A copper smelting method for an Ausmelt furnace without a top-blown lance

Abstract

The invention discloses a copper smelting method for an Ausmelt furnace without a top-blown lance, which relates to the technical field of copper smelting of an Ausmelt furnace, and includes: (1) injecting pulverized coal and ore powder into the molten bath through the ore lance and coal lance of the Ausmelt furnace without a top-blown lance; (2) injecting fuel into the molten bath by the side-blown combustion lance of the Ausmelt furnace without a top-blown lance; (3) ending the reaction when the copper matte reaches the target grade of 58% - 62%, recording the temperature distribution of the melt, measuring the viscosity of the slag, and taking a slag sample for analysis of the content of Fe3O4. The Ausmelt furnace without a top-blown lance includes a flue, a baffle, a combustion lance, an ore lance, and a coal lance; a flue is arranged at the upper part of the furnace body, a baffle is arranged below the flue, the combustion lances are symmetrically arranged on the furnace body above the slag layer, the coal lances are symmetrically arranged on the furnace body at the junction of the slag layer and the copper water molten bath, the ore lances are symmetrically arranged on the furnace body of the copper water molten bath layer, and pressure gauges are arranged on both the ore lance and the coal lance.

Description

Technical Field

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

[0002] Currently, Ausmelt furnaces mainly carry out smelting through top-blown submerged injection technology. During smelting, the lance is inserted from the top of the Ausmelt furnace and submerged into the molten pool composed of copper matte and slag in a vertically placed cylindrical furnace hearth. Fuel (heavy oil, natural gas, pulverized coal, etc.) and oxidizing gas (pure oxygen, air, oxygen-enriched air, etc.) are ejected from the end of the lance, and furnace charge (ore powder, auxiliary materials, fluxes, etc.) is directly added from the top charging port.

[0003] During the production of high-grade copper matte in Ausmelt smelting, the formation of Fe 3 O 4 is inevitable. Fe 3 O 4 will deteriorate the properties of the slag. Generally, in production practice, it is considered necessary to control the content of Fe 3 O 4 in the slag to be less than 15%. Due to the large temperature gradient existing in the melt layer, Fe 3 O 4 in the slag will be saturated or nearly saturated in some local areas of the molten pool, forming sticky slag, and in severe cases, it will become a furnace build-up, 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, an Ausmelt furnace uses a single Siro lance for top-blown submerged smelting process, and there are the following disadvantages and problems:

[0005] 1. Since the top-blown lance is fixed during production and cannot be moved. Therefore, during production, furnace charge can only be added through an opening on one side of the lance (the slag outlet is on the opposite side), and a flue is opened on the other side. This design will cause three problems: (1) Poor flexibility and low production stability. The furnace charge generally falls into the molten pool at a flux of 150 t / h to 200 t / h and accumulates on one side of the furnace body, forming an asymmetric furnace charge accumulation in the furnace body. The furnace charge is difficult to react and melt in a short time, resulting in a large difference in the temperature gradient of the molten pool, that is, the temperature on one side of the furnace charge is low, and the temperature at the copper matte outlet is high. The large temperature gradient of the molten pool will deteriorate the matte-making and slag-making reactions, making the reaction incomplete, and Fe 3 O 4Inadequate reduction, viscous slag, or even foaming of the slag, etc. (2) The lance is long, with a complex structure, high processing difficulty, and high cost. The furnace body of the Ausmelt furnace is slender, and the lance length is generally about 19 meters, serving functions such as fuel injection heating, oxygen supply for oxidation, and stirring of the bath. The processing of the lance body itself is difficult, the failure rate of the composite functions is high, and the lance is too long. The internal rotating blades added to play the stirring role cause large air pressure losses and low injection intensity, with the gauge pressure only about 250 kPa. Instead, the longitudinal stirring force decreases (commonly known as not being able to blow through, that is, the effective depth decreases), and the effective utilization rate of the lance is low. Especially when the furnace charge is unstable, the lance is difficult to move and cannot flexibly respond to the fluctuations of the bath liquid level, resulting in poor injection effect on the bath. (3) The top-blown lance has a short service life, high replacement cost, and long replacement time. The lance is continuously immersed in the bath for a long time, and the rising high-temperature furnace gas mixed with metal dust and the viscous slag in the gushing bath continuously erode and corrode the lance. The service life of the lance is short, and the furnace must be shut down for major repairs after continuous production for 1 to 3 months, and the lance is scrapped and repurchased accordingly.

[0006] 2. The pulverized coal is injected in the center of the furnace body by the lance, and the combustion speed of the pulverized coal is fast, resulting in uneven heat transfer in the bath, that is, the temperature of the bath near the lance is high, and the temperature of the bath near the furnace wall is low, thus generating a large temperature gradient, which is not conducive to the reduction process of Fe 3 O 4 in the bath (the operation requirement of the Ausmelt furnace is a smaller temperature gradient, that is, uniform temperature distribution). It is easy to deteriorate the slag phase composition, making the fluidity of the slag deteriorate, thus generating phenomena such as foaming slag and gushing slag, damaging the furnace lining and the lance, and further leading to problems such as difficult separation of slag and metal and difficult slag discharge at the weir, seriously affecting production.

[0007] 3. The large temperature gradient leads to untimely and inaccurate feedback of the actual temperature of the furnace body, extremely high operation requirements, low production operation fault tolerance, and easy frequent production accidents that do not meet the standards.

[0008] 4. FeS in the ore will be oxidized to FeO and Fe 3 O 4 under the injection of an oxidizing atmosphere, and the higher the content of Fe 3 O 4 , the more it will deteriorate the fluidity of the slag. In addition to being used as the fuel mentioned above, pulverized coal can also be used as a reducing agent to control the peroxidation process of FeO in the slag and reduce Fe 3 O 4 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 continuously inhibit the oxidation process of FeO in the melt and retain a part of Fe 3 O 4 to undergo a slag-making reaction (3Fe 3 O 4 +FeS+5SiO2 = 5(2FeO·SiO 2 ) + SO 2 ), rather than completely and quickly removing Fe directly 3 O 4 Due to the existence of 3 O 4 , the reactivity of pulverized coal is too active, and the content of Fe 3 O 4 in the molten slag near the lance in the molten bath is quickly reduced and its concentration is decreased. There is a concentration gradient of Fe Summary of the Invention

[0009] Aiming at the deficiencies of the prior art, the present invention provides a copper smelting method for an Ausmelt furnace without a top-blown lance, which solves the problems existing in the process of smelting high-grade matte in an Ausmelt furnace, such as large Fe 3 O 4 concentration gradient and high viscosity of molten slag.

[0010] The copper smelting method for an Ausmelt furnace without a top-blown lance according to the present invention includes the following steps:

[0011] (1) Controlling pulverized coal and ore powder to be blown into the molten bath through the ore lance and coal lance of the Ausmelt furnace without a top-blown lance respectively by the feeding system, along with the coal-carrying air and ore-carrying air, by side blowing;

[0012] (2) Blowing fuel into the molten bath through the side-blown combustion lance of the Ausmelt furnace without a top-blown lance;

[0013] (3) When the matte reaches the target grade of 58% - 62%, the reaction ends, recording the melt temperature distribution, measuring the viscosity of the molten slag, and taking a molten slag sample for Fe 3 O 4 content analysis.

[0014] Furthermore, the Ausmelt furnace without a top-blown lance consists of the following components: a flue, a baffle, a combustion lance, an ore lance, and a coal lance. Among them, a flue is arranged at the upper part of the furnace body, a baffle is arranged below the flue, the lower part of the furnace body is successively a molten slag layer and a copper water molten bath from top to bottom. The combustion lance is symmetrically arranged on the furnace body above the molten slag layer, the coal lance is symmetrically arranged on the furnace body at the junction of the molten slag layer and the copper water molten bath, the ore lance is symmetrically arranged on the furnace body of the copper water molten bath layer, and pressure gauges are arranged on both the ore lance and the coal lance.

[0015] The specifications and functions of the ore guns and coal guns are the same, and the number of each is 2. The number of fuel guns is 2 or 4. Among them, the coal guns and ore guns are evenly, alternately and symmetrically distributed around the furnace body, at the same height. The openings on the furnace body are 3000 mm to 4000 mm from the furnace bottom, and the adjustment range of the downward angle with the molten pool horizontal plane is 15° to 75°; the fuel guns are evenly, alternately and symmetrically distributed around the furnace body, the openings on the furnace body are 5000 mm to 6000 mm from the furnace bottom, and the downward angle with the molten pool horizontal plane is fixed at 45°.

[0016] The ore guns and coal guns have a two-layer jacket structure. The innermost layer is "coal-carrying air + pulverized coal" and "ore-carrying air + ore powder", and the outermost layer is the protective gas CO of the spray gun sleeve 2 。

[0017] The fuel guns are conventional fuel spray guns with a three-layer jacket structure. The innermost layer is fuel (pulverized coal, heavy oil, natural gas, etc.), the middle layer is oxygen-enriched air (oxygen content above 75%), and the outermost layer is a water-cooled jacket.

[0018] Further, in the step (1), the coal-carrying air is selected from the mixed gas of CO and CO 2 and the vented gas; the ore-carrying air is normal-temperature air. When the coal-carrying air is the mixed gas of CO and CO 2 , the content of CO accounts for 40% to 50%, and the content of CO 2 accounts for 50% to 60%.

[0019] Further, in the step (1), the ore powder is the raw ore containing iron, copper and sulfur elements, and the main components and contents are Cu: 22% to 25%, S: 26% to 31%, Fe: 25% to 30%, SiO 2 : 5% to 7%, CaO: 1.5% to 3%. The ore powder is obtained by grinding, the particle size of the ore powder is 0.1 mm to 3 mm, and the particle size of the pulverized coal is 0.1 mm to 6 mm.

[0020] Further, in the step (1), the pressure of the ore-carrying air in the ore gun is the same as that of the coal-carrying air in the coal gun. The external gauge pressure setting for a single ore gun or coal gun is 150 kPa to 250 kPa, and the air supply flow rate is 1500 Nm 3 / h to 2500 Nm 3 / h.

[0021] Further, in the step (2), the inlet air pressure of a single fuel gun is 200 kPa to 300 kPa, and the air supply flow rate is 3000 Nm 3 / h to 5000 Nm 3 / h.

[0022] Further, in the step (2), the fuel gun sprays oxygen-enriched air (O 2Fuels such as those with a content above 75%, heavy oil, natural gas, and / or pulverized coal are used to provide heat to the molten bath through the hot air generated after combustion.

[0023] Furthermore, in the step (3), the temperature difference between the center and the side wall of the molten slag is lower than 100 °C, the average content of Fe 3 O 4 in the molten slag is lower than 15%, the concentration difference of Fe 3 O 4 between the center and the side wall of the molten slag is lower than 5%, the viscosity of the molten slag is lower than 1.2 Pa·s, and preferably the viscosity of the molten slag is below 0.5 Pa·s. The viscosity of the molten slag is tested with reference to the YB / T 185-2017 standard.

[0024] Advantages of the present invention:

[0025] 1. For the Ausmelt furnace provided by the present invention, the top-blowing lance is not provided on the furnace body, and instead a side-blowing lance structure is provided on the side wall of the furnace body. The side-blowing lance is telescopic and can dynamically adjust the immersion depth of the lance according to the undulation of the molten bath surface.

[0026] 2. The side-blowing lance is arranged above the slag discharge weir opening and is divided into a coal lance and a combined ore-oxygen lance according to functions. The fuel lance is above the molten bath surface, providing combustion temperature, maintaining the fluidity of the molten bath, and performing secondary combustion on the components in the furnace gas. The ore lance and the coal lance are symmetrically distributed, uniformly adding the furnace charge ore powder and the reducing agent pulverized coal into the molten bath, and fully utilizing the air pressure of the injected raw materials to form sufficient stirring of the molten bath. Moreover, the pressure of the lance injecting the raw materials is higher, which can form a central circulation in the molten bath, improving the reaction activity of the molten bath, making the temperature gradient more uniform, and making the composition of the molten slag more stable, greatly improving the utilization rate of the lance.

[0027] 3. Using CO 2 and CO mixed gas as the "coal-carrying air" to replace nitrogen. Reducing the impact on the over-oxidation of FeO in the molten bath, and the heat capacity of CO 2 is higher than that of air, which can play a role in heat preservation for the molten bath and the furnace body. At the same time, CO 2 and the unreacted pulverized coal undergo a secondary reaction to generate CO for the indirect reduction of Fe 3 O 4 . CO 2 also has the effects of reducing dust and reducing the boiling intensity of the molten bath.

[0028] 4. The ore lance and the coal lance have the same specifications. In case of problems during the production cycle, their production functions can be replaced with each other at any time, and the side-blowing lance can be replaced in sequence, without the need to suspend production for major repairs, enabling longer continuous production. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1Schematic front sectional view of an Ausmelt furnace using a non-top-blown lance in an embodiment of the present invention.

[0030] Figure 2 Top view schematic of an Ausmelt furnace using a non-top-blown lance in an embodiment of the present invention.

[0031] Reference numerals: 1, flue; 2, baffle; 3, burner lance; 4, ore lance; 5, coal lance; 6, slag layer; 7, copper bath. Detailed implementation manners

[0032] The present invention provides a copper smelting method for an Ausmelt furnace with a non-top-blown lance. The structure of the Ausmelt furnace with the non-top-blown lance is as Figure 1 and Figure 2 shown, and it consists of the following components: flue 1, baffle 2, burner lance 3, ore lance 4, coal lance 5.

[0033] Among them, a flue 1 is arranged at the upper part of the furnace body, a baffle 2 is arranged below the flue 1, and the lower part of the furnace body successively has a slag layer 6 and a copper bath 7 from top to bottom. Symmetric burner lances 3 are arranged on the furnace body above the slag layer 6, a coal lance 5 is arranged at the junction of the slag layer 6 and the copper bath 7, and the ore lances 4 are symmetrically arranged on the furnace body of the copper bath layer.

[0034] The ore lances 4 and the coal lances 5 have the same specifications and functions, and the number of each is 2, and the number of burner lances is 2. The coal lances 5 and the ore lances 4 are evenly and alternately symmetrically distributed around the furnace body, at the same height, with the opening on the furnace body being 3000 mm to 4000 mm from the furnace bottom, and the angle adjustment range of the lower angle with the horizontal plane of the bath being 15° to 75°. The burner lances 3 are evenly and alternately symmetrically distributed around the furnace body, with the opening on the furnace body being 5000 mm to 6000 mm from the furnace bottom, and the lower angle with the horizontal plane of the bath being fixed at 45°.

[0035] The ore lances 4 and the coal lances 5 are of a two-layer sheath structure. The innermost layer is "coal-carrying air + pulverized coal" and "ore-carrying air + ore powder", and the outermost layer is the protective gas CO of the lance sleeve 2 .

[0036] The burner lance 3 is a conventional fuel lance, with a three-layer sheath structure. The innermost layer is fuel (pulverized coal, heavy oil, natural gas, etc.), the middle layer is oxygen-enriched air (oxygen content above 75%), and the outermost layer is a water-cooled jacket.

[0037] The furnace charge (including ore charge, auxiliary materials, flux, etc.) consumption of the Ausmelt furnace is 150 t / h to 200 t / h, the coal addition amount is 1 t / h to 3 t / h, and the bath depth is 2000 mm to 3000 mm.

[0038] The copper smelting method for the Ausmelt furnace with a non-top-blown lance of the present invention includes the following steps:

[0039] (1) The pulverized coal and ore powder are respectively controlled by the feeding system to be blown into the molten bath through the ore lance 4 and the coal lance 5 of the Ausmelt furnace with a non-top blowing lance by the side blowing of the coal-carrying air and the ore-carrying air; the ore lance 4 and the coal lance 5 are telescopically adjusted according to the change of the molten bath liquid level height;

[0040] The ore powder is the ore powder obtained by grinding the original ore containing iron, copper and sulfur elements, and the main components and contents are Cu: 22% - 25%, S: 26% - 31%, Fe: 25% - 30%, SiO 2 : 5% - 7%, CaO: 1.5% - 3%; the ore powder obtained by grinding, the particle size of the ore powder is 0.1mm - 3mm, and the particle size of the pulverized coal is 0.1mm - 6mm;

[0041] The ore-carrying air is normal-temperature air; the coal-carrying air is a mixed gas of CO and CO 2 or the blown-off gas; when the coal-carrying air is a mixed gas of CO and CO 2 the content of CO accounts for 40% - 50%, and the content of CO 2 accounts for 50% - 60%;

[0042] The external surface pressure settings of the ore lance 4 and the coal lance 5 are both 150 kPa - 250 kPa, and the gas supply flow rates are both 1500 Nm 3 / h - 2500 Nm 3 / h, and the pressures of the ore-carrying air and the coal-carrying air are the same;

[0043] (2) After adjusting the side burner lance 3 of the Ausmelt furnace with a non-top blowing lance to the specified production height, fuel is blown; the air inlet pressure of a single burner lance 3 is 200 kPa - 300 kPa, and the gas supply flow rate is 3000 Nm 3 / h - 5000 Nm 3 / h; the burner lance 3 blows fuel such as oxygen-enriched air (O 2 content above 75%), heavy oil, natural gas and / or pulverized coal, and the hot air generated by combustion provides heat for the molten bath;

[0044] (3) When the copper matte reaches the target grade of 58% - 62%, the reaction ends, the melt temperature distribution is recorded, the viscosity of the slag is measured, and a slag sample is taken for the content analysis of Fe 3 O 4 ;

[0045] The temperature difference between the center and the side wall of the slag is less than 100 °C, the average content of Fe 3 O 4 in the slag is less than 15%, and the Fe 3 O 4The concentration difference is less than 5%, the viscosity of the slag is less than 1.2 Pa·s, and preferably the viscosity of the slag is below 0.5 Pa·s.

[0046] In the following Examples 1-5, the average gauge pressure of the burner 3 during the production process was maintained at 280 kPa, the gas supply flow rate was 3800 Nm 3 / h, the gas blown was the hot air generated after the combustion of natural gas, the height of the molten bath surface was 2500 mm, the muzzles of the coal gun 5 and the ore gun 4 were immersed 450 mm below the molten bath surface level, and the muzzle of the burner 3 was 2000 mm above the molten bath surface level. When the copper matte reached the target grade of 58%, the reaction ended and the lance was raised.

[0047] Example 1

[0048] Copper smelting was carried out using the Ausmelt furnace with a non-top-blown lance of the present invention, and the side-blown lance replaced the top lance for blowing.

[0049] (1) The pulverized coal and ore powder were respectively blown into the molten bath through the side blowing of the ore gun 4 and the coal gun 5 by the feeding system; among them, the pulverized coal was blown into the molten bath by the coal-carrying air, and the ore powder was blown into the molten bath by the ore-carrying air; the pressures of both the coal-carrying air and the ore-carrying air were 150 kPa, and the gas supply flow rates were both 1500 Nm 3 / h; the coal-carrying air used was a mixed gas of CO and CO 2 , with a CO content of 40% and a CO 2 content of 60%;

[0050] (2) Adjust the side-blown burner 3 to the production height and then blow the fuel for heating;

[0051] (3) After the reaction ended, the lance was raised, the temperature distribution of the melt was recorded, the viscosity of the slag was measured, and a slag sample was taken for the content analysis of Fe 3 O 4 ;

[0052] The slag temperature at the side wall and the central slag temperature were recorded. In this Example 1, the central slag temperature was as high as 1283 °C, the slag temperature at the side wall was 1182 °C, and the temperature difference between the center and the side wall was about 101 °C;

[0053] The average Fe 3 O 4 content of the slag was 14.2%, the Fe 3 O 4 concentration difference in the slag between the center and the side wall was about 4.8%, and the high-temperature viscosity of the slag was about 1.11 Pa·s.

[0054] Example 2

[0055] Copper smelting was carried out using the Ausmelt furnace with a non-top-blown lance of the present invention, and the side-blown lance replaced the top lance for blowing.

[0056] (1) Control the pulverized coal and ore powder to be blown into the molten bath through the ore lance 4 and the coal lance 5 respectively by the feeding system; among them, the pulverized coal is blown into the molten bath by the coal-carrying air, and the ore powder is blown into the molten bath by the ore-carrying air; the pressures of the coal-carrying air and the ore-carrying air are both 200 kPa, and the gas supply flow rates are both 2000 Nm 3 / h; the coal-carrying air used is a mixed gas of CO and CO 2 , with a CO content of 40% and a CO 2 content of 60%;

[0057] (2) Adjust the side-blown combustion lance 3 to the production height and then blow the fuel to supply heat;

[0058] (3) After the reaction is completed, raise the lance, record the temperature distribution of the melt, measure the viscosity of the slag, and take a slag sample for the content analysis of Fe 3 O 4 ;

[0059] Record the slag temperature at the side wall and the central slag temperature. In this Example 2, the central slag temperature is as high as 1292 °C, the slag temperature at the side wall is 1202 °C, and the temperature difference between the central and side wall slags is about 90 °C;

[0060] The average Fe 3 O 4 content of the slag is 12.9%, the concentration difference of Fe 3 O 4 between the central and side wall slags is about 4.3%, and the high-temperature viscosity of the slag is about 0.96 Pa·s.

[0061] Example 3

[0062] Use the Ausmelt furnace without a top-blown lance of the present invention for copper smelting, and replace the top lance with a side-blown lance for blowing.

[0063] (1) Control the pulverized coal and ore powder to be blown into the molten bath through the ore lance 4 and the coal lance 5 respectively by the feeding system; among them, the pulverized coal is blown into the molten bath by the coal-carrying air, and the ore powder is blown into the molten bath by the ore-carrying air; the pressures of the coal-carrying air and the ore-carrying air are both 250 kPa, and the gas supply flow rates are both 2500 Nm 3 / h; the coal-carrying air used is a mixed gas of CO and CO 2 , with a CO content of 40% and a CO 2 content of 60%;

[0064] (2) Adjust the side-blown combustion lance 3 to the production height and then blow the fuel to supply heat;

[0065] (3) After the reaction is completed, raise the lance, record the temperature distribution of the melt, measure the viscosity of the slag, and take a slag sample for the content analysis of Fe 3 O 4 ;

[0066] Record the slag temperature at the side wall and the central slag temperature. In Example 3 of this embodiment, the central slag temperature is as high as 1314 °C, the slag temperature at the side wall is 1235 °C, and the temperature difference between the central and side wall slags is about 79 °C;

[0067] The average Fe 3 O 4 content is 11.6%. The concentration difference of Fe 3 O 4 in the slags at the center and the side wall is about 3.6%, and the high-temperature viscosity of the slag is about 0.76 Pa·s.

[0068] Example 4

[0069] Use the Ausmelt furnace with a non-top-blowing lance of the present invention for copper smelting, and replace the top lance with a side lance for blowing.

[0070] (1) Control the pulverized coal and ore powder to be blown into the molten bath through the ore lance 4 and the coal lance 5 respectively by the feeding system; among them, the pulverized coal is blown into the molten bath by the coal-carrying air, and the ore powder is blown into the molten bath by the ore-carrying air; the pressures of both the coal-carrying air and the ore-carrying air are 250 kPa, and the gas supply flow rates are both 2500 Nm 3 / h; the coal-carrying air used is a mixed gas of CO and CO 2 , with a CO content of 45% and a CO 2 content of 55%;

[0071] (2) Adjust the side-blowing combustion lance 3 to the production height and then blow the fuel for heat supply;

[0072] (3) After the reaction is completed, raise the lance, record the temperature distribution of the melt, measure the viscosity of the slag, and take a slag sample for the content analysis of Fe 3 O 4 ;

[0073] Record the slag temperature at the side wall and the central slag temperature. In Example 4 of this embodiment, the central slag temperature is as high as 1332 °C, the slag temperature at the side wall is 1280 °C, and the temperature difference between the central and side wall slags is about 52 °C;

[0074] The average Fe 3 O 4 content is 9.9%. The concentration difference of Fe 3 O 4 in the slags at the center and the side wall is about 2.1%, and the high-temperature viscosity of the slag is about 0.57 Pa·s.

[0075] Example 5

[0076] Use the Ausmelt furnace with a non-top-blowing lance of the present invention for copper smelting, and replace the top lance with a side lance for blowing.

[0077] (1) The pulverized coal and ore powder are respectively blown into the molten bath through the ore lance 4 and the coal lance 5 by the feeding system; among them, the pulverized coal is blown into the molten bath by the coal-carrying air, and the ore powder is blown into the molten bath by the ore-carrying air; the pressures of both the coal-carrying air and the ore-carrying air are 250 kPa, and the gas supply flow rates are both 2500 Nm 3 / h; the coal-carrying air used is a mixed gas of CO and CO 2 , with a CO content of 50% and a CO 2 content of 50%;

[0078] (2) After adjusting the side-blown combustion lance 3 to the production height, fuel is blown to supply heat;

[0079] (3) After the reaction is completed, the lance is raised, the temperature distribution of the melt is recorded, the viscosity of the molten slag is measured, and a molten slag sample is taken for the content analysis of Fe 3 O 4 ;

[0080] Record the molten slag temperature at the side wall and the central molten slag temperature. In this Example 5, the central molten slag temperature is as high as 1351 °C, the molten slag temperature at the side wall is 1315 °C, and the temperature difference between the central and side wall molten slag is about 36 °C;

[0081] The average Fe 3 O 4 content of the molten slag is 8.6%, and the Fe 3 O 4 concentration difference between the central and side wall molten slag is about 1.6%, and the high-temperature viscosity of the molten slag is about 0.46 Pa·s.

[0082] Comparative Example 1

[0083] Conventional Ausmelt furnace is used for copper smelting, with only top lance blowing and no side blowing.

[0084] (1) Record the molten slag temperature at the side wall and the central molten slag temperature. The central molten slag temperature is as high as 1372.5 °C, the molten slag temperature at the side wall is 1099.6 °C, and the temperature difference between the central and side wall molten slag is about 273 °C.

[0085] (2) The average Fe 3 O 4 content of the molten slag is 17.7%, and the Fe 3 O 4 concentration difference between the central and side wall molten slag is about 9.3%, and the high-temperature viscosity of the molten slag is about 1.39 Pa·s.

[0086] The following conclusions can be drawn from the above examples and comparative examples:

[0087] As can be seen from Examples 1-3, the higher the pressure of the coal-carrying air in the side-blown coal lance and the ore-carrying air in the side-blown ore lance, and the greater the air supply flow rate, the more intense the molten bath stirring, 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 bath, the lower the average Fe 3 O 4 content of the slag, and the lower the viscosity of the slag.

[0088] As can be seen from Examples 3-5, under the condition that the pressure of the coal-carrying air in the side-blown coal lance and the ore-carrying air in the side-blown ore lance and the air supply flow rate are constant, 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 bath, the lower the average Fe 3 O 4 content of the slag, and the lower the viscosity of the slag.

[0089] As can be seen from Comparative Example 1, the technical indicators of the top-blown spray gun deteriorate, the temperature difference between the center and the side wall of the molten bath is greater than 150 °C, the average Fe 3 O 4 content of the slag is greater than 15%, and the viscosity of the slag is greater than 1.2 Pa·s, seriously affecting the smelting process.

Claims

1. A copper smelting method using an Ausmelt furnace without a top-blowing lance, characterized in that: The Ausmelt furnace without a top-blowing lance is composed of the following components: a flue, a baffle, a burner, a blast 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 below the lower part of the furnace body, 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, the blast gun is symmetrically arranged on the furnace body at the copper molten pool layer, and pressure gauges are arranged on the blast gun and the coal gun; The copper smelting method of the Ausmelt furnace without a top-blowing lance comprises the following steps: (1) The feeding system controls the pulverized coal and mineral powder to pass through the lance and coal gun of the Ausmelt furnace without top-blowing lance, and to be sprayed into the molten pool with the coal-carrying air and pulverized coal air. The particle size of the pulverized coal is 0.1 mm to 3 mm, and the particle size of the pulverized coal is 0.1 mm to 6 mm. The coal-carrying air is a mixture of CO and CO2, with the content of CO accounting for 40% to 50% and the content of CO2 accounting for 50% to 60%. The pulverized coal air is air at room temperature. The pressure of the pulverized coal air in the lance is consistent with that in the coal gun. The external gauge pressure of a single lance or coal gun is set to 150 kPa to 250 kPa, and the gas flow rate is 1500 Nm 3 / h ~2500Nm 3 / h; (2) The fuel is sprayed into the molten pool through the side-blowing lance of the Ausmelt furnace without a top-blowing lance. The air inlet pressure of a single lance is 200kPa~300kPa, and the air flow rate is 3000Nm 3 / h~5000Nm 3 / h; (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 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.

3. 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%, and the ore powder is obtained by grinding.

4. 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.

5. 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.

6. The copper smelting method of the Ausmelt furnace without a top-blowing lance according to claim 5, characterized in that: The viscosity of the slag is below 0.5 Pa·s.

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