Smelting furnace configuration

Abstract

The present invention relates to a smelting furnace configuration comprising a first smelting furnace (15a) and a second smelting furnace (15b), wherein the first and second smelting furnaces (15a, 15b) each comprise a reaction shaft end with reaction shaft end walls (16a, 16b) and an intake shaft end with intake shaft end walls (21a, 21b), and the reaction shaft end wall (16a) of the first smelting furnace (15a) is located at a distance (X) from the reaction shaft end wall (16b) of the second smelting furnace (15b), the distance (X) being less than 20m.

Description

Technical Field

[0001] The present invention relates to a smelting furnace arrangement. The present invention also relates to a method of using said smelting furnace arrangement.

Background Art

[0002] Conventional processes for converting copper-containing concentrates typically include flash smelting and flash conversion.

[0003] This process usually oxidizes the concentrate in a flash smelting furnace (FSF) to produce matte. The matte is then fed to a flash conversion furnace (FCF), where the matte can be further oxidized to produce blister. The furnaces are typically located in different building sections and are thus quite far apart from each other.

[0004] In this process, slag is formed in both the FSF and the FCF. Since slag typically contains a significant amount of metal, it should be recycled back to one or more furnaces for further processing in order to improve the process yield.

[0005] Also, dust, returned materials, solidified matte and solidified slag are formed in the off-gas line, launder or ladle and in the furnace. Since these components also contain a significant amount of metal, they should be recycled back to one or more furnaces for further processing in order to improve the process yield. Further, the dust is mainly composed of oxides or sulfates and thus causes an endothermic reaction in the furnace.

[0006] Slag recycling is resource-intensive because slag is typically granulated by water spraying, stored in bins, sent to a dryer, and then returned to the furnace. The high water consumption in slag granulation is primarily due to its use in cooling the slag and breaking it down into smaller particles. This results in steam loss and particle contamination of the granulation water, requiring further processing before the water can be reused. When the slag is fed into the furnace where it is recycled, energy is needed to reheat it to a temperature sufficient to melt it. The slag granulation water also needs to be cooled by a secondary cooling water circuit, which further consumes energy and water.

[0007] Furthermore, to maximize the exchange of metals from slag to furnace products, it is crucial that the recycled slag is thoroughly mixed with the suspension in the furnace.

[0008] Recycling dust, returned materials, solidification mats, and solidified slag is cumbersome due to the long distances between furnaces. Materials must be transported between building sections, and there is a risk of contamination along the way.

[0009] Another drawback of conventional smelting furnace configurations is that the supply environment for the flux, dust, returned material, solidified mat, solidified slag, and concentrate is dusty due to the dryness and fineness of the materials, and therefore HSE (Heat, Sequestration, and Efficiency) issues. Since the furnaces are located in different building sections and are far apart from each other, several supply stations are required.

[0010] Furthermore, in conventional processes, dust from several furnaces (i.e., FSF and FCF) is fed into bins and can then be recycled back into the furnaces. As a result, the quality and composition of the dust in the bins are unknown, and for example, FSF dust and FCF dust can differ significantly. This leads to inadequate control of the dust recycling system. Also, since the dust is usually discarded in bins and solidifies there, it poses a problem even when the system is shut down.

[0011] Therefore, improvements to furnace configuration and methods are needed to recycle molten slag between furnaces and enable good mixing of slag and furnace products. Improved furnace configuration and methods are also needed to enable easy and safe recycling and / or supply to the furnace of dust, flux, returned material, solidified mat, solidified slag, and concentrate. Specifically, dust recycling should be improved to better control recycling and the system should be improved during shutdowns. [Overview of the Initiative]

[0012] According to the first embodiment, a smelting furnace configuration is provided comprising a first smelting furnace (15a) and a second smelting furnace (15b), wherein the first and second smelting furnaces (15a, 15b) each comprise a reaction shaft end with reaction shaft end walls (16a, 16b) and an uptake shaft end with take-up shaft end walls (21a, 21b), the reaction shaft end wall (16a) of the first smelting furnace (15a) being located at a distance (X) from the reaction shaft end wall (16b) of the second smelting furnace (15b), the distance (X) being less than 20m.

[0013] According to a second embodiment, a method is provided for manufacturing a blister in a suspension smelting furnace configuration, the method being i. A step of supplying the concentrate to the first smelting furnace (15a), iii. The step of forming a mat in the first smelting furnace (15a), iv. A step of transporting at least a portion of the mat from the first smelting furnace (15a) to the second smelting furnace (15b) via the second transport means (123), vi. The step of forming a blister in the second smelting furnace (15b), Includes, The first and second smelting furnaces (15a, 15b) each have a reaction shaft end with reaction shaft end walls (16a, 16b) and an intake shaft end with intake shaft end walls (21a, 21b), wherein the reaction shaft end wall (16a) of the first smelting furnace (15a) is located at a distance (X) from the reaction shaft end wall (16b) of the second smelting furnace (15b), and the distance (X) is less than 20m. [Brief explanation of the drawing]

[0014] The accompanying drawings, included to provide a further understanding of the present invention and to constitute part of this specification, illustrate embodiments of the invention and, together with the description, help to illustrate the principles of the invention.

[0015] [Figure 1] This is a schematic diagram of the smelting furnace configuration according to the first embodiment of the present invention. [Figure 2] This is a schematic diagram of a smelting furnace configuration according to a first embodiment of the present invention, wherein the first transport means (222) extends from the first taphole (111b) of the second smelting furnace (15b) to the supply means (120a) of the first smelting furnace (15a), and the second transport means (123) extends from the second taphole (112a) of the first smelting furnace (15a) to the burner (15b) for burning concentrate or matte (2b) of the second smelting furnace. [Figure 3] This is a schematic diagram of the smelting furnace configuration according to the first embodiment of the present invention, in which solid material (24a, 24b) is recycled from the intake shaft (10b) of the second smelting furnace (15b) to the first smelting furnace (15a), and from the intake shaft (10a) of the first smelting furnace (15a) to the second smelting furnace (15b). [Figure 4] This is a schematic diagram of a smelting furnace configuration according to a first embodiment of the present invention, wherein the first and second smelting furnaces (15a, 15b) are equipped with common supply means (18, 17a, 17b) for supplying flux, solidified mat, solidified slag and / or returned material. [Modes for carrying out the invention]

[0016] It will be apparent to those skilled in the art that, with the progress of technology, the basic idea of the present invention can be implemented in various ways. Therefore, the present invention and its embodiments are not limited to the examples described below, but instead can vary within the scope of the claims.

[0017] Smelting furnace configuration According to a first aspect, as shown in FIG. 1, a smelting furnace configuration is provided that includes a first smelting furnace (15a) and a second smelting furnace (15b). The first and second smelting furnaces (15a, 15b) each include a reaction shaft end with a reaction shaft end wall (16a, 16b) and a charging shaft end with a charging shaft end wall (21a, 21b). The reaction shaft end wall (16a) of the first smelting furnace (15a) is located at a distance (X) from the reaction shaft end wall (16b) of the second smelting furnace (15b), and the distance (X) is less than 20 m.

[0018] The distance (X) may be 2 - 20 m, or 4 - 17 m, or 7 - 13 m, or 9 - 11 m.

[0019] The first smelting furnace (15a) may be located vertically below the second smelting furnace (15b), for example, 1 - 7 m, or 2 - 5 m, or 3 - 4 m, or 1 m below.

[0020] The inventors have found that with the above distance (X), materials can be efficiently supplied between the smelting furnaces as described later. The vertical distance between the furnaces has the additional usefulness that gravity can be used to transport materials between the furnaces.

[0021] The first smelting furnace (15a) according to the first aspect may be a suspension smelting furnace, and / or the second smelting furnace (15b) according to the first aspect may be a suspension smelting furnace.

[0022] The first suspension smelting furnace (15a) may be a flash smelting furnace (FSF), and the second suspension smelting furnace (15b) may be a flash conversion furnace (FCF).

[0023] The first and second smelting furnaces (15a, 15b) are i. A reaction shaft (4a, 4b) comprising burners (2a, 2b), wherein the burners (2a, 2b) burn concentrate or matte, supply the concentrate or matte into the reaction shaft (4a, 4b), and form a jet of a suspension (3a, 3b) that is at least partially oxidized within the reaction shaft (4a, 4b); a reaction shaft (4a, 4b); ii. A settler (19a, 19b) communicating with the lower end of the reaction shaft (4a, 4b), the settler (19a, 19b) having an internal space (6a, 6b), reaction shaft end walls (16a, 16b) at the ends of the settler (19a, 19b), uptake shaft end walls (21a, 21b) at the opposite ends of the settler (19a, 19b), and a landing zone (5a, 5b) for the jet of the oxidized suspension (3a, 3b) in the internal space (6a, 6b) of the settler (19a, 19b) below the lower end of the reaction shaft (4a, 4b). The settler (19a, 19b) extends in two opposite directions from the landing zone (5a, 5b) such that the settler (19a, 19b) has a reaction shaft settler portion (14a, 14b) on the reaction shaft (4a, 4b) side of the landing zone (5a, 5b) and an uptake shaft settler portion (13a, 13b) on the uptake shaft (10a, 10b) side opposite the landing zone (5a, 5b). The settler (19a, 19b) receives the at least partially oxidized suspension (3a, 3b) from the reaction shaft (4a, 4b) at the landing zone (5a, 5b) and is configured to form a layer of matte or blister (7a, 7b) and a layer of slag (8a, 8b) on top of the layer of matte or blister (7a, 7b) within the internal space (6a, 6b) of the settler (19a, 19b); a settler (19a, 19b); iii. Supply means (120a, 120b) for supplying molten material (20a, 20b) to the smelting furnace, the supply means (120a, 120b) communicating with the settler (19a, 19b) within the reaction shaft settler portion (14a, 14b) above the layer of slag (8a, 8b) during use; supply means (120a, 120b); iv. In order to discharge the slag (11a, 11b) from the slag layer (8a, 8b) in the internal space (6a, 6b) of the settler (19a, 19b), a first tapping port (111a, 111b) is provided in the reaction shaft settler section (14a, 14b) or the intake shaft settler section (13a, 13b), v. In order to discharge the mat or blister (12a, 12b) from the mat or blister layer (7a, 7b) within the internal space (6a, 6b) of the settler (19a, 19b), a second tapping port (112a, 112b) is provided on the intake shaft settler section (13a, 13b), They may be provided, The first tapping ports (111a, 111b) are positioned vertically above the second tapping ports (112a, 112b).

[0024] Before supplying the concentrate or matte to the concentrate or matte burner (2a, 2b), it may preferably be dried in a steam dryer, rotary dryer, or matte grinding mill until the moisture content is 0-1%. This consumes steam or fuel in the form of natural gas or fuel oil.

[0025] Burners (2a, 2b) for burning concentrate or matte may be designed to symmetrically mix the feed material and oxygen-enriched gas. The oxygen-enriched gas may be air or oxygen-enriched air. In one embodiment, reaction shafts (4a, 4b) provide means for delivering natural gas or fuel oil to reaction shaft fuel burners (2a, 2b). When burned in the reaction shafts (4a, 4b), the natural gas or fuel oil provides additional heat, facilitating the melting of the concentrate or matte supplied thereto.

[0026] If the smelting furnace is FSF, concentrate may be supplied to the furnace (1a). If the smelting furnace is FCF, matte may be supplied to the furnace (1b). Similarly, if the smelting furnace is FSF, the settler (19a) may be configured to receive at least partially oxidized suspension (3a) from the reaction shaft (4a) in the landing zone (5a) and to form a layer of matte (7a) and a layer of slag (8a) on top of the layer of matte (7a) within the internal space (6a) of the settler (19a). Conversely, if the smelting furnace is FCF, the settler (19b) may be configured to receive at least partially oxidized suspension (3b) from the reaction shaft (4b) in the landing zone (5b) and to form a layer of blister (7b) and a layer of slag (8b) on top of the layer of blister (7b) within the internal space (6b) of the settler (19b).

[0027] A jet of at least partially oxidized suspension (3a, 3b) may be heated to a temperature sufficient to completely melt the concentrate or matte. The jet of at least partially oxidized suspension (3a, 3b) may be heated to a temperature of 1100–1600°C, or 1250–1450°C, for example, 1300°C. It has been found that heating the jet of at least partially oxidized suspension (3a, 3b) to these temperatures is suitable for completely melting the suspension and separating the viscosity of the slag into two phases, namely slag and matte or blister.

[0028] The term "concentrate" may refer to ore concentrate, which is a product of a metal ore mine. Specifically, the concentrate may include copper concentrate containing copper and iron in the form of copper and iron sulfides. The exact composition of the concentrate may vary depending on the geographical origin of the metal ore. In one embodiment, the concentrate is supplied to the reaction shaft in a solid state as fine granules.

[0029] To be at least partially oxidized may mean that at least 60%, 70%, 80%, 90%, or 100% by weight of the iron present in the furnace feed is in an oxidized state. The oxidized state may also mean that the iron element is in the form of an oxide compound, and the weight percentage may refer to the proportion of iron present in the furnace feed that is in an oxidized state. Forming a jet in which at least 70% by weight of the iron is in an oxidized state is particularly advantageous because it reduces the need for oxidation that would otherwise be carried out further downstream in the process line.

[0030] The term "to communicate with" refers to the existence of available open space between the components discussed, such that the components share open space and materials can be freely exchanged between them.

[0031] The settler (19a, 19b) may further comprise two side walls, a bottom extending between the reaction shaft and intake shaft end wall (16a, 16b, 21a, 21b) structures, and a roof. The reaction shaft and intake shaft end wall (16a, 16b, 21a, 21b) structures may have a square or rectangular shape, so that the side walls, bottom, and roof extend from the periphery of one end wall to the periphery of the other end wall, thereby forming a closed space between the end walls, bottom, roof, and side walls. The reaction shaft (4a, 4b) may be located on the roof, and layers of slag and mat or blister (8a, 8b, 7a, 7b) may be placed on the bottom when the device is in use. The bottom may be inclined and / or curved downward toward, for example, the first and / or second tapheads (111a, 112a, 112b) to facilitate the discharge of slag and / or mat or blister (11a, 12a, 12b).

[0032] In one embodiment, the reaction shaft end wall (16a) of the first smelting furnace (15a) faces the reaction shaft end wall (16b) of the second smelting furnace (15b).

[0033] In one embodiment, the internal spaces (6a, 6b) of the settlers (19a, 19b) communicate with the lower end of the reaction shaft (4a, 4b) at a point in the settler (19a, 19b) that is closer to the center of the settler (19a, 19b) than at one of the ends of the settler (19a, 19b).

[0034] The settlers (19a, 19b) may have an elongated configuration. In one embodiment, the settlers (19a, 19b) have a rectangular parallelepiped shape. The settlers may have a length of 12 to 30 m, a width of 4 to 12 m, and a height of 1 to 3 m.

[0035] The inventors have found that the configuration of the settlers (19a, 19b) offers many advantages. For example, the dust content at the intake shaft ends (13a, 13b) of the settlers (19a, 19b) is low because the gas and dust are drawn together with the off-gas through the gas phase at the intake shaft settler ends (13a, 13b) toward the intake shaft (10a, 10b). The low dust content creates a relatively dust-free atmosphere for the supply means (120a, 120b). This relatively dust-free atmosphere is beneficial in minimizing dust emission from the furnace through the supply means (120a, 120b). Furthermore, the reaction shaft section (14a, 14b) of the settler (19a, 19b) has a lower pressure than the intake shaft settler section (13a, 13b). This is because gas and dust are drawn together with the off-gas through the gas phase of the settler section towards the intake shaft (10a, 10b). This lower pressure is beneficial in minimizing SO2 emissions from the furnace through the supply means.

[0036] The smelting furnaces (15a, 15b) may be equipped with baffles to prevent oxidized dust generated in the smelting furnace from entering at least a portion of the reaction shaft settler section (14a, 14b). The baffles may extend downward from the roof of the reaction shaft settler section (14a, 14b) into the reaction shaft settler section (14a, 14b). The baffles can further minimize dust content and reduce pressure in the intake shaft settler section (13a, 13b).

[0037] For example, in conventional suspension smelting furnaces, such as the one disclosed in Finnish Patent No. 22694, the end of the settler wall closest to the reaction shaft is significantly worn because it is close to the reaction shaft, which is the hottest part of the settler. In the smelting furnace according to the present invention, the reaction shaft end walls (16a, 16b) of the settler (19a, 19b) are located away from this hottest part of the settler (19a, 19b), so wear is not a problem.

[0038] In one embodiment, the smelting furnace includes reducing agent supply means for supplying a reducing agent to at least one of the mat or blister layers and slag layers (7a, 7b, 8a, 8b) within the reaction shaft settler section (14a, 14b). The reaction shaft settler section (14a, 14b) may also include burners for generating a reducing atmosphere in at least a portion of the reaction shaft settler section (14a, 14b) by, for example, consuming oxygen present in the reaction shaft settler section (14a, 14b) during the combustion process. This further reduces the oxygen oxide content in the reaction shaft settler section.

[0039] The supply means (120a, 120b) may be located closer to the reaction shaft end wall structure (16a, 16b) within the reaction shaft settler section (14a, 14b) than to the center of the settler (19a, 19b). In one embodiment, the supply means (120a, 120b) are located within the reaction shaft end wall (16a, 16b) of the smelting furnace. Alternatively, the supply means (120a, 120b) may be located on the roof of the settler (19a, 19b) or on the side wall of the settler (19a, 19b) at the reaction shaft end of the settler (14a, 14b), at a distance of less than 2m from the end wall (16a, 16b). For example, the supply means may be located at a distance of 0.2 to 2m, 0.4 to 1.8m, or 0.6 to 1.6m from the end wall structure.

[0040] The supply means (120a, 120b) may include gutters extending from the end wall structure (16a, 16b) or side wall or roof of the settler (19a, 19b) to guide the molten material into the internal space of the settler (6a, 6b). The gutters can guide the molten material so that it does not come into direct contact with the end wall structure or side wall or roof of the settler (19a, 19b). In this way, the internal structure of the settler does not wear down by constantly being in contact with the newly introduced high-temperature molten material.

[0041] The first taphole 111b may be located within the reaction shaft end wall 16b if the smelting furnace is an FCF. Alternatively, the first taphole (111b) may be located on the side wall of the settler (19b) within the reaction shaft settler section (14b) at a distance of less than 2 m from the end wall (16b). These locations are beneficial because they allow solid copper scrap to be supplied to the FCF between the reaction shaft (4a) and the intake shaft (10b) without interfering with process control. Since the copper scrap is solid, discharging slag from near the solid supply section can cause fluctuations in the copper content of the slag, making slag discharge difficult. When FCF liquid slag is discharged from the FCF reaction shaft end (14b), the copper-containing scrap moves through the suspension coming from the reaction shaft (4b) and is forcibly mixed with the remaining molten material.

[0042] Scrap can refer to copper-containing materials generated from downstream processes.

[0043] The first tapping port (111a) may be located on the end wall (21a) of the intake shaft if the smelting furnace is FSF. Alternatively, the first tapping port (111a) may be located on the side wall of the settler (19a) within the intake shaft settler section (13a) at a distance of less than 2m from the end wall (21a).

[0044] In the configuration according to the first embodiment, a first transport means (222) may be provided between the first smelting furnace (15a) and the second smelting furnace (15b) for transporting the first material (22) from the second smelting furnace (15b) to the first smelting furnace (15a), preferably the first material (22) is transported as a molten material.

[0045] In the configuration according to the first embodiment, a second transport means (123) may be provided between the first smelting furnace (15a) and the second smelting furnace (15b) for transporting the second material (23) from the first smelting furnace (15a) to the second smelting furnace (15b), preferably the second material (23) is transported in granular form.

[0046] The first material (22) in the first embodiment may include slag, and / or the second material (23) may include mat.

[0047] In one embodiment, the first material (22) comprises at least 60% by weight, or at least 80% by weight, or 100% by weight of slag.

[0048] In one embodiment, the second material (23) comprises at least 60% by weight, or at least 80% by weight, or 100% by weight of mat.

[0049] As shown in Figure 2, the first transport means (222) may extend from the first tap (111b) of the second smelting furnace (15b) to the supply means (120a) of the first smelting furnace (120a). The second transport means (123) may extend from the second tap (112a) of the first smelting furnace (15a) to the burner for burning the concentrate or matte (2b) of the second smelting furnace (15a).

[0050] In one embodiment, the first transport means (222) is equipped with a trough for introducing the molten material continuously or in batches. Alternatively, the first transport means (222) may be equipped with a pot or ladle for supplying the molten material in batches. The molten material may be supplied to the first smelting furnace (15a) by gravity. This has the additional advantage of not requiring energy to transport the molten material. The temperature of the molten material is preferably 1000°C to 1450°C, or 1220°C to 1320°C, for example, 1270°C. These temperatures have been found to be high enough to maintain the slag, for example as molten metal, in liquid form, but low enough not to damage the equipment used.

[0051] In one embodiment, the matte is supplied in a solid state as fine granules to the reaction shaft (4b) of the second smelting furnace (15b). Therefore, it may be necessary to cool and granulate the matte originating from the first smelting furnace (15a) before supplying it to the second smelting furnace (15b). The matte is typically cooled, granulated by water spraying, ground into granules using a grinding mill, stored in a bin, supplied to a dryer, and then returned to the furnace. The matte may be transported pneumatically to the reaction shaft of the second smelting furnace (15b).

[0052] The grinding mill may use natural gas or steam as fuel. Depending on the furnace configuration, it is possible to place a mat discharge within the intake shaft end (13a) of the first smelting furnace (15a). Placing a mat tap port (112a) at the intake shaft end (13a) of the furnace is beneficial because it allows the mat to move along the entire length of the furnace, transfers heat to the intake shaft (10a) of the furnace (15a), and suppresses the solidification of the molten material in the intake shaft (10a) of the furnace (15a).

[0053] Placing the mat tapping port (112a) at the end of the FSF intake shaft (13a) is also beneficial because the distance from the reaction shaft (4a) to the mat tapping port (112a) becomes the same for each tapping port (if there are multiple tapping ports), resulting in a more uniform copper concentration in the discharged mat, which is beneficial for process control in the second furnace.

[0054] It was found that when molten material (31), particularly slag, is supplied to the settler (19a) above the slag layer (8a) and in the reaction shaft settler section (14a), the slag is struck against the intake shaft end wall (21a) or the side wall of the intake shaft end (13a), and the slag is forced to move through the suspension coming from the reaction shaft (4a). This is because the reaction shaft products are discharged out of the furnace from the settler on the opposite side of the supply means. As a result, the molten material, such as slag, mixes with the suspension, which contributes to the oxidation of the molten material, producing a homogeneous mixture and having a positive effect on the yield of metal recovered from the process.

[0055] We have also found that the furnace configuration disclosed herein is particularly advantageous. Specifically, molten material, such as slag, can be supplied in molten form between furnaces (15a, 15b) without the need to consume energy to heat the material during transport. We have also found that the transport of both the first and second materials (22, 23) is facilitated by the proximity of the furnaces. Furthermore, the configuration of the present invention allows the furnaces to be located in the same building section, which was not possible with conventional smelting furnace configurations.

[0056] The slag according to the first embodiment may contain copper oxide, iron oxide, and a flux.

[0057] The slag may contain 5-30% by weight of copper, or 10-25% by weight of copper, or 15-20% by weight of copper.

[0058] The flux may be a compound containing silica and / or calcium. In one embodiment, if the smelting furnace is FSF, silicon dioxide is used as the flux, and if the smelting furnace is FCF, lime, calcium carbonate, or calcium oxide is used as the flux. The flux may be supplied to the reaction shafts (4a, 4b). The flux reduces the viscosity of the slag, facilitates the discharge of the slag from the smelting furnace, and minimizes the formation of material to be reverted. In one embodiment, the weight ratio of iron to silicon dioxide in the FSF slag is 0.9 to 2.0, or 0.7 to 1.8, for example, 1.0 to 1.5. Silicon dioxide, lime, calcium carbonate, or calcium oxide are particularly useful as fluxes because they are relatively inexpensive and provide the desirable result of reducing the viscosity of the slag.

[0059] The mat according to the first embodiment may include a copper mat.

[0060] Matte can refer to the product of FSF supplied with concentrate and oxygen. Specifically, copper matte may contain iron and copper sulfide, and the copper content of the matte may be 40-75% by weight, or 45-70% by weight, or 50-65% by weight, when copper concentrate is used.

[0061] In the configuration according to the first embodiment, solid transport means (124a, 124b) may be provided between the first and second smelting furnaces (15a, 15b) for transporting solid material (24a, 24b) from the first smelting furnace (15a) to the second smelting furnace (15b) and / or from the second smelting furnace (15b) to the first smelting furnace (15a).

[0062] The solid material (24a, 24b) according to the first embodiment may contain dust.

[0063] The smelting furnace (15a, 15b) may be equipped with intake shafts (10a, 10b) through which process gas (9a, 9b) is introduced from the smelting furnace, and the intake shafts (10a, 10b) have ends that communicate with the settlers (19a, 19b) of the intake shaft settler section (13a, 13b).

[0064] The process gas may contain sulfur dioxide, carbon dioxide, water, metal-containing vapors, nitrogen, and several reaction shaft products in the form of unsettled suspended particles. Specifically, the unsettled suspended particles, which are dust, may contain copper compounds.

[0065] The process gas may be led to a heat exchanger to cool the process gas and subsequently separate the gas from the solids. The heat exchanger is typically, but not necessarily, a steam boiler that cools the gas by evaporating water into steam. Dust may be separated from the gas during the separation of the gas from the solids. In one embodiment, the gas and solid separator is an electrostatic precipitator that collects and separates the dust from the gas. In one embodiment, the dust is recycled and returned to the burner in the reaction shaft of the smelting furnace. The heat obtained from the cooling may be recovered and used as electricity.

[0066] The dust may be recycled from the intake shaft (10a, 10b) of a suspension smelting furnace (FSF or FCF) to the burner (2a, 2b) of the same smelting furnace (15a, 15b) via a heat exchanger and solid separator, or from another smelting furnace (15a, 15b) to the burner (2a, 2b) of the smelting furnace (15a, 15b).

[0067] For example, dust may be recycled from the FCF intake shaft (10b) to the FSF burner (1a) via a heat exchanger and solid separation, and / or from the FSF intake shaft (10a) to the FCF burner (2b) via a heat exchanger and solid separation. This is shown in Figure 3.

[0068] In one embodiment, dust from the first and second smelting furnaces (15a, 15b) may be supplied to separate dust bins, and the dust may then be supplied from there to the first and / or second smelting furnaces (15a, 15b).

[0069] Recycling dust improves the yield of copper in the final product because some copper is still present in the dust. Furthermore, the inventors have found that recycling dust between furnaces, as described above, is particularly beneficial because dust from different furnaces has different compositions and qualities. For example, it is common to recycle a portion of the dust from a second furnace into a first furnace. However, process control is highly sensitive to the exact amount of dust from the second furnace because the chemical analysis of the dust from the two furnaces differs. Therefore, flexible dust transfer between furnaces improves process control.

[0070] Furthermore, the inventors have found that recycling dust between furnaces, as described above, is particularly beneficial in solving the problem of dust solidifying during furnace shutdown. For example, if one furnace unexpectedly stops, the dust bin can be emptied into the other furnace.

[0071] It is also beneficial to place dust supply means in close proximity to each other. The supply means environment is dusty, and by placing the supply means in the same area, only one dust environment is required for both furnaces, rather than multiple. Dusty environments are harmful to health, safety, and the environment.

[0072] The configuration according to the first embodiment may include supply means (18, 17a, 17b) for supplying the flux, solidification mat, solidification slag and / or returned material to the first and / or second smelting furnaces (15a, 15b), and the supply means (18, 17a, 17b) are the same for the first and second smelting furnaces (15a, 15b). This is shown in Figure 4. The supply means (18, 17a, 17b) for supplying the flux, solidification mat, solidification slag and / or returned material may be suitable for supplying the material to the first and second smelting furnaces simultaneously. The supply means (18, 17a, 17b) for supplying the flux, solidification mat, solidification slag and / or returned material may be suitable for supplying the material to the first and second smelting furnaces separately.

[0073] In one embodiment, the concentrate (1a) and matte (1b) are also supplied to the first or second smelting furnace (15a, 15b) via a common supply means (18, 17a, 17b).

[0074] The returned material may be recycled from the output of one smelting furnace (15a, 15b) to the input of the same smelting furnace (15a, 15b), or from another smelting furnace (15a, 15b) to the input of another smelting furnace (15a, 15b). For example, the returned material may be recycled between the FSF and FCF. The returned material may refer to any reaction shaft products accumulated from the off-gas line, trough or ladle and furnace. The returned material may be fed into the smelting furnace by mixing with the main feed material or through a separate feeder.

[0075] In one embodiment, solidified slag refers to slag that is generated in the smelting furnace (15a, 15b), discharged through the first taphole (111a, 111b), and solidified. The slag may be discharged from, for example, the FCF and recycled into the FSF, or vice versa. The slag may be discharged from the same smelting furnace (15a, 15b) from which it is recycled. The slag may be solidified and granulated using water and / or air and / or nitrogen before being supplied to the smelting furnace (15a, 15b).

[0076] The solidified slag and the returned material typically contain a considerable amount of metal, and the remaining metal may be recovered by recycling them into a smelting furnace.

[0077] Alternatively, if the smelting furnace is FCF, no flux is supplied to the burners (2a, 2b). The copper present in the matte may be oxidized, and some of the copper may be converted into copper oxide. The presence of copper oxide in the slag promotes the liquefaction of the slag. It may be desirable to oxidize the copper to achieve at least 30 wt% copper oxide in the slag by weight of the total weight of the slag. The desired ratio may be achieved by injecting an oxygen-containing reaction gas through the burners (2a, 2b) to reach partial pressures (pO2) of 1 to 100 Pa, or 2 to 70 Pa, or 10 to 30 Pa. In one embodiment, the concentration of copper oxide in the slag is 30 to 90 wt%, or 35 to 70 wt%, or 40 to 60 wt% by weight of the total weight of the slag. Thus, it may be possible to convert copper-containing material into blister copper without using conventional flux. The desired temperature of the burners (2a, 2b) may depend on the desired concentration of copper oxide in the converter slag. The temperature is typically at least 1200°C to ensure the slag is in the molten phase and to achieve an acceptable yield of copper. If the concentration of copper oxide present in the slag is low, a higher temperature may be required. The temperature may be, for example, 1220–1450°C, 1250–1400°C, or 1300–1380°C.

[0078] The supply means (18, 17a, 17b) may include several bins (18) and troughs or pipes (17a, 17b).

[0079] The inventors have found it beneficial to supply the above material to one or both of the furnaces (15a, 15b) via the same supply means (18, 17a, 17b). For example, by using the same supply means (18, 17a, 17b) for the material returned from the second smelting furnace, the type of material being returned is always known, thus improving the accuracy of thermal balance control. However, the current state of technology mixes the different materials being returned from both smelting furnaces before the supply means (18, 17a, 17b), so the mixture of materials discharged from the supply means (18, 17a, 17b) into the furnace and returned is unknown. Specifically, by supplying the material being returned, an endothermic reaction occurs in the furnace, and by adjusting the amount of known material being returned to the different furnaces, more accurate thermal balance control becomes possible in both furnaces.

[0080] Furthermore, the inventors have found that it is beneficial to supply the above-mentioned material to the furnaces (15a, 15b) from the same supply area. For example, since the supply environment is dusty, by placing the supply means in the same area, only one dust environment is required for both furnaces (15a, 15b), rather than multiple dust environments. Dusty environments are harmful to health, safety, and the environment. The configuration and proximity of the furnaces (15a, 15b) make it possible to use a common supply means.

[0081] method The above description of the smelting furnace configuration applies to the smelting furnace in the following description of the method.

[0082] According to a second embodiment, a method is provided for manufacturing a blister in a suspension smelting furnace configuration, the method being i. A step of supplying the concentrate (1a) to the first smelting furnace (15a), iii. The step of forming a mat in the first smelting furnace (15a), iv. A step of transporting at least a portion of the mat from the first smelting furnace (15a) to the second smelting furnace (15b) via the second transport means (123), vi. The step of forming a blister in the second smelting furnace (15b), Includes, The first and second smelting furnaces (15a, 15b) each have a reaction shaft end with reaction shaft end walls (16a, 16b) and an intake shaft end with intake shaft end walls (21a, 21b), wherein the reaction shaft end wall (16a) of the first smelting furnace (15a) is located at a distance (X) from the reaction shaft end wall (16b) of the second smelting furnace (15b), and the distance (X) is less than 20m.

[0083] The first smelting furnace (15a) in the second embodiment may be a suspension smelting furnace, and / or the second smelting furnace (15b) in the second embodiment may be a suspension smelting furnace.

[0084] The mat according to the second embodiment may contain iron sulfide and copper sulfide.

[0085] The method according to the second embodiment may further include the step of transporting slag from a second smelting furnace (15b) to a first smelting furnace (15a), preferably the slag being transported as a molten material via a first transport means (222).

[0086] The slag according to the second embodiment may contain copper oxide, iron oxide, and a flux.

[0087] A method according to a second embodiment may further include the step of transporting solids (24a, 24b) from a second suspension smelting furnace (15b) to a first suspension smelting furnace (15a) and / or from a first suspension smelting furnace (15a) to a second suspension smelting furnace (15b), wherein the solids (24a, 24b) are transported via solid transport means (124a, 124b).

[0088] The solids (24a, 24b) according to the second embodiment may contain dust.

[0089] The blister according to the second embodiment may include a copper blister.

[0090] The blister may contain at least 60% by weight, or 80% by weight, or 100% by weight of copper blister. The copper blister may contain copper, iron, and sulfur. In one embodiment, the copper blister contains 96 to 99.5% by weight of copper and 0.01 to 0.5% by weight of iron.

[0091] The method according to the second embodiment may further include the step of supplying the flux, solidified mat, solidified slag, and / or returned material to the first and / or second smelting furnaces (15a, 15b) through supply means (18, 17a, 17b), wherein the supply means (18, 17a, 17b) are the same for the first and second smelting furnaces (15a, 15b).

Claims

1. A smelting furnace configuration comprising a first smelting furnace (15a) and a second smelting furnace (15b), wherein the first and second smelting furnaces (15a, 15b) each have reaction shaft ends with reaction shaft end walls (16a, 16b) and intake shaft ends with intake shaft end walls (21a, 21b), and the reaction shaft end wall (16a) of the first smelting furnace (15a) is located at a distance (X) from the reaction shaft end wall (16b) of the second smelting furnace (15b), and the distance (X) is less than 20m.

2. The smelting furnace configuration according to claim 1, wherein the first smelting furnace (15a) is a suspension smelting furnace, and / or the second smelting furnace (15b) is a suspension smelting furnace.

3. The smelting furnace configuration according to claim 1 or 2, wherein the configuration includes a first transport means (222) between the first smelting furnace (15a) and the second smelting furnace (15b) for transporting the first material (22) from the second smelting furnace (15b) to the first smelting furnace (15a), and preferably the first material (22) is transported as a molten material.

4. The configuration is as described in any one of claims 1 to 3, wherein a second transport means (123) is provided between the first smelting furnace (15a) and the second smelting furnace (15b) for transporting a second material (23) from the first smelting furnace (15a) to the second smelting furnace (15b), and preferably the second material (23) is transported as granules.

5. The smelting furnace configuration according to any one of claims 1 to 4, wherein the first material (22) includes slag and / or the second material (23) includes matte.

6. The smelting furnace configuration according to claim 5, wherein the slag comprises copper oxide, iron oxide, and a flux.

7. The smelting furnace configuration according to claim 5 or 6, wherein the mat includes a copper mat.

8. The smelting furnace configuration according to any one of claims 1 to 7, wherein the configuration includes solid transport means (9a, 9b) between the first and second smelting furnaces (124a, 124b) for transporting solid material (24a, 24b) from the first smelting furnace (15a) to the second smelting furnace (15b) and / or from the second smelting furnace (15b) to the first smelting furnace (15a).

9. The smelting furnace configuration according to claim 8, wherein the solid material (24a, 24b) includes dust.

10. The smelting furnace configuration according to any one of claims 1 to 9, wherein the configuration comprises supply means (18, 17a, 17b) for supplying a flux, a solidified mat, a solidified slag and / or a material to be returned to the first and / or second smelting furnaces (15a, 15b), and the supply means (18, 17a, 17b) are the same for the first and second smelting furnaces (15a, 15b).

11. A method for producing blisters in a suspension smelting furnace configuration, i. A step of supplying the concentrate to the first smelting furnace (15a), iii. The step of forming a mat in the first smelting furnace (15a), iv. A step of transporting at least a portion of the mat from the first smelting furnace (15a) to the second smelting furnace (15b) via a second transport means (123), vi. The step of forming a blister in the second smelting furnace (15b), Includes, The first and second smelting furnaces (15a, 15b) each have reaction shaft ends with reaction shaft end walls (16a, 16b) and intake shaft ends with intake shaft end walls (21a, 21b), wherein the reaction shaft end wall (16a) of the first smelting furnace (15a) is located at a distance (X) from the reaction shaft end wall (16b) of the second smelting furnace (15b), and the distance (X) is less than 20 m.

12. The method according to claim 11, wherein the first smelting furnace (15a) is a suspension smelting furnace and / or the second smelting furnace (15b) is a suspension smelting furnace.

13. The smelting furnace configuration according to claim 11 or 12, wherein the mat comprises iron sulfide and copper sulfide.

14. The method according to any one of claims 11 to 13, further comprising the step of transporting slag from the second smelting furnace (15b) to the first smelting furnace (15a), preferably the slag being transported as a molten material via a first transport means (222).

15. The smelting furnace configuration according to claim 14, wherein the slag comprises copper oxide, iron oxide, and a flux.

16. The method according to any one of claims 11 to 15, further comprising the step of transporting solids (24a, 24b) from the second suspension smelting furnace (15b) to the first suspension smelting furnace (15a) and / or from the first suspension smelting furnace (15a) to the second suspension smelting furnace (15b), wherein the solids (24a, 24b) are transported via solid transport means (124a, 124b).

17. The method according to any one of claims 11 to 16, wherein the solid (24a, 24b) includes dust.

18. The method according to any one of claims 11 to 17, wherein the blister includes a copper blister.

19. The method according to any one of claims 11 to 18, further comprising the step of supplying the flux, solidification mat, solidification slag, and / or returned material to the first and / or second smelting furnaces (15a, 15b) through supply means (18, 17a, 17b), wherein the supply means (18, 17a, 17b) is the same for the first and second smelting furnaces (15a, 15b).

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