Production method for smelting titanium-containing blast furnace slag by using bottom electrode direct current electric furnace
By using the production method of titanium -containing high dregs in the bottom electrode DC electric furnace, the process of double -out slag mouth design and high -voltage water slag quenching process are used to solve the problem of low titanium titanium titanium carbide content and high tail residue treatment costs. Increased titanium content and decrease in tail residue production.
Patent Information
- Application Number
- CN202411606434.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-12
- Publication Date
- 2025-01-28
AI Technical Summary
In the prior art, the production method of smelting titanium-containing blast furnaces using bottom electrode DC furnaces is low in efficiency, the titanium carbide content is low, the overall production process is low, and the tail slag treatment cost is high.
The production method of smelting titanium -containing dregs with a bottom electrode DC electric furnace is adopted. Through the design of dual output slag mouth design and high -voltage water, it improves the production and enrichment of titanium carbide, and increases the titanium carbide content by 5%to 10%.
Significantly reduce the output of titanium tail residue, effectively reduce the cost of treatment agent and tail residue, and improve the content of titanium carbonized and production efficiency.
Smart Images
Figure CN119372404A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of titanium extraction from blast furnace slag, and in particular to a production method for smelting titanium-containing blast furnace slag using a bottom electrode direct current electric furnace. Background Art
[0002] my country's Panxi region is rich in vanadium-titanium magnetite resources. The proven reserves of vanadium-titanium magnetite account for more than 95% of the country's total reserves, and the titanium resources are 870 million tons, accounting for 90.54% and 35.17% of my country's and the world's titanium resources respectively. After the "blast furnace ironmaking" process, about half of the titanium in the Panxi vanadium-titanium magnetite enters the blast furnace slag and becomes titanium-containing blast furnace slag, with TiO 2 The estimated content is 20~25%. In order to comprehensively recycle the titanium resources in titanium-containing blast furnace slag and turn waste into treasure, Panzhihua Iron and Steel independently developed the "high-temperature carbonization-low-temperature chlorination" titanium extraction process route for titanium-containing blast furnace slag.
[0003] The main principle of preparing carbide slag by high-temperature carbonization of titanium-containing blast furnace slag is: using titanium-containing blast furnace slag as raw material, solid reducing agent anthracite, coke or blue coke as reducing agent, smelting in an AC furnace at a high temperature of 1300~1600℃ to obtain molten carbide slag, and using water quenching process to obtain water-quenched slag during slag removal, and then dehydrating and grinding the water-quenched slag to obtain finished carbide slag of suitable particle size. However, the TiC content in the finished carbide slag produced by the existing technology is generally 10%~15%, and the rest is oxides such as calcium, magnesium, aluminum and silicon, the titanium carbide content is low, and the overall production process efficiency is low.
[0004] Therefore, there is a need in the prior art for improving the production method of smelting titanium-containing blast furnace slag using a bottom electrode DC electric furnace. Summary of the invention
[0005] In view of this, the purpose of the embodiment of the present invention is to propose a production method for smelting titanium-containing blast furnace slag using a bottom electrode DC electric furnace, which can achieve the enrichment of titanium carbide. The titanium carbide content is increased by 5% to 10% compared with the existing technology, which greatly reduces the output of titanium extraction tailings, effectively reduces the cost of reducing agents and tailings treatment, and can be further promoted to other slag smelting industries.
[0006] Based on the above purpose, an embodiment of the present invention provides a production method for smelting titanium-containing blast furnace slag using a bottom electrode DC electric furnace, comprising: S1: transferring the molten titanium-containing blast furnace slag to a bottom electrode DC electric furnace through a slag pot, wherein the bottom electrode DC electric furnace has a first slag outlet and a second slag outlet; S2: When the titanium-containing blast furnace slag is poured into the electric furnace, coke powder is added for the first time. After 40 minutes of smelting, coke powder is added for the second time based on the CO gas concentration in the furnace and smelting is continued; S3: After the coke powder is completely added, smelting is continued until slag is discharged; S4: when slag is discharged, the slag is discharged from the first slag outlet first, and the slag is directly impacted by high-pressure water during the slag discharge process to obtain the first water-quenched slag; S5: After the slag is discharged from the first slag outlet, the slag is discharged from the second slag outlet. The slag is discharged by directly impacting the molten slag with high-pressure water to obtain the second water-quenched slag; S6: The second water-quenched slag is stored in the slag yard for 2-3 days to reduce the moisture content, and then the second water-quenched slag is ground to obtain raw material slag rich in titanium carbide for use in the low-temperature chloride titanium dioxide process.
[0007] In some embodiments, in S1, the first slag outlet is 1.5m~2m away from the magnesia carbon bricks at the bottom of the furnace, and the diameter of the slag outlet is 20cm~40cm.
[0008] In some embodiments, in S1, the second slag outlet is 0.5m~1m away from the magnesia carbon bricks at the bottom of the furnace, and the diameter of the slag outlet is 30cm~50cm.
[0009] In some embodiments, in S1, the molten titanium-containing blast furnace slag is loaded into a slag pot from a slag outlet of the blast furnace, and transported to a slag turning place of a bottom electrode DC electric furnace by rail.
[0010] In some embodiments, the mass of titanium-containing blast furnace slag poured in is 80t~100t, and the number of slag pouring is 4 to 6 cans.
[0011] In some embodiments, in S2, the total amount of coke powder added for the first time is 6t~10t.
[0012] In some embodiments, the ratio of the number of times the slag pot is turned over to the amount of coke powder added includes: for the first three times the slag pot is turned over, 1 t to 2 t of coke powder is added after each slag pot is turned over, and the remaining coke powder is added after the fourth slag pot is turned over.
[0013] In some embodiments, in S2, after 40 minutes of power smelting, when the CO gas concentration reaches more than 40% and begins to decrease, coke powder is added for the second time, and the mass of the coke powder added for the second time is 4t~9t.
[0014] In some embodiments, in S3, the average current value A within one minute after the coke powder is completely added is recorded. 1 Continue smelting until the average current value is 4 / 3A within one minute 1 ~3 / 2A 1 Continue smelting for 10 to 30 minutes. When the TiC generated by the carburization reaction is deposited at the bottom of the slag, slag tapping begins.
[0015] In some embodiments, in S6, the TiC content in the raw slag rich in titanium carbide is 15% to 25%.
[0016] The present invention has at least the following beneficial technical effects: The present invention provides a production method for smelting titanium-containing blast furnace slag using a bottom electrode DC electric furnace. The bottom electrode DC electric furnace has a high furnace bottom temperature due to the presence of a bottom electrode (heat source). The high furnace bottom temperature leads to a high temperature of the carburized slag at the bottom of the furnace, a fast TiC generation rate, and a large amount of TiC. The TiC in the carburized slag generated by smelting is a solid particle, has a high density in the molten carburized slag, and will be deposited at the bottom of the electric furnace. The DC electric furnace adopts a double slag outlet design. In terms of height, the slag outlet A is 0.5m-1m away from the magnesia carbon brick at the bottom of the furnace, and the slag outlet B is 1.5m-2m away from the magnesia carbon brick at the bottom of the furnace. After the smelting is completed, the slag is first discharged from the slag outlet B, and then discharged from the slag outlet A after the slag discharge from the slag outlet B is completed. Since TiC is deposited at the bottom of the electric furnace, the slag is mainly discharged through the slag outlet A, and the titanium carbide content is high. After water quenching + drying + grinding, a raw material rich in titanium carbide is obtained, and the titanium carbide content is increased by 5%-10% compared with the prior art, which greatly reduces the output of titanium tailings and effectively reduces the cost of tailings treatment. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.
[0018] Figure 1 The present invention provides a flow chart of an embodiment of a production method for smelting titanium-containing blast furnace slag using a bottom electrode DC electric furnace. DETAILED DESCRIPTION
[0019] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are further described in detail below in combination with specific embodiments and with reference to the accompanying drawings.
[0020] The terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the above-mentioned drawings are intended to cover non-exclusive inclusions; the terms "first", "second", etc. in the specification and claims of the present invention or the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order. "Multiple" means two or more, unless otherwise clearly and specifically defined.
[0021] In addition, reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.
[0022] The present invention adopts a bottom electrode DC furnace to smelt titanium-containing blast furnace slag. A graphite electrode is arranged on the top of the bottom electrode DC furnace, which is a negative electrode, and a positive electrode is at the bottom of the furnace, which is called a bottom electrode. The bottom electrode DC furnace converts AC power into DC power through a rectifier circuit. The furnace bottom is built with conductive magnesium carbon bricks. The bottom electrode contacts the conductive magnesium carbon bricks at the bottom of the furnace, and the conductive magnesium carbon bricks contact the liquid blast furnace slag in the furnace, thereby smelting titanium-containing blast furnace slag to prepare carbided slag.
[0023] like Figure 1 As shown, the present invention provides a production method for smelting titanium-containing blast furnace slag using a bottom electrode DC electric furnace, comprising the following steps: S1: transferring the molten titanium-containing blast furnace slag to a bottom electrode DC electric furnace through a slag pot, wherein the bottom electrode DC electric furnace has a first slag outlet and a second slag outlet; S2: When the titanium-containing blast furnace slag is poured into the electric furnace, coke powder is added for the first time. After 40 minutes of smelting, coke powder is added for the second time based on the CO gas concentration in the furnace and smelting is continued; S3: After the coke powder is completely added, smelting is continued until slag is discharged; S4: when slag is discharged, the slag is discharged from the first slag outlet first, and the slag is directly impacted by high-pressure water during the slag discharge process to obtain the first water-quenched slag; S5: After the slag is discharged from the first slag outlet, the slag is discharged from the second slag outlet. The slag is discharged by directly impacting the molten slag with high-pressure water to obtain the second water-quenched slag; S6: The second water-quenched slag is stored in the slag yard for 2-3 days to reduce the moisture content, and then the second water-quenched slag is ground to obtain raw material slag rich in titanium carbide for use in the low-temperature chloride titanium dioxide process.
[0024] Furthermore, in S1, the first slag outlet is 1.5m~2m away from the furnace bottom magnesia carbon bricks, and the diameter of the slag outlet is 20cm~40cm. The second slag outlet is 0.5m~1m away from the furnace bottom magnesia carbon bricks, and the diameter of the slag outlet is 30cm~50cm. The slag outlets are on the same side of the bottom electrode DC furnace, and the same set of water quenching equipment is used.
[0025] Further, in S1, the molten titanium-containing blast furnace slag is loaded into a slag pot from the blast furnace slag outlet, and transported to the slag turning place of the bottom electrode DC electric furnace by rail transportation. In some embodiments, the mass of the titanium-containing blast furnace slag turned in is 80t~100t, and the number of slag turning pots is 4 to 6 pots.
[0026] Further, in S2, the total amount of coke powder added for the first time is 6t~10t. In some embodiments, the ratio of the number of times the slag pot is turned over and the coke powder added includes: for the first three times of the slag pot, 1t~2t of coke powder is added after each slag pot is turned over, and the remaining coke powder is added after the fourth slag pot is turned over. This adding method is conducive to the full mixing of the pre-prepared reducing agent and the turned-in titanium-containing blast furnace slag, which is conducive to the carbonization reaction of the titanium-containing blast furnace slag.
[0027] Furthermore, in S2, after 40 minutes of power smelting, when the CO gas concentration reaches more than 40% and begins to decrease, coke powder is added for the second time, and the mass of the second coke powder added is 4t~9t.
[0028] Further, in S3, the average current value A within one minute after the coke powder is completely added is recorded. 1 Continue smelting until the average current value is 4 / 3A within one minute 1 ~3 / 2A 1 Continue smelting for 10 to 30 minutes. When the TiC generated by the carburization reaction is deposited at the bottom of the slag, slag tapping begins.
[0029] Furthermore, in S6, the TiC content in the raw slag rich in titanium carbide is 15% to 25%.
[0030] Compared with AC furnaces, DC furnaces have stable and concentrated arcs, good molten pool stirring, uniform temperature distribution in the furnace, and less lining erosion; DC furnaces have small current and voltage fluctuations, less impact on the power grid, and longer cable life. At the same time, the bottom electrode DC furnace has a high furnace bottom temperature due to the presence of the bottom electrode (heat source). The high furnace bottom temperature means a high temperature of the carburized slag at the bottom of the furnace, a fast TiC generation rate, and a large amount of TiC. The TiC in the carburized slag generated by smelting is a solid particle with a high density in the molten carburized slag and will be deposited to the bottom of the electric furnace. After the smelting is completed, the slag is first discharged from the B slag outlet, and then from the A slag outlet after the slag discharge from the B slag outlet is completed. Since TiC is deposited at the bottom of the electric furnace, it is mainly discharged through the A slag outlet, and its titanium carbide content is high. After water quenching + drying + grinding, a raw material rich in titanium carbide is obtained for low-temperature chlorination process.
[0031] Compared with the existing technology, the present invention can achieve the enrichment of titanium carbide, and the titanium carbide content is increased by 5%-10% compared with the existing technology, which greatly reduces the output of titanium extraction tailings, effectively reduces the cost of reducing agents and tailings treatment, and can be further promoted to other slag smelting industries.
[0032] The present invention will be further explained below in conjunction with specific embodiments.
[0033] Example 1 This invention was implemented in a certain factory, and the rated power of the bottom electrode DC furnace was 35MVA. The molten titanium-containing blast furnace slag (the composition is shown in Table 1) was transported by rail to the slag turning point of the bottom electrode DC furnace through a slag tank car, and then the shell was broken by a heavy hammer and added to the bottom electrode DC furnace through a chute. The weight of the empty tank and the full tank were weighed by a railway weighing device, and the difference was the weight of the molten titanium-containing blast furnace slag added to the bottom electrode DC furnace, and the actual loading amount was 92t. The number of slag turnings this time was 5 tanks. When turning the slag, 1.5t of coke powder was added to the first 3 slag tanks after each slag tank was turned over, and 2.5t of pre-formulated reducing agent was added after the fourth slag tank was turned over, and a total of 7t of pre-formulated coke powder was added. The pre-formulated coke powder is coke powder, and the composition is shown in Table 2, and the particle size is 1mm-200 mesh.
[0034] After the slag turning is completed and 7t of pre-mixed reducing agent is added, power supply and smelting are started, and the active power of the electric furnace is controlled at 30MW. After smelting for 40 minutes, the CO gas concentration reaches more than 40% and begins to decrease, and the remaining coke powder is added. The mass of the remaining coke powder added is 6t, and the adding speed is 100kg / min. After the coke powder is completely added, the average current value of 32500A is recorded one minute after the coke powder is completely added. Smelting continues for 18 minutes, and the average current value of one minute is 43130A. After continuing smelting for another 15 minutes, slag discharge begins. When slag is discharged, slag is discharged from the B slag discharge port first, and the slag discharge time is 35 minutes. The slag discharge process uses high-pressure water to directly impact the slag. After the slag discharge from the B slag discharge port is completed, the slag is discharged from the A slag discharge port again, and the slag discharge time is 45 minutes. The slag discharge process uses high-pressure water to directly impact the slag to obtain A water-quenched slag. The A water-quenched slag is stored in the slag yard for 2-3 days to reduce the moisture content, and then the A water-quenched slag is ground to 100-450 meshes through a vertical mill process to obtain raw material A slag rich in titanium carbide for use in the low-temperature chlorination titanium dioxide process. After testing, the TiC content of the A slag is 22.10%, and the specific composition is shown in Table 3. Compared with the existing technology, the TiC content increases by about 5%-10%. The particles rich in titanium carbide are used to produce titanium dioxide by low-temperature chlorination, and the output of titanium tailings will be reduced by about 10%-15%.
[0035] Table 1 Main component indexes of titanium-containing blast furnace slag / %
[0036] Table 2 Industrial analysis composition of reducing agent / % reducing agent <![CDATA[Volatile matter daf > <![CDATA[Fixed carbon d > <![CDATA[Ash d > Coke powder 2.31 84.60 13.09 daf: dry ash-free basis; d: dry basis Table 3 Main components of carbonized slag / %
[0037] The above are exemplary embodiments disclosed in the present invention, but it should be noted that various changes and modifications may be made without departing from the scope disclosed in the embodiments of the present invention as defined in the claims. The functions, steps and / or actions of the method claims according to the disclosed embodiments described herein do not need to be performed in any particular order. In addition, although the elements disclosed in the embodiments of the present invention may be described or required in individual form, they may also be understood as multiple unless explicitly limited to the singular.
[0038] It should be understood that, as used herein, the singular forms "a", "an" are intended to include the plural forms as well, unless the context clearly supports an exception. It should also be understood that, as used herein, "and / or" refers to any and all possible combinations including one or more of the associated listed items.
[0039] The serial numbers of the embodiments disclosed in the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.
[0040] A person skilled in the art should understand that the discussion of any of the above embodiments is only exemplary and is not intended to imply that the scope of the disclosure of the embodiments of the present invention (including the claims) is limited to these examples; under the concept of the embodiments of the present invention, the technical features in the above embodiments or different embodiments can also be combined, and there are many other changes in different aspects of the above embodiments of the present invention, which are not provided in detail for the sake of simplicity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the embodiments of the present invention should be included in the protection scope of the embodiments of the present invention.
Claims
1. A production method for smelting titanium-containing blast furnace slag using a bottom electrode DC electric furnace, characterized in that: include: S1: transferring molten titanium-containing blast furnace slag to a bottom electrode DC electric furnace through a slag pot, wherein the bottom electrode DC electric furnace has a first slag outlet and a second slag outlet; S2: When the titanium-containing blast furnace slag is poured into the electric furnace, coke powder is added for the first time, and after 40 minutes of smelting, the coke powder is added for the second time based on the CO gas concentration in the furnace and the smelting is continued; S3: After the coke powder is completely added, smelting is continued until slag is discharged; S4: when slag is discharged, the slag is discharged from the first slag outlet first, and the slag is directly impacted by high-pressure water during the slag discharge process to obtain the first water-quenched slag; S5: After the slag is discharged from the first slag outlet, the slag is discharged from the second slag outlet. The slag is discharged by directly impacting the molten slag with high-pressure water to obtain the second water-quenched slag; S6: the second water-quenched slag is stored in a slag yard for 2-3 days to reduce moisture, and then the second water-quenched slag is ground to obtain raw material slag rich in titanium carbide for use in a low-temperature chloride titanium dioxide process.
2. The method for smelting titanium-containing blast furnace slag using a bottom electrode DC electric furnace according to claim 1, characterized in that: In S1, the first slag outlet is 1.5m~2m away from the magnesia carbon bricks at the bottom of the furnace, and the diameter of the slag outlet is 20cm~40cm.
3. The method for smelting titanium-containing blast furnace slag using a bottom electrode DC electric furnace according to claim 1, characterized in that: In S1, the second slag outlet is 0.5m~1m away from the magnesia carbon bricks at the bottom of the furnace, and the diameter of the slag outlet is 30cm~50cm.
4. The method for smelting titanium-containing blast furnace slag using a bottom electrode DC electric furnace according to claim 1, characterized in that: In S1, the molten titanium-containing blast furnace slag is loaded into a slag pot from the slag outlet of the blast furnace and transported to the slag turning point of the bottom electrode DC electric furnace by rail transportation.
5. The method for smelting titanium-containing blast furnace slag using a bottom electrode DC electric furnace according to claim 4, characterized in that: The mass of titanium-containing blast furnace slag turned into is 80t~100t, and the number of slag turning tanks is 4~6 tanks.
6. The method for smelting titanium-containing blast furnace slag using a bottom electrode DC electric furnace according to claim 1, characterized in that: In S2, the total amount of coke powder added for the first time is 6t~10t.
7. The method for smelting titanium-containing blast furnace slag using a bottom electrode DC electric furnace according to claim 6, characterized in that: The ratio of the number of times the slag pot is turned over and the coke powder added includes: for the first three times of turning over the slag pot, 1t~2t of coke powder is added after each turning over of the slag pot, and the remaining coke powder is added after the fourth slag pot is turned over.
8. The method for smelting titanium-containing blast furnace slag using a bottom electrode DC electric furnace according to claim 1, characterized in that: In S2, after power supply and smelting for 40 minutes, when the CO gas concentration exceeds 40% and begins to decrease, the coke powder is added for the second time, and the mass of the coke powder added for the second time is 4t~9t.
9. The method for smelting titanium-containing blast furnace slag using a bottom electrode DC electric furnace according to claim 1, characterized in that: In S3, the average current value A1 within one minute after the coke powder is completely added is recorded, and smelting is continued. When the average current value within one minute is 4 / 3A1~3 / 2A1, smelting is continued for 10~30 minutes. When TiC generated by the carburization reaction is deposited at the bottom of the slag, slag discharge begins.
10. The method for smelting titanium-containing blast furnace slag using a bottom electrode DC electric furnace according to claim 1, characterized in that: In S6, the TiC content in the raw slag rich in titanium carbide is 15% to 25%.