Slag treatment container

Abstract

To provide a slag treatment container which prevents corrosion even when copper refining slag containing iron oxide such as FeO is treated, and to provide a slag treatment method for preventing corrosion even when copper refining slag containing iron oxide such as FeO is treated, and a slag reduction method capable of efficiently recovering valuable metal from copper refining slag.SOLUTION: A slag treatment container for treating slag containing iron oxide includes at least an outer shell 1, a refractory layer 2, and an inner layer 3, wherein the inner layer 3 is a layer brought into contact with the slag and is formed so as to coat the refractory layer 2, and the inner layer 3 is formed of a stainless-based steel plate or a heat-resistant steel plate.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a slag treatment vessel. [Background technology]

[0002] Conventionally, copper smelting has been carried out by roasting copper concentrate in a flash furnace or the like. This copper smelting process allows the recovery of necessary metals such as copper, and the remaining part is a by-product known as "slag." Methods for recovering additional metals from the slag produced by copper smelting have also been widely studied.

[0003] For example, Patent Document 1 discloses a method for recovering valuable metals from copper smelting slag. The technology disclosed in Patent Document 1 includes Step 1, in which copper smelting slag is oxidized using an oxygen-containing gas in the presence of a flux; Step 2, in which the oxidized reaction product obtained in Step 1 is brought into contact with a Cu-Fe alloy bath; and Step 3, in which the contacted Cu-Fe alloy bath obtained in Step 3 is subjected to a smelting process to recover valuable metals. This recovery method is believed to enable efficient removal of harmful compounds from copper smelting slag. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 6516264 Summary of the Invention [Problem to be solved by the invention]

[0005] However, various slags, such as copper smelting slag, contain iron oxides, typically FeO, which severely corrode various refractory equipment used in smelting and recovery processes. Magnesia-chrome bricks are generally used for FeO-containing slag, but even so, areas in contact with high concentrations of FeO-containing slag are subject to severe corrosion, necessitating frequent repairs of equipment, and regular maintenance is essential.

[0006] A typical example is the formation of fayalite-based slag in a flash smelting furnace, which oxidizes copper concentrate. The FeO content of flash smelting furnace slag is high (approximately 60%) in the slag line in the settler section, where the slag flows toward the slag outlet, and in the slag outlet trough, which removes molten slag from the flash smelting furnace and sends it to the slag furnace. This results in a large workload for repairs and replacement.

[0007] From this perspective, there has been a strong demand for the construction of a container that is resistant to corrosion even when treating copper smelting slag containing iron oxides such as FeO. Furthermore, if such a container could be constructed, it would be possible to more easily and efficiently recover metals and other substances produced by the reduction treatment of copper smelting slag, and this would be extremely valuable.

[0008] The present invention has been made in view of the above, and aims to provide a slag treatment vessel that is less susceptible to erosion even when treating copper smelting slag containing iron oxide such as FeO. [Means for solving the problem]

[0009] As a result of extensive research into achieving the above object, the inventors have discovered that the above object can be achieved by covering a refractory layer with a stainless steel plate in a slag treatment vessel for treating slag containing iron oxide, and have thus completed the present invention.

[0010] That is, the present invention includes, for example, the subject matter described in the following sections. Item 1 A slag treatment vessel for treating slag containing iron oxide, comprising: The furnace comprises at least an outer shell, a refractory layer, and an inner layer; the inner layer is a layer that comes into contact with the slag and is formed to cover the refractory layer, The slag treatment vessel, wherein the inner layer is formed of a stainless steel plate or a heat-resistant steel plate. Section 2 The outer shell is made of ordinary steel, Item 1. The slag treatment vessel according to item 1, wherein a heat insulating layer is provided between the outer shell and the refractory layer. Section 3 Item 1 or 2. A slag treatment vessel according to item 1 or 2, wherein the innermost surface of the lid or ceiling is made of stainless steel plate or heat-resistant steel plate. Section 4 Item 4. A method for treating slag, comprising a step of treating slag containing iron oxide in the slag treatment vessel according to any one of Items 1 to 3. [Effects of the Invention]

[0011] The slag treatment vessel of the present invention is less susceptible to corrosion even when treating copper smelting slag containing iron oxides such as FeO. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram showing an example of an embodiment of a slag treatment vessel according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0013]

[0023] In the present specification, the terms "contain" and "comprise" include the concepts of "contain," "comprise," "consist essentially of," and "consist only of."

[0014] Slag treatment vessel The slag treatment vessel of the present invention is a slag treatment vessel for treating slag containing iron oxide, and comprises at least an outer shell, a refractory layer, and an inner layer, the inner layer being a layer that comes into contact with the slag and is formed to cover the refractory layer, and the inner layer is formed of a stainless steel plate or a heat-resistant steel plate.

[0015] The slag treatment vessel of the present invention is less susceptible to corrosion even when treating copper smelting slag containing iron oxides such as FeO.

[0016] Copper smelting slag refers to the residue generated when copper is smelted, and contains, for example, iron oxide such as FeO.

[0017] Fig. 1 is a schematic diagram showing an example of an embodiment of a slag treatment vessel of the present invention. As shown in Fig. 1, a slag treatment vessel A, which is one embodiment of the slag treatment vessel of the present invention, comprises at least an outer shell 1, a refractory layer 2, and an inner layer 3. The inner layer 3 is a layer that comes into contact with the slag S contained in the slag treatment vessel A and is formed so as to cover the refractory layer 2.

[0018] Here, the stainless steel sheet referred to in this specification includes various stainless steel sheets listed in JIS G0203 (2009), such as stainless steel, austenitic stainless steel, ferritic stainless steel, austenitic-ferritic stainless steel, precipitation hardened stainless steel, low-carbon stainless steel, stabilized stainless steel, free-cutting stainless steel, and painted stainless steel.

[0019] The heat-resistant steel plate referred to in this specification may include various heat-resistant steel plates listed in JIS G0203 (2009), such as heat-resistant steel, martensitic heat-resistant steel, ferritic heat-resistant steel, austenitic heat-resistant steel, and precipitation-hardened heat-resistant steel.

[0020] The inner layer 3 is formed of a stainless steel plate or a heat-resistant steel plate. For example, the inner layer 3 can be formed of SUS308.

[0021] Furthermore, the inside of the stainless steel plate or heat-resistant steel plate, i.e., the inside of the vessel, is preferably made of a highly corrosion-resistant material, which makes corrosion by slag less likely to occur.

[0022] The refractory layer 2 is a layer formed of a refractory material. The refractory layer 2 can be formed of, for example, a known refractory material. Specifically, a wide range of refractory materials that can be used in a container for treating slag can be used. Examples of such refractory materials include magnesium oxide-chromium oxide refractory materials, alumina-silica refractory materials, silicon carbide refractory materials, and alumina-chromium oxide refractory materials.

[0023] The outer shell 1 is the layer that forms the outermost part of the container and can be made of, for example, the same material as the outer shell of the slag treatment container inside the container, such as ordinary steel. By making the outer shell 1 out of ordinary steel, it can have sufficient strength to support the weight of the contents of the slag treatment container.

[0024] The slag treatment vessel of the present invention may be provided with a heat insulating material. For example, as shown in FIG. 1, a heat insulating layer 4 may be provided between the refractory layer 2 and the outer shell 1. By providing such a heat insulating layer 4, it is possible to prevent the outer shell 1 from becoming too hot. For example, a wide range of known heat insulating materials can be used as the heat insulating material.

[0025] A lid 5 can be provided on the top opening of the slag treatment vessel of the present invention, as shown in FIG. 1, to seal the vessel. Alternatively, a ceiling can be provided on the top opening of the slag treatment vessel of the present invention to seal the vessel. In this case, the inner surface of the lid or ceiling may be made of the aforementioned ordinary steel, or it is also preferable that it be made of stainless steel plate or heat-resistant steel plate. In particular, when the atmospheric gas inside the vessel contains SO2, forming the innermost surface of the lid or ceiling of the vessel from stainless steel plate or heat-resistant steel plate instead of ordinary steel can easily prevent the lid or ceiling from being corroded by SO2.

[0026] The embodiment shown in Fig. 1 is an example of a slag treatment vessel equipped with a lid. As shown in Fig. 1, the lid 5 is made of a heat insulating material 4 covered with a steel plate 8. The steel plate 8 may be ordinary steel, or may be a stainless steel plate or a heat-resistant steel plate.

[0027] Even if the top surface of the slag treatment vessel of the present invention is not a lid but a ceiling portion integral with the vessel, the interior of such a ceiling portion may contain a heat insulating material.

[0028] It should be noted that the inner surface of the lid and the inner surface of the ceiling refer to the surfaces facing the inside of the container.

[0029] As described above, in the slag treatment container of the present invention, the refractory layer 2 is covered with the inner layer 3, i.e., a stainless steel plate or a heat-resistant steel plate. This prevents direct contact between the refractory layer 2 and the slag containing iron oxides such as FeO in the slag treatment container, thereby reducing the risk of the refractory layer 2 being corroded by the slag. Therefore, even when copper smelting slag is treated in the slag treatment container of the present invention, corrosion of the refractory layer 2 is unlikely to occur, reducing repair work compared to conventional methods, extending the life of the container, and achieving energy savings and improved work efficiency. Furthermore, since corrosion of the refractory layer 2 is unlikely to occur, the risk of slag leaking from the inside of the container to the outside can be reduced, and therefore, using the slag treatment container of the present invention allows for safer work.

[0030] The slag treatment vessel of the present invention can have the same configuration as known slag treatment vessels, as long as it has at least an outer shell 1, a refractory layer 2, and an inner layer 3. For example, as shown in Fig. 1, an air inlet 6 and an exhaust port 7 for introducing gas into the vessel can be provided, and these can be appropriately equipped with valves as shown in Fig. 1.

[0031] The slag treatment vessel of the present invention can be used to treat slag containing iron oxide (i.e., copper smelting slag, hereinafter sometimes simply referred to as "slag"). As described above, slag is formed by copper smelting and contains iron oxides such as FeO, Fe2O3, and Fe3O4. Among these, FeO is contained in large amounts in slag.

[0032] When treating slag using the slag treatment vessel of the present invention, the treatment temperature is preferably lower than the melting point of the inner lining 3, i.e., the melting point of the stainless steel plate or heat-resistant steel plate. In Fig. 1, the slag in the vessel is shown as molten slag, i.e., molten slag.

[0033] The slag treatment method using the slag treatment vessel of the present invention can include a step of treating slag containing iron oxide in the slag treatment vessel. Since the slag treatment method using the slag treatment vessel of the present invention uses the slag treatment vessel, erosion of the vessel due to slag treatment can be reduced. Examples of slag treatment include slag oxidation treatment, slag reduction treatment, and slag purification treatment.

[0034] When treating slag using the slag treatment vessel of the present invention, it is preferable that the atmosphere inside the slag treatment vessel has a low oxygen partial pressure. However, since the stainless steel or heat-resistant steel plate used inside is less likely to react with oxygen, the vessel can also be kept in an oxygen gas atmosphere. However, if the oxygen partial pressure inside the slag treatment vessel is high, even stainless steel or heat-resistant steel plate will oxidize, and there may be a limit to its lifespan. To prepare for such a situation, it is advisable to prepare multiple vessels for slag treatment so that they can be hot-replaced when their lifespan expires.

Claims

1. A slag treatment vessel for treating slag containing iron oxide, comprising: The furnace comprises at least an outer shell, a refractory layer, and an inner layer; the inner layer is a layer that comes into contact with the slag and is formed to cover the refractory layer, The slag treatment vessel, wherein the inner layer is formed of a stainless steel plate or a heat-resistant steel plate.

2. The outer shell is made of ordinary steel, 2. The slag treating vessel of claim 1, wherein a layer of insulation is disposed between the shell and the refractory layer.

3. 3. The slag treatment vessel according to claim 1, wherein the innermost surface of the lid or the ceiling is formed of a stainless steel plate or a heat-resistant steel plate.

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