Suspension smelting furnace

Abstract

The utility model relates to a suspension smelting furnace which comprises a reaction furnace body (5), a settler (8), a first discharge port (15), a second discharge port (17) and a supply device (30) used for supplying molten materials (31) to the suspension smelting furnace.

Description

Technical Field

[0001] The utility model relates to a suspension smelting furnace and also relates to a method for using the suspension smelting furnace. Background Art

[0002] Conventional processes for converting metalliferous concentrates generally involve flash smelting and flash converting.

[0003] The process typically involves oxidation of a concentrate in a flash smelting furnace (FSF) to produce copper matte. The matte may then be sent to a flash converting furnace (FCF) or a Peirce Smith converter where it is further oxidized. In this process, slag is formed in both the FSF and the FCF or the Peirce Smith converter. The slag typically contains a large amount of metal and should therefore be recycled back to one or more furnaces for further processing, thereby increasing the yield of the process. In one embodiment, the slag from the FCF or the Peirce Smith converter should be recycled to the FSF.

[0004] The recycling of slag consumes many resources, since the slag is usually granulated by water spraying, stored in silos and fed into dryers before being sent back to the furnace. The granulation of slag consumes a lot of water, since the water is mainly used to cool the slag and break it into smaller particles. This leads to steam losses and particle contamination of the granulation water, which needs to be further treated before the water can be reused. When the slag is sent to the furnace into which it will be recycled, energy is required to heat the slag again to a temperature sufficient to melt the slag. The slag granulation water needs to be cooled by a secondary cooling water circuit, which further consumes energy and water.

[0005] Furthermore, it is important that the recycled slag is thoroughly mixed with the reaction mixture in the furnace in order to allow as much metal exchange as possible from the slag to the products of the furnace.

[0006] Therefore, there is a need for an improved furnace and method that allows recycling of molten material between furnaces.There is also a need for an improved furnace and method that allows good mixing of slag and furnace products. Utility Model Content

[0007] In a first aspect, a suspension smelting furnace is provided according to the accompanying drawings, comprising:

[0008] i. a reaction shaft provided with burners for burning the concentrate or copper matte and feeding the concentrate or copper matte into the reaction shaft to form a jet of at least partially oxidized suspension in the reaction shaft,

[0009] ii. a settler connected to the lower end of the reaction shaft, wherein the settler has: an interior space, and a first end wall structure at one end of the settler, and a second end wall structure at the opposite end of the settler, and a landing zone for a jet of oxidized suspension in the interior space of the settler below the lower end of the reaction shaft, and wherein the settler extends from the landing zone in two opposite directions so that the settler includes a first settler portion on a first side of the landing zone and a second settler portion on an opposite second side of the landing zone, and wherein the settler is configured to receive at least partially oxidized suspension from the reaction shaft at the landing zone and form a layer of matte or metal alloy in the interior space of the settler and a layer of matte slag on the top of the matte space,

[0010] iii. a first tapping port, which is arranged in the second settler part, for discharging slag from the slag layer in the inner space of the settler, and

[0011] iv. a second tapping port, which is arranged in the second settler part, for discharging the matte or metal alloy from the matte or metal alloy layer in the inner space of the settler,

[0012] wherein the first tapping port is arranged at a height above the second tapping port in the vertical direction, and wherein the suspension smelting furnace further comprises

[0013] v. A supply device for supplying molten material to the suspension smelting furnace, wherein the supply device, in use, communicates with the settler in the first settler part above the slag layer.

[0014] Preferably, the suspension smelting furnace further comprises an uptake chimney for guiding process gas from the suspension smelting furnace via the uptake chimney, wherein the uptake chimney has a lower end communicating with the settler in the second settler section.

[0015] Preferably, the burner is also suitable for supplying flux, oxygen-containing reaction gas, solidified slag, dust and / or material to be reduced.

[0016] Preferably, the copper matte comprises copper matte and the metal alloy comprises blister copper, or wherein the copper matte comprises nickel matte.

[0017] Preferably, the molten material comprises slag.

[0018] Preferably, the slag comprises iron and copper oxides and a flux, or wherein the slag comprises iron and nickel oxides and a flux.

[0019] Preferably, the feed arrangement is located in the first settler section closer to the first end wall structure than to the middle of the settler.

[0020] Preferably, the internal space of the settler is in communication with the lower end of the reaction shaft at a point of the settler, the point being closer to the middle of the settler than to one of the ends of the settler.

[0021] Preferably, the settler has an elongated configuration.

[0022] Preferably, the first settler portion has a first proximal end at the landing zone and a first distal end at the opposite end of the first settler portion, the first distal end being also the first end wall structure of the settler, and wherein the supply device is arranged at the first distal end of the first settler portion.

[0023] Preferably, the second settler portion has a second proximal end at the landing zone and a second distal end at the opposite end of the second settler portion, the second distal end also being the second end wall structure of the settler, and wherein the first tapping port and the second tapping port are arranged at the second distal end of the second settler portion.

[0024] Preferably, the suspension smelting furnace comprises a suction device for conducting process gas from the suspension smelting furnace.

[0025] According to a second aspect, there is provided a method for producing copper matte or a metal alloy in a suspension smelting furnace, comprising:

[0026] i. feeding the concentrate or copper matte into the reaction shaft of the suspension smelting furnace via a burner for burning the concentrate or copper matte to form a jet of at least partially oxidized suspension in the reaction shaft,

[0027] ii. receiving a jet of at least partially oxidized suspension in a landing zone of a settler in communication with the lower end of the reactor shaft, wherein the settler has: an interior space, and a first end wall structure at one end of the settler, and a second end wall structure at an opposite end of the settler, and wherein the settler extends from the landing zone in two opposite directions so that the settler includes a first settler portion on a first side of the landing zone and a second settler portion on an opposite second side of the landing zone,

[0028] iii. forming a matte or metal alloy layer in the inner space of the settler and a slag layer on top of the matte or metal alloy layer,

[0029] iv. discharging slag from the slag layer in the settler through a first tapping port arranged in the second settler section, and

[0030] v. discharging the matte or metal alloy from the matte or metal alloy layer in the settler through a second tapping port arranged in the second settler section,

[0031] wherein the first discharge port is arranged at a height above the second discharge port in a vertical direction, and wherein the method further comprises:

[0032] vi. Supplying molten material into the suspension smelting furnace by means of a supply device, wherein the supply device communicates with the settler in the first settler section and the molten material is supplied to the first settler section above the slag layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The accompanying drawings are included to provide a further understanding of the present invention and constitute a part of this specification. The accompanying drawings illustrate embodiments of the present invention and together with the specification help explain the principles of the present invention. In the accompanying drawings:

[0034] Figure 1 Schematic diagram of a suspension smelting furnace according to a first embodiment of the utility model, wherein a feeding device (30) is arranged in a first distal end of a first settler part (18), and a first tapping port (15) and a second tapping port (17) are arranged in a second distal end of a second settler part (19).

[0035] Figure 2 Schematic diagram of a suspension smelting furnace according to a first embodiment of the utility model, wherein a feeding device (30) is arranged in the top of the settler in a first settler part (18), and a first tapping port (15) and a second tapping port (17) are arranged in a second distal end of a second settler part (19).

[0036] Figure 3 The invention is a schematic diagram of a suspension smelting furnace according to a first embodiment of the invention, wherein a feeding device (30) is arranged in a side wall of a settler in a first settler part (18), and a first discharge port (15) and a second discharge port (17) are arranged in a second distal end of a second settler part (19).

[0037] Figure 4 Schematic diagram of a suspension smelting furnace according to a first embodiment of the utility model, wherein a supply device (30) is arranged in a first distal end of a first settler part (18), and a first discharge port (15) is arranged in a second distal end of a second settler part (19), and a second discharge port (17) is arranged in a side wall of the second settler part (19).

[0038] Figure 5Schematic diagram of a suspension smelting furnace according to a first embodiment of the utility model, wherein a supply device (30) is arranged in a first distal end of a first settler part (18), and a second discharge port (17) is arranged in a second distal end of a second settler part (19), and a first discharge port (15) is arranged in a side wall of the second settler part (19). DETAILED DESCRIPTION

[0039] It is obvious to those skilled in the art that the basic idea of ​​the present invention can be implemented in various ways as technology advances. Therefore, the present invention and its embodiments are not limited to the examples described below, but they can be varied within the scope of the claims.

[0040] Suspension smelting furnace

[0041] In a first aspect, a suspension smelting furnace is provided according to the accompanying drawings, comprising:

[0042] i. a reaction shaft (5) provided with burners for burning concentrate or copper matte (4) and feeding the concentrate or copper matte (1) into the reaction shaft (5) to form a jet of at least partially oxidized suspension (6) in the reaction shaft (5),

[0043] ii. A settler (8) in communication with the lower end of the reaction shaft (5), wherein the settler (8) has: an interior space (9), and a first end wall structure (27) at one end of the settler (8), and a second end wall structure (28) at the opposite end of the settler (8), and a landing area (7) for a jet of oxidizing suspension (6) in the interior space (9) of the settler (8) below the lower end of the reaction shaft (5), and wherein the settler (8) extends from the landing area (7) in two opposite directions so that The settler (8) comprises a first settler section (18) on a first side of a landing zone (7) and a second settler section (19) on an opposite second side of the landing zone (7), and wherein the settler (8) is configured to receive at least partially oxidized suspension (6) from a reaction shaft (5) at the landing zone (7) and to form a layer (10) of matte or metal alloy and a layer (11) of matte slag on top of the layer (10) of matte or metal alloy in an inner space (9) of the settler (8),

[0044] iii. a first tapping port (15) arranged in the second settler section (19) for discharging slag (14) from the slag layer (11) in the inner space (9) of the settler (8), and

[0045] iv. a second tapping port (17) arranged in the second settler section (19) for discharging the matte or metal alloy (16) from the matte or metal alloy layer (10) in the inner space (9) of the settler (8),

[0046] wherein the first tapping port (15) is arranged at a height above the second tapping port (17) in the vertical direction, and wherein the suspension smelting furnace further comprises

[0047] v. A supply device (30) for supplying molten material (31) to the suspension smelting furnace, wherein the supply device (30) communicates with the settler (8) in the first settler section (18) above the slag layer (11) during use.

[0048] Before the concentrate or matte (1) is fed to the concentrate or matte burner (4) it may be dried to a moisture content of 0-1%, preferably in a steam or rotary dryer or matte grinder. This consumes steam or fuel in the form of natural gas or fuel oil.

[0049] The burners for burning the concentrate or matte (4) can be designed to symmetrically mix the feed and the oxygen-enriched gas. The oxygen-enriched gas can be air or oxygen-enriched air. In one embodiment, the reaction shaft (5) provides means for delivering natural gas or fuel oil to the reaction shaft fuel burners. When burned in the reaction shaft (5), the natural gas or fuel oil provides additional heat, which helps to melt the concentrate or matte (1) fed thereto.

[0050] The suspension smelting furnace may be a flash smelting furnace (FSF) or a flash converting furnace (FCF). If the suspension smelting furnace is a FSF, concentrate may be fed into the furnace. If the suspension smelting furnace is a FCF, matte may be fed into the furnace. However, some low-grade matte may be fed into the FSF for further processing. Similarly, if the suspension smelting furnace is a FSF, the settler (8) may be configured to receive at least partially oxidized suspension (6) from the reaction shaft (5) at a landing zone (7), and to form a matte layer (10) and a slag layer (11) on top of the matte layer (10) in the inner space (9) of the settler (8). In contrast, if the suspension smelting furnace is an FCF, the settler (8) can be configured to receive at least partially oxidized suspension (6) from the reaction shaft (5) at the landing zone (7) and to form a metal alloy layer (10) and a slag layer (11) on top of the metal alloy layer (10) in the inner space (9) of the settler (8).

[0051] The jet of at least partially oxidized suspension can be formed in the burner and directed through the reaction shaft to the settler. In one embodiment, the jet of at least partially oxidized suspension (6) is heated to a temperature sufficient to completely melt the concentrate or matte. Preferably, the jet of at least partially oxidized suspension (6) is heated to a temperature of 1100-1600°C, or 1250-1450°C, for example 1300-1300°C. It has been found that heating the jet of at least partially oxidized suspension (6) to these temperatures ensures complete melting of the suspension (6) and that the viscosity of the slag is suitable for separating the two phases, i.e. slag and matte or metal alloy.

[0052] Concentrate may refer to a concentrate that is a mineral product of a metal ore. Specifically, the concentrate may include a copper or nickel concentrate, which includes copper and iron or nickel and iron in the form of copper or nickel 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 fed to the reaction shaft in a solid state as fine particles.

[0053] If copper concentrate is used, the suspension smelting furnace may be a FSF and / or FCF and the metal alloy may include blister copper. In one embodiment, the metal alloy comprises at least 60 wt%, or at least 80 wt% or 100 wt% blister copper.

[0054] The blister copper may comprise copper, iron and sulfur. In one embodiment, the blister copper comprises 96-99.5 wt. % copper and 0.01-0.5 wt. % iron.

[0055] If nickel concentrate is used, the suspension smelting furnace can be a FSF. The FSF can be used in conjunction with a PeirceSmith converter to produce high grade nickel matte.

[0056] High grade nickel matte may include nickel, iron and sulfur. In one embodiment, the high grade nickel matte comprises 96-99.5 wt % nickel and 0.01-0.5 wt % iron.

[0057] Davenport et al. disclose a conventional Pierce Smith converter, 2002, Extractive Metallurgy of Copper, ELSEVIER SCIENCE Ltd, ISBN: 0-08-044029-0.

[0058] At least partially oxidized may refer to at least 60%, 70%, 80%, 90% or 100% by weight of the iron present in the furnace feed being in an oxidized state. The oxidized state may refer to the form of the elemental iron in an oxidized compound and the weight % may refer to the percentage of the iron present in the furnace feed being in an oxidized state. It is particularly advantageous to form a jet in which at least 70% by weight of the iron is in an oxidized state as this reduces the oxidation requirements which would otherwise be performed further downstream in the production line.

[0059] If copper concentrate is used, the slag may include copper and iron oxides and a flux, and if nickel concentrate is used, nickel and iron oxides and a flux. The flux may be a compound including silicon dioxide and / or calcium. In one embodiment, when the suspension smelting furnace is FSF, silicon dioxide is used as a flux, and when the suspension smelting furnace is FCF, lime, calcium carbonate or calcium oxide is used as a flux. The flux may be added to the reaction shaft. The flux reduces the viscosity of the slag, which facilitates the discharge of the slag from the suspension smelting furnace and minimizes the formation of the material to be reduced. Preferably, 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 suitable for use as fluxes because they are relatively cheap while still being able to obtain the desired result of reducing the viscosity of the slag.

[0060] The term "communication" means that there is open space between the components in question such that the components share the open space and such that material can freely exchange between the components.

[0061] The settler (8) may further comprise two side walls, a bottom and a top extending between a first end wall structure (27) and a second end wall structure (28). The end wall structures (27, 28) may have a square or rectangular form, such that the side walls, the bottom and the top extend from the periphery of the first end wall (27) to the periphery of the second end wall (28), and thereby form a closed space between the end walls (27, 28), the bottom, the top and the side walls. The reaction shaft (5) may be located in the top, and when the device is used, the slag layer and the matte or metal alloy layer (10, 11) may be on the bottom. The bottom may be inclined downwardly towards the first and second tapping ports (15, 17), for example in an inclined and / or curved manner, to facilitate the discharge of the slag and the matte or metal alloy.

[0062] In one embodiment, the supply device (30) for supplying the molten material (31) to the suspension smelting furnace comprises a launder or opening for introducing the molten material (31) continuously or in batches. Alternatively, the supply device (30) for supplying the molten material (31) to the suspension smelting furnace may comprise a tank or ladle for supplying the molten material (31) in batches. The molten material (31) may be supplied to the suspension smelting furnace by gravity. This has the additional benefit of not requiring energy to transport the molten material (31). The temperature of the molten material (31) is preferably between 1000°C and 1450°C, or between 1220°C and 1320°C, for example 1270°C. It has been found that these temperatures are high enough to keep, for example, slag as the molten material in liquid form, but low enough not to damage the equipment used.

[0063] The suspension smelting furnace according to the first aspect may comprise an uptake chimney (13) for guiding process gas (12) from the suspension smelting furnace via the uptake chimney (13), wherein the uptake chimney (13) has a lower end communicating with the settler (8) in the second settler section (19).

[0064] The process gas (12) may include sulfur dioxide, carbon dioxide, water, metal-containing steam, nitrogen and some reaction shaft products in the form of unsettled suspended particles. Specifically, the unsettled suspended particles (which are dust) contain copper or nickel compounds, depending on whether copper or nickel concentrate is used in one embodiment.

[0065] The process gas (12) may be directed to a heat exchanger to cool the process gas prior to gas and solid separation. 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 in the gas and solid separation. The gas-solid separator may be an electrostatic precipitator that collects and separates dust from the gas. In one embodiment, the dust is recycled back to the burner (4) of the reaction shaft (5) of the suspension smelting furnace. The heat from the cooling may be recovered and used as electricity.

[0066] The dust may be recycled from the uptake (13) of a suspension smelting furnace (FSF or FCF) via a heat exchanger and solids separation to the burners (4) of the same suspension smelting furnace. Alternatively, the dust may be recycled from the uptake (13) of one suspension smelting furnace (e.g. FCF) via a heat exchanger and solids separator, for example, from the uptake of one suspension smelting furnace to the burners (4) of another suspension smelting furnace (e.g. FSF). Since some copper or nickel is still present in the dust, recycling the dust increases the yield of copper or nickel in the final product. For the avoidance of doubt, if copper concentrate is used, the copper yield may be increased, and if nickel concentrate is used, the nickel yield may be increased.

[0067] The burner (4) according to the first aspect is also suitable for supplying flux (1), oxygen-containing reaction gas (1), solidified slag (1), dust and / or material to be reduced (1).

[0068] The dust may be recovered and disposed of as described above. The flux may be as described above.

[0069] The oxygen-containing reaction gas promotes the oxidation of the concentrate / matte in the reaction shaft (5).

[0070] The material to be reduced can be fed into the FSF or FCF and circulated from the outlet of a suspension smelting furnace to the inlet of the same suspension smelting furnace or from another suspension smelting furnace to the inlet of the suspension smelting furnace.

[0071] In one embodiment, solidified slag refers to slag produced in the suspension smelting furnace, which has been discharged via the first tapping port and solidified. For example, if copper concentrate is used, the slag can be discharged from the FCF and recycled to the FSF. If nickel concentrate is used, the slag can be recycled from the Pierce Smith converter to the FSF. The slag can also be discharged from the same suspension smelting furnace into which it is recycled, regardless of whether copper or nickel concentrate is used. Before the slag is fed to the suspension smelting furnace, the slag can be solidified and granulated using water and / or air and / or nitrogen.

[0072] The material to be reduced may refer to any reaction shaft product accumulated from off-gas lines, ladles or ladles and furnaces.The material to be reduced may be fed to the suspension smelting furnace by mixing it with the main feed or by a separate feeder.

[0073] The solidified slag and the material to be reduced generally contain a large amount of metal and by recycling them to the suspension smelting furnace (the same suspension smelting furnace from which they originated or another suspension smelting furnace), the remaining metal can be recovered.

[0074] Alternatively, when the suspension smelting furnace is FCF and copper concentrate is used, no flux is supplied to the burner (4). The copper present in the matte can be oxidized to convert part of the copper into copper oxide. The presence of copper oxide in the slag helps to liquefy the slag. It may be desirable to oxidize the copper to obtain at least 30% by weight of oxidized copper in the slag, which accounts for the total weight of the slag. The desired ratio can be obtained by injecting an oxygen-containing reaction gas through the burner to obtain a partial pressure (pO2) of 1-100Pa, or 2-70Pa, or 10-30Pa. In one embodiment, the concentration of oxidized copper in the slag is 30-90% by weight, or 35-70% by weight, or 40-60% by weight of the total weight of the slag. Therefore, conventional fluxes can be used to convert copper-containing materials into blister copper. The required temperature of the burner may depend on the required concentration of copper oxide in the converter slag. The temperature is typically at least 1200°C to ensure that the slag is in a molten state and an acceptable copper yield is obtained. When there is a lower concentration of copper oxide in the slag, a higher temperature may be required. The temperature is, for example, 1220 to 1450°C, 1250 to 1400°C, or 1300 to 1380°C.

[0075] When flux and copper concentrate are used, the oxidized copper concentration in the FCF slag can be 5-30 wt%.

[0076] The copper matte according to the first aspect may include copper matte, the metal alloy may include blister copper, or the copper matte may include nickel matte.

[0077] The copper matte according to the first aspect may comprise copper matte or nickel matte, depending on whether copper or nickel concentrate is used. In one embodiment, the copper matte comprises at least 60 wt%, or at least 80 wt%, or 100 wt% copper matte or nickel matte.

[0078] Copper matte may refer to the product of a FSF into which a concentrate and oxygen have been supplied. Specifically, if copper concentrate is used, the copper matte may contain iron and copper sulfides, and the copper content of the copper matte may be 40-75% by weight. Conversely, if nickel concentrate is used, the copper matte may include iron and nickel sulfides, and the nickel content of the copper matte may be 13-72% by weight.

[0079] In one embodiment, if copper concentrate is used, copper matte is fed to the reaction shaft (5) of the FCF in a solid state as fine particles. Therefore, it may be necessary to cool and granulate the copper matte from the FSF before sending it to the FCF. The copper matte is usually cooled and granulated by water and / or air and / or nitrogen and crushed into fine particles using a grinder. The grinder can use natural gas or steam as fuel. In one embodiment, if nickel concentrate is used, copper matte is added to the Pierce Smith converter in liquid form.

[0080] The molten material (31) according to the first aspect may comprise slag, preferably wherein the slag comprises iron and copper oxides and a flux, or wherein the slag comprises iron and nickel oxides and a flux.

[0081] The molten material (31) may comprise at least 60 wt%, or at least 80 wt%, or 100 wt% slag. In one embodiment, if copper concentrate is used, the slag comprises iron and copper oxides and a flux. The slag may comprise 0.4-40 wt% copper and 5-55 wt% iron. In one embodiment, if nickel concentrate is used, the slag comprises iron and nickel oxides and a flux. The slag may comprise 0.3-30 wt% nickel and 25-60 wt% iron.

[0082] The slag can be recycled from the suspension smelting furnace slag tap to the feed device of the same suspension smelting furnace or to another suspension smelting furnace. For example, the FSF can be used to produce copper matte, which can be fed to the FCF, and then if copper concentrate is used, the slag from the FCF can be recycled to the FSF in molten form. For example, the FSF can be used to produce nickel matte, and this nickel matte can be fed to a Pierce Smith converter, and then if nickel concentrate is used, the slag from the Pierce Smith converter can be recycled to the FSF in molten form.

[0083] The inventors have surprisingly found that by recycling molten material and in particular slag in molten form from one suspension smelting furnace to another suspension smelting furnace or from a Pierce Smith converter to a suspension smelting furnace via a supply device (30) as described herein, a number of advantages can be achieved. Firstly, energy is saved since the material does not need to be cooled, granulated and reheated between furnaces. Furthermore, water and / or air and / or nitrogen used in granulation are saved. Furthermore, by enabling the material to be supplied between furnaces in liquid form, material such as slag can be continuously removed and supplied between furnaces.

[0084] The supply device (30) according to the first aspect may be located in the first settler section (18) closer to the first end wall structure (27) than to the middle of the settler (8).

[0085] It has been found that when molten material (31), and in particular slag, is fed into the settler (8) above the slag layer (11) in the first settler section (18), the slag is forced to move through the suspension from the reaction shaft (5). The reason for this is that the reaction shaft product is discharged from the furnace from the opposite side of the settler (8) compared to the feed device (30). As a result, molten material, such as slag, mixes with the reaction shaft output material, which aids oxidation of the melt and produces a homogenous mixture, and this has a positive effect on the yield of metal recovered from the process.

[0086] The internal space (9) of the settler (8) according to the first aspect may communicate with the lower end of the reaction shaft (5) at a point of the settler (8) closer to the middle of the settler (8) than one of the ends of the settler (8).

[0087] The settler (8) according to the first aspect may have an elongated configuration. In one embodiment, the settler has the shape of a cuboid, wherein the cuboid rests on its base in a horizontal position. The settler may be 12-30 m long, 4-12 m wide and 1-3 m high.

[0088] The inventors have discovered that the structure of the settler (8) has many advantages. For example, the first part (18) of the settler has a low dust content because the gases and dust are sucked toward the riser (13) along with the exhaust gases through the gas section of the second settler part (19). This lower dust content creates a relatively dust-free environment for the feed device (30). This relatively dust-free atmosphere helps minimize the dust discharged from the furnace through the feed device (30). In addition, the first part (18) of the settler has a lower pressure than the second settler part (19) because the gases and dust are sucked toward the riser shaft (13) along with the exhaust gases through the gas section of the second settler part (19). This lower pressure helps minimize the emission of SO2 from the furnace through the feed device (30).

[0089] The suspension smelting furnace may include a partition baffle for preventing oxidized dust generated in the suspension smelting furnace from entering at least a portion of the first settler section (18). The partition baffle may extend downward from the top of the first settler section (18) into the first settler section (18). The partition baffle may further minimize dust content in the first settler section (18) and reduce pressure.

[0090] In conventional suspension smelting furnaces, such as the one disclosed in Finnish Patent No. 22694, the end of the settler wall close to the reaction shaft is subject to significant wear due to the tightness of the reaction shaft, which is the hottest part of the settler. In the suspension smelting furnace according to the present invention, the end wall of the settler is located at a distance from the hottest part of the settler, so wear will not be a problem.

[0091] In one embodiment, the suspension smelting furnace comprises a reducing agent supply device for supplying a reducing agent to at least one of the matte or metal alloy layer and the slag layer (10, 11) in the first settler section (18). The first settler section (18) may also comprise a burner for generating a reducing atmosphere in at least a portion of the first settler section (18). The burner may be used to generate a reducing atmosphere in at least a portion of the first settler section (18), for example by consuming oxygen present in the first settler section (18) during the combustion process. This further reduces the oxygen content in the first settler section (18).

[0092] According to the first aspect, the first settler portion (18) may have a first proximal end at the landing area (7) and a first distal end at the opposite end of the first settler portion (18), the first distal end being also a first end wall structure (27) of the settler (8), and wherein the supply device (30) is arranged at the first distal end of the first settler portion (18).

[0093] Alternatively, the feed device (30) may be arranged in the side wall of the settler in the first settler section (18). Figure 3 Alternatively, the supply device (30) may be arranged in the first settler section 18 at the top of the settler. Figure 2 As shown in FIG. 2 , the supply device ( 30 ) may be 0.2 to 2 m, or 0.4 to 1.8 m, or 0.6 to 1.6 m away from the first end wall structure 27 .

[0094] The supply device (30) may include a flow channel for guiding the molten material from the end wall structure (27) or the side wall or the top of the settler (8) into the internal space of the settler (9). The flow channel is capable of guiding the molten material so that the molten material does not directly contact the end wall structure (27) or the side wall or the top of the settler (8). In this way, the internal structure of the settler will not be worn due to continuous contact with the newly introduced hot molten material.

[0095] The position of the feed device (30) has the advantage of maximizing the distance between the inlet of the feed device (30) and the reaction shaft (5), which maximizes the contact time between the molten material and the products of the furnace. This is beneficial because the amount of material exchange between the molten material, especially the slag, and the reaction shaft products is maximized.

[0096] The second settler portion (19) according to the first aspect may have a second proximal end at the landing area (7) and a second distal end at the opposite end of the second settler portion (19), the second distal end also being the second end wall structure (28) of the settler (8), and wherein the first discharge port (15) and the second discharge port (17) are arranged at the second distal end of the second settler portion (19).

[0097] Alternatively, the first tapping opening (15) may be arranged in the side wall of the settler (8) in the second settler section (19), preferably at a distance of less than 2 m from the end wall (28). Figure 5 Alternatively, the second tapping opening (17) can be arranged in the side wall of the settler (8) in the second settler section (19), preferably at a distance of less than 2 m from the end wall (28). Figure 4 The first and second tapping ports (15, 17) may both be located in the side wall, or one of the first or second tapping ports (15, 17) may be located in the side wall and one of the first or second tapping ports (15, 17) may be located in the end wall (28).

[0098] The location of the first and second tapholes (15, 17) has the advantage of forcing the melt from the feed means (30) to move through the reaction shaft to discharge the material before entering the tapholes.

[0099] The suspension smelting furnace according to the first aspect may comprise a suction device for conducting process gas (12) from the suspension smelting furnace.

[0100] In one embodiment, the suction device is a blower further along the process gas line.

[0101] method

[0102] The description related to the above suspension smelting furnace applies to the suspension smelting furnace in the description related to the following method.

[0103] According to a second aspect, there is provided a method for producing copper matte or a metal alloy in a suspension smelting furnace, comprising:

[0104] i. feeding the concentrate or copper matte (1) into a reaction shaft (5) of a suspension smelting furnace via a burner for burning the concentrate or copper matte (4) to form a jet of at least partially oxidized suspension (6) in the reaction shaft (5),

[0105] ii. receiving a jet of at least partially oxidized suspension (6) in a landing zone (7) of a settler (8) communicating with the lower end of the reaction shaft (5), wherein the settler (8) has an interior space (9) and a first end wall structure (27) at one end of the settler (8) and a second end wall structure (28) at an opposite end of the settler (8), and wherein the settler (8) extends from the landing zone (7) in two opposite directions so that the settler (8) comprises a first settler portion (18) on a first side of the landing zone (7) and a second settler portion (19) on an opposite second side of the landing zone (7),

[0106] iii. forming a matte or metal alloy layer (10) in the inner space (9) of the settler (8) and a slag layer (11) on top of the matte or metal alloy layer (10),

[0107] iv. discharging slag (14) from the slag layer (11) in the settler (8) through a first tapping port (15) arranged in the second settler section (19), and

[0108] v. discharging the matte or metal alloy (16) from the matte or metal alloy layer (10) in the settler (8) through a second tapping port (17) arranged in the second settler section (19),

[0109] wherein the first discharge port (15) is arranged at a height above the second discharge port (17) in the vertical direction, and wherein the method further comprises

[0110] vi. supplying molten material (31) into the suspension smelting furnace via a supply device (30), wherein the supply device (30) is connected to the settler (8) in the first settler section (18), and the molten material (31) is supplied to the first settler section (18) above the slag layer (11).

[0111] If the suspension smelting furnace is an FSF, the concentrate (1) may be fed to the burner (4), and if the suspension smelting furnace is an FCF, the matte (1) may be fed to the burner (4). If the suspension smelting furnace is an FSF, the method may include forming a layer of matte (10) below the slag layer (11), and if the suspension smelting furnace is an FCF, the method may include forming a layer of metal alloy (10) below the slag layer (11). If the suspension smelting furnace is an FSF, copper or nickel concentrate may be fed to the burner.

[0112] The method according to the second aspect may further comprise directing process gas (12) from the suspension smelting furnace via an uptake chimney (13) having a lower end communicating with the settler (8) in the second settler section (19).

[0113] The method according to the second aspect may further include supplying flux (1), oxygen-containing reaction gas (1), solidified slag (1), dust (1) and / or material to be reduced (1) through a concentrate burner or a matte burner (4).

[0114] According to a second aspect, the copper matte may include copper matte, the metal alloy may include blister copper, or the copper matte may include nickel matte.

[0115] The copper matte according to the second aspect may comprise copper or nickel matte, depending on whether copper or nickel concentrate is used.The metal alloy according to the second aspect may comprise blister copper.

[0116] The molten material (31) according to the second aspect may include slag, wherein the slag may include iron and copper oxides and a flux, or wherein the slag may include iron and nickel oxides and a flux.

[0117] The feeding device (30) according to the second aspect may be located in the first settler section (18) closer to the first end wall structure (27) than in the middle of the settler (8).

[0118] The molten material (31) according to the second aspect may be recycled from the second suspension smelting furnace or the Pierce Smith converter to the supply device (30).

[0119] The molten material may be circulated from the FCF to the FSF if copper concentrate is used, or from the Pierce Smith converter to the FSF if nickel concentrate is used. In one embodiment, if copper concentrate is used, matte is added from the FSF to the FCF and the slag is circulated from the FCF back to the FSF. In one embodiment, if nickel concentrate is used, matte is added from the FSF to the Pierce Smith converter and the slag is circulated from the converter back to the FSF.

[0120] The internal space (9) of the settler (8) according to the second aspect may communicate with the lower end of the reaction shaft (5) at a point of the settler (8) closer to the middle of the settler (8) than one of the ends of the settler (8).

[0121] The settler (8) according to the second aspect may have an elongated configuration.

[0122] According to the second aspect, the first settler portion (18) may have a first proximal end at the landing area (7) and a first distal end at the opposite end of the first settler portion (18), the first distal end being also a first end wall structure (27) of the settler (8), and wherein the supply device (30) may be arranged at the first distal end of the first settler portion (18).

[0123] The second settler portion according to the second aspect may have a second proximal end at the landing area (7) and a second distal end at the opposite end of the second settler portion (18), the second distal end also being the second end wall structure (28) of the settler (8), and the first discharge port (15) and the second discharge port (17) may be arranged at the second distal end of the second settler portion (19).

[0124] According to a second aspect, process gases (12) coming from the suspension smelting furnace can be guided by suction via an uptake chimney (13).

[0125] example

[0126] The following examples show two processes in which blister copper is produced in a process of the present invention comprising an FSF and an FCF. In the processes, copper concentrate is added to the FSF where matte and slag are produced. Copper matte is then added to the FCF where blister copper and slag are produced. In process 1, no slag is recycled from the FCF to the FSF in molten form. However, some slag is recycled from the FCF to the FSF in solid form. In process 2, the slag is recycled from the FCF to the FSF in a molten state and some of the slag is recycled in solid form.

[0127] The following stream is evaluated in the example.

[0128] Table 1. Stream definitions

[0129]

[0130]

[0131] Details and results of these processes are shown in the table below.

[0132] Table 2. Details of the process and results

[0133]

[0134]

[0135] As shown in the table above, Process 2 results in several OPEX savings. The most significant OPEX savings are listed in the table below.

[0136] Table 3. OPEX savings

[0137]

[0138]

[0139] In addition, compared with process 1, water consumption in process 2 was reduced by about -3m3 / h.

[0140] Therefore, Process 2 brings multiple OPEX savings and reduces water consumption compared to Process 1. This has a significant positive impact on both the environment and the economy.

Claims

1. A suspension smelting furnace, comprising: i. a reaction shaft (5) provided with burners for burning concentrate or copper matte (4) and feeding the concentrate or copper matte (1) into the reaction shaft (5) to form a jet of at least partially oxidized suspension (6) in the reaction shaft (5), ii. A settler (8) in communication with the lower end of the reaction shaft (5), wherein the settler (8) has: an interior space (9), and a first end wall structure (27) at one end of the settler (8), and a second end wall structure (28) at the opposite end of the settler (8), and a landing area (7) for the jet of the at least partially oxidized suspension (6) in the interior space (9) of the settler (8) below the lower end of the reaction shaft (5), and wherein the settler (8) extends from the landing area (7) in two opposite directions. The settler (8) is configured to receive the at least partially oxidized suspension (6) from the reaction shaft (5) at the landing zone (7) and to form a layer (10) of matte or metal alloy and a layer of slag (11) on top of the layer (10) of matte or metal alloy in the inner space (9) of the settler (8), iii. a first tapping port (15) arranged in the second settler portion (19) for discharging slag (14) from the slag layer (11) in the inner space (9) of the settler (8), and iv. a second tapping port (17) arranged in the second settler portion (19) for discharging the matte or metal alloy (16) from the layer (10) of the matte or metal alloy in the inner space (9) of the settler (8), wherein the first tapping port (15) is arranged at a height above the second tapping port (17) in the vertical direction, and wherein the suspension smelting furnace further comprises v. A supply device (30) for supplying molten material (31) to the suspension smelting furnace, wherein the supply device (30) when in use communicates with the settler (8) in the first settler section (18) above the slag layer (11).

2. The suspension smelting furnace according to claim 1, characterized in that: The suspension smelting furnace further comprises an uptake chimney (13) for conducting process gas (12) from the suspension smelting furnace via the uptake chimney (13), wherein the uptake chimney (13) has a lower end communicating with the settler (8) in the second settler section (19).

3. The suspension smelting furnace according to claim 1, characterized in that: The burner (4) is also suitable for supplying flux, oxygen-containing reaction gas, solidified slag, dust and / or material to be reduced.

4. The suspension smelting furnace according to claim 1, characterized in that: The copper matte comprises copper matte and the metal alloy comprises blister copper, or wherein the copper matte comprises nickel matte.

5. The suspension smelting furnace according to claim 1, characterized in that: The molten material (31) includes slag.

6. The suspension smelting furnace according to claim 5, characterized in that: The slag comprises iron and copper oxides and a flux, or wherein the slag comprises iron and nickel oxides and a flux.

7. The suspension smelting furnace according to claim 1, characterized in that: The supply device (30) is positioned in the first settler section (18), closer to the first end wall structure (27) than to the middle of the settler (8).

8. The suspension smelting furnace according to claim 1, characterized in that: The internal space (9) of the settler (8) is connected to the lower end of the reaction furnace shaft (5) at a point of the settler (8), and the point is closer to the middle of the settler (8) than one of the ends of the settler (8).

9. The suspension smelting furnace according to claim 1, characterized in that: The settler (8) has an elongated configuration.

10. The suspension smelting furnace according to claim 1, characterized in that: The first settler portion (18) has a first proximal end at the landing area (7) and a first distal end at the opposite end of the first settler portion (18), the first distal end being also the first end wall structure (27) of the settler (8), and wherein the supply device (30) is arranged at the first distal end of the first settler portion (18).

11. The suspension smelting furnace according to claim 1, characterized in that: The second settler portion (19) has a second proximal end at the landing area (7) and a second distal end at the opposite end of the second settler portion (19), the second distal end also being the second end wall structure (28) of the settler (8), and wherein the first tapping port (15) and the second tapping port (17) are arranged at the second distal end of the second settler portion (19).

12. The suspension smelting furnace according to any one of claims 2 to 11, characterized in that: The suspension smelting furnace comprises a suction device for conducting process gas (12) from the suspension smelting furnace.

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