Inner surface of smelting furnace

Abstract

The present invention relates to a furnace comprising a wall having an inner surface (2) comprising a plurality of bricks (102) and / or compressible ramming mass (103) and a plurality of first steel inserts (104). The first steel inserts (104) are arranged between the bricks (102) and / or compressible ramming mass (103). The present invention also relates to a cooling element comprising a plurality of bricks (102) and / or compressible ramming mass (103), a plurality of first steel inserts (104), a method for generating an autogenous protective layer on an inner surface (2) of the furnace and to the use of the furnace in a direct iron reduction process, electric smelting process, electric reduction process, flash smelting process, flash converting process, bath smelting process or bath converting process is provided.

Description

[0001] INNER SURFACE OF SMELTING FURNACE

[0002] FIELD OF THE INVENTION

[0003] The invention relates to a furnace comprising a wall having an inner surface comprising a plurality of bricks and / or compressible ramming mass and a plurality of first steel inserts . The invention also relates to a cooling element comprising a plurality of bricks and / or compressible ramming mass and a plurality of first steel inserts , a method for generating an autogenous protective layer on the inner surface of a furnace , and the use of the furnace in a direct iron reduction process , electric smelting process , electric reduction process , flash smelting process , flash converting process , bath smelting process or bath converting process is provided .

[0004] BACKGROUND OF THE INVENTION

[0005] Furnaces used in electric smelting processes , electric reduction processes , flash smelting processes , flash converting processes , bath smelting processes and bath converting processes typically have a gas phase zone and a liquid phase zone . The liquid phase zone may be the lower portion of a furnace where , e . g . , matte or metal alloy or metal and slag would be present when the furnace is in operation . The gas phase zone may be the corresponding upper portion of the furnace . During operation, gas may be fed to the furnace and gas may also be generated in the furnace . The gas usually has a high temperature and may contain small , melted particles , which move in a vertical direction. This vertical movement may cause abrasion on the inner surface of the furnace in the gas and liquid phase zone.

[0006] The inner surface of furnaces often contain bricks. However, the bricks may wear over time due to the hot gas and small melted particles, which move in a vertical direction and might need to be replaced at certain intervals.

[0007] As such, there in a need for improving the inner surface of furnaces.

[0008] SUMMARY

[0009] According to a first aspect, a furnace comprising a wall, the wall having an inner surface, the inner surface comprising: a plurality of bricks (102) and / or compressible ramming mass (103) ; and a plurality of first steel inserts (104) , wherein the first steel inserts (104) are arranged between the bricks (102) and / or compressible ramming mass is provided.

[0010] According to a second aspect, a cooling element (17) for a furnace is provided, the cooling element (17) comprising a housing (18) , the housing comprising channels (19) for the flow of cooling water or refrigerants, wherein the cooling element further comprises: a plurality of bricks (102) and / or compressible ramming mass (103) ; and a plurality of first steel inserts (104) , wherein the first steel inserts (104) are arranged between the bricks (102) and / or compressible ramming mass (103) . According to a third aspect , a method for generating an autogenous protective layer on an inner surface of a furnace having an inner surface according to the first aspect is provided, the method comprising capturing melted or solid particles present in the furnace during operation, wherein the melted or solid particles are captured on the first steel inserts .

[0011] According to a fourth aspect , a use of the furnace according to the first aspect , or a use of the cooling element according to the second aspect in a furnace , in a direct iron reduction process , electric smelting process , electric reduction process , flash smelting process , flash converting process , bath smelting process or bath converting process is provided .

[0012] BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings , which are included to provide a further understanding of the invention and constitute a part of this specification, illustrate embodiments of the invention and together with the description help to explain the principles of the invention . In the drawings :

[0014] Figure 1 shows a furnace having an inner surface comprising a plurality of bricks , compressible ramming mass , a plurality of first steel inserts and second steel inserts ;

[0015] Figure 2 shows a part of an inner surface of a furnace , the inner surface comprising a plurality of bricks , compressible ramming mass , a plurality of first steel inserts and second steel inserts ; and Figure 3 shows a cooling element comprising a plurality of bricks, compressible ramming mass, a plurality of first steel inserts and second steel inserts.

[0016] DETAILED DESCRIPTION

[0017] It is obvious to a person skilled in the art that with the advancement of technology, the basic idea of the invention may be implemented in various ways. The invention and its embodiments are thus not limited to the examples described below, instead they may vary within the scope of the claims.

[0018] The description related to the furnace having an inner surface described below also apply to the cooling element described below and vice versa.

[0019] A furnace having an inner surface comprising steel inserts

[0020] According to a first aspect and as seen in figure 1, a furnace comprising a wall, the wall having an inner surface (2) , the inner surface (2) comprising: a plurality of bricks (102) and / or compressible ramming mass (103) ; and a plurality of first steel inserts (104) , wherein the first steel inserts (104) are arranged between the bricks (102) and / or compressible ramming mass is provided.

[0021] The furnace may be a furnace for an electric smelting process, electric reduction process, flash smelting process, flash converting process, bath smelting process or bath converting process. The furnace may be a flash smelting or flash converting furnace and comprise the following: i. a reaction shaft (3) provided with a burner (5) for burning concentrate or matte (6) and feeding concentrate or matte (6) into the reaction shaft (3) to form a jet of an at least partially oxidised suspension in the reaction shaft (3) ; ii. a settler (8) in communication with a lower end of the reaction shaft (3) , wherein the settler (8) has an inner space and a first end wall structure (16) at one end of the settler (8) and a second end wall structure (15) at the opposite end of the settler (8) and a landing zone for the jet of the at least partially oxidised suspension in the inner space of the settler (8) below the lower end of the reaction shaft (3) , and wherein the settler (8) is configured to receive the at least partially oxidised suspension from the reaction shaft (3) at the landing zone and to form a layer of matte or metal alloy (10) and a layer of slag (9) on top of the layer of matte or metal alloy (10) in the inner space of the settler (8) ; iii. a first taphole (11) for discharging slag (12) from the layer of slag (9) in the inner space of the settler (8) , and a second taphole (14) for discharging matte or metal alloy (13) from the layer of matte or metal alloy (10) in the inner space of the settler ( 8 ) ; and vi . an uptake shaft (4) for leading process gases (7) from the smelting furnace via the uptake shaft (4) , wherein the uptake shaft (4) has a lower end in communication with the settler (8) . The term in communication with may refer to an open space being available between the discussed components such that the components share the open space, and such that material can be freely exchanged between the components .

[0022] The settler (8) may further comprise two side walls, a bottom and a roof extending between the first end wall structure (16) and second end wall structure (15) . The end wall structures (16, 15) may have the form of a square or rectangle such that the side walls, bottom and roof extend from the peripheries of the first end wall (16) to the peripheries of the second end wall (15) , and thereby form a closed space between the end walls (27,28) , bottom, roof and sidewalls. The reaction and uptake shafts (3, 4) may be located in or on the roof and the layer of slag and matte or metal alloy (9, 10) may rest on the bottom when the device is in operation.

[0023] Accordingly, the bottom and the roof may extend substantially in the horizontal direction and the end walls (16, 15) as well as the side walls may extend substantially in the vertical direction when the device is placed on the surface on which it is to be used.

[0024] In this disclosure, vertical may mean the direction of gravity and horizontal may mean the direction that is perpendicular to the vertical direction.

[0025] Also in this disclosure, substantially horizontally and / or vertically may mean to a great or significant extent horizontally and / or vertically. For instance, substantially vertically / horizontally could mean a completely vertical / horizontal direction or a deviation from the vertical / hori zontal direction with 2°, or 4°, or 6°, or 8°, or 10° .

[0026] The reaction and uptake shafts ( 3 , 4 ) may have the shape of a cylinder, cube or cuboid, or anything there between, such that they have a bottom, roof and one or more walls . The bottom and roof may extend substantially in the hori zontal direction and the one or more walls may extend substantially in the vertical direction . The reaction and uptake shafts ( 3 , 4 ) may be arranged in or on the roof of the settler ( 8 ) . Therefore , the reaction and uptake shafts ( 3 , 4 ) may have an opening in the bottom or may lack a bottom such that the reaction and uptake shafts ( 3 , 4 ) are in communication with the settler ( 8 ) .

[0027] The furnace may be an electric furnace . The furnace may comprise the following : i . a roof with openings for feeding concentrate or matte in a solid and / or liquid phase , at least one electrode and means for releasing process gases from the furnace ; ii . a furnace space having at least one wall and a bottom for receiving the concentrate or matte and the at least one electrode and for forming a layer of matte or metal alloy and a layer of slag on top of the layer of matte or metal alloy in the furnace space on the bottom, the at least one wall may comprise openings for feeding concentrate or matte in a solid and / or liquid phase ; iii . a first taphole for discharging slag from the layer of slag in the furnace space , and a second taphole for discharging matte or metal alloy from the layer of matte or metal alloy in the furnace space . The roof and bottom may be round and the wall may extend between the roof and bottom. The furnace space may thus have the shape of a cylinder. The bottom and roof may extend substantially in the horizontal direction and the wall in the vertical direction when the furnace is placed on the surface, on which it is to be used. The layer of slag and matte or metal alloy may rest on the bottom when the device is in operation.

[0028] The electric furnace may be a direct iron reduction furnace.

[0029] The furnace may be a bath smelting furnace, bath converting furnace or electric reduction furnace.

[0030] For the avoidance of doubt, some examples of the embodiments are given in connection with a flash smelting / converting furnace throughout the specification. However, the skilled person understands that the embodiments may relate to a flash smelting / converting furnace, electric furnace, bath smelting furnace or bath converting furnace, throughout the specification. The electric furnace may be a direct iron reduction furnace.

[0031] For the avoidance of doubt, the wall having an inner surface (2) may refer to the side walls and / or end wall structures (16, 15) of the settler (8) and / or the one or more walls of the reaction and / or uptake shafts (3, 4) of the flash smelting / converting furnace or to the wall of the electric furnace. The wall having an inner surface (2) may refer to any wall structure of the inner space of a bath smelting furnace, bath converting furnace or electric reduction furnace.

[0032] The inner surface (2) of the wall (s) of the furnace may be partially or completely covered with bricks (102) and / or compressible ramming mass (103) . The wall (s) of the furnace may also comprise copper. The copper may be partially or completely covered with bricks (102) and / or compressible ramming mass and, thus, the inner surface (2) may also comprise copper. The inner surface (2) may be composed of one or more cooling element (s) (17) . Accordingly, the inner surface (2) may comprise one or more cooling element (17) comprising a housing (18) comprising copper. A cooling element may refer to a component designed to manage extreme temperatures generated during the process in the furnace. The cooling element (17) may contain channels (19) for the flow of cooling water or refrigerants. The housing (18) may be partially or completely covered with bricks (102) and / or compressible ramming mass (103) .

[0033] The inner surface (2) of a wall of a furnace may refer to the internal lining that come into direct contact with the materials being processed and / or the high temperatures generated during the process.

[0034] A brick may refer to a refractory brick, also known as firebrick, which is a type of brick that is specially designed to withstand high temperatures and thermal stresses. The brick may be a rectangular building unit made from clay, concrete, or other ceramic materials. The bricks (102) may have a size 0.03 x 0.03 x 0.03 m to 0.4 x 0.4 x 0.4 m. The bricks (102) may comprise clay or shale; a mixture of cement, sand, and water; or a mixture of sand and lime.

[0035] The above dimensions may refer to the length x the height x the width. In other words, the above dimensions may refer to the smallest box into which one brick (102) would fit. The first steel inserts (104) may each have an elongated shape.

[0036] In this disclosure, elongated shape may refer to a geometric form that is characterized by having one dimension significantly longer than the others.

[0037] The first steel inserts (104) may each have the shape of a rod or beam. The first steel inserts (104) may have the shape of a beam in the longitudinal direction and the shape of a rectangle or rounded rectangle or hourglass or double dovetail or a combination of these in the transverse direction.

[0038] For the avoidance of doubt, the longitudinal direction may refer to the direction along the length of the elongated shape and the transverse directions may refer to the directions perpendicular to the longitudinal direction, encompassing both width and height or diameter .

[0039] The above dimensions may refer to the length of the longitudinal direction x the height of the transverse direction x the width of the transverse direction. In other words, the above dimensions may refer to the smallest box into which the first steel insert (104) would fit.

[0040] As seen in figure 2, each brick (102) according to the first aspect may have a top surface, a bottom surface, two end surfaces and two side surfaces, and the bricks (102) may be arranged in the inner surface (2) on top of each other such that the bottom surface of an upper brick (102) faces the top surface of a lower brick (102) , and a first steel insert (104) may be arranged between the bottom surface of an upper brick (102) and the top surface of a lower brick (102) . The first steel insert (104) according to the first aspect may be arranged between the bottom surface of an upper brick (102) and the top surface of a lower brick (102) and compressible ramming mass (103) may be arranged between the bottom surface of an upper brick (102) and the top surface of a lower brick (102) , preferably such that the first steel insert (104) and compressible ramming mass (103) are arranged between the same upper and lower brick (102) .

[0041] For the avoidance of doubt, the bricks (102) may be arranged in the inner surface (2) such that the bottom surfaces of the bricks (102) point towards the bottom of the furnace and the top surfaces of the bricks (102) point towards the roof of the furnace.

[0042] Also for the avoidance of doubt, "some sides of the bricks" facing each other may refer to the sides being placed such that the sides are directed towards each other. The sides do not necessarily touch each other .

[0043] The first steel inserts (104) may be partially embedded in the wall of the furnace. The first steel inserts (104) may be embedded in the wall of the furnace such that the first steel inserts (104) are embedded in the part of the wall that is behind the bricks (102) , e.g. the housing (18) of the cooling element (s) (17) . For example, the wall may comprise a layer of copper, or another material, and a plurality of bricks (102) and / or compressible ramming mass (103) arranged in front of the layer of copper or other material. The layer of copper, or another material may refer to the housing (18) of the cooling element (17) . In front of may refer to the bricks (102) and / or compressible ramming mass (103) being arranged between the interior of the furnace and the layer of copper, or another material. The first steel inserts (104) may be embedded in the layer of copper, or other material, such that the longitudinal direction of the first steel inserts (104) extend substantially horizontally along the inner surface (2) of the wall and create a protrusion extending towards the interior of the furnace. The bricks (102) may be arranged between the protruding first steel inserts (104) , such that the top and / or bottom surface (s) of a brick (102) face the first steel inserts (104) . Further, the compressible ramming mass (103) may be arranged between the bricks (102) and the first steel inserts (104) .

[0044] The first steel inserts (104) may additionally or alternatively be attached to the wall through attaching means . The attaching means may extend through the wall of the furnace such that the attaching means are attached to the first steel inserts (104) in one end and attached to the outside of the wall of the furnace in another end. When attaching means are used, the first steel inserts (104) may be partially embedded in the wall of the furnace, or the first steel inserts (104) may be attached to the attaching means such that the attaching means extends through the wall all the way to the layer of bricks (102) . The first steel inserts may be attached to the layer of copper, or another material though a dove tail shape.

[0045] The inventors have found that arranging the first steel inserts (104) and compressible ramming mass and / or the bricks (102) as described above is beneficial because the first steel inserts (104) protect the bricks (102) and / or compressible ramming mass from wear due to melt or gas moving in a perpendicular direction of the steel inserts (104) , that are present in the interior of the furnace, adjacent to the bricks (102) and / or compressible ramming mass (103) . The first steel inserts (104) may also capture solid or melted particles present in the gas. Further, the compressible ramming mass (103) alone or between the bricks (102) and the first steel inserts (104) allows for thermal expansion / contraction of both the first steel inserts (104) and the bricks

[0046] (102) , while still insulating the layer of the wall behind the bricks (102) and / or compressible ramming mass

[0047] (103) and first steel inserts (104) .

[0048] The compressible ramming mass (103) may be arranged between each first steel insert (104) and brick (102) or on one side of the brick (102) such that the top surface of the brick (102) is in contact with the compressible ramming mass (103) and the bottom surface of the brick (102) is in contact with the first steel insert (104) or vice versa.

[0049] Optionally, the inner surface (2) comprises no bricks (102) but instead compressible ramming mass (103) and first steel inserts (104) at certain intervals such that protection of the compressible ramming mass (103) against wear is achieved. Optionally, the inner surface (2) comprises no compressible ramming mass (103) but instead bricks (102) and first steel inserts (104) at certain intervals such that protection of the bricks (102) against wear is achieved. If no compressible ramming mass (103) is present, some other elastic material or sacrificial material may be present between the bricks (102) and the steel inserts (104) such that thermal expansion of the bricks (102) and steel inserts (104) is allowed. Sacrificial material may refer to a material that can react or degrade under specific conditions to prevent the degradation of a critical component .

[0050] The first steel inserts (104) may be arranged in the inner surface (2) of the furnace such that the direction of flow of gas, when the furnace is in operation, is substantially perpendicular to the longitudinal direction of the first steel inserts (104) . Accordingly, the longitudinal direction of the first steel inserts (104) may extend substantially parallel to the bottom and roof of the furnace.

[0051] The inventors have found that first steel inserts (104) having the above discussed shape, orientation and dimensions is particularly useful for protecting the bricks from wear due to movement of hot gas and melted material adjacent to the bricks (102) both in the liquid and gas phase of the furnace.

[0052] For the avoidance of doubt, first steel inserts (104) and compressible ramming mass (103) , elastic material or sacrificial material may be present between each brick (102) in the inner surface (2) of the furnace. Alternatively, first steel inserts (104) and compressible ramming mass (103) , elastic material or sacrificial material may be present between some of the brick (102) in the inner surface (2) of the furnace.

[0053] Each brick (102) according to the first aspect may have a top surface, a bottom surface, two end surfaces and two side surfaces, and the bricks (102) may be arranged in the inner surface (2) next to each other such that the end surface of one brick (102) faces the end surface of another brick (102) , and second steel inserts (105) may be arranged between the end surfaces of the bricks (102) .

[0054] Each brick (102) may have two end surfaces that have a smaller surface area and two side surfaces that have a larger surface area. The two end surfaces may be on opposite sides and the two side surfaces may be on opposite sides of the brick (102) . Accordingly, the bricks (102) may have the shape of a cuboid.

[0055] The second steel inserts (105) may have an elongated shape and extend substantially vertically along the inner surface (2) of the furnace.

[0056] The second steel inserts (105) may be partially embedded in the wall of the furnace or attached to the wall of the furnace through attaching means, as described above in relation to the first steel inserts (104) .

[0057] The inventors have found that it is beneficial to use second steel inserts (105) because the first steel insert are not able to protect the bricks if the distance to the bricks is too long.

[0058] For the avoidance of doubt, second steel inserts (105) may be present between each brick (102) in the inner surface (2) of the furnace. Alternatively, second steel inserts (105) may be present between some of the brick (102) in the inner surface (2) of the furnace .

[0059] Second steel inserts (105) may be arranged between compressible ramming mass (103) as described above in also in cases where no bricks (102) are present.

[0060] Compressible ramming mass (103) according to the first aspect may comprise magnesium oxide, graphite, asphalt or a naphtalene mixture. Sacrificial material may comprise expansion strips such as tar paper and / or bitumen .

[0061] The above compressible ramming mass (103) is beneficial because it provides sufficient elasticity and allows the bricks (102) and steel inserts (104, 105) to expand and withstands high temperatures.

[0062] The first steel inserts (104) according to the first aspect may create protrusions extending from the inner surface (2) .

[0063] In this disclosure, a protrusion typically refers to an insert or feature that extends outward from a surface or structure. It could be a raised portion, a bulge, or an extension that extends beyond the general profile of the object, i.e. the inner surface (2) of the furnace .

[0064] For the avoidance of doubt, the first steel inserts (104) may be embedded in the layer of copper, or other material, such that the longitudinal direction of the first steel inserts (104) extend substantially horizontally along the inner surface (2) of the wall and create a protrusion extending towards the interior of the furnace. The bricks (102) and / or compressible ramming mass (103) may be arranged between the protruding first steel inserts (104) . Accordingly, the first steel inserts (104) may extend beyond the general profile of the layer of copper, or other material. The first steel inserts (104) may further extend beyond the general profile of the bricks (102) and / or compressible ramming mass (103) .

[0065] The inventors have found that first steel inserts (104) creating protrusions in the inner surface (2) of furnaces protect the inner surface (2) and prevent abrasion of the bricks (102) . These inserts are more resistant to heat compared to an inner surface (2) comprising copper or bricks (102) . Without wishing to be bound by theory, it is believed that the protrusions decrease the velocity of hot gas and melted material inside the furnace between the protrusions, which prevents or decreases the wear of the inner surface (2) . Additionally, solid or melted particles inside the furnace may attach to the protrusions, thus not causing wear on the bricks (102) and / or compressible ramming mass (103) of the inner surface (2) .

[0066] The bricks (102) and / or compressible ramming mass (103) and first steel inserts (104) according to the first aspect may be arranged in the gas phase zone of the furnace.

[0067] The bricks (102) and / or compressible ramming mass (103) and first steel inserts (104) according to the first aspect may be arranged in the liquid phase zone of the furnace.

[0068] For the avoidance of doubt, the bricks (102) and / or compressible ramming mass (103) and first steel inserts (104) may be arranged in the inner surface (2) of the wall in the gas or liquid phase zone of the furnace .

[0069] A layer of matte or metal alloy or metal (10) and a layer of slag (9) on top of the layer of matte or metal alloy or metal (10) may be formed in the inner space of the furnace when the furnace is in operation. The gas phase zone of the furnace may refer to the inner space of the furnace that is above the layer of slag (9) when the furnace is in use. The liquid phase zone of the furnace may refer to the inner space of the furnace that is below the gas phase zone of the furnace.

[0070] The furnace according to the first aspect may comprises a reaction shaft (3) and a settler (8) the bricks (102) and / or compressible ramming mass (103) and first steel inserts (104) may be arranged in the settler (8) under the reaction shaft (3) .

[0071] For the avoidance of doubt, the bricks (102) and / or compressible ramming mass (103) and first steel inserts (104) may be arranged in the inner surface (2) of the wall of the settler (8) under the reaction shaft

[0072] (3) .

[0073] The furnace according to the first aspect may comprises an uptake shaft (4) and a settler (8) and the bricks (102) and / or compressible ramming mass (103) and first steel inserts (104) may be arranged in the settler (8) under the uptake shaft (4) .

[0074] For the avoidance of doubt, the bricks (102) and / or compressible ramming mass (103) and first steel inserts (104) may be arranged in the inner surface (2) of the wall of the settler (8) under the uptake shaft

[0075] (4) .

[0076] The inventors have found that the inner surface (2) of the gas phase zone and specifically in the settler (8) under the reaction and uptake shafts (3, 4) is particularly exposed to gas having a high temperature and to solid or melted particles present in the gas. Thus, the inner surface (2) described herein is particularly useful when placed in these locations.

[0077] The first and / or second steel inserts (104, 105) may comprise steel and in particular high temperature resistant steel and / or high corrosion resistant steel. The first and / or second steel inserts (104, 105) may consist of steel and in particular high temperature resistant steel and / or high corrosion resistant steel.

[0078] A cooling element for a furnace

[0079] According to a second aspect and as seen in figure 3, a cooling element (17) for a furnace is provided, the cooling element (17) comprising a housing (18) , the housing comprising channels (19) for the flow of cooling water or refrigerants, wherein the cooling element further comprises: a plurality of bricks (102) and / or compressible ramming mass (103) ; and a plurality of first steel inserts (104) , wherein the first steel inserts (104) are arranged between the bricks (102) and / or compressible ramming mass

[0080] (103) .

[0081] The furnace may be a flash smelting furnace, a flash converting furnace, an electric furnace, bath smelting furnace, bath converting furnace or electric reduction furnace.

[0082] The first steel inserts (104) may each have an elongated shape. The first steel inserts (104) may each have the shape of a rod or beam. The first steel inserts

[0083] (104) may have the shape of a beam in the longitudinal direction and the shape of a rectangle or rounded rectangle or hourglass or a double dove tail shape or a combination of these in the transverse direction.

[0084] The above dimensions may refer to the length of the longitudinal direction x the height of the transverse direction x the width of the transverse direction. In other words, the above dimensions may refer to the smallest box into which the first steel insert (104) would fit.

[0085] The cooling element according to the second aspect may have a hot side and a cold side and each brick (102) may have a top surface, a bottom surface, two end surfaces and two side surfaces, and the bricks (102) may be arranged on the hot side of the housing (18) such that a side surface of the bricks face the housing (18) and such that the bricks are arranged on top of each other such that the bottom surface of an upper brick (102) faces the top surface of a lower brick (102) , and a first steel insert (104) may be arranged between the bottom surface of an upper brick (102) and the top surface of a lower brick (102) .

[0086] The first steel insert (104) according to the second aspect may be arranged between the bottom surface of an upper brick (102) and the top surface of a lower brick (102) and compressible ramming mass (103) may be arranged between the bottom surface of an upper brick (102) and the top surface of a lower brick (102) , preferably such that the first steel insert (104) and compressible ramming mass (103) are arranged between the same upper and lower brick (102) .

[0087] The first steel inserts (104) may be partially embedded in the housing (18) . The first steel inserts (104) may be embedded in the housing (18) such that the longitudinal direction of the first steel inserts (104) extend substantially horizontally along the inner surface (2) of the wall of a furnace and create a protrusion extending towards the interior of the furnace, when the cooling element (17) is used in a furnace. The bricks (102) and / or compressible ramming mass (103) may be arranged between the protruding first steel inserts (104) , such that the top and / or bottom surface (s) of a brick (102) face the first steel inserts (104) . Further, the compressible ramming mass (103) may be arranged between the bricks (102) and the first steel inserts (104) .

[0088] The housing (18) may refer to the outer structure that contains and protects the channels (19) . The housing (18) may comprise or consist of copper. The channels (19) may comprise copper or consist of copper.

[0089] The hot side of the cooling element (17) may refer to the side of the cooling element (17) that faces the inside of the furnace when the cooling element is used in a furnace. The cold side of the cooling element may refer to the opposite side.

[0090] The cooling element (17) may comprise on its hot side compressible ramming mass (103) arranged between first steel inserts (104) such that no bricks (102) are present.

[0091] The cooling element (17) may comprise on its hot side bricks (102) and first steel inserts (104) arranged there between such that no compressible ramming mass is present. If no compressible ramming mass (103) is present, some other elastic material or sacrificial material may be present between the bricks (102) and the first steel inserts (104) such that thermal expansion of the bricks (102) and first steel inserts (104) is allowed .

[0092] The inventors have found that arranging the first steel inserts (104) , the bricks (102) and / or compressible ramming mass (103) as described above is beneficial because the first steel inserts (104) protect the bricks (102) and / or compressible ramming mass (103) from wear due to melt or gas moving in a perpendicular direction of the steel inserts, that are present in the interior of a furnace, adjacent to the bricks (102) and / or compressible ramming mass. The first steel inserts (104) may also capture solid or melted particles present in the gas. Further, the compressible ramming mass (103) alone or between the bricks (102) and the first steel inserts (104) allow for thermal expansion / contraction of both the first steel inserts (104) and the bricks (102) , while still insulating the layer of the cooling element (17) behind the bricks (102) and / or compressible ramming mass (103) .

[0093] The compressible ramming mass (103) may be arranged between each first steel insert (104) and brick (102) or on one side of the brick (102) such that the top surface of the brick (102) is in contact with the compressible ramming mass (103) and the bottom surface of the brick (102) is in contact with the first steel insert (104) or vice versa.

[0094] The cooling element according to the second aspect may have a hot side and a cold side and each brick (102) may have a top surface, a bottom surface, two end surfaces and two side surfaces, and the bricks (102) may be arranged on the hot side of the housing (18) such that a side surface of the bricks face the housing (18) and such that the bricks (102) are arranged next to each other such that the end surface of one brick (102) faces the end surface of another brick (102) , and second steel inserts (105) may be arranged between the end surfaces of the bricks (102) . The second steel inserts (105) may have an elongated shape and may be arranged on the housing (18) such that they extend substantially vertically along the inner surface (2) of a surface when the cooling element (17) is used in a furnace.

[0095] The second steel inserts (105) may be partially embedded in the housing (18) .

[0096] The compressible ramming mass (103) accordimg to the second aspect may comprise magnesium oxide, graphite, asphalt or a naphtalene mixture. Sacrificial material may comprise expansion strips such as tar paper and / or bitumen.

[0097] The first steel inserts (104) according to the second aspect may create protrusions extending from the cooling element (17) .

[0098] The bricks (102) and / or compressible ramming mass (103) may be arranged between the protruding first steel inserts (104) . The top and / or bottom surface (s) of the brick (102) may face the first steel inserts (104) . Accordingly, the first steel inserts (104) may extend beyond the general profile of the housing (18) . The first steel inserts (104) may further extend beyond the general profile of the bricks (102) and / or compressible ramming mass (103) .

[0099] The inventors have found that first steel inserts (104) creating protrusions in the inner surface (2) of furnaces protect the inner surface (2) and prevent abrasion of the bricks (102) and / or compressible ramming mass (103) . These inserts are more resistant to heat compared to an inner surface (2) comprising copper or bricks (102) and / or compressible ramming mass (103) . Without wishing to be bound by theory, it is believed that the protrusions decrease the velocity of hot gas and melted material inside the furnace between the protrusions, which prevents or decreases the wear of the inner surface (2) . Additionally, solid or melted particles inside the furnace may attach to the protrusions, thus not causing wear on the inner surface (2) .

[0100] The first steel inserts (104) according to the second aspect may have an elongated shape and the longitudinal direction of the steel inserts (104) may extend perpendicularly to the channels (19) .

[0101] It has been found that the first and second steel inserts (104, 105) being embedded in the housing (18) are cooled upon action from cooling water or refrigerants flowing in the channels (19) . Specifically, heat transfer to the first steel inserts (104) is significant when they are arranged perpendicularly to the channels (19) .

[0102] The first and / or second steel inserts (104, 105) may comprise steel and in particular high temperature resistant steel and / or high corrosion resistant steel. The first and / or second steel inserts (104, 105) may consist of steel and in particular high temperature resistant steel and / or high corrosion resistant steel.

[0103] For the avoidance of doubt, figure 3 shows a few of the bricks (102) , compressible ramming mass (103) and first steel inserts (104) and second steel inserts (105) . However, the entire hot side of the housing (18) may be covered with the bricks (102) and / or compressible ramming mass (103) , first steel inserts (104) and second steel inserts (105) . Alternatively, a part of the hot side of the housing (18) may be covered with the bricks (102) and / or compressible ramming mass (103) , first steel inserts (104) and second steel inserts (105) .

[0104] A method for protecting the inner surface of a furnace

[0105] According to a third aspect, a method for generating an autogenous protective layer on an inner surface (2) of a furnace having an inner surface (2) according to the first aspect is provided, the method comprising capturing melted or solid particles present in the furnace during operation, wherein the melted or solid particles are captured on the first steel inserts (104) .

[0106] In this disclosure, generating an autogenous protective layer may refer to the spontaneous or selfgenerated buildup of a layer.

[0107] Operation of a flash smelting or flash converting furnace may comprise the following: i. feeding concentrate or matte (6) by means of a burner (5) for burning concentrate or matte (6) into a reaction shaft (3) of the smelting furnace to form a jet of an at least partially oxidised suspension in the reaction shaft (3) ; ii. receiving the jet of an at least partially oxidised suspension in a landing zone of a settler (8) in communication with a lower end of the reaction shaft (3) ; iii. forming a layer of matte or metal alloy (10) and a layer of slag (9) on top of the layer of matte or metal alloy (10) in the inner space of the settler ( 8 ) ; iv. discharging slag (12) from the layer of slag (9) in the settler (8) through a first taphole (11) and discharging matte or metal alloy (13) from the layer of matte or metal alloy (10) in the settler (8) through a second taphole (14) ; and v. leading process gases (7) from the smelting furnace via an uptake shaft (4) having a lower end in communication with the settler (8) .

[0108] The process gases (7) may comprise sulfur dioxide, carbon dioxide, water, metal containing vapors, nitrogen and some reaction shaft product in the form of unsettled suspension particles. The unsettled suspension particles may be the solid or melted particles.

[0109] The inventors have found that these solid or melted particles surprisingly may attach to the first steel inserts (104) described herein. The first steel inserts (104) do not wear as easily as the bricks (102) and / or compressible ramming mass (103) . The solid or melted particles may adhere to the first steel inserts (104) and gradually accumulate during operation of the furnace. This may result in the formation of the autogenous protective layer on the inner surface (2) of a furnace .

[0110] Use

[0111] According to a fourth aspect, the use of the furnace according to the first aspect, or the use of the cooling element according to the second aspect in a furnace, in a direct iron reduction process, electric smelting process, electric reduction process, flash smelting process, flash converting process, bath smelting process or bath converting process is provided.

Claims

CLAIMS1. A furnace comprising a wall, the wall having an inner surface (2) , the inner surface (2) comprising: a plurality of bricks (102) and / or compressible ramming mass (103) ; and a plurality of first steel inserts (104) , wherein the first steel inserts (104) are arranged between the bricks (102) and / or compressible ramming mass.

2. The furnace according to claim 1, wherein each brick (102) has a top surface, a bottom surface, two end surfaces and two side surfaces, and wherein the bricks (102) are arranged in the inner surface (2) on top of each other such that the bottom surface of an upper brick (102) faces the top surface of a lower brick (102) , and wherein a first steel insert (104) is arranged between the bottom surface of an upper brick (102) and the top surface of a lower brick (102) .

3. The furnace according to claim 2, wherein the first steel insert (104) are arranged between the bottom surface of an upper brick (102) and the top surface of a lower brick (102) and wherein compressible ramming mass (103) is arranged between the bottom surface of an upper brick (102) and the top surface of a lower brick (102) , preferably such that the first steel insert (104) and compressible ramming mass (103) are arranged between the same upper and lower brick (102) .

4. The furnace according to any preceding claims, wherein each brick (102) has a top surface, a bottom surface, two end surfaces and two side surfaces,and wherein the bricks (102) are arranged in the inner surface (2) next to each other such that the end surface of one brick (102) faces the end surface of another brick (102) , and wherein second steel inserts (105) are arranged between the end surfaces of the bricks (102) .

5. The furnace according to any preceding claims, wherein the compressible ramming mass (103) comprises magnesium oxide, graphite, asphalt or a naph- talene mixture.

6. The furnace according to any preceding claims, wherein the first steel inserts (104) create protrusions extending from the inner surface (2) .

7. The furnace according to any preceding claims, wherein the bricks (102) and / or compressible ramming mass (103) and first steel inserts (104) are arranged in the gas and / or liquid phase zone of the furnace .

8. The furnace according to claim 7, wherein the furnace comprises a reaction shaft (3) and a settler (8) , and wherein the bricks (102) and / or compressible ramming mass (103) and first steel inserts (104) are arranged in the settler (8) under the reaction shaft (3) .

9. The furnace according to claims 7 or 8, wherein the furnace comprises an uptake shaft (4) and a settler (8) , and wherein the bricks (102) and / or compressible ramming mass (103) and first steel inserts(104) are arranged in the settler (8) under the uptake shaft ( 4 ) .

10. A cooling element (17) for a furnace, the cooling element (17) comprising a housing (18) , the housing comprising channels (19) for the flow of cooling water or refrigerants, wherein the cooling element further comprises: a plurality of bricks (102) and / or compressible ramming mass (103) ; and a plurality of first steel inserts (104) , wherein the first steel inserts (104) are arranged between the bricks (102) and / or compressible ramming mass(103) .

11. The cooling element according to claim 10, wherein the cooling element has a hot side and a cold side and wherein each brick (102) has a top surface, a bottom surface, two end surfaces and two side surfaces, and wherein the bricks (102) are arranged on the hot side of the housing (18) such that a side surface of the bricks face the housing (18) and such that the bricks are arranged on top of each other such that the bottom surface of an upper brick (102) faces the top surface of a lower brick (102) , and wherein a first steel insert(104) is arranged between the bottom surface of an upper brick (102) and the top surface of a lower brick (102) .

12. The cooling element according to claim 11, wherein the first steel inserts (104) are arranged between the bottom surface of an upper brick (102) and thetop surface of a lower brick (102) and wherein compressible ramming mass (103) is arranged between the bottom surface of an upper brick (102) and the top surface of a lower brick (102) , preferably such that the first steel inserts (104) and compressible ramming mass (103) are arranged between the same upper and lower brick(102) .

13. The cooling element according to any of claims 10 to 12, wherein the cooling element has a hot side and a cold side and wherein each brick (102) has a top surface, a bottom surface, two end surfaces and two side surfaces, and wherein the bricks (102) are arranged on the hot side of the housing (18) such that a side surface of the bricks face the housing (18) and such that the bricks (102) are arranged next to each other such that the end surface of one brick (102) faces the end surface of another brick (102) , and wherein second steel inserts (105) are arranged between the end surfaces of the bricks (102) .

14. The cooling element according to any of claims 10 to 13, wherein the compressible ramming mass(103) comprises magnesium oxide, graphite, asphalt or a naphtalene mixture.

15. The cooling element according to any of claims 10 to 14, wherein the first steel inserts (104) create protrusions extending from the cooling element (17) .

16. The cooling element according to any of claims 10 to 15, wherein the first steel inserts (1) have an elongated shape and wherein the longitudinal direction of the steel inserts (1) extend perpendicularly to the channels (19) .

17. A method for generating an autogenous protective layer on an inner surface (2) of a furnace having an inner surface (2) according to claim 1, the method comprising capturing melted or solid particles present in the furnace during operation, wherein the melted or solid particles are captured on the first steel inserts (104) .

18. Use of the furnace according to claim 1, or of the cooling element according to claim 10 in a furnace, in a direct iron reduction process, electric smelting process, electric reduction process, flash smelting process, flash converting process, bath smelting process or bath converting process.

Images