Method for long-time shut-down heat preservation operation of Ausmelt smelting furnace

Abstract

The invention discloses a method for long-time blowing-out heat preservation operation of an Ausmelt smelting furnace, which comprises the following steps: S1, before blowing-out, reducing the grade of matte, the concentration of enriched oxygen and the ratio of iron to silicon, increasing the furnace temperature of the Ausmelt smelting furnace and increasing the use amount of lump coal; s2, when the furnace is shut down, the spray gun discontinuously descends to immerse the molten pool; s3, the water circulation amount of the austenite furnace cooling system is reduced, and the heat loss is reduced; s4, a diesel burner is additionally arranged at the weir crest and used for burning diesel, and the temperature of a weir well solution is kept; by optimizing the operation method of the long-time blowing-out heat preservation process of the Australian furnace, under the condition that the Australian furnace is blown out for more than 4 hours, the situation that the Australian furnace is dead due to solidification and caking of a solution in the Australian furnace can be effectively avoided, the longest blowing-out heat preservation in the practice process reaches 50 hours, normal production is recovered after blowing-in temperature rising for 1 hour, and the production cost is reduced. The technological method has great guiding significance on the smelting technology of the copper smelting molten pool, and a good work guarantee is provided for the long-time blowing-out heat preservation technology of all molten pool smelting furnace types.

Description

Technical Field

[0001] The invention relates to the technical field of production process for shutdown and heat preservation of an Ausmelt furnace for copper pyrometallurgy, and in particular to a method for long-term shutdown and heat preservation of an Ausmelt furnace. Background Art

[0002] The Ausmelt furnace (abbreviated as "Ausmelt") molten pool smelting method is one of the main methods of copper smelting at present. The Ausmelt furnace adds copper concentrate, solvent, lump coal and other mixed materials from the top of the furnace through the charging system, and blows the oxygen, air and pulverized coal required for copper concentrate smelting from the top into the molten pool through the spray gun, which reacts violently with the concentrate near the spray gun nozzle, provides heat and continuously stirs the molten pool. The concentrate quickly completes the melting, oxidation and desulfurization process, and produces matte, slag and high-temperature flue gas. Ausmelt furnace smelting is a top-blown molten pool smelting technology for copper smelting. Different from the top-blown molten pool smelting of the Isa furnace, the Ausmelt furnace molten pool smelting is designed with an overflow port (internal weir port). The mixed solution of matte and slag produced by the molten pool smelting in the furnace flows out through the internal weir port into the weir well, and then flows out through the weir well, and enters the settling electric furnace for clarification and separation through the chute.

[0003] The Ausmelt furnace molten pool smelting design has many cooling facilities to cool the refractory bricks in the furnace and reduce the ambient temperature around the furnace to optimize the on-site environment. Figure 1 As shown, the cooling facilities of the Australian furnace are mainly divided into two parts: Cooling of the upper furnace shell: It adopts the method of external hot metal jacket, internal water flow, and bottom-up cooling. There are 24 groups of 4 hot metal jackets around the Australian furnace shell, totaling 96 hot metal jackets; Cooling of the lower discharge port: It adopts copper water jacket and internal water cooling, which is mainly divided into the large copper water jacket of the weir mouth, the copper water jacket of the discharge port and the copper water jacket of the cleaning hole; During normal production, the temperature difference between the inlet and outlet water of the iron jacket cooling water is controlled at 5-7℃, and the water volume is about 350m³ / h; the cooling water of the lower copper jacket is opened to the maximum, with a water volume of 70m³ / h (including 15m³ / h of the large copper jacket at the weir mouth), to ensure sufficient cooling effect of the furnace shell, weir mouth, discharge port, and cleaning hole, extend the life of the Australian furnace and ensure the safety of the discharge port. In addition, during normal production, Daye Nonferrous Australian furnace currently adopts high-grade and high-oxygen concentration operation, with a matte grade of 60-62%, an oxygen-enriched concentration of 72-75%, an iron-silicon ratio of 1.2-1.4, and the magnetic iron content of the Australian furnace slag is controlled at 8-10%.

[0004] In the domestic industry, Australia's top-blowing molten pool smelting technology is relatively mature, with an operating rate of more than 97%. However, during the production process, it is inevitable to encounter some equipment or process failures, which require furnace shutdown for processing. During the shutdown period, the Australian furnace uses a spray gun to burn pulverized coal for insulation or a heat preservation burner to burn diesel for insulation. The shutdown time is generally within 4 hours. Pulverized coal and diesel can effectively keep the temperature of the high-temperature solution in the molten pool in the Australian furnace. By using a spray gun to burn pulverized coal (or other fuels such as diesel) at a height of 1m above the molten pool, it is ensured that the molten pool is not sticky, and the Australian furnace can be emptied in a short time. However, if the shutdown time exceeds 6 hours, it is generally considered to empty the high-temperature solution in the Australian furnace molten pool. Otherwise, the high-temperature solution in the molten pool and the high-temperature solution in the weir well will easily cause the solution in the furnace to solidify due to the drop in temperature and the rise of magnets. In severe cases, the Australian furnace needs to be shut down for overhaul. Therefore, the industry generally adopts the method of emptying the Australian furnace as long as the furnace is shut down for a long time (more than 6 hours). After the fault is eliminated, the Australian furnace reuses the water-quenched slag to make the molten pool. This process generally takes more than 1 day, which has a huge impact on the operation rate of the Australian furnace. In order to solve the above problems, a method for long-term shutdown and insulation operation of the Australian Smelter is proposed. Summary of the invention

[0005] The purpose of the present invention is to solve the above problems and to provide a method for long-term shutdown and heat preservation of an Ausmelt smelting furnace.

[0006] The specific scheme of the present invention is: a method for long-term shutdown and heat preservation of an Ausmelt smelting furnace, comprising the following steps: S1: Before stopping the furnace, reduce the matte grade, oxygen enrichment concentration, iron-silicon ratio, increase the temperature of the Austenitic furnace, and increase the amount of lump coal to suppress the generation of magnetic iron in the Austenitic furnace slag; S2: When the furnace is stopped, the spray gun intermittently descends to immerse the molten pool to increase the temperature of the high-temperature solution in the molten pool; S3: Reduce the water circulation volume of the cooling system of the Ao furnace to reduce heat loss; S4: Weir mouth insulation, add a diesel burner at the weir mouth to burn diesel and maintain the melt temperature of the weir well.

[0007] Furthermore, in the S1, 20 minutes before the furnace is shut down, the matte grade is controlled at 55%-58%; the oxygen enrichment concentration is reduced to below 68% to ensure that the total amount of air and oxygen reaches 3000m³ / h; the iron-silicon ratio is reduced to 1.1-1.2; and the slag magnetic iron is controlled at 6%-8%.

[0008] Furthermore, in S2, the interval time for the spray gun to descend to immerse the molten pool is 4 hours / time.

[0009] Furthermore, in S2, the spray gun is set at a height of 1000 mm from the immersion pool, and is lowered to a depth of 300-500 mm in the immersion pool, and the time for heating the immersion pool is 10 minutes.

[0010] Furthermore, when the lance is lowered to submerge the molten pool for heating, 100 kg of lump coal is added every four hours.

[0011] Furthermore, in S3, the cooling water circulation volume of the Ao furnace cooling system is reduced from 350m³ / h to 200m³ / h, and the water volume of the large copper water jacket at the weir in the lower cooling is reduced from 15m³ / h to 5m³ / h.

[0012] Furthermore, in S4, the diesel burner at the weir burns 20 kg / h of diesel, and at the same time, a layer of machine-made charcoal is laid on the surface of the high-temperature melt in the weir for insulation.

[0013] Furthermore, in S1, the consumption of lump coal is increased from 1.5 tons / h to 2 tons / h, and the temperature of the Ao furnace is increased from 1180-1200°C to 1210°C.

[0014] Furthermore, in S1, the oxygen enrichment concentration is reduced to 65%-66.5%.

[0015] Furthermore, in the S1, the matte grade is controlled at 55%-56%.

[0016] The present invention has the following beneficial effects: by optimizing the operation method of the long-term shutdown and insulation process of the Australian furnace, when the Australian furnace is shut down for more than 4 hours, it can effectively avoid the solidification of the solution in the Australian furnace and cause the Australian furnace to die. In practice, the longest shutdown and insulation period reaches 50 hours, and the normal production is restored after the furnace is started and the temperature is raised for 1 hour. This process method has great guiding significance for copper smelting molten pool smelting technology, and provides a good working guarantee for the long-term shutdown and insulation process of all molten pool smelting furnace types. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structural principle of the present invention; Figure 2 This is a schematic diagram of the structure of the weir well; In the figure: 1. Ao furnace; 2. Spray gun; 3. Molten pool; 4. Cooling system; 5. Weir; 501. Weir mouth; 502. Diesel burner; 6. Large copper water jacket. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0019] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0020] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme that satisfies both A and B. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in the field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0021] Please refer to Figure 1-Figure 2 , a method for long-term shutdown and heat preservation of an Ausmelt smelting furnace, comprising the following steps: S1: Before stopping the furnace, reduce the matte grade, oxygen enrichment concentration, iron-silicon ratio, increase the temperature of Ao Furnace 1, and increase the amount of lump coal to suppress the generation of magnetic iron in Ao Furnace 1 slag; S2: When the furnace is stopped, the spray gun 2 intermittently descends to immerse the molten pool 3 to increase the temperature of the high-temperature solution in the molten pool 3; S3: reduce the water circulation volume of the cooling system 4 of the Ao furnace 1 to reduce heat loss; S4: The weir 501 is kept warm by installing a diesel burner 502 at the weir 501 to burn diesel and maintain the melt temperature of the weir 5.

[0022] In this embodiment, in S1, 20 minutes before the furnace is shut down, the matte grade is controlled at 55%-58%; the oxygen enrichment concentration is reduced to below 68% to ensure that the total amount of air and oxygen reaches 3000m³ / h; the iron-silicon ratio is reduced to 1.1-1.2; and the slag magnetic iron is controlled at 6%-8%.

[0023] In this embodiment, in S2, the interval time for the spray gun 2 to descend to immerse the molten pool 3 is 4 hours / time.

[0024] In this embodiment, in S2, the spray gun 2 is set at a height of 1000 mm from the immersion pool 3, and is lowered to a depth of 300-500 mm in the immersion pool 3, and the time for heating the immersion pool 3 is 10 minutes.

[0025] In this embodiment, when the lance 2 is lowered to submerge the molten pool 3 for heating, 100 kg of lump coal is added every four hours.

[0026] In this embodiment, in S3, the cooling water circulation volume of the cooling system 4 of the Ao furnace 1 is reduced from 350m³ / h to 200m³ / h, and the water volume of the large copper water jacket 6 of the weir 501 in the lower cooling is reduced from 15m³ / h to 5m³ / h.

[0027] In this embodiment, in S4, the diesel burner 502 of the weir 501 burns 20 kg / h of diesel, and at the same time, a layer of machine-made charcoal is laid on the surface of the high-temperature melt of the weir 5 for insulation.

[0028] In this embodiment, in S1, the amount of lump coal is increased from 1.5 tons / h to 2 tons / h, and the temperature of the A furnace 1 is increased from 1180-1200°C to 1210°C.

[0029] In this embodiment, in S1, the oxygen enrichment concentration is reduced to 65%-66.5%.

[0030] In this embodiment, in S1, the matte grade is controlled at 55%-56%.

[0031] The present invention has the following beneficial effects: by optimizing the operation method of the long-term shutdown insulation process of the Australian furnace, the Australian furnace can effectively avoid the solidification of the solution in the Australian furnace and cause the Australian furnace to die when the furnace is shut down for more than 4 hours. In practice, the longest shutdown insulation period is 50 hours, and normal production is restored after the furnace is started and the temperature is raised for 1 hour. This process method has great guiding significance for the copper smelting molten pool 3 smelting technology, and provides a good working guarantee for the long-term shutdown insulation process of all molten pool 3 smelting furnace types.

Claims

1. A method for long-term shutdown and heat preservation of an Ausmelt smelting furnace, characterized in that : It includes the following steps: S1: Before stopping the furnace, reduce the matte grade, oxygen enrichment concentration, iron-silicon ratio, increase the temperature of the Austenitic furnace, and increase the amount of lump coal to suppress the generation of magnetic iron in the Austenitic furnace slag; S2: When the furnace is stopped, the spray gun intermittently descends to immerse the molten pool to increase the temperature of the high-temperature solution in the molten pool; S3: Reduce the water circulation volume of the cooling system of the Ao furnace to reduce heat loss; S4: Weir mouth insulation, add a diesel burner at the weir mouth to burn diesel and maintain the melt temperature of the weir well.

2. The method for long-term shutdown and heat preservation of an Ausmelt smelting furnace according to claim 1, characterized in that: In the S1, 20 minutes before the furnace is shut down, the matte grade is controlled at 55%-58%; the oxygen enrichment concentration is reduced to below 68%, ensuring that the total amount of air and oxygen reaches 3000m³ / h; the iron-silicon ratio is reduced to 1.1-1.2; and the slag magnetic iron is controlled at 6%-8%.

3. The method for long-term shutdown and heat preservation of an Ausmelt smelting furnace according to claim 1, characterized in that: In S2, the interval between the lance being lowered to immerse the molten pool is 4 hours / time.

4. The method for long-term shutdown and heat preservation of an Ausmelt smelting furnace according to claim 1, characterized in that: In S2, the spray gun is set at a height of 1000 mm from the immersion pool, and is lowered to a depth of 300-500 mm in the immersion pool. The time for heating the immersion pool is 10 minutes.

5. The method for long-term shutdown and heat preservation of an Ausmelt smelting furnace according to claim 4, characterized in that: When the lance is lowered to submerge the molten pool for heating, 100 kg of lump coal is added every four hours.

6. The method for long-term shutdown and heat preservation of an Ausmelt smelting furnace according to claim 1, characterized in that: In S3, the cooling water circulation volume of the Ao furnace cooling system is reduced from 350m³ / h to 200m³ / h, and the water volume of the large copper water jacket at the weir in the lower cooling is reduced from 15m³ / h to 5m³ / h.

7. The method for long-term shutdown and heat preservation of an Ausmelt smelting furnace according to claim 1, characterized in that: In S4, the diesel burner at the weir burns 20 kg / h of diesel, and at the same time, a layer of machine-made charcoal is laid on the surface of the high-temperature melt in the weir for insulation.

8. The method for long-term shutdown and heat preservation of an Ausmelt smelting furnace according to claim 1, characterized in that: In S1, the consumption of lump coal is increased from 1.5 tons / h to 2 tons / h, and the temperature of the Ao furnace is increased from 1180-1200°C to 1210°C.

9. The method for long-term shutdown and heat preservation of an Ausmelt smelting furnace according to claim 2, characterized in that: In the S1, the oxygen enrichment concentration is reduced to 65%-66.5%.

10. The method for long-term shutdown and heat preservation of an Ausmelt smelting furnace according to claim 2, characterized in that: In the S1, the matte grade is controlled at 55%-56%.

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