Preparation method of high-vanadium cold-pressed pellets

Abstract

The invention discloses a preparation method of high-vanadium cold-pressed pellets, which belongs to the field of metallurgical materials and comprises the following steps: uniformly mixing vanadium titano-magnetite powder, vanadium slag and an antioxidant calcium oxide binder, adding water, carrying out cold pressing on a semi-dry material to form green pellets, then drying, and putting the green pellets into a heating furnace for low-temperature calcination; putting the pellets into the heating furnace again for high-temperature calcination to obtain primary cold-pressed pellets; and standing the primary cold-pressed pellets subjected to high-temperature calcination to obtain the high-vanadium cold-pressed pellets. The prepared high-vanadium cold-pressed pellets are high in vanadium content, compact in structure, stable in performance and suitable for wider industrial fields. According to the preparation method of the high-vanadium cold-pressed pellets, the resource utilization efficiency is improved, the production process is optimized, and the physical performance and the environment-friendly characteristic of products are remarkably enhanced.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgical materials, in particular to a method for preparing high-vanadium cold-pressed pellets. Background Art

[0002] Vanadium is an important alloying element, mainly used in the steel industry. Vanadium-containing steel has excellent properties such as high strength, high toughness, and good wear resistance. Therefore, it is widely used in machinery, automobiles, shipbuilding, railways, aviation, bridges, electronic technology, defense industry and other industries. Its consumption accounts for about 85% of vanadium consumption, and the consumption in the steel industry accounts for the largest proportion of vanadium use. The demand of the steel industry directly affects the vanadium market. About 10% of vanadium is used to produce titanium alloys required by the aerospace industry. Vanadium can be used as a stabilizer and strengthener in titanium alloys, giving titanium alloys good ductility and plasticity. In addition, vanadium is mainly used as a catalyst and colorant in the chemical industry. Vanadium is also used in the production of rechargeable hydrogen batteries or vanadium redox batteries.

[0003] High vanadium cold pressed pellets are located in Panzhihua City, the third largest city in the world, with unique resource conditions; Panzhihua City has proven iron ore (mainly vanadium-titanium magnetite) of 7.18 billion tons, accounting for 72.3% of Sichuan Province's proven iron ore reserves, and is one of China's four major iron ore areas; associated titanium resource reserves account for 93% of the country, ranking first in the world; associated vanadium resource reserves account for 63% of the country, ranking third in the world. Proven graphite resource reserves are third in the country. After years of development and utilization, the city's vanadium-titanium magnetite reserves are 6.64 billion tons, including 430 million tons of associated titanium ore and 10.203 million tons of associated vanadium ore.

[0004] However, the high vanadium cold pressed pellets prepared by the existing schemes have the disadvantages of low pelletization rate, low production efficiency and low strength. Therefore, providing a preparation method of high vanadium cold pressed pellets with high pelletization rate and higher strength is a technical problem that technicians in this field need to solve urgently. Summary of the invention

[0005] In view of this, the present invention provides a method for preparing high-vanadium cold-pressed pellets with high pelletization rate and higher strength.

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

[0007] A method for preparing high-vanadium cold-pressed pellets comprises the following steps:

[0008] (1) mixing vanadium-titanium magnetite powder, vanadium slag, and antioxidant calcium binder to obtain a mixture, and then adding 0.1-0.2 times the amount of water to the mixture to obtain a semi-dry material;

[0009] (2) cold pressing the semi-dry material into green balls with a diameter of 50-60 mm, then drying the green balls, and placing them in a heating furnace for low-temperature calcination after drying;

[0010] (3) taking out the green balls after low-temperature calcination and letting them stand to cool naturally to room temperature, and then putting them into the heating furnace again for high-temperature calcination to obtain primary cold-pressed balls;

[0011] (4) The primary cold-pressed pellets after high-temperature calcination are allowed to stand for 20-40 hours again to obtain high-vanadium cold-pressed pellets.

[0012] Furthermore, the mass ratio of the vanadium-titanium magnetite powder, vanadium slag and antioxidant calcium binder in step (1) is 100:1-3:2-3.

[0013] The beneficial effect of adopting the above further scheme is that the present invention effectively utilizes the vanadium element in the raw material by adjusting the ratio of vanadium-titanium magnetite powder, vanadium slag and antioxidant calcium binder, improves the vanadium recovery rate and the vanadium content in the pellets, and not only improves the comprehensive utilization rate of vanadium resources, but also improves the forming rate and strength of the pellets.

[0014] Furthermore, the antioxidant calcium binder is composed of the following raw materials in parts by mass: 3-7 parts of magnesium oxide, 2-5 parts of magnesium sulfate, 2-6 parts of water glass, 5-15 parts of corn protein, and 2-5 parts of high-viscosity polyvinyl alcohol.

[0015] Furthermore, the molecular weight of the high viscosity polyvinyl alcohol is 120,000-150,000.

[0016] The beneficial effect of adopting the above further scheme is that the antioxidant calcium binder used in the present invention not only enhances the cold pressing effect of the pellets, but also significantly improves the physical strength and other properties of the pellets, ensures the subsequent processing performance of the pellets, and improves the stability and durability of the product. The binder raw materials used in the present invention interact with each other to form a strong bonding network, which significantly improves the internal structure and strength of the pellets. Further, the cold pressing pressure in step (2) is 6-10MPa.

[0017] Furthermore, in step (2), the drying temperature is 40-60° C., and the drying time is 2-5 h.

[0018] Furthermore, the low-temperature calcination temperature in step (2) is 400-550°C, and the low-temperature calcination method is to increase the temperature from room temperature to the target temperature at a heating rate of 5°C / min, and then keep it warm for 1-2h.

[0019] Furthermore, the high temperature calcination temperature in step (3) is 900-1050°C, and the high temperature calcination method is to increase the temperature from room temperature to 500°C at a heating rate of 10°C / min, then increase the temperature to the target temperature at a heating rate of 5°C / min, and then keep warm for 1-2h.

[0020] The beneficial effect of adopting the above further scheme is that the present invention realizes the refined control of process parameters by regulating the cold pressing pressure, drying conditions, and calcination temperature and time, which not only ensures the optimization of the internal structure of the pellets, but also improves production efficiency and reduces energy consumption. At the same time, the method of the present invention adopts a staged temperature increase calcination strategy, which reduces energy waste compared with traditional methods.

[0021] The beneficial effects of the present invention are as follows: the high-vanadium cold-pressed pellets prepared by the present invention have high vanadium content, compact structure, stable performance, and are applicable to a wider range of industrial fields, such as steel smelting, chemical industry, etc., providing downstream users with higher quality product options. The high-vanadium cold-pressed pellet preparation method of the present invention not only improves resource utilization efficiency and optimizes production technology, but also significantly enhances the physical properties and environmental protection characteristics of the product, opening up a new path for the deep processing and sustainable development of vanadium resources. DETAILED DESCRIPTION

[0022] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] In the embodiment of the present invention, the antioxidant calcium binder is composed of the following raw materials: 5 kg of magnesium oxide, 3 kg of magnesium sulfate, 5 kg of water glass, 12 kg of corn protein, and 3 kg of high-viscosity polyvinyl alcohol with a molecular weight of 120,000.

[0024] Example 1

[0025] A method for preparing high-vanadium cold-pressed pellets:

[0026] (1) mixing vanadium-titanium magnetite powder, vanadium slag, and antioxidant calcium binder in a mass ratio of 100:3:2 to obtain a mixture, and then adding 0.1 times the amount of water to the mixture to obtain a semi-dry material;

[0027] (2) The semi-dried material is cold pressed at a pressure of 10 MPa to form green balls with a diameter of 50 mm, and then the green balls are dried at 60°C for 2 h. After drying, they are placed in a heating furnace and heated from room temperature to 550°C at a heating rate of 5°C / min, and then kept warm for 1 h;

[0028] (3) taking out the green balls after low-temperature calcination and letting them stand to cool naturally to room temperature, then putting them into the heating furnace again and heating them from room temperature to 500°C at a heating rate of 10°C / min, then heating them to 900°C at a heating rate of 5°C / min, and then keeping them warm for 2 hours to obtain primary cold-pressed balls;

[0029] (4) The primary cold-pressed pellets after high-temperature calcination are allowed to stand for another 40 hours to obtain high-vanadium cold-pressed pellets.

[0030] Example 2

[0031] A method for preparing high-vanadium cold-pressed pellets:

[0032] (1) mixing vanadium-titanium magnetite powder, vanadium slag, and antioxidant calcium binder in a mass ratio of 100:1:3 to obtain a mixture, and then adding 0.2 times the amount of water to the mixture to obtain a semi-dry material;

[0033] (2) The semi-dry material is cold pressed at a pressure of 6 MPa to form green balls with a diameter of 60 mm, and then the green balls are dried at 40°C for 5 h. After drying, the green balls are placed in a heating furnace and heated from room temperature to 400°C at a heating rate of 5°C / min, and then kept warm for 2 h;

[0034] (3) taking out the green pellets after low-temperature calcination and letting them stand to cool naturally to room temperature, then putting them into the heating furnace again and heating them from room temperature to 500°C at a heating rate of 10°C / min, then heating them to 1050°C at a heating rate of 5°C / min, and then keeping them warm for 1 hour to obtain primary cold-pressed pellets;

[0035] (4) The primary cold-pressed pellets after high-temperature calcination are allowed to stand for 20 hours again to obtain high-vanadium cold-pressed pellets.

[0036] Example 3

[0037] A method for preparing high-vanadium cold-pressed pellets:

[0038] (1) mixing and stirring vanadium-titanium magnetite powder, vanadium slag, and antioxidant calcium binder in a mass ratio of 100:2:3 to obtain a mixture, and then adding 0.2 times the amount of water to the mixture to obtain a semi-dry material;

[0039] (2) The semi-dry material is cold pressed at a pressure of 10 MPa to form green balls with a diameter of 55 mm, and then the green balls are dried at 50°C for 4 h. After drying, they are placed in a heating furnace and heated from room temperature to 500°C at a heating rate of 5°C / min, and then kept warm for 1-2 h;

[0040] (3) taking out the green balls after low-temperature calcination and letting them stand to cool naturally to room temperature, then putting them into the heating furnace again and heating them from room temperature to 500°C at a heating rate of 10°C / min, then heating them to 1000°C at a heating rate of 5°C / min, and then keeping them warm for 2 hours to obtain primary cold-pressed balls;

[0041] (4) The primary cold-pressed pellets after high-temperature calcination are allowed to stand for 30 hours again to obtain high-vanadium cold-pressed pellets.

[0042] Example 4

[0043] A method for preparing high-vanadium cold-pressed pellets:

[0044] (1) mixing vanadium-titanium magnetite powder, vanadium slag, and antioxidant calcium binder in a mass ratio of 100:2.5:2.5 to obtain a mixture, and then adding 0.1 times the amount of water to the mixture to obtain a semi-dry material;

[0045] (2) cold pressing the semi-dry material with a pressure of 6-10 MPa to form green balls with a diameter of 55 mm, then drying the green balls at 50°C for 3 h, placing them in a heating furnace and heating them from room temperature to 450°C at a heating rate of 5°C / min, and then keeping them warm for 1-2 h;

[0046] (3) taking out the green pellets after low-temperature calcination and letting them stand to cool naturally to room temperature, then putting them into the heating furnace again and heating them from room temperature to 500°C at a heating rate of 10°C / min, then heating them to 1050°C at a heating rate of 5°C / min, and then keeping them warm for 2 hours to obtain primary cold-pressed pellets;

[0047] (4) The primary cold-pressed pellets after high-temperature calcination are allowed to stand for 35 hours again to obtain high-vanadium cold-pressed pellets.

[0048] Comparative Example 1

[0049] JH-2105 antioxidant calcium binder was used, and other operations were exactly the same as in Example 4.

[0050] Comparative Example 2

[0051] (1) mixing vanadium-titanium magnetite powder, vanadium slag, and antioxidant calcium binder in a mass ratio of 100:2.5:2.5 to obtain a mixture, and then adding 0.1 times the amount of water to the mixture to obtain a semi-dry material;

[0052] (2) The semi-dry material is cold-pressed at a pressure of 6-10 MPa to form green balls with a diameter of 55 mm, and then the green balls are dried at 50°C for 3 hours and then allowed to stand for 35 hours to obtain high-vanadium cold-pressed balls.

[0053] Test example

[0054] The high vanadium cold pressed pellets prepared in Examples 1-4 and Comparative Examples 1-2 were tested, and the results are shown in Table 1.

[0055]

[0056] The experimental results show that the high vanadium cold pressed pellets prepared by the method of the present invention have higher pelletization rate and pelletization strength. The method of the present invention improves the impact resistance of the high vanadium cold pressed pellets.

[0057] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for preparing high-vanadium cold-pressed pellets, characterized in that: The following steps are involved: (1) mixing vanadium-titanium magnetite powder, vanadium slag, and antioxidant calcium binder to obtain a mixture, and then adding 0.1-0.2 times the amount of water to the mixture to obtain a semi-dry material; (2) cold pressing the semi-dry material into green balls with a diameter of 50-60 mm, then drying the green balls, and placing them in a heating furnace for low-temperature calcination after drying; (3) taking out the green balls after low-temperature calcination and letting them stand to cool naturally to room temperature, and then putting them into the heating furnace again for high-temperature calcination to obtain primary cold-pressed balls; (4) The primary cold-pressed pellets after high-temperature calcination are allowed to stand for 20-40 hours again to obtain high-vanadium cold-pressed pellets.

2. The method for preparing high-vanadium cold-pressed pellets according to claim 1, characterized in that: The mass ratio of the vanadium-titanium magnetite powder, vanadium slag and antioxidant calcium binder in step (1) is 100:1-3:2-3.

3. The method for preparing high-vanadium cold-pressed pellets according to claim 2, characterized in that: The antioxidant calcium binder is composed of the following raw materials in parts by mass: 3-7 parts of magnesium oxide, 2-5 parts of magnesium sulfate, 2-6 parts of water glass, 5-15 parts of corn protein, and 2-5 parts of high-viscosity polyvinyl alcohol.

4. The method for preparing high-vanadium cold-pressed pellets according to claim 3, characterized in that: The molecular weight of the high-viscosity polyvinyl alcohol is 120,000-150,000.

5. The method for preparing high-vanadium cold-pressed pellets according to claim 1, characterized in that: The cold pressing pressure in step (2) is 6-10 MPa.

6. The method for preparing high-vanadium cold-pressed pellets according to claim 1, characterized in that: The drying temperature in step (2) is 40-60° C. and the drying time is 2-5 h.

7. The method for preparing high-vanadium cold-pressed pellets according to claim 1, characterized in that: The low-temperature calcination temperature in step (2) is 400-550°C, and the low-temperature calcination method is to increase the temperature from room temperature to the target temperature at a heating rate of 5°C / min, and then keep it warm for 1-2h.

8. The method for preparing high-vanadium cold-pressed pellets according to claim 1, characterized in that: The high temperature calcination temperature in step (3) is 900-1050°C, and the high temperature calcination method is to increase the temperature from room temperature to 500°C at a heating rate of 10°C / min, then increase the temperature to the target temperature at a heating rate of 5°C / min, and then keep warm for 1-2h.

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