal is 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 concentrated vanadium is extracted from the solution. This traditional process involves sodium roasting and water leaching, which uses high-temperature conditions to produce water-soluble sodium vanadates. This process has problems such as serious waste gas pollution, low recovery rate, and complex waste liquid 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+ In general, due to the complex occurrence of vanadium, stone coal vanadium ores often contain a large number of substances that interfere with subsequent vanadium extraction operations, which can adversely affect roasting conversion or leaching rates, resulting in very low vanadium recovery rates and excessively high costs. The extraction process also produces large amounts of waste gas, wastewater, and waste residue, exacerbating environmental pollution. With increasingly stringent environmental protection requirements, it is imperative to find a vanadium extraction process that can avoid these problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for extracting vanadium from vanadium-titanium magnetite concentrate and vanadium-containing stone coal based on a blast furnace-converter process, and to jointly extract vanadium from the vanadium-titanium magnetite concentrate and vanadium-containing stone coal to make full use of the valuable elements in the two minerals.

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

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

[0008] (1) crushing and grinding vanadium-containing stone coal ore and then sorting it to obtain high-vanadium low-carbon stone coal powder and high-carbon stone coal powder;

[0009] (2) mixing the high-vanadium low-carbon stone coal powder obtained in step (1) with vanadium-titanium magnetite concentrate and a binder to form pellets, and then drying, preheating and roasting to obtain vanadium-containing oxide pellets;

[0010] (3) The vanadium-containing oxide pellets obtained in step (2) are fed into a blast furnace for smelting, and the high-carbon stone coal powder obtained in step (1) is mixed into the blast furnace pulverized coal according to a predetermined ratio to obtain mixed pulverized coal, and the mixed pulverized coal is sprayed into the blast furnace using a spray gun, and hydrogen-rich gas is sprayed into the blast furnace at the same time, and vanadium-containing molten iron is obtained after smelting in the blast furnace. The obtained vanadium-containing molten iron is subjected to a converter vanadium extraction process to recover vanadium.

[0011] In a preferred embodiment, in step (1), the vanadium-containing coal ore is crushed to a particle size of -200 mesh greater than 80%.

[0012] In a preferred embodiment, in step (1), the V2O5 content in the vanadium-containing stone coal is above 0.8%; and the C content in the vanadium-containing stone coal is above 8.0%.

[0013] In a preferred solution, in step (1), the vanadium-containing stone coal is separated by flotation, gravity separation or other commonly used separation methods.

[0014] In a preferred embodiment, in step (2), the mass ratio of the high-vanadium low-carbon stone coal powder to the vanadium-titanium magnetite concentrate and the binder is (5-20): (79-94): (1-2);

[0015] The binder is one or more of bentonite, organic binder and slaked lime.

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

[0017] In a preferred embodiment, in step (3), the proportion of vanadium-containing oxide pellets in the blast furnace charge structure is greater than 60%.

[0018] In a preferred embodiment, 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.

[0019] In a specific embodiment, the lance includes a coal conveying pipe, a mixer, a distributor, a straight blowing pipe and a coal injection port;

[0020] The mixer is provided with a feeding port;

[0021] A gas inlet is provided on the top of the distributor;

[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 arranged inside the side wall of the direct blowing pipe; the number of the coal injection pipes is set to be 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] Furthermore, a vibrator or ultrasonic device is provided in the mixer to facilitate uniform mixing of the vanadium-containing stone coal powder and the ordinary coal powder.

[0026] Furthermore, there are four coal injection pipes, which are symmetrically arranged inside the direct blowing pipe.

[0027] Furthermore, a gas inlet is provided on the top of the distributor.

[0028] Furthermore, the heating chamber is provided with a heating medium inlet and a heating medium outlet.

[0029] Compared with the prior art, the advantages of the present invention are:

[0030] The present invention discloses a method for extracting vanadium from vanadium-titanium magnetite concentrate and vanadium-containing stone coal based on a blast furnace-converter process. First, vanadium-containing stone coal powder is sorted to obtain high-vanadium low-carbon stone coal powder and high-carbon stone coal powder. The high-vanadium low-carbon stone coal powder and high-carbon stone coal powder are added to a pelletizing process and a blast furnace process, respectively. Hydrogen-rich gas is sprayed into the blast furnace smelting process to further improve the recovery rate of vanadium, give full play to the synergistic effect between the two minerals, reduce carbon emissions, and realize the recycling of vanadium. Moreover, no additional new production line needs to be built, and the method has the advantages of low cost, large processing scale, high vanadium recovery rate, and the like. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The present invention is a process flow chart of a method for extracting vanadium from vanadium-titanium magnetite concentrate and vanadium-containing stone coal based on a blast furnace-converter process.

[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 2 Sectional view at the AB position.

[0034] 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

[0035] 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.

[0036] Example 1

[0037] A method for extracting vanadium from vanadium-titanium magnetite concentrate and vanadium-containing stone coal based on a blast furnace-converter process comprises the following steps:

[0038] (1) Crushing and grinding vanadium-containing stone coal ore with a V2O5 content of 0.97% and a C content of 8.86% and then sorting the vanadium-containing stone coal powder with a V2O5 content of 1.06% and a C content of 5.29% and a high-carbon stone coal powder with a V2O5 content of 0.46% and a C content of 26.15% were obtained;

[0039] (2) mixing the high-vanadium, low-carbon stone coal powder with a vanadium-titanium magnetite concentrate containing 58.12% TFe and 0.68% V2O5, and bentonite to form pellets, which are then dried, preheated, and roasted to obtain vanadium-containing oxide pellets;

[0040] (3) The vanadium-containing oxide pellets are fed into a blast furnace for smelting, and high-carbon stone coal powder is mixed into the blast furnace pulverized coal in a predetermined proportion to obtain mixed pulverized coal. The mixed pulverized coal is sprayed into the blast furnace using 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 with a vanadium content of 0.84% is obtained. The obtained vanadium-containing molten iron is subjected to a converter vanadium extraction process to recover vanadium. The recovery rate calculated based on the vanadium entering the vanadium-containing molten iron is 93.54%. The process flow is as follows: Figure 1 shown.

[0041] Specifically, in step (1), the vanadium-containing coal ore is crushed to a particle size of -200 mesh greater than 80%.

[0042] Specifically, in step (1), flotation method is used for separation, and the reagent system is: 600g / t of water glass as inhibitor and 200g / t of kerosene as collector.

[0043] Specifically, in step (2), the mass ratio of high-vanadium low-carbon stone coal powder to vanadium-titanium magnetite concentrate and bentonite is 10:89:1.

[0044] Specifically, in step (3), the mass ratio of high-carbon stone coal powder to ordinary coal powder is 20:80; the injection amount of hydrogen-rich gas accounts for 5% of the injection amount of hot air, and the hydrogen-rich gas is hydrogen.

[0045] Specifically, in step (3), the proportion of vanadium-containing oxide pellets in the blast furnace charge structure is 75%.

[0046] Specifically, in step (3), the converter vanadium extraction process is as follows: after charging vanadium-containing molten iron into the furnace, oxygen is introduced, the molten pool temperature is controlled at 1400°C, and oxygen is blown for 10 minutes. After the blowing is completed, the converter is tilted to first release the semi-steel, and then the vanadium slag is poured out for recovery.

[0047] like Figures 2-3 As shown, the lance includes a coal conveying pipe 1, a mixer 2, a distributor 3, a straight blowing pipe 4 and a coal injection port 5; a feed port 202 is provided on the mixer 2; a gas feed port 301 is provided on the top of the distributor 3;

[0048] The mixer 2 and the distributor 3 are connected through the coal conveying pipe 1. The output end of the distributor 3 is connected to the input end of the 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.

[0049] The heating chamber 401 is provided inside the side wall of the straight blowing pipe 4; the number of the coal injection pipes 402 is set to be 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;

[0050] 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 .

[0051] Furthermore, a vibrator or ultrasonic device is provided in the mixer 2 to facilitate uniform mixing of the vanadium-containing stone coal powder and the ordinary coal powder.

[0052] Furthermore, there are four coal injection pipes 402 , which are symmetrically arranged inside the direct blowing pipe 4 .

[0053] Furthermore, a gas inlet is provided on the top of the distributor 3 .

[0054] 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 .

[0055] 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.

[0056] 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; high carbon stone coal powder is added to the mixer 2 through the feeding port 202, and the vibrator 201 in the mixer 2 is used to mix the high carbon stone coal powder and the coal powder evenly; the mixed coal powder is added to the distributor 3 through the coal conveying pipe 1, and the distributor 3 transports the mixed coal powder to the coal injection pipe 402, and the mixed coal powder enters the coal injection port 5 from different angles; at the same time, hydrogen-rich gas 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 coal powder, so that the hydrogen-rich gas and the mixed coal powder are completely mixed, and finally blown into the blast furnace for combustion.

[0057] Comparative Example 1

[0058] 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 0.58% was obtained, and the vanadium recovery rate was 68.45%.

[0059] Comparative Example 2

[0060] Other conditions are consistent with those of Example 1, except that no sorting is performed in step (1), and the vanadium-containing stone coal powder is directly added in step (2). Other systems remain unchanged, and pellets with a compressive strength of 1385 N / P are obtained. The pellet strength does not meet the requirements for blast furnace smelting. After blast furnace smelting, vanadium-containing molten iron with a V content of 0.74% is obtained, and the vanadium recovery rate is 83.76%.

[0061] 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 vanadium-titanium magnetite concentrate and vanadium-containing stone coal based on a blast furnace-converter process, characterized in that: The following steps are involved: (1) crushing and grinding vanadium-containing stone coal ore and then sorting it to obtain high-vanadium low-carbon stone coal powder and high-carbon stone coal powder; (2) mixing the high-vanadium low-carbon stone coal powder obtained in step (1) with vanadium-titanium magnetite concentrate and a binder to form pellets, and then drying, preheating and roasting to obtain vanadium-containing oxide pellets; (3) The vanadium-containing oxide pellets obtained in step (2) are fed into a blast furnace for smelting, and the high-carbon stone coal powder obtained in step (1) is mixed into the blast furnace pulverized coal according to a predetermined ratio to obtain mixed pulverized coal, and the mixed pulverized coal is sprayed into the blast furnace using a spray gun, and hydrogen-rich gas is sprayed into the blast furnace at the same time, and vanadium-containing molten iron is obtained after smelting in the blast furnace. The obtained vanadium-containing molten iron is subjected to a converter vanadium extraction process to recover vanadium.

2. The method for extracting vanadium from vanadium-titanium magnetite concentrate and vanadium-containing stone coal based on the 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 -200 mesh greater than 80%.

3. The method for extracting vanadium from vanadium-titanium magnetite concentrate and vanadium-containing stone coal based on the 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%; and the C content in the vanadium-containing stone coal is above 8.0%.

4. The method for extracting vanadium from vanadium-titanium magnetite concentrate and vanadium-containing stone coal based on the blast furnace-converter process according to claim 1, characterized in that: In step (1), vanadium-containing stone coal is separated by flotation, gravity separation and other commonly used separation methods.

5. The method for extracting vanadium from vanadium-titanium magnetite concentrate and vanadium-containing stone coal based on the blast furnace-converter process according to claim 1, characterized in that: In step (2), the mass ratio of the high-vanadium low-carbon stone coal powder to the vanadium-titanium magnetite concentrate and the binder is (5-20): (79-94): (1-2); The binder is one or more of bentonite, organic binder and slaked lime.

6. The method for extracting vanadium from vanadium-titanium magnetite concentrate and vanadium-containing stone coal based on the blast furnace-converter process according to claim 1, characterized in that: In step (3), the mass ratio of high-carbon 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.

7. The method for extracting vanadium from vanadium-titanium magnetite concentrate and vanadium-containing stone coal based on the blast furnace-converter process according to claim 1, characterized in that: In step (3), the proportion of vanadium-containing oxide pellets in the blast furnace charge structure is greater than 60%.

8. The method for extracting vanadium from vanadium-titanium magnetite concentrate and vanadium-containing stone coal based on the 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 vanadium-titanium magnetite concentrate and vanadium-containing stone coal based on the 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 vanadium-titanium magnetite concentrate and vanadium-containing stone coal based on the 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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