A high-grade, high-oxygen-enriched smelting method in an Ausmelt smelting furnace

Abstract

The present invention relates to a high-grade, high-oxygen and concentrated smelting method for an Ausmelt smelting furnace, which specifically comprises the following steps: (1) ore blending before starting the furnace for smelting: miscellaneous ores are eliminated, copper concentrate raw materials are used, and the contents of magnesium oxide and aluminum oxide in the raw materials are controlled to be below 2%; (2) the angle between the oxygen air outlet of the spray gun and the horizontal plane of the molten pool is adjusted from 65° to 45-58°; (3) the furnace is started for smelting, and the position of the spray gun is controlled to be 300-500 mm below the liquid surface for spray smelting; (4) during the smelting process, solvent SiO2 is added to the molten pool, and the amount of solvent added is such that the iron-silicon ratio of the slag is controlled to be between 1.1 and 1.3. The method of the present invention replaces the traditional production process method by optimizing the Ausmelt furnace process operation method. When the Ausmelt furnace has a matte grade of 65% and an oxygen-enriched concentration of 75%, the semi-solvent basically disappears, eliminating the large flow rate at the weir, and the magnetic iron of the slag can be well controlled to be about 7%, thereby ensuring that the slag has a certain viscosity and the fluidity of the slag.

Description

Technical Field

[0001] The invention relates to the technical field of copper pyrometallurgy, in particular to a high-grade and high-oxygen concentration smelting method in an Ausmelt smelting furnace. Background Art

[0002] The Ausmelt furnace 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 feeding 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. It reacts violently with the concentrate near the spray gun nozzle, provides heat and continuously stirs the molten pool, and the concentrate quickly completes the melting, oxidation and desulfurization process. The Ausmelt furnace molten pool smelting is designed to have a matte grade of 50-60% and an oxygen enrichment concentration of 62%. There are the following main problems: First, the oxygen enrichment concentration is low, resulting in SO 2 Low concentration, large flue gas volume, large fluctuation of furnace negative pressure. Second, the matte grade is low, the self-heating reaction is insufficient, and the smelting process has high energy consumption; if the amount of matte is large, it will lead to high converter blowing load.

[0003] Improving the matte grade and oxygen-enriched concentration during the smelting process has become a development trend in the future smelting industry. Flash smelting controls the grade to more than 45%, and increases the oxygen-enriched concentration to more than 65%, so that the self-heating reaction of copper concentrate can be achieved without the need to burn additional pulverized coal to supplement heat. Compared with the flash furnace, the Ausmelt furnace has better adaptability in processing concentrate materials and has low requirements for raw materials. However, the Ausmelt furnace also has the disadvantages of high energy consumption and large flue gas volume. Therefore, research on improving the oxygen-enriched concentration and matte grade of the Ausmelt furnace is of great significance to the future industrial development of the Ausmelt furnace.

[0004] The grade of Australian copper matte was raised to 65%, and the oxygen-enriched concentration was raised to 75%. Under this high-grade and high-oxygen concentration operation, the Ausmelt furnace, as a top-blown smelting furnace, has a reaction zone mainly in the slag layer, which has the following problems: First, the physical and chemical properties and composition of the melt smelted in the high-oxygen concentration and high-grade copper matte molten pool will change, especially the magnetic iron will increase sharply under high-grade operation, and the magnetic iron content of the slag will reach 30% at the highest; second, the stirring effect of the spray gun on the molten pool becomes worse, the wind oxygen volume of the high-oxygen concentration operation is reduced, and the mass transfer and heat transfer effect of the molten pool becomes worse, resulting in an unbalanced reaction problem, which will cause local overoxidation of the molten pool and incomplete local reaction. The weir mouth reaction is mostly semi-solvent and coke, and large flow occurs frequently, reaching 4-6 times a day. Summary of the invention

[0005] The purpose of the present invention is to provide a high-grade and high-oxygen concentration smelting method for an Ausmelt smelting furnace in view of the above situation. The method achieves the stability of the production process under the high-grade and high-oxygen concentration operation of the Ausmelt furnace by taking improvement and optimization measures.

[0006] The specific scheme of the present invention is: a high-grade, high-oxygen-enriched smelting method in an Ausmelt smelting furnace, which specifically includes the following steps:

[0007] (1) Ore blending before starting the furnace for smelting: eliminate miscellaneous ores, use copper concentrate as raw material, and control the content of magnesium oxide and aluminum oxide in the raw materials to less than 2%;

[0008] (2) Adjust the angle between the oxygen and air outlet of the spray gun and the horizontal plane of the molten pool from 65° to 45-58°;

[0009] (3) Start the furnace for smelting, and control the position of the spray gun to 300-500 mm below the liquid surface for spray smelting;

[0010] (4) Adding solvent SiO to the molten pool during the smelting process 2 The amount added is such that the iron-silicon ratio of the slag is controlled at 1.1 to 1.3.

[0011] Furthermore, in the above process of the present invention, the copper concentrate smelting is controlled to have a matte grade of 65%, and the oxygen enrichment concentration is controlled to 75%.

[0012] The present invention has the following beneficial effects: the method of the present invention replaces the traditional production process method by optimizing the Ausmelt furnace process operation method. At a matte grade of 65% and an oxygen enrichment concentration of 75%, the semi-solvent in the Ausmelt furnace basically disappears, eliminating the large flow at the weir mouth. At the same time, the magnetic iron content of the slag can be well controlled at about 7%, which can ensure that the slag has a certain viscosity, ensure the slag hanging on the furnace lining, and ensure the fluidity of the slag. DETAILED DESCRIPTION

[0013] The technical solution of the present invention will be described clearly and completely below. 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 belong to the protection scope of the present invention.

[0014] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "setting", "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0015] The present invention is a high-grade, high-oxygen-concentrated smelting method of an Ausmelt smelting furnace, which specifically comprises the following steps:

[0016] (1) Ore blending before starting the furnace for smelting: eliminate miscellaneous ores, use copper concentrate as raw material, and control the content of magnesium oxide and aluminum oxide in the raw materials to less than 2%;

[0017] (2) Adjust the angle between the oxygen and air outlet of the spray gun and the horizontal plane of the molten pool from 65° to 45-58°;

[0018] (3) Start the furnace for smelting, and control the position of the spray gun to 300-500 mm below the liquid surface for spray smelting;

[0019] (4) Adding solvent SiO to the molten pool during the smelting process 2 The amount added is such that the iron-silicon ratio of the slag is controlled at 1.1 to 1.3.

[0020] Furthermore, in the above process of the present invention, the copper concentrate smelting is controlled to have a matte grade of 65%, and the oxygen enrichment concentration is controlled to 75%.

[0021] The following is a specific implementation method of the method adopted by the smelter under the high-grade and high-oxygen concentration (65% grade, 75% oxygen concentration) operation of the Ausmelt smelting furnace:

[0022] ① Raw material control: Eliminate mixed ores, use imported ores, domestic ores and recycled materials, and control the content of magnesium oxide and aluminum oxide in the raw materials to less than 2%.

[0023] ② Spray gun structure control: Use a rotating fixing mechanism to reduce the angle of the oxygen and wind outlet on the spray gun from the original 65° to 52°.

[0024] ③ Gun position adjustment: During the smelting process, the spray gun position is adjusted from the original control of 200mm below the liquid level to 400mm below the liquid level.

[0025] ④Alkalinity adjustment: Reduce the slag iron-silicon ratio from the traditional 1.2-1.4 to 1.1 for control.

[0026] By optimizing the Ausmelt furnace process operation method and replacing the original design production process method, the semi-solvent basically disappears at the Ausmelt furnace at 65% matte grade and 75% oxygen enrichment concentration, eliminating the problem of large flow at the weir. At the same time, the magnetic iron of the slag is well controlled at around 7%, which can ensure that the slag has a certain viscosity and the furnace lining is not slag-hanging, and that the slag has a certain fluidity. The entire Ausmelt furnace production process is more stable and reliable.

Claims

1. A high-grade, high-oxygen, concentrated smelting method in an Ausmelt smelting furnace, characterized in that: The specific steps include: (1) Ore blending before starting the furnace for smelting: eliminate miscellaneous ores, use copper concentrate as raw material, and control the content of magnesium oxide and aluminum oxide in the raw materials to less than 2%; (2) Adjust the angle between the oxygen and air outlet of the spray gun and the horizontal plane of the molten pool from 65° to 45-58°; (3) Start the furnace for smelting, and control the position of the spray gun to 300-500 mm below the liquid surface for spray smelting; (4) adding SiO2 solvent to the molten pool during the smelting process in an amount that controls the slag iron-silicon ratio to 1.1-1.3; During the above smelting process, the copper concentrate smelting controls the matte grade to 65%, and the oxygen enrichment concentration to 75%.