Rotary reduction furnace and reduction smelting method

Abstract

The present invention discloses a rotary reduction electric furnace and a reduction smelting method. The rotary reduction electric furnace comprises: a rotary electric furnace, an electrode and a driving device, wherein the rotary electric furnace comprises an electric furnace shell, a furnace mouth, a chute, a melt discharge port, a slag discharge port, a burner and an air port, the electric furnace shell defines a flue gas zone and a melt zone from top to bottom, and the melt zone is distributed with a slag layer, a matte layer and a metal layer from top to bottom; the furnace mouth is arranged in the flue gas zone; the chute can be raised and lowered in the flue gas zone; the melt discharge port is arranged in the metal layer; the slag discharge port is arranged in the slag layer; the burner is arranged in the melt zone and is located at the end of the electric furnace shell; the air port is arranged in the melt zone; the electrode can be raised and lowered and inserted into the slag layer from the upper part of the electric furnace shell; and the driving device drives the rotary electric furnace to rotate. The rotary reduction electric furnace can efficiently process materials such as pyrometallurgical slag, wet leaching slag, medium and low-grade metal blocks, and smelting ash generated in the non-ferrous metal smelting process and the hazardous waste resource treatment process.

Description

Technical Field

[0001] The invention belongs to the field of metallurgy, and in particular relates to a rotary reduction electric furnace and a reduction smelting method. Background Art

[0002] In the process of nonferrous smelting, in addition to producing valuable metal products, solid wastes or hazardous wastes such as pyrometallurgical slag, hydrometallurgical leaching slag, medium and low-grade metal blocks, and smelting soot are often produced at the same time. These materials need to be further treated by pyrometallurgy to achieve harmless disposal. However, the valuable metal content of these materials is low, and some of them also contain refractory materials with high melting points, which require extremely high smelting strength and material adaptability of smelting equipment. At present, large-scale ore-fired electric furnaces, depletion electric furnaces, sedimentation electric furnaces, etc. in nonferrous metal smelting have relatively single functions and can only be applied to certain specific smelting processes; at the same time, these electric furnaces are fixed structures, and there are smelting dead zones at the corners, which are prone to slag and nodules, causing a certain degree of metal waste; in addition, traditional reduction electric furnaces create a reducing atmosphere by spraying reducing media such as coal powder, and reducing agents such as coal powder are added from the top of the furnace. Solid reducing agents can only react with the surface of the uppermost melt, and the reaction kinetics are poor, and the reduction effect is limited, which limits its application to a certain extent. Since the recycling of hazardous waste has only just emerged in recent years, there is no efficient method to deal with the waste generated by this industry. Therefore, the treatment methods of non-ferrous metal smelting slag still need to be further improved. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems in the related art to a certain extent. To this end, one object of the present invention is to provide a rotary reduction furnace and a reduction smelting method. The rotary reduction furnace can simultaneously process materials such as pyrometallurgical slag, hydrometallurgical leaching slag, medium and low-grade metal blocks, smelting ash, etc., and has the advantages of fast reaction speed, high smelting intensity, flexible operation and strong raw material adaptability.

[0004] According to a first aspect of the present invention, the present invention provides a rotary reduction furnace. According to an embodiment of the present invention, the rotary reduction furnace comprises:

[0005] A rotary electric furnace, comprising:

[0006] An electric furnace shell, wherein a fume zone and a melt zone are defined from top to bottom in the electric furnace shell, and a slag layer, a matte layer and a metal layer are distributed from top to bottom in the melt zone;

[0007] A furnace mouth, the furnace mouth being arranged in the flue gas zone;

[0008] A slide pipe, the slide pipe is arranged in the smoke zone in a manner that it can be raised and lowered;

[0009] A melt discharge port, the melt discharge port being arranged in the metal layer;

[0010] a slag discharge port, the slag discharge port being arranged at the slag layer;

[0011] A burner, the burner is arranged in the melt zone and located at the end of the electric furnace shell;

[0012] A tuyere, the tuyere being arranged in the melt zone;

[0013] An electrode, wherein the electrode can be lifted and lowered and inserted into the slag layer from the upper part of the electric furnace shell;

[0014] A driving device drives the rotary electric furnace to rotate.

[0015] According to the rotary reduction electric furnace of the above embodiment of the present invention, the rotary electric furnace structure is adopted to avoid the occurrence of smelting dead zones on the one hand, and on the other hand, the working position can be rotated to adjust, thereby improving the flexibility of charging and operation; at the same time, the electrode is inserted into the slag layer for heating, which can not only heat the slag layer by the electric arc, but also release a large amount of heat in the slag layer, and quickly and efficiently heat the melt with a thicker slag layer, and the heating speed is much higher than that of burner heating, but also the eddy current generated by the electric arc can drive the melt to stir; in addition, a spray gun can be used to blow jet gas into the melt through the tuyere, thereby not only controlling the redox atmosphere in the furnace body and realizing efficient removal of impurity metals in the smelting slag, but also making the melt form turbulence and strengthening the reaction between the gas, solid and liquid phases; further, solid reducing agent can be sprayed into the furnace body with gas as a carrier to improve the reducing atmosphere in the furnace body and reduce energy consumption. In summary, the rotary reduction electric furnace can efficiently process solid waste or hazardous waste generated by non-ferrous smelting on a large scale, such as simultaneously processing pyrometallurgical slag, hydrometallurgical leaching slag, medium and low-grade metal blocks, smelting fly ash and other materials. It has the advantages of fast reaction speed, high smelting intensity, flexible operation and strong raw material adaptability, achieving a win-win situation of economic and environmental benefits.

[0016] In addition, the rotary reduction furnace according to the above embodiment of the present invention may also have the following additional technical features:

[0017] In some embodiments of the present invention, the rotary electric furnace comprises 1 to 2 layers of the melt discharge ports.

[0018] In some embodiments of the present invention, the rotary electric furnace comprises a plurality of the chute pipes, and the plurality of the chute pipes are located on one side or both sides of the rotation axis of the electric furnace shell.

[0019] In some embodiments of the present invention, the rotary electric furnace comprises a plurality of tuyere, and the plurality of tuyere are located on one side or both sides of the rotation axis of the electric furnace shell.

[0020] In some embodiments of the present invention, the rotary reduction furnace further includes a hydraulic device, which is connected to the electrode and controls the electrode to be inserted into or pulled out of the slag layer.

[0021] In some embodiments of the present invention, the electrode is perpendicular to the length direction of the electric furnace shell and an extension line of the electrode intersects with the rotation axis of the electric furnace shell.

[0022] In some embodiments of the present invention, the rotary reduction furnace comprises a plurality of electrodes, and the plurality of electrodes are spaced apart and distributed along the length direction of the furnace shell.

[0023] In some embodiments of the present invention, there are 1 to 2 furnace openings, 1 to 5 melt discharge openings, 1 to 5 slag discharge openings, 1 to 10 chutes, 5 to 30 tuyere openings, and 1 to 5 electrodes.

[0024] According to a second aspect of the present invention, the present invention provides a method for reduction smelting using the above rotary reduction furnace. According to an embodiment of the present invention, the method comprises:

[0025] (1) adding hot melt and / or large cold metal blocks into the rotary electric furnace through the furnace port, adding granular materials into the rotary electric furnace through the chute, spraying solid reducing agent and / or gas into the melt through the tuyere, and inserting the electrode into the slag layer from the upper part of the electric furnace shell to perform reduction smelting;

[0026] (2) exhausting smoke from the furnace port, and discharging metal phase, smelting slag and matte phase through the melt discharge port and the slag discharge port.

[0027] The reduction smelting method of the above embodiment of the present invention has at least the following advantages: (1) it can not only avoid the occurrence of smelting dead zones, but also can be rotated to adjust the working position, and the feeding and operation are flexible; (2) the electrode is inserted into the slag layer for heating, which can quickly and efficiently heat the melt with a thicker slag layer; (3) a spray gun can be used to blow jet gas into the melt through the tuyere, thereby not only controlling the redox atmosphere in the furnace body and achieving efficient removal of impurity metals in the smelting slag; but also making the melt form turbulence and strengthening the reaction between the gas, solid and liquid phases; (4) solid reducing agent can be sprayed into the furnace body with gas as a carrier to improve the reducing atmosphere in the furnace body and reduce energy consumption; (5) solid waste or hazardous waste generated by non-ferrous smelting can be treated on a large scale, for example, pyrometallurgical slag, wet leaching slag, medium and low-grade metal blocks, smelting ash and other materials can be treated at the same time, with the advantages of fast reaction speed, high smelting intensity, flexible operation and strong raw material adaptability, achieving a win-win situation of economic benefits and environmental benefits.

[0028] In some embodiments of the present invention, the granular material is at least one selected from pulverized coal, coke, quartz, limestone, sulfide concentrate, pyrometallurgical slag, wet leaching slag, medium and low grade metal blocks and smelting ash, and the particle size of the granular material is not greater than 10 cm.

[0029] In some embodiments of the present invention, the gas is at least one selected from nitrogen, natural gas, air and compressed gas.

[0030] In some embodiments of the present invention, the spraying pressure of the spray gun is 0.1-2 MPa.

[0031] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0033] Figure 1 1 is a front view of a rotary reduction furnace according to an embodiment of the present invention.

[0034] Figure 2 1 is a cross-sectional view of section AA of a rotary reduction furnace according to an embodiment of the present invention.

[0035] Figure 3 It is a cross-sectional view of section AA of a rotary reduction furnace according to another embodiment of the present invention. DETAILED DESCRIPTION

[0036] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0037] According to a first aspect of the present invention, the present invention provides a rotary reduction furnace. According to an embodiment of the present invention, Figure 1As shown, the rotary reduction furnace includes: a rotary electric furnace 100, an electrode 200 and a driving device 300. The rotary electric furnace 100 includes an electric furnace shell 110, a furnace mouth 120, a chute 130, a melt discharge port 140, a slag discharge port 150, a burner 160 and an air port 170. The electric furnace shell 110 defines a flue gas zone 111 and a melt zone 112 from top to bottom. The melt zone 112 is provided with a slag layer, a matte layer and a metal layer from top to bottom. The furnace mouth 120 is arranged in the flue gas zone 111; the chute 130 is arranged in the flue gas zone 111 in a manner that it can be raised and lowered; the melt discharge port 140 is arranged in the metal layer; the slag discharge port 150 is arranged in the slag layer; the burner 160 is arranged in the melt zone 112 and is located at the end of the electric furnace shell 110; the air port 170 is arranged in the melt zone 112; the electrode 200 is inserted into the slag layer in a manner that it can be raised and lowered from the upper part of the electric furnace shell 110; and the driving device 300 drives the rotary electric furnace 100 to rotate.

[0038] Reference below Figures 1 to 3 The rotary reduction electric furnace of the above embodiment of the present invention is described in detail.

[0039] Rotary electric furnace 100

[0040] According to an embodiment of the present invention, a rotary electric furnace 100 includes an electric furnace shell 110, a furnace mouth 120, a chute 130, a melt discharge port 140, a slag discharge port 150, a burner 160 and a tuyere 170. The electric furnace shell 110 defines a flue gas zone 111 and a melt zone 112 from top to bottom. The melt zone 112 is provided with a slag layer, a matte layer and a metal layer from top to bottom. The furnace mouth 120 is provided in the flue gas zone 111. The chute 130 is provided in the flue gas zone 111 in a manner that it can be raised and lowered. The melt discharge port 140 is provided in the metal layer. The slag discharge port 150 is provided in the slag layer. The burner 160 is provided in the melt zone 112 and is located at the end of the electric furnace shell 110. The tuyere 170 is provided in the melt zone 112. Among them, the use of a rotary electric furnace structure can, on the one hand, avoid the appearance of smelting dead zones, and on the other hand, it can be rotated to adjust the working position, thereby improving the flexibility of charging and operation; at the same time, a spray gun can be used to blow jet gas into the melt through the tuyere, thereby not only controlling the redox atmosphere in the furnace body and achieving efficient removal of impurity metals in the smelting slag; it can also make the melt form turbulence and strengthen the reaction between the gas, solid and liquid phases; further, solid reducing agents can be sprayed into the furnace body with gas as a carrier to improve the reducing atmosphere in the furnace body and reduce energy consumption.

[0041] According to a specific embodiment of the present invention, in addition to the production of valuable metal products, solid wastes or hazardous wastes such as pyrometallurgical slag, hydrometallurgical leaching slag, medium- and low-grade metal blocks, and smelting ash are often produced during the nonferrous smelting process. These materials need to be further treated by pyrometallurgy to achieve harmless disposal. However, the valuable metal content of these materials is relatively low, and some of them also contain refractory substances with high melting points, which require extremely high smelting intensity and material adaptability of smelting equipment. The rotary reduction electric furnace of the above embodiment of the present invention can adapt to a variety of smelting raw materials, can simultaneously process pyrometallurgical slag, hydrometallurgical leaching slag, medium- and low-grade metal blocks, smelting ash and other materials, and has the advantages of fast reaction speed, high smelting intensity, flexible operation and strong raw material adaptability, achieving a win-win situation of economic benefits and environmental benefits.

[0042] According to another specific embodiment of the present invention, the furnace opening 120 has two functions of exhausting smoke and adding hot melt and / or large cold metal blocks into the rotary electric furnace 100. The furnace opening 120 can be arranged at the end or adjacent to the end of the electric furnace shell 110, and the number of furnace openings 120 can be 1 to 2. When two furnace openings are included, they can be used for exhausting smoke and adding materials respectively.

[0043] According to another specific embodiment of the present invention, particulate material can be added into the rotary electric furnace 100 through the chute 130, wherein the particulate material can be flux, fuel, raw material, etc., for example, it can be at least one selected from pulverized coal, coke, quartz stone, limestone, sulfide concentrate, pyrometallurgical slag, wet leaching slag, medium and low grade metal blocks and smelting fly ash; further, the particle size of the particulate material can be no more than 10 cm, for example, no more than 8 cm or no more than 5 cm, etc., thereby significantly increasing the contact area between the particulate material and the melt.

[0044] According to another specific embodiment of the present invention, the rotary electric furnace 100 may include a plurality of chutes 130, and the plurality of chutes may be located on one side or both sides of the rotation axis of the electric furnace shell, thereby using the plurality of chutes to add granular material into the rotary electric furnace, so that the granular material is quickly dispersed in the melt and the uniformity of dispersion is improved; in addition, different chutes may be selected for addition according to the type of granular material. According to a specific example of the present invention, the number of chutes in the present invention is not particularly limited, and those skilled in the art may select according to actual needs, for example, the number of chutes may be 1 to 10.

[0045] According to another specific embodiment of the present invention, the melt discharge port 140 may be located at the bottom or side wall of one end of the electric furnace shell 110, and the slag discharge port 150 may be located on the side wall of the electric furnace shell 110 away from the melt discharge port 140. Specifically, the melt discharge port 140 and the slag discharge port 150 may be set according to the material type and layering of the smelting melt, wherein the rotary electric furnace 100 may include 1 to 2 layers of melt discharge ports 140, when the rotary electric furnace 100 has only 1 layer of melt discharge ports 140, the melt discharge ports 140 are spaced apart in the horizontal direction, and when there are 2 layers of melt discharge ports 140, the melt discharge ports 140 may be spaced apart in the horizontal direction and the vertical direction respectively; the slag discharge ports 150 are spaced apart in the horizontal direction, thereby realizing the separation and discharge of each phase according to the composition and layering of the metal phase, matte phase and slag phase in the melt. According to a specific example of the present invention, there may be 1 to 5 melt discharge ports 140 and 1 to 5 slag discharge ports.

[0046] According to another specific embodiment of the present invention, a solid reducing agent and / or gas can be sprayed into the melt through the tuyere 170 by using a spray gun, wherein the solid reducing agent can be sulfide and / or pulverized coal, the gas can be at least one selected from nitrogen, natural gas, air and compressed gas, and the spray pressure of the spray gun can be 0.1-2 MPa. In this way, not only can the redox atmosphere of the furnace body be effectively adjusted to achieve efficient removal of impurity metals in smelting slag, but also the stirring of the melt can be driven by the airflow to promote more intense stirring of the melt and make the gas-liquid-solid three-phase reaction more sufficient; further, the stirring degree of the melt can be effectively controlled by controlling the spray pressure of the spray gun; in addition, spraying a solid reducing agent into the furnace body can further improve the reducing atmosphere in the furnace body and reduce energy consumption.

[0047] According to another specific embodiment of the present invention, the rotary electric furnace 100 may include a plurality of tuyere 170, wherein Figure 2 As shown, multiple tuyere 170 can be located on both sides of the rotation axis of the electric furnace shell; or as shown in Figure 3 As shown, a plurality of tuyere 170 can be located on one side of the rotation axis of the electric furnace shell, and preferably, the tuyere on each side is arranged in a line. Thus, by spraying solid reducing agent and / or gas into the melt through a plurality of tuyere 170, not only can the solid reducing agent be quickly dispersed in the melt and the dispersion effect be improved, ensuring a uniform and stable reducing atmosphere in the melt, but it is also more conducive to controlling the turbulence degree of the melt, thereby further accelerating the reaction between the gas, solid and liquid phases. Specifically, a plurality of tuyere 170 can be arranged in the slag layer area, thereby further improving the smelting efficiency; further, a plurality of tuyere 170 can be distributed at intervals on the same horizontal plane of the slag layer area, so as to further improve the operability during the reduction smelting process.

[0048] According to another specific embodiment of the present invention, a water jacket may be provided at a position adjacent to the tuyere 170 on the electric furnace shell 110. When a solid reducing agent and / or jet gas is blown into the melt to adjust the redox atmosphere of the reaction or the melt dynamics, the reaction degree at the tuyere and its vicinity is more intense and more heat is released. Therefore, the temperature at the tuyere and its vicinity is also relatively high, which may easily lead to damage to the structure of the electric furnace shell. In the present invention, by providing a water jacket at a position adjacent to the tuyere, it is possible to effectively avoid the temperature at a position adjacent to the tuyere on the electric furnace shell being too high, thereby significantly reducing the risk of damage to the furnace structure.

[0049] According to another specific embodiment of the present invention, the burner 160 can be arranged in the melt zone 112 and at the end of the electric furnace shell 110, preferably arranged in the slag layer or close to the slag layer. The burner 160 is mainly used for heating when the furnace is opened.

[0050] According to an embodiment of the present invention, during the reduction smelting process, hot melt and / or large cold metal blocks can be added into the rotary electric furnace 100 through the furnace mouth 120, granular material can be added into the rotary electric furnace 100 through the chute 130, and solid reducing agent and / or gas can be sprayed into the melt through the tuyere 170; in addition, smoke can be discharged from the furnace mouth 120, and the metal phase, smelting slag and matte phase can be discharged through the melt discharge port 140 and the slag discharge port 150.

[0051] Electrode 200

[0052] According to the embodiment of the present invention, the electrode 200 can be lifted and lowered and inserted into the slag layer from the upper part of the electric furnace shell 110. In this way, electrical energy can be converted into thermal energy to melt the material, wherein the heating speed of the electrode is much higher than that of the burner. When one end of the electrode is inserted into the slag layer, the slag layer can be heated by the electric arc, and the eddy current generated by the electric arc drives the melt to stir, so that the melt with a thick slag layer can be heated quickly and efficiently.

[0053] According to a specific embodiment of the present invention, the electrode 200 is perpendicular to the length direction of the electric furnace shell 110 and its extension line intersects with the rotation axis of the electric furnace shell 110, thereby allowing the electrode to be vertically inserted into or pulled out of the slag layer, greatly reducing the space environment required for the electrode during its activity and significantly reducing the risk of damage to the electrode during insertion or removal.

[0054] According to another specific embodiment of the present invention, the rotary reduction furnace may include a plurality of electrodes 200, for example, 1 to 5 electrodes, and the plurality of electrodes 200 may be spaced apart and distributed along the length direction of the furnace shell 110, thereby not only allowing the slag layer to be heated evenly, but also facilitating controlling the degree of heating of the slag layer by the electrodes.

[0055] According to another specific embodiment of the present invention, the rotary reduction furnace may further include a hydraulic device, which is connected to the electrode, and the electrode can be controlled to be inserted into or pulled out of the slag layer by the hydraulic device.

[0056] Driving device 300

[0057] According to an embodiment of the present invention, the rotary electric furnace 100 is driven to rotate by a driving device 300. Specifically, a support ring 400 may be provided on the electric furnace shell, and when the rotary electric furnace needs to be rotated, the driving device drives the coupling gear, further driving the support ring to rotate, so that the rotary electric furnace rotates.

[0058] According to a specific embodiment of the present invention, the slag melt can be added to the electric furnace from the furnace mouth through a chute, and the cold medium and low-grade metal blocks can be added from the furnace mouth through a hopper; the flux, coke and smelting ash are transported to the silo through a metering belt, and then added through a chute at the bottom of the silo; the electrode inserted into the furnace is inserted into the slag layer, the slag layer is heated by an electric arc, and the eddy current generated by the electric arc drives the melt to stir. During the smelting process, a spray gun is inserted into the tuyere area, and natural gas is sprayed into the furnace to increase the reducing atmosphere of the furnace body to ensure that the valuable metals are reduced into the metal phase; after the smelting is completed, the generated slag is discharged from the slag discharge port, and the generated different metal melts are discharged from a specific melt discharge port; the smoke generated by the smelting enters the secondary combustion chamber from the furnace mouth for further treatment; when the furnace body has special circumstances such as splashing and foam slag overflow, the electrode can be pulled out by a hydraulic device, and the furnace body can be rotated to dump the melt into the emergency slag bag.

[0059] To sum up, in the rotary reduction electric furnace of the above-mentioned embodiment of the present invention, the rotary electric furnace structure is adopted to avoid the occurrence of smelting dead zones on the one hand, and on the other hand, the working position can be rotated to adjust, thereby improving the flexibility of charging and operation; at the same time, the electrode is inserted into the slag layer for heating, which can not only heat the slag layer by the electric arc, but also release a large amount of heat in the slag layer, and quickly and efficiently heat the melt with a thicker slag layer, and the heating speed is much higher than that of burner heating, but also the eddy current generated by the electric arc can drive the melt to stir; in addition, a spray gun can be used to blow jet gas into the melt through the tuyere, thereby not only controlling the redox atmosphere in the furnace body and realizing efficient removal of impurity metals in the smelting slag; but also making the melt form turbulence and strengthening the reaction between the gas, solid and liquid phases; further, solid reducing agent can be sprayed into the furnace body with gas as a carrier to improve the reducing atmosphere in the furnace body and reduce energy consumption. In summary, the rotary reduction electric furnace can process solid waste or hazardous waste generated by non-ferrous smelting on a large scale, such as simultaneously processing pyrometallurgical slag, wet leaching slag, medium and low-grade metal blocks, smelting fly ash and other materials. It has the advantages of fast reaction speed, high smelting intensity, flexible operation and strong raw material adaptability, achieving a win-win situation of economic and environmental benefits.

[0060] According to the second aspect of the present invention, the present invention provides a method for reduction smelting using the above rotary reduction furnace. According to an embodiment of the present invention, the method comprises: (1) adding hot melt and / or large cold metal blocks into the rotary electric furnace through the furnace mouth, adding granular materials into the rotary electric furnace through the chute, spraying solid reducing agent and / or gas into the melt through the tuyere, and inserting electrodes from the upper part of the electric furnace shell into the slag layer to perform reduction smelting; (2) exhausting smoke from the furnace mouth, and discharging metal phase, smelting slag and matte phase through the melt discharge port and the slag discharge port.

[0061] According to a specific embodiment of the present invention, the granular material can be a flux, a fuel, a raw material, etc. For example, it can be at least one selected from pulverized coal, coke, quartz stone, limestone, sulfide concentrate, pyrometallurgical slag, wet leaching slag, medium and low grade metal blocks and smelting ash. The particle size of the granular material can be no more than 10 cm, thereby significantly increasing the contact area between the granular material and the melt, thereby accelerating the redox reaction rate.

[0062] According to another specific embodiment of the present invention, the solid reducing agent may be sulfide and / or pulverized coal, and the gas may be at least one selected from nitrogen, natural gas, air and compressed gas. This can not only effectively adjust the redox atmosphere of the furnace body and achieve efficient removal of impurity metals in smelting slag, but also drive the stirring of the melt through the airflow to promote more intense stirring of the melt and make the gas-liquid-solid three-phase reaction more complete; further, the stirring degree of the melt can be effectively controlled by controlling the injection pressure of the spray gun; in addition, spraying the solid reducing agent into the furnace body can further improve the reducing atmosphere in the furnace body and reduce energy consumption.

[0063] According to another specific embodiment of the present invention, the spraying pressure of the spray gun can be 0.1-2 MPa. The inventor found that if the spraying pressure of the spray gun is too small, the stirring effect on the melt is not obvious, and it is not enough to fully spray the solid reducing agent into the melt, and if the spraying pressure of the spray gun is too large, it is easy to cause the melt to splash or the foam slag to overflow. In the present invention, by controlling the spraying pressure of the spray gun to 0.1-2 MPa, not only can the melt have a suitable stirring degree, accelerate the gas-liquid-solid three-phase reaction, but also avoid the phenomenon of melt splashing and foam slag overflow.

[0064] In summary, the reduction smelting method of the above embodiment of the present invention has at least the following advantages: (1) it can not only avoid the occurrence of smelting dead zones, but also can be rotated to adjust the working position, and the feeding and operation are flexible; (2) the electrode is inserted into the slag layer for heating, which can quickly and efficiently heat the melt with a thicker slag layer; (3) a spray gun can be used to blow jet gas into the melt through the tuyere, thereby not only controlling the redox atmosphere in the furnace body and realizing efficient removal of impurity metals in the smelting slag; but also making the melt form turbulence and strengthening the reaction between the gas, solid and liquid phases; (4) solid reducing agent can be sprayed into the furnace body with gas as a carrier to improve the reducing atmosphere in the furnace body and reduce energy consumption; (5) solid waste or hazardous waste generated by non-ferrous smelting can be treated on a large scale, for example, pyrometallurgical slag, wet leaching slag, medium and low-grade metal blocks, smelting ash and other materials can be treated at the same time, with the advantages of fast reaction speed, high smelting intensity, flexible operation and strong raw material adaptability, achieving a win-win situation of economic benefits and environmental benefits.

[0065] The present invention is described below with reference to specific embodiments. It should be noted that these embodiments are merely illustrative and do not limit the present invention in any way.

[0066] Example 1

[0067] In the rotary reduction furnace, the rotary furnace is a cylindrical structure, in which the rotary furnace is provided with two furnace openings, one as a smoke exhaust port and the other as a melt addition port, as well as two melt discharge ports and two slag discharge ports; four chutes are provided on the top of the furnace shell, which are used to add limestone, quartz stone, coke and smelting ash respectively, and the particle sizes of these materials are independently 3 to 5 cm; three electrodes are inserted into the slag layer through the top of the furnace shell; 12 tuyere are distributed on one side of the rotation axis of the furnace shell, lined up in a row.

[0068] Hot copper smelting slag and smelting soot are added to the rotary reduction electric furnace. During the smelting process, 0.6MPa natural gas is introduced into the tuyere to control the reducing atmosphere of the furnace body. At the same time, pulverized coal solid reducing agent is sprayed to enhance the reduction effect. The smelting melt is divided into three phases: matte layer, metal layer and slag layer.

[0069] The main technical operating conditions of the reduction smelting method of this embodiment are as follows:

[0070] Crude metal temperature: about 1200~1300℃

[0071] Slag temperature: about 1220~1350℃

[0072] Natural gas injection pressure: 0.1~0.5MPa

[0073] O2 concentration of flue gas at furnace mouth: 5~15%

[0074] Furnace top negative pressure: -100Pa~-400Pa

[0075] Flue gas temperature: 1200~1300℃

[0076] Products: Blister copper and black copper

[0077] By-products: smelting slag, flue gas and smoke

[0078] The main technical and economic indicators of the reduction smelting method of this embodiment are as follows:

[0079] Blister copper grade: about 75-95%

[0080] Black copper grade: 35-50%

[0081] Copper content in slag: about 0.8-1.5%

[0082] Smoke rate: 1~3%

[0083] Direct yield: about 60-96%

[0084] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0085] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A rotary reduction furnace, characterized in that: include: A rotary electric furnace, comprising: An electric furnace shell, wherein a fume zone and a melt zone are defined from top to bottom in the electric furnace shell, and a slag layer, a matte layer and a metal layer are distributed from top to bottom in the melt zone; A furnace mouth, the furnace mouth being arranged in the flue gas zone; A slide pipe, the slide pipe is arranged in the smoke zone in a manner that it can be raised and lowered; A melt discharge port, the melt discharge port being arranged in the metal layer; a slag discharge port, the slag discharge port being arranged at the slag layer; A burner, the burner is arranged in the melt zone and located at the end of the electric furnace shell; A tuyere, the tuyere being arranged in the melt zone; An electrode, wherein the electrode can be lifted and lowered and inserted into the slag layer from the upper part of the electric furnace shell; A driving device drives the rotary electric furnace to rotate.

2. The rotary reduction furnace according to claim 1, characterized in that: It comprises 1 to 2 layers of melt discharge ports.

3. The rotary reduction furnace according to claim 1 or 2, characterized in that: It comprises a plurality of slide pipes, and the plurality of slide pipes are located on one side or both sides of the rotation axis of the electric furnace shell.

4. The rotary reduction furnace according to claim 3, characterized in that: It comprises a plurality of tuyere, and the plurality of tuyere are located on one side or both sides of the rotation axis of the electric furnace shell.

5. The rotary reduction furnace according to claim 1 or 4, characterized in that: The invention further comprises a hydraulic device, wherein the hydraulic device is connected to the electrode and the hydraulic device controls the electrode to be inserted into or pulled out of the slag layer.

6. The rotary reduction furnace according to claim 5, characterized in that: The electrode is perpendicular to the length direction of the electric furnace shell, and an extension line of the electrode intersects with the rotation axis of the electric furnace shell.

7. The rotary reduction furnace according to claim 1 or 6, characterized in that: The plurality of electrodes are included and are spaced apart and distributed along the length direction of the electric furnace shell.

8. The rotary reduction furnace according to claim 7, characterized in that: The number of the furnace openings is 1 to 2, the number of the melt discharge openings is 1 to 5, the number of the slag discharge openings is 1 to 5, the number of the chute is 1 to 10, the number of the tuyere is 5 to 30, and the number of the electrode is 1 to 5.

9. A method for reduction smelting using a rotary reduction furnace according to any one of claims 1 to 8, characterized in that: include: (1) adding hot melt and / or large cold metal blocks into the rotary electric furnace through the furnace port, adding granular materials into the rotary electric furnace through the chute, spraying solid reducing agent and / or gas into the melt through the tuyere, and inserting the electrode into the slag layer from the upper part of the electric furnace shell to perform reduction smelting; (2) exhausting smoke from the furnace port, and discharging metal phase, smelting slag and matte phase through the melt discharge port and the slag discharge port.

10. The method according to claim 9, characterized in that: The granular material is at least one selected from pulverized coal, coke, quartz, limestone, sulfide concentrate, pyrometallurgical slag, wet leaching slag and smelting ash, and the particle size of the granular material is not greater than 10 cm.

11. The method according to claim 9 or 10, characterized in that: The gas is at least one selected from nitrogen, natural gas, air and compressed air.

12. The method according to claim 9 or 10, characterized in that: The solid reducing agent and / or the gas is sprayed into the melt through the tuyere by using a spray gun, and the spraying pressure of the spray gun is 0.1-2 MPa.

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