A rapid pool-making method for pre-charging crude copper into a converting furnace

Abstract

The present application relates to non-ferrous metallurgy technical field, specifically to a kind of quick pool-making method of preloading crude copper in converter, after completing furnace lining construction in converter, before oven drying, dry converter slag is laid on the bottom of converter as bottom protection layer;Quantitative crude copper is loaded on the bottom protection layer, and the loading amount of the crude copper is determined according to the target pool height, so that the pool height formed by the melting of crude copper after oven drying reaches the target pool height required for starting the converter;Converter slag is added to the converter in batches;Converter is oven dried using oven drying device, the temperature in the furnace is continuously monitored during oven drying, and the temperature rising rate is controlled according to the preset oven drying curve;The oven drying time is determined according to the melting rate of crude copper and the oven drying curve, so that the crude copper and converter slag are completely melted to form a pool and a slag layer at the end of oven drying.The present application greatly shortens the starting time, from 7-10 days of traditional method to 12-20 hours, improves energy utilization efficiency and production capacity release speed.

Description

Technical Field

[0001] This invention relates to the field of non-ferrous metal metallurgy technology, specifically to a method for rapidly creating a molten pool by preloading crude copper into a blowing furnace. Background Technology

[0002] In the copper smelting process chain, the blowing furnace plays a crucial role in refining copper matte (white copper matte) into blister copper. Its start-up efficiency and lining life directly determine the economy and stability of the smelting production line. With the upgrading of industry technology, continuous blowing and pool smelting technologies have become the mainstream development direction, driving a significant increase in the production efficiency of blowing furnaces.

[0003] Significant progress has been made in process optimization for the continuous production stage of blowing furnaces in existing technologies. Among these, the bottom-blown continuous copper smelting process disclosed in Chinese patent CN101328547A is highly representative. This patent, through an innovative design of continuously injecting liquid copper matte and oxygen-enriched air, breaks through the capacity bottleneck of traditional intermittent blowing, achieving continuous operation of the blowing process. This not only improves production efficiency but also optimizes the quality of crude copper products, providing crucial technical support for continuous production in the industry. Such technologies generally focus on process control and parameter optimization during the stable production stage, accumulating rich experience in improving the stability of continuous operations.

[0004] However, there is a significant research gap in the existing technology system, namely, a lack of targeted technical solutions for the "furnace start-up and baking stage" of newly built or overhauled blowing furnaces. The traditional furnace baking mode commonly used in the industry is "empty furnace baking," which involves directly heating the furnace body through burners. This mode has revealed many unavoidable technical defects in long-term practice.

[0005] Firstly, the furnace lining protection is poor. During the initial furnace start-up phase, the burner flame directly scorches the refractory material at the furnace bottom. Due to the uneven thermal conductivity of the refractory material, localized overheating or thermal shock damage is easily triggered, leading to problems such as spalling and cracking of the refractory material. This significantly shortens the service life of the furnace bottom, increasing equipment maintenance frequency and costs. Actual production data shows that the average lifespan of the furnace bottom refractory material after start-up using traditional methods is reduced by more than 30% compared to the theoretical value, and in some operating conditions, it even results in complete scrapping.

[0006] Secondly, the furnace start-up efficiency is low. After the furnace is dried out, there is no initial molten pool inside. A large amount of cold material needs to be added subsequently, and a long melting process is required to establish the target liquid level and temperature field that meets the blowing requirements. Statistical data shows that the traditional method takes 7-10 days to start up the entire system, which not only wastes a lot of energy but also prevents the production line from forming effective capacity for a long time, seriously affecting the company's production plan. At the same time, due to uneven melting of materials during the initial molten pool formation stage, liquid level fluctuations and composition deviations are prone to occur, increasing the difficulty of subsequent stable production control. Summary of the Invention

[0007] To address the problems existing in the prior art, the present invention provides a method for rapidly creating a molten pool by preloading crude copper into a blowing furnace.

[0008] To achieve the above objectives, the technical solution of the present invention is as follows:

[0009] A method for rapidly creating a molten pool in a pre-loaded blister copper furnace includes the following steps:

[0010] S1. Laying of the furnace bottom protective layer: After the furnace lining of the blowing furnace is completed and before the furnace is dried, dry blowing slag is laid on the furnace bottom as a furnace bottom protective layer. The dry blowing slag is used to isolate the furnace bottom from the direct burning of the furnace bottom by the furnace drying flame during the furnace drying process and protect the refractory material of the furnace bottom.

[0011] S2. Pre-loading of crude copper: A certain amount of crude copper is loaded onto the furnace bottom protective layer. The amount of crude copper loaded is determined based on the target molten pool height, so that the height of the molten pool formed by the melting of crude copper after the furnace is dried reaches the target molten pool height required for furnace start-up.

[0012] S3. Batch slag addition: After the crude copper is pre-loaded, slag is added to the smelting furnace in batches. The slag covers the crude copper and is used to form a pre-slag layer during the furnace drying process.

[0013] S4. Furnace Drying: The furnace is dried using a furnace drying device. During the drying process, the furnace temperature is continuously monitored, and the heating rate is controlled according to the preset furnace drying curve. The furnace drying time is determined based on the melting rate of crude copper and the furnace drying curve, so that the crude copper and smelting slag are completely melted to form a molten pool and slag layer at the end of the furnace drying.

[0014] S5. White matte feeding: After the furnace is dried, white matte is fed into the blowing furnace. The white matte mixes with the crude copper in the molten pool. When the liquid level in the furnace reaches the target level, the feeding of white matte is stopped.

[0015] S6. Smelting Start-up: After stopping the supply of white copper matte, process gas is introduced into the smelting furnace to start the smelting process and enter a stable production state.

[0016] Furthermore, in S1, the dried slag is a slag with a moisture content of less than 3% and a laying thickness of 50-200mm.

[0017] Furthermore, in S2, the crude copper is an anode copper residue plate with a copper content of ≥99%, and the target molten pool height is 200-400mm.

[0018] Furthermore, in S3, the blowing slag is added in 2-4 batches, with the interval between each batch being 1 / 3-1 / 2 of the furnace drying time.

[0019] Furthermore, in S4, the oven drying device uses a diesel burner, the oven drying time is 12-20 hours, and the heating rate is strictly implemented according to the preset oven drying curve.

[0020] Furthermore, in S4, thermocouples are used to monitor the furnace temperature in real time, and the final temperature of the furnace drying is 1100-1250℃.

[0021] Furthermore, in S6, the process gas is oxygen-enriched air with an oxygen concentration of 30-35%.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] This invention provides a rapid method for creating a molten pool in a smelting furnace by preloading crude copper. By laying a dry smelting slag layer at the furnace bottom to form a protective layer, the direct burning of the furnace bottom refractory material by the furnace-heating flame is effectively isolated, avoiding localized overheating or thermal shock damage, significantly extending the furnace lining's service life, and reducing maintenance costs. Simultaneously, the preloading of crude copper, combined with batch slag addition, allows the furnace-heating process to occur concurrently with the formation of the molten pool and slag layer. This eliminates the need for additional cold materials to be added after furnace-heating to create the molten pool, drastically shortening the start-up time from the traditional 7-10 days to 12-20 hours, improving energy efficiency and production capacity release speed. Furthermore, the molten pool and slag layer formed after furnace-heating are uniform and stable, allowing for rapid attainment of smelting requirements after the subsequent addition of white matte, reducing initial liquid level fluctuations and compositional deviations, lowering the difficulty of controlling stable production, and reducing the consumption of equipment such as oxygen lances, further improving the economy and stability of smelting production. Attached Figure Description

[0024] Figure 1 A process flow diagram of the present invention is shown. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0026] Example 1

[0027] This embodiment provides a rapid method for creating a molten pool by pre-loading crude copper into a blowing furnace, applicable to the start-up process of a multi-lance top-blown continuous blowing furnace. The specific steps are as follows:

[0028] (1) Laying of the furnace bottom protective layer: After the furnace lining of the blowing furnace is completed, a dry blowing slag with a thickness of 100mm is evenly laid on the furnace bottom before the furnace is dried. The moisture content of the dry blowing slag is 2%. This slag layer is used to isolate the furnace bottom from the direct burning of the furnace bottom by the furnace flame during the subsequent furnace drying process and to protect the furnace bottom refractory material from high temperature erosion.

[0029] (2) Pre-loading of crude copper: Calculate the required amount of crude copper based on the furnace chamber size and the target molten pool height of 300mm. Load the corresponding mass of anode plate residues onto the furnace bottom protective layer. The copper content of the anode plate residues is 99%.

[0030] (3) Adding slag in batches: After the crude copper is pre-loaded, the smelting slag is added to the smelting furnace in three batches. The first batch is added before the furnace drying begins, the second batch is added after the furnace drying has been carried out for 6 hours, and the third batch is added after the furnace drying has been carried out for 12 hours. The smelting slag covers the crude copper to form a pre-slag layer.

[0031] (4) Furnace drying: A diesel burner is used for furnace drying, which takes 18 hours. Thermocouples are used to monitor the furnace temperature in real time. The heating rate is strictly controlled according to the furnace drying curve. The final temperature of the furnace drying is 1200℃. During the furnace drying process, the furnace bottom protective layer effectively isolates the furnace bottom from direct burning by the flame. The crude copper and smelting slag gradually melt to form a molten pool and slag layer.

[0032] (5) White matte feeding: After the furnace is baked, white matte from the smelting furnace is continuously fed into the blowing furnace through the chute. The white matte mixes with the crude copper in the molten pool. When the liquid level in the furnace reaches the preset target liquid level, the white matte feeding is stopped.

[0033] (6) Blowing start-up: After stopping the supply of white matte, oxygen-enriched air with an oxygen concentration of 35% is introduced into the blowing furnace as process gas to start the blowing process, complete the blowing slag formation and heat release process, and enter a stable production state.

[0034] Using the method of this embodiment, the entire system startup time is 18 hours, which is significantly shorter than the traditional method; there is no overheating deformation of the furnace bottom during the start-up process, and the furnace expansion and refractory material conditions are all within the standard requirements; oxygen lance consumption is reduced by 62%.

[0035] Example 2

[0036] The difference between this embodiment and Embodiment 1 lies in the adjustment of furnace parameters and molten pool height. The specific steps are as follows:

[0037] (1) Laying of the protective layer at the bottom of the furnace: A layer of dry slag with a thickness of 80 mm and a moisture content of 1.5% is evenly laid at the bottom of the furnace.

[0038] (2) Pre-loading of crude copper: Calculate the amount of crude copper to be loaded based on the target molten pool height of 200mm, and load the anode plate residue with a copper content of 99%.

[0039] (3) Add slag in batches: Add the blowing slag in two batches. The first batch is added before the furnace drying begins, and the second batch is added when the furnace drying has been going on for 8 hours.

[0040] (4) Furnace drying: The furnace is dried using a diesel burner for 16 hours. The heating rate is strictly controlled according to the furnace drying curve. The final temperature of the furnace is 1100℃.

[0041] (5) White matte feeding: After the furnace is dried, white matte is continuously fed into the blowing furnace through the chute to the target liquid level.

[0042] (6) Blowing start-up: Introduce oxygen-enriched air with an oxygen concentration of 30% into the blowing furnace to start the blowing process and enter stable production.

[0043] In this embodiment, the entire system startup time is 16 hours, oxygen lance consumption is reduced by 58%, and the start-up effect is good.

[0044] Example 3

[0045] This embodiment uses a larger molten pool height and a longer furnace baking time, making it suitable for large blowing furnaces. The specific steps are as follows:

[0046] (1) Laying of the protective layer at the bottom of the furnace: A layer of dry slag with a thickness of 200 mm and a moisture content of 2.5% is evenly laid at the bottom of the furnace.

[0047] (2) Pre-loading of crude copper: Calculate the amount of crude copper to be loaded based on the target molten pool height of 400mm, and load the anode plate residue with a copper content of 99%.

[0048] (3) Add slag in batches: Add the blowing slag in 4 batches, at the beginning of the furnace drying, 5 hours, 10 hours and 15 hours after the furnace drying.

[0049] (4) Furnace drying: The furnace is dried using a diesel burner for 20 hours. The heating rate is strictly controlled according to the furnace drying curve. The final temperature of the furnace is 1250℃.

[0050] (5) White matte feeding: After the furnace is dried, white matte is continuously fed into the blowing furnace through the chute to the target liquid level.

[0051] (6) Blowing start-up: Introduce oxygen-enriched air with an oxygen concentration of 35% into the blowing furnace to start the blowing process and enter stable production.

[0052] In this embodiment, the entire system takes 20 hours to start up. Due to the greater depth of the molten pool, the crude copper is melted more thoroughly, resulting in better production stability after furnace start-up and a 55% reduction in oxygen lance consumption.

[0053] Example 4

[0054] This embodiment uses a rapid furnace start-up mode, which is suitable for emergency production recovery situations. The specific steps are as follows:

[0055] (1) Laying of the bottom protective layer: A layer of dry slag with a thickness of 50 mm and a moisture content of 1% is evenly laid on the bottom of the smelting furnace.

[0056] (2) Pre-loading of crude copper: Calculate the amount of crude copper to be loaded based on the target molten pool height of 200mm, and load the anode plate residue with a copper content of 99%.

[0057] (3) Add slag in batches: Add the blowing slag in two batches, one before the start of the furnace drying and the other 6 hours after the start of the furnace drying.

[0058] (4) Furnace drying: Natural gas burners are used for furnace drying. The drying time is 12 hours. The heating rate is strictly implemented according to the furnace drying heating curve. The final temperature of the furnace drying is 1150℃.

[0059] (5) White matte feeding: After the furnace is dried, white matte is continuously fed into the blowing furnace through the chute to the target liquid level.

[0060] (6) Blowing start-up: Introduce oxygen-enriched air with an oxygen concentration of 32% into the blowing furnace to start the blowing process and enter stable production.

[0061] In this embodiment, the entire system startup time is only 12 hours, achieving the goal of rapid furnace start-up and reducing oxygen lance consumption by 50%.

[0062] Example 5

[0063] This embodiment uses thermocouple temperature measurement, and the specific steps are as follows:

[0064] (1) Laying of the furnace bottom protective layer: A layer of dry slag with a thickness of 120 mm and a moisture content of 2% is evenly laid on the bottom of the smelting furnace.

[0065] (2) Pre-loading of crude copper: Calculate the amount of crude copper to be loaded based on the target molten pool height of 350mm, and load the anode plate residue with a copper content of 99%.

[0066] (3) Add slag in batches: Add the blowing slag in three batches, at the beginning of the furnace drying, 6 hours after the furnace drying, and 12 hours after the furnace drying.

[0067] (4) Furnace drying: The furnace is dried using a diesel burner for 17 hours. The furnace temperature is monitored in real time using thermocouples. The heating rate is strictly in accordance with the furnace drying heating curve of the blowing furnace. The final temperature of the furnace drying is 1220℃.

[0068] (5) White matte feeding: After the furnace is dried, white matte is continuously fed into the blowing furnace through the chute to the target liquid level.

[0069] (6) Blowing start-up: Introduce oxygen-enriched air with an oxygen concentration of 35% into the blowing furnace to start the blowing process and enter stable production.

[0070] In this embodiment, the entire system takes 17 hours to start up. The thermocouple temperature measurement is highly accurate, which is beneficial for precise control of the furnace baking process. The oxygen lance consumption is reduced by 60%.

[0071] Comparative Example 1

[0072] Using the traditional furnace start-up method as a comparative example, the specific steps are as follows:

[0073] (1) The furnace is directly baked, and the baking flame directly acts on the refractory material at the bottom of the furnace.

[0074] (2) After the furnace is baked, cold copper matte and flux are added in batches to create a molten pool.

[0075] (3) After the molten pool is formed, continue to add flux and cold material to form slag.

[0076] (4) After the molten pool and slag layer are formed, process gas is introduced for blowing.

[0077] The traditional method takes about 7-10 days (168-240 hours) to start up the entire system. During the start-up process, the furnace bottom temperature is uneven, there is local overheating, the refractory material peels off slightly, and the oxygen lance consumption is 100 lances per start-up.

[0078] Table 1. Effects of each embodiment and comparative example

[0079]

[0080] As shown in the table above, the start-up time of each embodiment of the present invention is within the range of 12-20 hours, which is significantly shorter than the 168-240 hours of the traditional method; oxygen lance consumption is reduced by 50%-62%; and the furnace bottom protection effect is good to excellent. The present invention can achieve the technical effects of rapid furnace start-up and effective protection of the furnace bottom under different process parameter conditions.

[0081] This invention provides a rapid method for creating a molten pool in a smelting furnace by preloading crude copper. By laying a dry smelting slag layer at the furnace bottom to form a protective layer, the direct burning of the furnace bottom refractory material by the furnace-heating flame is effectively isolated, avoiding localized overheating or thermal shock damage, significantly extending the furnace lining's service life, and reducing maintenance costs. Simultaneously, the preloading of crude copper, combined with batch slag addition, allows the furnace-heating process to occur concurrently with the formation of the molten pool and slag layer. This eliminates the need for additional cold materials to be added after furnace-heating to create the molten pool, drastically shortening the start-up time from the traditional 7-10 days to 12-20 hours, improving energy efficiency and production capacity release speed. Furthermore, the molten pool and slag layer formed after furnace-heating are uniform and stable, allowing for rapid attainment of smelting requirements after the subsequent addition of white matte, reducing initial liquid level fluctuations and compositional deviations, lowering the difficulty of controlling stable production, and reducing the consumption of equipment such as oxygen lances, further improving the economy and stability of smelting production.

[0082] The foregoing descriptions have outlined some exemplary embodiments of the present invention. It is understood that these embodiments are merely illustrative and do not constitute a limitation on the scope of protection of the present invention. Features in these embodiments can be rearranged in suitable ways, and the resulting solutions remain within the scope of protection claimed by the present invention. All other embodiments obtained by those skilled in the art based on the foregoing embodiments without inventive effort, i.e., all modifications, equivalent substitutions, and improvements made within the spirit and principles of this application, fall within the scope of protection claimed by the present invention.

Claims

1. A method for rapidly creating a molten pool by preloading crude copper into a blowing furnace, characterized in that, Includes the following steps: S1. Laying of the furnace bottom protective layer: After the furnace lining of the blowing furnace is completed and before the furnace is dried, dry blowing slag is laid on the furnace bottom as a furnace bottom protective layer. The dry blowing slag is used to isolate the furnace bottom from the direct burning of the furnace bottom by the furnace drying flame during the furnace drying process and protect the refractory material of the furnace bottom. S2. Pre-loading of crude copper: A certain amount of crude copper is loaded onto the furnace bottom protective layer. The amount of crude copper loaded is determined based on the target molten pool height, so that the height of the molten pool formed by the melting of crude copper after the furnace is dried reaches the target molten pool height required for furnace start-up. S3. Batch slag addition: After the crude copper is pre-loaded, slag is added to the smelting furnace in batches. The slag covers the crude copper and is used to form a pre-slag layer during the furnace drying process. S4. Furnace Drying: The furnace is dried using a furnace drying device. During the drying process, the furnace temperature is continuously monitored, and the heating rate is controlled according to the preset furnace drying curve. The furnace drying time is determined based on the melting rate of crude copper and the furnace drying curve, so that the crude copper and smelting slag are completely melted to form a molten pool and slag layer at the end of the furnace drying. S5. White matte feeding: After the furnace is dried, white matte is fed into the blowing furnace. The white matte mixes with the crude copper in the molten pool. When the liquid level in the furnace reaches the target level, the feeding of white matte is stopped. S6. Smelting Start-up: After stopping the supply of white copper matte, process gas is introduced into the smelting furnace to start the smelting process and enter a stable production state.

2. The method for rapidly creating a molten pool in a pre-loaded blister furnace according to claim 1, characterized in that, In S1, the dried slag is a slag with a moisture content of less than 3% and a laying thickness of 50-200mm.

3. The method for rapidly creating a molten pool in a pre-loaded blister copper furnace according to claim 1, characterized in that, In S2, the crude copper is an anode copper residue plate with a copper content ≥99%, and the target molten pool height is 200-400mm.

4. The method for rapidly creating a molten pool in a pre-loaded blister copper furnace according to claim 1, characterized in that, In S3, the blowing slag is added in 2-4 batches, with the interval between each batch being 1 / 3-1 / 2 of the furnace drying time.

5. The method for rapidly creating a molten pool in a pre-loaded blister furnace according to claim 1, characterized in that, In S4, the oven device uses a diesel burner, the oven drying time is 12-20 hours, and the heating rate is strictly implemented according to the preset oven drying curve.

6. The method for rapidly creating a molten pool in a pre-loaded blister copper furnace according to claim 1, characterized in that, In S4, thermocouples are used to monitor the furnace temperature in real time, and the final temperature of the furnace drying is 1100-1250℃.

7. The method for rapidly creating a molten pool in a blowing furnace pre-loaded with crude copper according to claim 1, characterized in that, In S6, the process gas is oxygen-enriched air with an oxygen concentration of 30-35%.

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