AU2005227642B2

AU2005227642B2 - Casting trough and method for casting copper anodes

Info

Publication number: AU2005227642B2
Application number: AU2005227642A
Authority: AU
Inventors: Juha Lumppio
Original assignee: Outotec Oyj
Current assignee: Metso Corp
Priority date: 2004-04-01
Filing date: 2005-03-07
Publication date: 2009-09-10
Anticipated expiration: 2025-03-07
Also published as: FI20040477A0; EA008872B1; EA200601572A1; PE20060063A1; AU2005227642A1; DE112005000742B4; CN100553824C; CN1938113A; DE112005000742T5; AR049795A1; ZA200607694B; CA2564631A1; FI20040477A; WO2005095027A1; FI120577B

Description

WO 2005/095027 PCT/F12005/000138 1 CASTING TROUGH AND METHOD FOR CASTING COPPER ANODES The invention relates to a method and arrangement for pouring molten material, such as molten metal, into a casting mold. More precisely, the invention relates to a method and equipment for casting anodes used in electrolytic refining. Controlled pouring and precise feeding in the casting mold is essential for example in connection with the casting of metal anodes. In the production of metals, the next process step after the casting of metal anodes is electrolytic refining, where a prerequisite for achieving a high cathode quality and high efficiency is, among others, a homogeneous quality of the anodes with respect to both shape and weight. In most known methods, anodes are cast in open molds. In the casting of anodes, such as copper anodes, the melt is conducted from the anode furnace for example along a chute to the intermediate trough of the casting equipment, from where the molten metal is further poured to the casting trough. The volume of the intermediate trough is remarkably larger than the volume of the casting trough proper, and it also serves as a balancing intermediate storage between the anode furnace and the casting trough. The quantity of metal contained in the casting trough at the beginning of the pouring step is somewhat larger than the quantity of metal to be administered in the casting mold in each batch. Usually the quantity of metal to be poured to in the casting trough is about double the quantity to be poured in the casting mold. From the casting trough, molten metal is precisely administered in the open casting mold. The casting trough is never completely emptied, but a so-called copper base is left on the bottom. Modern anode casting is realized as an automated process in so-called casting tables, where the casting molds are shifted on a round casting table to the front of the casting trough. When pouring from the casting trough, the feeding is controlled by means of monitoring the trajectory and motional speed of the casting trough as well as its weight. Typically the quantity of melt to be poured into the casting mold of a copper WO 2005/095027 PCT/F12005/000138 2 anode is administered at the accuracy of 3 percentages. Usually the anode weight is within the range 300 - 600 kilograms. For accurately controlling the feeding of the quantity of melt to be poured, the casting trough is provided with weight sensors. The pouring is controlled automatically, and it begins when the casting trough is filled with melt, the initial weight of the trough is measured, and the casting mold is placed in front of the casting trough. In the pouring process, the casting trough is tilted so that the molten metal flows over the casting trough spout to the casting mold. The pouring is arranged to be stopped, when the weight of the casting trough is reduced for the amount of the target weigh of the anode to be cast. Then the casting trough is returned to its initial position to be refilled. During one anode casting process, usually several hundreds of anodes are cast in succession. At the end of the casting process, the casting trough is typically left filled with metal, and the metal is allowed to be solidified in the casting trough. The casting trough is subjected to the necessary maintenance procedures, which often include the renewal of the whole lining of the trough. The present invention makes it possible that the casting trough can be completely emptied of metal, in which case the trough requires lesser maintenance operations. In shape, the anodes used in the electrolytic refining of metals are thick plates, with a thickness of about 30 - 100 millimeters. The height of the anodes is about 900 - 1,500 millimeters, and their width is about 700 - 1,200 millimeters. In the electrolytic tank, the electrode plates are suspended in a vertical position from the protruding brackets, so-called lugs, formed at the top edge of the plate, supported against the tank edges. The anode lugs are formed of the anode metal, often in connection with the casting process. Hence an anode casting mold comprises a flat recess, i.e. cavity, that has the shape of the anode cross-section and is somewhat deeper than the anode thickness.

- 3 Several requirements and problems are connected to the pouring of molten metal in the anode casting mold. In the pouring process, the molten metal must not be splashed to outside the cavity, neither shall it be spilt nor moved so 5 that the melt rises up to the cavity edges and is solidified as edge fin. Consequently the surface of the molten metal poured into the mold must remain tranquil, in order to make the cast to be solidified in the desired shape. On the other hand, the time used for pouring must 10 be as short as possible for maintaining the production capacity on an economically profitable level. The flow of molten metal contains a lot of kinetic energy, which in the pouring of the cast is directed to the bottom 15 of the casting mold and to the melt already contained in the mold, thus causing spilling and splashing. Therefore it is essentially important that the melt pouring height is as low as possible. On the other hand, the kinetic energy of the melt also disturbs the weighing of the 20 casting trough. For minimizing weighing errors, spilling and splashing, it has been attempted to make the pouring step as even as possible. The patent publication US 5,967,219 describes a method for 25 pouring molten metal into a casting mold so that weighing errors are reduced and the pouring step is tranquil. The invention described in said publication is based on the design of the casting trough bottom and on a controlled trajectory of the pouring motion, which conforms to the 30 shape of the casting trough bottom. For achieving the desired result, the described motion of the casting trough must be peaceful and slow. However, this kind of slow pouring results in that the casting step becomes the bottleneck of the overall process. 35 The present invention is based on the basic principle that the direction and quantity of the kinetic energy of the 1610867_1 (GHMatters) 6/08/09 - 4 melt to be poured in the casting trough is affected by the shape of the casting trough. Thus the pouring of the metal into the mold is realized at a pouring height that is as low as possible, in order to prevent the metal from 5 obtaining high potential energy for rising over the edges of the casting mold. The pouring is also realized so that the flowing of the molten metal obtains a high horizontal flow rate with respect to the vertical flow rate. 10 The rapid pouring according to the invention is based on a large mass flow at the beginning of the pouring step. According to an embodiment, the weight-accurate casting according to the invention is realized by slowing the mass flow down at the end of the pouring step. According to the 15 most preferred embodiment of the invention, choking is carried out by means of a choke element, such as a choke brick, arranged in the casting trough; the positioning and design of the choke element is such that an unchoked flow of the molten metal is realized at the beginning of the 20 pouring step, and that a choked flow at the end of the pouring step ensures an accurate feeding in the mold. The choke element enables a rapid inclining of the casting trough, without the flow of the molten metal becoming uncontrolled. 25 According to an embodiment, the flow profile of the molten metal discharged from the casting trough is essentially spread along the whole width of the anode mold. The flow is directed essentially horizontally towards that wall of 30 the casting mold that is opposite with respect to the casting trough, i.e. the rear wall of the casting mold. The horizontal kinetic energy of the flow is first stalled as the melt hits the bottom of the casting mold, and then as the melt collides the pressure wall created by the 35 molten metal already present in the casting trough. The spreading of the flow profile is realized by means of the design of the casting trough spout, for example a spout 1610867_1 (GHMatters) 6/08109 -5 brick. Remarkable advantages are achieved by the invention. An embodiment of the invention enables a casting operation 5 that is more rapid than in the prior art, and as a consequence, the capacity of the casting machine and the casting table are increased. The arrangement according to the invention essentially reduces the undulation of the molten metal during the filling of the casting trough and 10 thus increases feasible casting volume. Owing to the invention, also the undulation of the molten metal in the casting trough is reduced. The fact that the casting operation is speeded up is also based on the fact that the start and end weighings of the casting trough can be made is more rapidly, without waiting for the motions of the molten metal to end, and on the fact that the casting can be started at maximum pouring rate, without harmful spilling and splashing as a result. By means of the invention, the wearing of the casting mold is reduced, and 20 also the need for a coating agent spread in the mold is reduced. According to the present invention there is provided a cast trough for casting metal into a casting mold, said 25 casting trough including a bottom, a spout, side walls and a rear wall opposite to the spout, characterised in that the casting trough has a pouring mechanism provided with at least one weight sensor for accurately feeding the metal in the casting mold, and that the spout comprises a 30 pouring surface that widens towards a pouring edge of the spout that is directed downwardly with respect to the bottom of the casting trough when oriented substantially horizontally, and the side walls extending upwardly from pouring surface define the width of the pouring surface 35 that are essentially parallel with the melt flow. 16108671 (GHMatters) 6/08/09 -6 According to a preferred embodiment of the invention, against the bottom and side walls of the casting trough, 5 in between the spout and the rear wall, there is fitted a choke element for slowing down the mass flow of the molten metal that is directed from the space between the rear wall and the choke element towards the spout. 10 The frame of the casting trough according to the invention can be made for example of steel, in which case the lining of the trough is made by fireproof brickwork or by some other corresponding agent. The choke element of a casting trough according to a preferred embodiment of the 15 invention is designed so that when fitting it in between the side walls of the trough, there is left, between the casting trough bottom and the choke element, an orifice of the desired size, irrespective of the skills of the engineer. The choke element is arranged so that in a 20 casting situation, the orifice is located completely underneath the molten metal surface. The choke element can be a choke brick, and preferably it is a plate-like structure that is arranged in a perpendicular position with respect to the flowing direction of the molten metal 25 and in an essentially vertical position with respect to the bottom of the casting trough. Advantageously the choke element is dented at the bottom edge, so that the orifice is defined by the denting notches of the choke element and the bottom of the casting trough. The denting brackets may 30 extend as far as the bottom of the casting trough. The choke brick can be formed by casting it permanently in the casting trough by means of a suitable mold, by brickwork or by fastening a suitable element to the casting trough. The employed fastening elements can be for instance steel 35 wedges. 16108671 (GHMaters) 6/08/09 - 7 In a casting trough according to an embodiment of the invention, the choke element is advantageously arranged between the spout and the rear wall, so that 40 - 90% of the quantity of metal of the object to be cast can be fed 5 in the space of the casting trough defined by the choke element and the spout. The weight of the casting trough according to an embodiment of the invention is measured by means of one or 1o several weight sensors arranged in connection with the trough tilting mechanism. According to an embodiment of the invention, the tilting of the casting trough can be realized by the mechanism suggested in the patent publication US 5,967,219. According to another embodiment 15 of the invention, the tilting of the casting trough can be realized by a mechanism where the forepart of the casting trough is supported underneath against a stationary support, so that the casting trough can, when being tilted, turn with respect to said support, and the back 20 end of the casting trough is raised by a lifting mechanism, such as a hydraulic cylinder. The tilting of the casting trough can also be realized by some other suitable mechanism. 25 In an arrangement according to an embodiment of the invention, the flow of the molten metal proceeding from the casting trough to the casting mold is adjusted to the desired shape by the casting trough spout. The spout comprises a curved pouring surface directed downwardly 30 from the casting trough bottom. The pouring surface is defined by the pouring edge of the spout and the bottom of the casting trough or by an element of the spout that is parallel with the bottom of the casting trough. The advantageous design of the spout according to the 35 invention is realized by all spout forms that protrude from that element of the spout that is parallel with the bottom of the casting trough and divide the flow of the 1610867_1 (GHMatters) 6/08109 - 8 molten metal evenly along the width of the casting mold at the pouring spot. When viewed from the top, the pouring edge of the spout is curved, parabolic or with a variable radius. When viewed from the top, the pouring edge 5 particularly advantageously constitutes part of the circumference of a circle. The pouring surface is widened towards the pouring edge. The pouring surface is defined by essentially straight lines drawn from the pouring edge to the bottom of the casting trough. The angle of the 10 pouring surface with respect to the bottom of the casting trough can vary within the range 12 - 55 degrees. Advantageously the pouring surface is a conic section. The width of the pouring edge is proportioned to the width of the casting mold cavity, so that the width of the pouring is edge approaches the width of the casting mold cavity. According to a preferred embodiment of the invention, the spout is a spout brick that can be manufactured separately. The spout brick according can be manufactured 20 for example by casting in a mold. The material is some fireproof material, such as brickwork or cast iron. The spout brick can be fitted in many casting troughs with different designs, so that the desired objects are 25 achieved, i.e. an advantageous shaping of the molten metal flow, a desired flow rate and direction of the flow to the casting mold. According to the present invention there is also provided 30 a spout brick that is able to be fitted in a metal casting trough, characterized in that the spout brick includes (i) a pouring surface and a bottom element that fits with a bottom of the casting trough, the pouring surface is angled downwardly from the bottom element, when 35 viewed in an in use orientation and widens towards the pouring edge, and (ii) side walls that are essentially vertical 16108671 (GHMatters) 6108/09 - 8a with respect to the bottom element. In a method according to the invention, the molten metal of the metal anodes is poured to a flat casting trough, s from the casting trough the metal is poured to the casting mold, the mass flow rate of the molten metal from the casting trough to the casting mold is controlled for achieving an even casting surface, and by means of one or several weight sensors arranged in the tilting mechanism 10 of the casting trough, the weight of the cast object is controlled. The mass flow rate of the molten metal from the casting trough to the casting mold is higher at the beginning of the pouring process, when at least 40%, preferably 70 - 80% of the cast metal is poured in the 15 casting mold. According to an embodiment of the invention, in the final stage of the pouring process, the mass flow rate of the molten metal from the casting trough to the casting mold is controlled by means of a choke element installed in the casting trough. According to an 20 embodiment of the invention, at the beginning of the pouring process, the mass flow rate is controlled by means of the trajectory of the casting trough. According to another embodiment of the invention, in the final stage of the pouring process, the mass flow rate is controlled both 25 by means of the trajectory of the casting trough and the choke element of the casting trough. Figures la and lb illustrate casting troughs according to embodiments of the invention. 30 Figure 2a is a side-view illustration of a casting trough and casting mold according to an embodiment of the invention, seen from the direction of the casting mold. 35 Figure 2b is a top-view illustration of the casting trough and casting mold of figure 2a 1610867_1 (GHMetters) 6/08/09 WO 2005/095027 PCT/F12005/000138 9 Figures 3a and 3b illustrate the casting trough and casting mold according to figure 2a, seen along the section A-A. Figures 3a and 3b also illustrate how the molten metal is placed in the casting trough and poured into the casting mold. Figure 4a is a top-view illustration of a spout brick according to an embodiment of the invention. Figure 4b is a side-view illustration of the spout brick of figure 4a. Figures 5a and 5b illustrate a choke brick according to a preferred embodiment of the invention. The casting trough according to figure 1a has a curved bottom 16, side walls 14 and a rear wall 13. The choke brick 12 is placed between the spout, in this case the spout brick 15, and the rear wall 13. The choke brick 12 divides the space defined by the bottom and walls to the casting trough forepart 11 and the casting trough back end 10. The notches made at the bottom edge of the choke brick 12 and the bottom 16 of the casting trough define the slots 19 through which the molten metal flows from the back end 10 to the forepart 11. The height of the choke element is advantageously chosen so that it extends from the bottom of the casting trough to at least the surface level of the melt, while the casting trough is in the filling position. When feeding molten metal in the casting trough, the metal is divided between the casting trough forepart 11 and back end 10. Advantageously the molten metal is fed in the space 10. The spout brick 15 has vertical side walls 17 and a pouring surface 9. The pouring surface 9 is curved downwards and widened towards the spout edge 18. When viewed from above, the spout edge 18 is curved, and the pouring surface 9 is a conic section. The volume of the back end 10 of the casting trough according to the embodiment illustrated in figure 1 is larger than the volume of the forepart 11, because the casting trough is widened at the choke brick 12 towards the rear wall 13. This arrangement makes it possible that a remarkably larger quantity of molten metal can be fed behind the choke brick in the space 10 than in the space 11.

WO 2005/095027 PCT/F12005/000138 10 Figure 1 b illustrates a casting trough according to a preferred embodiment of the invention, provided with a curved bottom 16, side walls 14 and a rear wall 13. The spout brick 15 has vertical side walls 17 and a pouring surface 9. The pouring surface 9 is curved downwardly and widened towards the spout edge 18. When viewed from above, the spout edge 18 is curved, and the pouring surface 9 is a conic section. In the casting troughs according to figures la and 1b, the lining is made of fireproof brickwork, and the frame is made of steel. Figures 2a and 2b show a casting trough 30 and in front of it a casting mold for a copper anode 24. The casting mold 24 has an anode-shaped casting cavity 31. In the embodiment according to figure 2, the side walls 27 of the casting trough continue in parallel and in a straight line as far as the spout brick 25 of the rear wall 23, in which case the bottom 26 of the casting trough is essentially rectangular when viewed from the top. The choke brick 22 is arranged at right angles to the side walls 27, and it extends from side wall to side wall. The bottom edge of the choke brick 22 is provided with two notches that define the slots left between the bottom 26 and the choke brick 22, through which slots the molten metal flows from the space 20 to the space 21. Against the side walls 27, there are arranged three pairs of upwardly directed support beams 39 for fitting the spout brick 22 in the desired spot in between the rear wall 23 and the spout brick 25. When necessary, the location of the choke brick can be adjusted at the spots defined by the three pairs of support beams. The choke brick 22 is supported in place by two wedges 61 and fastening elements 62. The arrows 28 show the direction of the molten metal flow as well as turbulences when the metal flows out of the casting trough 30 and settles in the cavity 31 of the casting mold 24. Figures 3a, 3b and 3c illustrate the embodiment of the invention seen in figures 2a and 2b, viewed along the section A - A. In figure 3a, the casting trough 30 is WO 2005/095027 PCT/F12005/000138 11 in the filling position, filled with molten metal 32. In figure 3b, the casting trough 30 is inclined for pouring, and the molten metal 32 flows from the casting trough 30 to the casting mold 24. In figure 3c, the casting trough 30 is returned to the filling position after pouring. The bottom 26 of the casting trough is curved, so that the height hm of the molten metal remains low in relation to the length of the casting trough, when measured from the rear wall 23 to the spout brick 25. The spout brick 40 according to figure 4 is fitted in the casting trough. The spout brick can be manufactured for example separately, by casting of fireproof material. The spout brick comprises a pouring surface 49 and a bottom element 41 fitted in parallel with the casting trough bottom. The pouring surface 49 of the spout brick is curved downwardly from the casting trough bottom, and it is a conic section. The spout brick has essentially vertical side walls 42, 43. At the pouring surface, the side walls 43 are lowered towards the pouring surface edge 45. The corner radius of the edge between the surfaces 41 and 49 is preferably 0.5 - 800 mm. Figures 4a and 4b illustrate a spout brick according to figure 4 when installed in front of the casting mold 44 and above it, in operating position. The pouring surface 49 of the spout brick is widened towards the pouring edge 45. The radius of curvature r of the pouring edge is proportioned to the width A of the casting mold cavity, and the length of the radius of curvature r is advantageously 0.2 - 6 times the measure of A. The length B of the pouring surface depends on the chosen brick height E in proportion to the casting mold, and on the angle epsilon (E) of the cone surface in relation to the direction of the bottom element 41 of the spout brick. The size of the angle epsilon (E) is advantageously within the range 12 - 55 degrees. The width C of the spout brick is advantageously 0.3 - 0.95 times the width A of the casting mold cavity, particularly advantageously 0.5 - 0.8 times the width A of the casting mold cavity. The measure D of the spout brick surface 41 is chosen so that the spout brick is suitably integrated with the rest of the design of the casting trough. The operation of the spout brick is advantageously affected by minimizing the - 12 pouring height F. The pouring height can be for example within the range 70 - 400 mm, preferably 130 - 200 mm. The width K of the pouring edge 45 is advantageously 0.5 0.98 times the width A of the casting mold cavity, s preferably 0.6 - 0.7 times the width A of the casting mold cavity. The choke brick 50 illustrated in figures 5a and 5b is provided with denting formed by three notches 51 , 52, 53. 10 The height of the choke brick extends at least from the bottom of the casting trough to the level of the top edge of the side walls. In the casting of copper, the height hi of the notches is preferably 10 - 100 millimeters. The total area of the notches is preferably within the range 15 1500 - 17000 square millimeters. In practical work, the total area of the notches can easily be increased simply by breaking some dents off the brick. Consequently, for finding a suitable notch area, it is advantageous to start the casting with a choke brick provided with several 20 dents. From the point of view of pouring a cast according to the invention, the essential factors are the height and total area of the notch or notches in the choke brick. The sum of the notch widths I1+I2+I3 is preferably 0.05 - 0.9 times the brick width It. The thickness dt of the brick 25 can be less than 5 millimeters or over 100 millimeters, advantageously it is 5 - 100 mm. For a man skilled in the art, it is obvious that the various embodiments of the invention are not restricted to 30 the ones described above, but may vary within the scope of the appended claims. In the claims which follow and in the preceding description of the invention, except where the context 35 requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, 1610867_1 (GHMatters) 6/08/09 - 13 i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. 5 It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common general knowledge in the art, in Australia or any other country. 10 1610867_1 (GHMatters) 6108109

Claims

1. A casting trough for casting metal into a casting mold, said casting trough including a bottom, a spout, 5 side walls and a rear wall opposite to the spout, characterised in that the casting trough has a pouring mechanism provided with at least one weight sensor for accurately feeding the metal in the casting mold, and that the spout comprises a pouring surface that widens towards 10 a pouring edge of the spout that is directed downwardly with respect to the bottom of the casting trough when oriented substantially horizontally, and the side walls extending upwardly from pouring surface define the width of the pouring surface that are essentially parallel with 15 the melt flow.

2. The casting trough according to claim 1, characterized in that the casting trough includes a choke element, between the spout and the rear wall for slowing 20 down the mass flow of the molten metal from a space between the rear wall and the choke element towards the spout.

3. The casting trough according to claim 2, 25 characterized in that the choke element is arranged between the spout and the rear wall of the casting trough, so that in the space of the casting trough between the choke element and the spout, there can receive 40 - 90% of the metal to be poured in the casting mold. 30

4. The casting trough according to any one of claims 2 or 3, characterized in that the choke element is a plate-like structure that is arranged at right angles to the flowing direction of the molten metal, and in an 35 essentially vertical position with respect to the casting trough bottom. 1610867_1 (GHMatlers) 6108109 - 15

5. The casting trough according to any one of claims 2 or 4, characterized in that the choke element is located against the bottom and side walls of the casting trough 5 and the choke includes one or several orifices that are located completely underneath the surface of the molten metal.

6. The casting trough according to claim 5, 10 characterized in that the choke element is dented at the bottom edge, in which case the orifice is defined by the denting notches of the choke element and the bottom of the casting trough. 15

7. The casting trough according to claim 6, characterized in that the height of the choke element notches is 10 - 100 millimetres.

8. The casting trough according to claim 6 or 7, 20 characterized in that the total area of the choke element notches is within the range 1,500 - 17,000 square millimeters.

9. The casting trough according to claim 6, 25 characterized in that the sum of the widths of the choke element notches is 0.05 - 0.9 times the choke element width.

10. The casting trough according to any one of claims 30 2 to 9, characterized in that the height of the choke element is chosen so that it extends from the casting trough bottom to at least the melt surface level when the casting trough is in the filling position. 35

11. The casting trough according to any one of claims 1 to 10, characterized in that when viewed from above, the pouring edge is curved, parabolic or with a variable 16108671 (GHMatters) 6/08/09 - 16 radius, advantageously part of the circumference of a circle.

12. The casting trough according to any one of 5 claims 1 to 11, characterized in that the pouring surface of the spout is defined by essentially straight lines drawn from the pouring edge to the casting trough bottom, and that the pouring surface angle with respect to the casting trough bottom varies within the range 12 - 55 10 degrees.

13. The casting trough according to any one of claims 1 to 12, characterized in that the pouring surface is a conic section. 15

14. The casting trough according to any one of claims 1 to 12, characterized in that the width of the pouring edge is advantageously 0.5 - 0.98 times the casting cavity width of the casting mould. 20

15. The casting trough according to any one of claims 1 to 13, characterized in that the width of the pouring edge is 0.6 to 0.7 times the casting cavity of casting mould. 25

16. The casting trough according to any one of claims 1 to 15, characterized in that the spout is formed by a spout brick that can be separately manufactured and fitted in the casting trough. 30

17. The casting trough according to claim 16, characterized in that the spout brick is made of a fireproof material, and casting in a mold. 35

18. The casting trough according to claim 15, characterized in that the spout brick includes a bottom element to be arranged in parallel with the casting trough 1610867_1 (GHMatters) 6/08/09 - 17 bottom, a pouring surface that is curved downwardly from the bottom element and widened towards the pouring edge, and side walls that are essentially vertical in relation to the bottom element. 5

19. The casting trough according to claim 18, characterized in that the pouring edge of the spout brick has a radius of curvature that is proportioned to the width of the casting cavity, so that the radius of 10 curvature is advantageously 0.2 - 6 times the width of the casting cavity.

20. The casting trough according to claim 18, characterized in that the inclination of the pouring 15 surface of the spout brick is 12 - 55 degrees with respect to the spout brick bottom element.

21. The casting trough according to claim 18, characterized in that the narrowest width of the spout 20 brick is 0.3 - 0.8 times the width of the casting mold cavity.

22. A spout brick that is able to be fitted in a metal casting trough, characterized in that the spout 25 brick includes (i) a pouring surface and a bottom element that fits with a bottom of the casting trough, the pouring surface is angled downwardly from the bottom element, when viewed in an in use orientation and widens towards the 30 pouring edge, and (ii) side walls that are essentially vertical with respect to the bottom element.

23. The spout brick according to claim 22, 35 characterized in that the pouring edge has a radius of curvature that is proportioned to the width of the casting cavity of a mould. 1610867_1 (GHMatters) 6/08109 - 18

24. The spout brick according to claim 23, characterized in that the radius of curvature is 0.2 - 6 times the width of the casting cavity. 5

25. The spout brick according to any one of claims 22 to 24, characterized in that the inclination pouring surface is angled with respect to the bottom element at an inclination in the range of 12 - 55 degrees. 10

26. The spout brick according to any one of claims 22 to 25, characterized in that the narrowest width of the spout brick is 0.3 - 0.95 times the width of a casting mold cavity. 15

27. The spout brick according to any one of claims 22 to 26, characterized in that when viewed from above, the spout edge is curved with a variable radius. 20

28. The spout brick according to any one of claims 22 to 27, characterized in that when viewed from above, the spout edge forms part of the circumference of a circle. 25

29. The spout brick according to any one of claims 22 to 27, characterized in that the pouring surface is defined by essentially straight lines drawn from the pouring edge to the bottom element o the spout brick, and the angle of the pouring surface in relation to the 30 casting trough bottom varies within the range 12 - 55 degrees.

30. The spout brick according to any one of claims 22 to 28, characterized in that the pouring surface of the 35 spout is a conic section. 1610867_1 (GHMatters) 6/08/09 - 19

31. The spout brick according to any one of claims 22 to 30, characterized in that the spout brick is made of a fireproof material, that is cast in a mold. 5

32. The spout brick according to any one of claims 22 to 31, characterized in that the width of the pouring edge is advantageously 0.5 - 0.98 times the width (A) of the casting cavity. 10

33. The spout brick according to any one of claims 22 to 31, characterized in that the width of the pouring edge is 0.6 - 0.7 times the width of the casting cavity. 1610867_1 (GHMatters) 6108/09