Method for improving the balling performance of laboratory vanadium-titanium pellets

Abstract

The application discloses a method for improving the balling performance of laboratory vanadium-titanium pellets, and the method is characterized in that: the balling is performed through a commonly used balling disc and a screen in a laboratory, and the mother pellets with a particle size of 10-12.5 mm are screened out as qualified vanadium-titanium pellets; the size of the pellets obtained through the method is uniform, and the green and baked compressive strength, the drop strength performance and the finished product rate are all superior to those of a conventional balling method; the pellet performance fully meets the requirements of experimental research, and the target required by experiments can be accurately controlled, so that the steel enterprises or research units can better complete various pellet balling experiments, the method can provide the adjustment basis of operation parameters for a pellet production plant, and is favorable for improving the green pellet quality and the finished product yield of vanadium-titanium ore pellets, and has certain popularization and application value.

Description

Technical Field

[0001] This invention belongs to the field of iron and steel metallurgy technology, and specifically relates to a method for improving the pelletizing performance of laboratory vanadium-titanium pellets. Background Technology

[0002] Blast furnaces are the core equipment in the steel industry, responsible for converting iron ore into molten iron. In recent years, with the rapid development of my country's steel industry, higher demands have been placed on improving blast furnace production efficiency and resource utilization. As a type of blast furnace raw material, iron ore pellets play an increasingly prominent role in blast furnace production. Increasing the proportion of pellets is beneficial for optimizing the blast furnace burden structure, improving resource utilization, and reducing production costs, which is of great significance. Iron ore pellets are a high-grade, high-utilization blast furnace raw material produced from iron ore through processes such as fine grinding, mixing, pelletizing, drying, and roasting. Iron ore pellets are characterized by high grade, low moisture content, high strength, and uniform particle size, which can improve the permeability and liquid permeability of the blast furnace, reduce furnace resistance, reduce fuel consumption, and improve production efficiency.

[0003] In blast furnace production, iron ore pellets are primarily used to provide iron ore resources, and their proportion in the blast furnace charge directly affects the furnace's production performance. Increasing the proportion of pellets can effectively improve the grade of iron ore fed into the blast furnace, reduce production costs, and improve resource utilization. Furthermore, iron ore pellets also have good environmental performance, reducing emissions of pollutants such as dust and SO2 during blast furnace production.

[0004] Vanadium-titanium magnetite concentrate has a high TiO2 content, coarse particle size, and small specific surface area, resulting in poor pelletizing performance, poor high-temperature consolidation, and low compressive strength of the finished pellets. Common vanadium-titanium ore pelletizing methods utilize disc pelletizers, with a continuous process from concentrate nucleation to mother pellet formation and finally to finished green pellets. However, due to uneven moisture distribution and material adhesion, irregular mother pellets are prone to occur, leading to problems such as poor sphericity, large particle size variations, and low yield in the finished pellets. Summary of the Invention

[0005] To overcome the shortcomings of the existing technology, this invention uses a pelletizing disc and sieve commonly used in laboratories to pelletize the pellets, ensuring that the performance of the pellets meets the requirements of experimental research and that experimental conditions can be accurately controlled. This helps steel companies or research units to better complete various pelletizing experiments and provides a basis for adjusting operating parameters for pellet production plants.

[0006] To achieve the above-mentioned objective, the present invention provides a method for improving the pelletizing performance of laboratory vanadium-titanium pellets, the method comprising the following steps:

[0007] ①The materials are mixed according to the specified ratio to create mother balls on a pelletizing plate with a diameter of 1m;

[0008] ② The obtained mother balls are screened for the first time using a sieve with a mesh size of 3mm. Balls that pass through the sieve are discarded, and the mother balls that pass through the sieve are retained to continue making balls.

[0009] ③ Continue to add material to the undersized mother balls obtained in step ② to form balls. When the particle size of the mother balls is greater than 3mm, use sieves with a mesh size of 3mm and 6mm to screen them. Keep the mother balls with a particle size between 3 and 6mm and discard the rest.

[0010] ④ Continue to add material to the mother balls obtained in step ③, which are between 3 and 6 mm in size, to form balls. When the particle size of the mother balls is greater than 6 mm, use sieves with a mesh size of 6 mm and 8 mm to screen them, and keep the mother balls between 6 and 8 mm in size, and discard the rest of the mother balls.

[0011] ⑤ Continue to add materials to the mother balls with a particle size of 6-8 mm obtained in step ④ until the particle size of the mother balls is greater than 10 mm. Then, screen out the mother balls with a particle size of 10-12.5 mm as qualified vanadium-titanium pellets. The mother balls with a particle size greater than 12.5 mm are returned to the raw materials. The pelletizing process is completed, and vanadium-titanium pellets are obtained.

[0012] In the above technical solution, the material is vanadium-titanium magnetite concentrate, with bentonite as a binder; the amount of binder added is 1-3% of the mass of vanadium-titanium magnetite concentrate.

[0013] Furthermore, the moisture content of the mother pellet is controlled to be 7.8%–8.2% in the above steps.

[0014] Furthermore, the mother balls discarded during the pelletizing process in the above steps are broken up and returned to the pelletizing process as raw materials to ensure that no raw materials are wasted.

[0015] The vanadium-titanium pellets produced by this method are uniform in size, and their raw and cooked compressive strength, drop strength, and yield are all superior to those of conventional pelletizing methods.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] This invention uses pelletizing discs and sieves commonly used in laboratories to produce pellets that meet the performance requirements of experimental research and accurately achieve the experimental objectives. It helps steel companies or research units to better complete various pelletizing experiments, provides a basis for adjusting operating parameters for pellet production plants, and is conducive to improving the quality of green vanadium-titanium ore pellets and the yield of finished products. It has certain innovative value and potential for widespread application. Detailed Implementation

[0018] The present invention will be further described below with reference to specific embodiments, but this does not limit the invention in any way. To avoid redundancy, unless otherwise specified, the raw materials used in the following embodiments are all commercially available products, and the methods used are all conventional methods unless otherwise specified.

[0019] A method for improving the pelletizing performance of laboratory vanadium-titanium pellets, the method comprising the following steps:

[0020] ①The materials are mixed according to the specified ratio to create mother balls on a pelletizing plate with a diameter of 1m;

[0021] ② The obtained mother balls are screened for the first time using a sieve with a mesh size of 3mm. Balls that pass through the sieve are discarded, and the mother balls that pass through the sieve are retained to continue making balls.

[0022] ③ Continue to add material to the undersized mother balls obtained in step ② to form balls. When the particle size of the mother balls is greater than 3mm, use sieves with a mesh size of 3mm and 6mm to screen them. Keep the mother balls with a particle size between 3 and 6mm and discard the rest.

[0023] ④ Continue to add material to the mother balls obtained in step ③, which are between 3 and 6 mm in size, to form balls. When the particle size of the mother balls is greater than 6 mm, use sieves with a mesh size of 6 mm and 8 mm to screen them, and keep the mother balls between 6 and 8 mm in size, and discard the rest of the mother balls.

[0024] ⑤ Continue to add materials to the mother balls with a particle size of 6-8 mm obtained in step ④ to form pellets until the particle size of the mother balls is greater than 10 mm. Then, screen out the mother balls with a particle size of 10-12.5 mm as qualified vanadium-titanium pellets.

[0025] Any aspects not described in the following embodiments are the same as those described in the specific embodiments above.

[0026] Example 1

[0027] A method for improving the pelletizing performance of laboratory vanadium-titanium pellets, using vanadium-titanium magnetite concentrate as raw material and bentonite as binder; the amount of binder added is 2% of the mass of vanadium-titanium magnetite concentrate; the moisture content of the mother pellets is controlled at 8.0% during the preparation process; the specific process flow is as follows:

[0028] ①The materials are mixed according to the specified ratio to create mother balls on a pelletizing plate with a diameter of 1m;

[0029] ② The obtained mother balls are screened for the first time using a sieve with a mesh size of 3mm. Balls that pass through the sieve are discarded, and the mother balls that pass through the sieve are retained to continue making balls.

[0030] ③ Continue to add material to the undersized mother balls obtained in step ② to form balls. When the particle size of the mother balls is greater than 3mm, use sieves with a mesh size of 3mm and 6mm to screen them. Keep the mother balls with a particle size between 3 and 6mm and discard the rest.

[0031] ④ Continue to add material to the mother balls obtained in step ③, which are between 3 and 6 mm in size, to form balls. When the particle size of the mother balls is greater than 6 mm, use sieves with a mesh size of 6 mm and 8 mm to screen them, and keep the mother balls between 6 and 8 mm in size, and discard the rest of the mother balls.

[0032] ⑤ Continue to add materials to the mother balls with a particle size of 6-8 mm obtained in step ④ to form pellets until the particle size of the mother balls is greater than 10 mm. Then, screen out the mother balls with a particle size of 10-12.5 mm as qualified vanadium-titanium pellets.

[0033] The vanadium-titanium pellets prepared in Example 1 were tested and found to have a drop strength of 9 times, a green pellet compressive strength of 12.3 N, a cooked pellet compressive strength of 2861 N, and a yield of 90%.

[0034] Example 2

[0035] A method for improving the pelletizing performance of laboratory vanadium-titanium pellets, using vanadium-titanium magnetite concentrate as raw material and bentonite as binder; the amount of binder added is 2% of the mass of vanadium-titanium magnetite concentrate; the moisture content of the mother pellets is controlled at 8.0% during the preparation process; the specific process flow is as follows:

[0036] ①The materials are mixed according to the specified ratio to create mother balls on a pelletizing plate with a diameter of 1m;

[0037] ② The obtained mother balls are screened for the first time using a sieve with a mesh size of 3mm. Balls that pass through the sieve are discarded, and the mother balls that pass through the sieve are retained to continue making balls.

[0038] ③ Continue to sphericalize the sieved mother balls obtained in step ②. When the particle size of the mother balls is greater than 3mm, use sieves with a mesh size of 3mm and 6mm to screen them, retaining mother balls with a particle size between 3 and 6mm and discarding the rest.

[0039] ④ Continue to form the mother balls between 3 and 6 mm obtained in step ③. When the size of the mother balls is greater than 6 mm, use sieves with 6 mm and 8 mm mesh to screen them, and keep the mother balls between 6 and 8 mm, and discard the rest.

[0040] ⑤ Continue to pelletize the mother balls with a particle size of 6-8 mm obtained in step ④ until the particle size of all mother balls is greater than 10 mm. Then, screen out the mother balls with a particle size of 10-12.5 mm as qualified vanadium-titanium pellets.

[0041] The vanadium-titanium pellets prepared in Example 2 were tested and found to have a drop strength of 8 times, a green pellet compressive strength of 13.1 N, a cooked pellet compressive strength of 2653 N, and a yield of 83%.

[0042] Comparative Example 1

[0043] A method for improving the pelletizing performance of laboratory vanadium-titanium pellets, using vanadium-titanium magnetite concentrate as raw material and bentonite as binder; the amount of binder added is 2% of the mass of vanadium-titanium magnetite concentrate; the moisture content of the mother pellets is controlled at 8.0% during the preparation process; the specific process flow is as follows:

[0044] ①The materials are mixed according to the specified ratio to create mother balls on a pelletizing plate with a diameter of 1m;

[0045] ② Stop pelletizing when all mother pellets are larger than 10mm;

[0046] ③ Select mother balls with a particle size of 10-12.5 mm from the mother balls obtained in step ② to obtain qualified vanadium-titanium pellets, and discard the rest; thus obtaining vanadium-titanium pellets.

[0047] The vanadium-titanium pellets obtained in Comparative Example 1 were tested and found to have a drop strength of 2.5 times, a green pellet compressive strength of 9.4 N, a cooked pellet compressive strength of 2249 N, and a yield of 65%. The conventional pelletizing process in Comparative Example 1 lacked intermediate screening of the mother pellets and multiple particle size classifications, resulting in a low yield of mother pellets and poor pellet performance.

[0048] The experimental data from the above embodiments and comparative examples show that the vanadium-titanium pellets produced by this technical solution are uniform in size, and their raw and cooked compressive strength, drop strength, and yield are all superior to those of conventional pelletizing methods.

[0049] For anyone skilled in the art, many possible variations and modifications can be made to the technical solutions of this invention, or equivalent embodiments can be modified based on the disclosed technical content, without departing from the scope of the technical solutions of this invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of this invention, without departing from the content of the technical solutions of this invention, should still fall within the protection scope of the technical solutions of this invention.

Claims

1. A method for improving the pelletizing performance of laboratory vanadium-titanium pellets, characterized in that, The method includes the following steps: ① Prepare mother balls by mixing the materials according to the specified ratio on a pelletizing plate with a diameter of 1m; ② The obtained mother balls are screened for the first time using a sieve with a mesh size of 3mm. Balls that pass through the sieve are discarded, and the mother balls that pass through the sieve are retained to continue making balls. ③ Continue to sphericalize the sieved mother balls obtained in step ②. When the particle size of the mother balls is greater than 3mm, use sieves with a mesh size of 3mm and 6mm to screen them, retaining mother balls with a particle size between 3 and 6mm and discarding the rest. ④ Continue to form the mother balls between 3 and 6 mm obtained in step ③. When the size of the mother balls is greater than 6 mm, use sieves with 6 mm and 8 mm mesh to screen them, and keep the mother balls between 6 and 8 mm, and discard the rest. ⑤ Continue to pelletize the mother balls with a particle size of 6-8 mm obtained in step ④ until the particle size of all mother balls is greater than 10 mm. Then, screen out the mother balls with a particle size of 10-12.5 mm as qualified vanadium-titanium pellets.

2. The method according to claim 1, characterized in that, The material mentioned in step ① is vanadium-titanium magnetite concentrate, with bentonite as a binder; the amount of binder added is 1% to 3% of the mass of vanadium-titanium magnetite concentrate.

3. The method according to claim 1, characterized in that, The moisture content of the mother pellet is controlled at 7.8% to 8.2%.

4. The method according to claim 1, characterized in that, After the mother balls discarded during the pelletizing process are broken down, they are returned to the pelletizing process as raw materials.