Copper smelting method of Ausmelt furnace without top blowing spray gun

Abstract

The invention discloses a copper smelting method of an Ausmelt furnace without a top-blowing spray gun, and relates to the technical field of copper smelting of the Ausmelt furnace, and the copper smelting method comprises the following steps: (1) spraying coal powder and mineral powder into a molten pool through an ore gun and a coal gun of the Ausmelt furnace without the top-blowing spray gun; (2) a side-blowing combustion gun of the Ausmelt furnace without the top-blowing spray gun sprays fuel to the molten pool; and (3) when the copper matte reaches the target grade 58-62%, ending the reaction, recording the melt temperature distribution, measuring the viscosity of the slag, and taking the slag sample for analyzing the content of Fe3O4. The Ausmelt furnace without the top blowing spray gun comprises a flue, a baffle, a combustion gun, an ore gun and a coal gun, a flue is arranged on the upper portion of the furnace body, a baffle is arranged below the flue, combustion guns are symmetrically arranged on the furnace body above a slag layer, coal guns are symmetrically arranged on the furnace body at the junction of the slag layer and a molten copper bath, ore guns are symmetrically arranged on the furnace body at a molten copper bath layer, and pressure gauges are arranged on the ore guns and the coal guns.

Description

Technical Field

[0001] The invention relates to the technical field of copper smelting of an Ausmelt furnace, and in particular to a copper smelting method of an Ausmelt furnace without a top-blowing lance. Background Art

[0002] At present, Ausmelt furnace mainly uses top-blowing submerged injection technology for smelting. During smelting, the lance is inserted from the top of the Ausmelt furnace and immersed in the molten pool composed of copper matte and slag in the vertically placed cylindrical furnace. Fuel (heavy oil, natural gas, pulverized coal, etc.) and oxidizing gas (pure oxygen, air, oxygen-enriched air, etc.) are sprayed from the end of the lance, and the charge (ore powder, auxiliary materials, flux, etc.) is directly added from the top charging port.

[0003] The formation of Fe3O4 is inevitable during the production of high-grade copper matte by Ausmelt. Fe3O4 will deteriorate the properties of the slag. In general, it is considered necessary to control the content of Fe3O4 in the slag to less than 15% in production practice. Due to the large temperature gradient in the melt layer, the Fe3O4 in the slag will be saturated or nearly saturated in some local areas of the molten pool, forming sticky slag. In severe cases, it will become furnace agglomeration, reducing the volume of the molten pool. Therefore, reducing the temperature gradient, reasonably controlling the melt temperature, and reducing the harm of sticky slag are one of the key issues in production operations.

[0004] Currently, the Ausmelt furnace uses a Silo lance for top-blowing submerged smelting, which has the following disadvantages and problems: 1. Since the top-blowing lance is fixed and cannot be moved during the production process, during production, the charge can only be added through the opening on one side of the lance (the slag outlet is on the opposite side), and the flue is opened on the other side. This design will lead to three problems: (1) Poor flexibility and low production stability. The charge generally falls into the molten pool at a flux of 150t / h~200t / h and accumulates on one side of the furnace body, forming an asymmetric charge accumulation in the furnace body. The charge is difficult to react and melt in a short period of time, which will lead to a large difference in the temperature gradient of the molten pool, that is, the temperature on one side of the charge is low, the temperature of the copper matte outlet is high, and the temperature gradient of the molten pool is large, which will deteriorate the matte and slag reactions, resulting in incomplete reactions, insufficient reduction of Fe3O4, and viscous or even foamy slag. (2) The lance is long, complex in structure, difficult to process, and high in cost. The furnace body of the Ausmelt furnace is slender, and the length of the spray gun is generally about 19 meters. It takes into account the functions of fuel injection heating, oxygen supply oxidation, and stirring the molten pool. The gun body itself is difficult to process and has a high failure rate for complex functions. The gun body is too long. The internal rotary blades added to achieve the stirring effect cause large air pressure loss, low spray intensity, and a gauge pressure of only about 250kPa. On the contrary, the longitudinal stirring force is reduced (commonly known as "poor blowing", that is, the effective depth is reduced), and the effective utilization rate of the spray gun is low. Especially when the charge is unstable, the spray gun is difficult to move and cannot flexibly respond to the fluctuations of the molten pool liquid level, resulting in poor spraying effect on the molten pool. (3) The top-blowing spray gun has a short lifespan and high replacement cost and time. The spray gun is continuously immersed in the molten pool for a long time, and the rising high-temperature furnace gas mixed with metal dust and the sticky slag in the gushing molten pool scours and corrodes the spray gun for a long time. The lifespan of the spray gun is short. The furnace must be stopped for overhaul after 1 to 3 months of continuous production, and the spray gun is also scrapped and repurchased.

[0005] 2. The spray gun sprays pulverized coal in the center of the furnace body. The pulverized coal burns quickly, resulting in uneven heat transfer in the molten pool, that is, the molten pool temperature near the spray gun is high, and the molten pool temperature near the furnace wall is low, thereby generating a large temperature gradient, which is not conducive to the reduction process of Fe3O4 in the molten pool (the operation requirements of the Ausmelt furnace are a small temperature gradient, that is, uniform temperature distribution), and is likely to deteriorate the slag phase composition, making the slag fluidity worse, thereby generating foamy slag, slag surge and other phenomena, damaging the furnace lining and spray gun, and further leading to problems such as difficulty in separating slag from metal and difficulty in slag discharge at the weir, which seriously affect production.

[0006] 3. The large temperature gradient leads to untimely and inaccurate feedback on the actual temperature of the furnace, extremely high operating requirements, low tolerance for production operations, and frequent production accidents that easily lead to substandard production.

[0007] 4. FeS in the ore will be oxidized to FeO and Fe3O4 under the injection of oxidizing atmosphere, and the higher the content of Fe3O4, the worse the fluidity of the slag will be. In addition to being the fuel mentioned above, pulverized coal can also be used as a reducing agent to control the overoxidation process of FeO in the slag and reduce Fe3O4 to FeO. However, the reaction speed of pulverized coal is too fast. During the production process, it is necessary to control the reducing agent to slowly and long-term suppress the FeO oxidation process in the melt, and it is necessary to retain a part of Fe3O4 for slagging reaction (3Fe3O4+FeS+5SiO2=5(2FeO·SiO2)+SO2), rather than completely and quickly directly removing the existence of Fe3O4. The reactivity of pulverized coal is too active, which quickly reduces the content of Fe3O4 in the molten pool slag near the spray gun and reduces its concentration. There is a concentration gradient of Fe3O4 in the molten pool slag near the furnace wall, and the viscosity of the slag also deteriorates. This makes it extremely difficult to control the oxygen potential in the molten pool, and it is also difficult to control the degree of deterioration of the slag viscosity, resulting in large production fluctuations and difficult operation. Summary of the invention

[0008] In view of the deficiencies in the prior art, the present invention provides a copper smelting method of an Ausmelt furnace without a top-blowing lance, which solves the problems of large Fe3O4 concentration gradient and high slag viscosity in the process of smelting high-grade matte in the Ausmelt furnace.

[0009] The copper smelting method of the Ausmelt furnace without a top-blowing lance of the present invention comprises the following steps: (1) The feeding system controls the pulverized coal and mineral powder to pass through the mineral gun and coal gun of the Ausmelt furnace without top-blowing lance, and spray into the molten pool along with the side blowing of the coal-carrying air and mineral-carrying air; (2) Spraying fuel into the molten pool through the side-blowing lance of the Ausmelt furnace without a top-blowing lance; (3) When the copper matte reaches the target grade of 58%~62%, the reaction is completed, the melt temperature distribution is recorded, the slag viscosity is measured, and the slag sample is taken for Fe3O4 content analysis.

[0010] Furthermore, the Ausmelt furnace without top-blowing lance is composed of the following components: flue, baffle, burner, ore gun, coal gun. The flue is arranged on the upper part of the furnace body, and the baffle is arranged below the flue. The lower part of the furnace body is successively downwardly provided with a slag layer and a copper molten pool. The burner is symmetrically arranged on the furnace body above the slag layer, the coal gun is symmetrically arranged on the furnace body at the junction of the slag layer and the copper molten pool, and the ore gun is symmetrically arranged on the furnace body at the copper molten pool layer. Pressure gauges are arranged on the ore gun and the coal gun.

[0011] The specifications and functions of the ore gun and coal gun are the same, and the number is 2, while the number of fuel guns is 2 or 4. Among them, the coal gun and ore gun are evenly and alternately distributed symmetrically around the furnace body, all at the same height, with the opening of the furnace body 3000mm~4000mm from the furnace bottom, and the angle adjustment range of the lower angle with the horizontal plane of the molten pool is 15°~75°; the fuel gun is evenly and alternately distributed symmetrically around the furnace body, with the opening of the furnace body 5000mm~6000mm from the furnace bottom, and the angle of the lower angle with the horizontal plane of the molten pool is fixed at 45°.

[0012] The ore gun and coal gun are of a two-layer sheath structure, the innermost layer is "coal-carrying air + coal powder" and "ore-carrying air + ore powder", and the outermost layer is the spray gun sleeve protective gas CO2.

[0013] The burner is a conventional fuel spray gun with a three-layer jacket structure, the innermost layer is fuel (coal powder, heavy oil, natural gas, etc.), the middle layer is oxygen-enriched air (oxygen content above 75%), and the outermost layer is a water cooling jacket.

[0014] Furthermore, in step (1), the coal-carrying air is selected from a mixture of CO and CO2 and a diffused coal gas; the ore-carrying air is air at room temperature. When the coal-carrying air is a mixture of CO and CO2, the content of CO is 40% to 50%, and the content of CO2 is 50% to 60%.

[0015] Furthermore, in step (1), the mineral powder is raw ore containing iron, copper and sulfur elements, and its main components and contents are Cu: 22%~25%, S: 26%~31%, Fe: 25%~30%, SiO2: 5%~7%, CaO: 1.5%~3%. The mineral powder obtained by grinding has a particle size of 0.1mm~3mm, and the coal powder has a particle size of 0.1mm~6mm.

[0016] Furthermore, in step (1), the pressure of the ore-carrying air in the ore gun is consistent with the pressure of the coal-carrying air in the coal gun, the external gauge pressure of a single ore gun or coal gun is set to 150 kPa~250 kPa, and the air supply flow rate is 1500 Nm 3 / h ~2500Nm 3 / h.

[0017] Furthermore, in step (2), the air inlet pressure of a single burner is 200 kPa~300 kPa, and the air flow rate is 3000 Nm 3 / h~5000Nm 3 / h.

[0018] Furthermore, in step (2), the burner sprays fuels such as oxygen-enriched air (with an O2 content of more than 75%), heavy oil, natural gas and / or coal powder, and the hot air generated after combustion provides heat to the molten pool.

[0019] Furthermore, in step (3), the temperature difference between the center and the side wall of the slag is less than 100°C, the average content of Fe3O4 in the slag is less than 15%, the concentration difference of Fe3O4 in the slag between the center and the side wall is less than 5%, and the viscosity of the slag is less than 1.2 Pa·s, preferably the viscosity of the slag is less than 0.5 Pa·s. The viscosity of the slag is tested in accordance with the YB / T 185-2017 standard.

[0020] Beneficial effects of the present invention: 1. The Ausmelt furnace provided by the present invention has no top-blowing lance on the furnace body, but a side-blowing lance structure is arranged on the side wall of the furnace body. The side-blowing lance is retractable, and the immersion depth of the lance is dynamically adjusted according to the fluctuation of the molten pool liquid level.

[0021] 2. The side-blowing spray gun is set above the slag discharge weir, and is divided into coal gun and mineral oxygen composite spray gun according to its function. The burner gun is on the surface of the molten pool, providing combustion temperature, maintaining the fluidity of the molten pool, and performing secondary combustion on the components in the furnace gas. The mineral gun and the coal gun are symmetrically distributed, and the charge mineral powder and the reducing agent coal powder are evenly added to the molten pool, and the air pressure of the sprayed raw materials is fully utilized to fully stir the molten pool. The pressure of the spray gun for spraying raw materials is higher, which can form a central circulation in the molten pool, thereby improving the reaction activity of the molten pool, making the temperature gradient more uniform, and the composition of the slag more stable, which greatly improves the utilization rate of the spray gun.

[0022] 3. Use CO2 and CO mixed gas as "coal-carrying air" instead of nitrogen. Reduce the impact on the overoxidation of FeO in the molten pool, and the heat capacity of CO2 is higher than that of air, which can keep the molten pool and the furnace body warm. At the same time, CO2 and unreacted coal powder react secondary to generate CO to indirectly reduce Fe3O4. CO2 also has the effect of reducing dust and reducing the boiling intensity of the molten pool.

[0023] 4. The specifications of the mine gun and the coal gun are consistent. If there are any problems during the production cycle, the production functions can be replaced at any time, and the side-blowing spray gun can be replaced in turn. There is no need to stop production for overhaul, and continuous production can be achieved for a longer period of time. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic cross-sectional view of an Ausmelt furnace without a top-blowing lance according to an embodiment of the present invention.

[0025] Figure 2 A schematic top view of an Ausmelt furnace without a top-blowing lance used in an embodiment of the present invention.

[0026] Figure numerals: 1. flue, 2. baffle, 3. combustion gun, 4. ore gun, 5. coal gun, 6. slag layer, 7. copper molten pool. DETAILED DESCRIPTION

[0027] The present invention provides a copper smelting method using an Ausmelt furnace without a top-blowing lance. The structure of the Ausmelt furnace without a top-blowing lance is as follows: Figure 1 and Figure 2 As shown, it is composed of the following components: flue 1, baffle 2, combustion gun 3, ore gun 4, and coal gun 5.

[0028] A flue 1 is arranged on the upper part of the furnace body, a baffle 2 is arranged below the flue 1, a slag layer 6 and a copper molten pool 7 are arranged in sequence at the lower part of the furnace body, a symmetrical combustion gun 3 is arranged on the furnace body above the slag layer 6, a coal gun 5 is arranged at the junction of the slag layer 6 and the copper molten pool 7, and a mine gun 4 is symmetrically arranged on the furnace body of the copper molten pool layer.

[0029] The specifications and functions of the ore gun 4 and coal gun 5 are the same, and the number is 2. The number of the combustion guns is 2. The coal gun 5 and the ore gun 4 are evenly and alternately distributed symmetrically around the furnace body, all at the same height, and the opening of the furnace body is 3000mm~4000mm from the furnace bottom, and the angle adjustment range of the lower angle with the horizontal plane of the molten pool is 15°~75°. The combustion gun 3 is evenly and alternately distributed symmetrically around the furnace body, and the opening of the furnace body is 5000mm~6000mm from the furnace bottom, and the angle of the lower angle with the horizontal plane of the molten pool is fixed at 45°.

[0030] The ore gun 4 and the coal gun 5 are of a two-layer sheath structure, the innermost layer is "coal-carrying air + coal powder" and "ore-carrying air + ore powder", and the outermost layer is the spray gun sleeve protective gas CO2.

[0031] The burner 3 is a conventional fuel spray gun with a three-layer jacket structure, the innermost layer is fuel (coal powder, heavy oil, natural gas, etc.), the middle layer is oxygen-enriched air (oxygen content is above 75%), and the outermost layer is a water cooling jacket.

[0032] The charge consumption of Ausmelt furnace (including ore, auxiliary materials and flux, etc.) is 150t / h~200t / h, the coal addition amount is 1t / h~3t / h, and the molten pool depth is 2000mm~3000mm.

[0033] The copper smelting method of the Ausmelt furnace without a top-blowing lance of the present invention comprises the following steps: (1) The feeding system controls the coal powder and mineral powder to be sprayed into the molten pool through the ore gun 4 and coal gun 5 of the Ausmelt furnace without top-blowing lances through the side blowing of coal-carrying air and mineral-carrying air; the ore gun 4 and coal gun 5 are adjusted in extension and contraction according to the change of the molten pool liquid level; The ore powder is obtained by grinding the raw ore containing iron, copper and sulfur elements. The main components and contents are Cu: 22%~25%, S: 26%~31%, Fe: 25%~30%, SiO2: 5%~7%, CaO: 1.5%~3%; the ore powder obtained by grinding has a particle size of 0.1mm~3mm, and the coal powder has a particle size of 0.1mm~6mm; The mine-carrying air is air at room temperature; the coal-carrying air is a mixture of CO and CO2, or is released coal gas; when the coal-carrying air is a mixture of CO and CO2, the content of CO is 40%~50%, and the content of CO2 is 50%~60%; The external gauge pressure of mine gun 4 and coal gun 5 are set to 150kPa~250kPa, and the gas flow rate is 1500Nm 3 / h~2500Nm 3 / h, and the pressure of the ore-carrying air is consistent with that of the coal-carrying air; (2) Adjust the side burner 3 of the Ausmelt furnace without top-blowing lance to the specified production height and then spray the fuel; the air inlet pressure of a single burner 3 is 200kPa~300kPa, and the air supply flow rate is 3000Nm 3 / h~5000Nm 3 / h; the burner 3 sprays oxygen-enriched air (O2 content is above 75%), heavy oil, natural gas and / or pulverized coal and other fuels, and the hot air generated after combustion provides heat to the molten pool; (3) When the copper matte reaches the target grade of 58% to 62%, the reaction is completed, the melt temperature distribution is recorded, the slag viscosity is measured, and the slag sample is taken for Fe3O4 content analysis; The temperature difference between the center and the side wall of the slag is lower than 100°C, the average content of Fe3O4 in the slag is lower than 15%, the concentration difference of Fe3O4 in the slag between the center and the side wall is lower than 5%, the viscosity of the slag is lower than 1.2 Pa·s, and the preferred slag viscosity is below 0.5 Pa·s.

[0034] In the following Examples 1-5, the average gauge pressure of the burner 3 during the production process was maintained at 280 kPa, and the gas flow rate was 3800 Nm 3 / h, the gas injected is the hot air generated by the combustion of natural gas, the molten pool liquid level is 2500mm, the muzzles of the coal gun 5 and the ore gun 4 are immersed 450mm below the molten pool liquid level, and the muzzle of the combustion gun 3 is 2000mm above the molten pool liquid level. When the copper matte reaches the target grade of 58%, the reaction ends and the spray gun is raised.

[0035] Example 1 The Ausmelt furnace without a top-blowing lance of the present invention is used for copper smelting, and the side-blowing lance replaces the top-blowing lance.

[0036] (1) The feeding system controls the coal powder and mineral powder to be sprayed into the molten pool through the side blowing of the mineral gun 4 and the coal gun 5 respectively; the coal powder is sprayed into the molten pool by the coal-carrying air, and the mineral powder is sprayed into the molten pool by the mineral-carrying air; the pressure of the coal-carrying air and the mineral-carrying air are both 150kPa, and the air supply flow rate is 1500Nm 3 / h; the coal-carrying air used is a mixture of CO and CO2, with a CO content of 40% and a CO2 content of 60%; (2) Adjust the side-blowing lance 3 to the production height and then spray fuel for heating; (3) After the reaction is completed, the spray gun is raised, the melt temperature distribution is recorded, the slag viscosity is measured, and the slag sample is taken for Fe3O4 content analysis; Record the slag temperature at the side wall and the center slag temperature. In Example 1, the center slag temperature is as high as 1283°C, the slag temperature at the side wall is 1182°C, and the temperature difference between the center and the side wall is about 101°C. The average Fe3O4 content of the slag is 14.2%, the Fe3O4 concentration difference between the center and the side wall of the slag is about 4.8%, and the high-temperature viscosity of the slag is about 1.11 Pa·s.

[0037] Example 2 The Ausmelt furnace without a top-blowing lance of the present invention is used for copper smelting, and the side-blowing lance replaces the top-blowing lance.

[0038] (1) The feeding system controls the coal powder and mineral powder to be sprayed into the molten pool through the side blowing of the mineral gun 4 and the coal gun 5 respectively; the coal powder is sprayed into the molten pool by the coal-carrying air, and the mineral powder is sprayed into the molten pool by the mineral-carrying air; the pressure of the coal-carrying air and the mineral-carrying air are both 200 kPa, and the air supply flow rate is 2000 Nm 3 / h; the coal-carrying air used is a mixture of CO and CO2, with a CO content of 40% and a CO2 content of 60%; (2) Adjust the side-blowing lance 3 to the production height and then spray fuel for heating; (3) After the reaction is completed, the spray gun is raised, the melt temperature distribution is recorded, the slag viscosity is measured, and the slag sample is taken for Fe3O4 content analysis; Record the slag temperature at the side wall and the center slag temperature. In Example 2, the center slag temperature is as high as 1292°C, the slag temperature at the side wall is 1202°C, and the slag temperature difference between the center and the side wall is about 90°C. The average Fe3O4 content of the slag is 12.9%, the Fe3O4 concentration difference between the center and the side wall of the slag is about 4.3%, and the high-temperature viscosity of the slag is about 0.96 Pa·s.

[0039] Example 3 The Ausmelt furnace without a top-blowing lance of the present invention is used for copper smelting, and the side-blowing lance replaces the top-blowing lance.

[0040] (1) The feeding system controls the coal powder and mineral powder to be sprayed into the molten pool through the side blowing of the mineral gun 4 and the coal gun 5 respectively; the coal powder is sprayed into the molten pool by the coal-carrying air, and the mineral powder is sprayed into the molten pool by the mineral-carrying air; the pressure of the coal-carrying air and the mineral-carrying air are both 250kPa, and the air supply flow rate is 2500Nm 3 / h; the coal-carrying air used is a mixture of CO and CO2, with a CO content of 40% and a CO2 content of 60%; (2) Adjust the side-blowing lance 3 to the production height and then spray fuel for heating; (3) After the reaction is completed, the spray gun is raised, the melt temperature distribution is recorded, the slag viscosity is measured, and the slag sample is taken for Fe3O4 content analysis; Record the slag temperature at the side wall and the center slag temperature. In Example 3, the center slag temperature is as high as 1314°C, the slag temperature at the side wall is 1235°C, and the slag temperature difference between the center and the side wall is about 79°C. The average Fe3O4 content of the slag is 11.6%. The difference in Fe3O4 concentration between the center and the side wall of the slag is about 3.6%. The high-temperature viscosity of the slag is about 0.76 Pa·s.

[0041] Example 4 The Ausmelt furnace without a top-blowing lance of the present invention is used for copper smelting, and the side-blowing lance replaces the top-blowing lance.

[0042] (1) The feeding system controls the coal powder and mineral powder to be sprayed into the molten pool through the side blowing of the mineral gun 4 and the coal gun 5 respectively; the coal powder is sprayed into the molten pool by the coal-carrying air, and the mineral powder is sprayed into the molten pool by the mineral-carrying air; the pressure of the coal-carrying air and the mineral-carrying air are both 250kPa, and the air supply flow rate is 2500Nm 3 / h; the coal-carrying air used is a mixture of CO and CO2, with a CO content of 45% and a CO2 content of 55%; (2) Adjust the side-blowing lance 3 to the production height and then spray fuel for heating; (3) After the reaction is completed, the spray gun is raised, the melt temperature distribution is recorded, the slag viscosity is measured, and the slag sample is taken for Fe3O4 content analysis; Record the slag temperature at the side wall and the center slag temperature. In Example 4, the center slag temperature is as high as 1332°C, the slag temperature at the side wall is 1280°C, and the slag temperature difference between the center and the side wall is about 52°C. The average Fe3O4 content of the slag is 9.9%, the difference in Fe3O4 concentration between the center and the side wall of the slag is about 2.1%, and the high-temperature viscosity of the slag is about 0.57 Pa·s.

[0043] Example 5 The Ausmelt furnace without a top-blowing lance of the present invention is used for copper smelting, and the side-blowing lance replaces the top-blowing lance.

[0044] (1) The feeding system controls the coal powder and mineral powder to be sprayed into the molten pool through the side blowing of the mineral gun 4 and the coal gun 5 respectively; the coal powder is sprayed into the molten pool by the coal-carrying air, and the mineral powder is sprayed into the molten pool by the mineral-carrying air; the pressure of the coal-carrying air and the mineral-carrying air are both 250kPa, and the air supply flow rate is 2500Nm 3 / h; the coal-carrying air used is a mixture of CO and CO2, with a CO content of 50% and a CO2 content of 50%; (2) Adjust the side-blowing lance 3 to the production height and then spray fuel for heating; (3) After the reaction is completed, the spray gun is raised, the melt temperature distribution is recorded, the slag viscosity is measured, and the slag sample is taken for Fe3O4 content analysis; Record the slag temperature at the side wall and the center slag temperature. In Example 5, the center slag temperature is as high as 1351°C, the slag temperature at the side wall is 1315°C, and the slag temperature difference between the center and the side wall is about 36°C. The average Fe3O4 content of the slag is 8.6%. The difference in Fe3O4 concentration between the center and the side wall of the slag is about 1.6%. The high-temperature viscosity of the slag is about 0.46 Pa·s.

[0045] Comparative Example 1 A conventional Ausmelt furnace is used for copper smelting, with only top lance injection and no side blowing.

[0046] (1) The slag temperature at the side wall and the slag temperature at the center were recorded. The slag temperature at the center was as high as 1372.5°C, and the slag temperature at the side wall was 1099.6°C. The temperature difference between the center and the side wall was about 273°C.

[0047] (2) The average Fe3O4 content of the slag is 17.7%. The difference in Fe3O4 concentration between the center and the side wall of the slag is about 9.3%. The high-temperature viscosity of the slag is about 1.39 Pa·s.

[0048] The following conclusions can be drawn from the above embodiments and comparative examples: It can be seen from Examples 1-3 that the higher the coal-carrying air pressure of the side-blowing coal gun and the ore-carrying air pressure of the side-blowing ore gun, the greater the gas supply flow rate, the more intense the stirring of the molten pool, the more complete the reaction, the more uniform the temperature field, the smaller the temperature difference between the center and the side wall of the molten pool, the lower the average Fe3O4 content of the slag, and the lower the viscosity of the slag.

[0049] It can be seen from Examples 3-5 that, under certain conditions of the coal-carrying air pressure and gas supply flow rate of the side-blowing coal gun and the ore-carrying air pressure of the side-blowing ore gun, the higher the CO content in the coal-carrying air, the smaller the temperature difference between the center and the side wall of the molten pool, the lower the average Fe3O4 content of the slag, and the smaller the viscosity of the slag.

[0050] It can be seen from Comparative Example 1 that the technical indicators of the top-blowing lance deteriorate, the temperature difference between the center and the side wall of the molten pool is greater than 150°C, the average Fe3O4 content of the slag is greater than 15%, and the viscosity of the slag is greater than 1.2 Pa·s, which seriously affects the smelting process.

Claims

1. A copper smelting method using an Ausmelt furnace without a top-blowing lance, characterized in that: The following steps are involved: (1) The feeding system controls the pulverized coal and mineral powder to pass through the mineral gun and coal gun of the Ausmelt furnace without top-blowing lance, and spray into the molten pool along with the side blowing of the coal-carrying air and mineral-carrying air; (2) Spraying fuel into the molten pool through the side-blowing lance of the Ausmelt furnace without a top-blowing lance; (3) When the copper matte reaches the target grade of 58%~62%, the reaction is completed, the melt temperature distribution is recorded, the slag viscosity is measured, and the slag sample is taken for Fe3O4 content analysis.

2. The copper smelting method of the Ausmelt furnace without a top-blowing lance according to claim 1, characterized in that: The Ausmelt furnace without a top-blowing lance is composed of the following components: a flue, a baffle, a combustion gun, a ore gun, and a coal gun; wherein a flue is arranged on the upper part of the furnace body, a baffle is arranged below the flue, a slag layer and a copper molten pool are arranged in sequence from the lower part of the furnace body downward, the combustion guns are symmetrically arranged on the furnace body above the slag layer, the coal guns are symmetrically arranged on the furnace body at the junction of the slag layer and the copper molten pool, the ore guns are symmetrically arranged on the furnace body at the copper molten pool layer, and pressure gauges are arranged on the ore guns and the coal guns.

3. The copper smelting method of the Ausmelt furnace without a top-blowing lance according to claim 2, characterized in that: The specifications and functions of the ore gun and coal gun are the same, with two in number, and the number of fuel guns is two or four; the coal gun and ore gun are evenly and alternately distributed symmetrically around the furnace body, all at the same height, with the opening of the furnace body 3000mm~4000mm from the furnace bottom, and the angle adjustment range of the lower angle with the horizontal plane of the molten pool is 15°~75°; the fuel gun is evenly and alternately distributed symmetrically around the furnace body, with the opening of the furnace body 5000mm~6000mm from the furnace bottom, and the angle of the lower angle with the horizontal plane of the molten pool is fixed at 45°; The ore gun and coal gun are two-layer jacket structure, the innermost layer is coal-carrying air + coal powder and ore-carrying air + ore powder, and the outermost layer is the gun sleeve protective gas CO2; The burner is a conventional fuel spray gun with a three-layer jacket structure, the innermost layer is fuel, the middle layer is oxygen-enriched air, and the outermost layer is a water cooling jacket.

4. The copper smelting method of the Ausmelt furnace without a top-blowing lance according to claim 1, characterized in that: In the step (1), the coal-carrying air is selected from a mixture of CO and CO2 and diffused coal gas; the coal-carrying air is air at room temperature; when the coal-carrying air is a mixture of CO and CO2, the content of CO is 40% to 50%, and the content of CO2 is 50% to 60%.

5. The copper smelting method of the Ausmelt furnace without a top-blowing lance according to claim 1, characterized in that: In the step (1), the ore powder is raw ore containing iron, copper and sulfur elements, and its main components and contents are Cu: 22%~25%, S: 26%~31%, Fe: 25%~30%, SiO2: 5%~7%, CaO: 1.5%~3%. The ore powder obtained by grinding has a particle size of 0.1mm~3mm, and the coal powder has a particle size of 0.1mm~6mm.

6. The copper smelting method of the Ausmelt furnace without a top-blowing lance according to claim 1, characterized in that: In step (1), the pressure of the ore-carrying air in the ore gun is consistent with that of the coal-carrying air in the coal gun. The external gauge pressure of a single ore gun or coal gun is set to 150 kPa~250 kPa, and the air supply flow rate is 1500 Nm 3 / h ~2500Nm 3 / h.

7. The copper smelting method of the Ausmelt furnace without a top-blowing lance according to claim 1, characterized in that: In step (2), the air inlet pressure of a single burner is 200kPa~300kPa, and the air flow rate is 3000Nm 3 / h~5000Nm 3 / h.

8. The copper smelting method of the Ausmelt furnace without a top-blowing lance according to claim 1, characterized in that: In step (2), the burner sprays oxygen-enriched air, heavy oil, natural gas and / or pulverized coal fuel, and the hot air generated after combustion provides heat to the molten pool.

9. The copper smelting method of the Ausmelt furnace without a top-blowing lance according to claim 1, characterized in that: In the step (3), the temperature difference between the center and the side wall of the slag is less than 100°C, the average content of Fe3O4 in the slag is less than 15%, the difference in Fe3O4 concentration in the slag between the center and the side wall is less than 5%, and the viscosity of the slag is less than 1.2 Pa·s.

10. The copper smelting method of the Ausmelt furnace without a top-blowing lance according to claim 9, characterized in that: The viscosity of the slag is below 0.5 Pa·s.

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