WO2004065871A1

WO2004065871A1 - Arrangemnt and method for opening and closing the taphole of a smelting reactor

Info

Publication number: WO2004065871A1
Application number: PCT/FI2003/000993
Authority: WO
Inventors: Risto Saarinen; Jussi SIPILÄ
Original assignee: Outokumpu Oyj
Current assignee: Outokumpu Oyj
Priority date: 2003-01-17
Filing date: 2003-12-31
Publication date: 2004-08-05
Anticipated expiration: 2005-07-17
Also published as: PE20040824A1; AR042879A1; FI20030077A7; FI20030077A0; FI20030077L; AU2003290138A1

Abstract

The invention relates to an arrangement (1) for opening and closing the taphole (2) of a molten phase (2) tapped out of a metallurgic smelting reactor, said arrangement comprising at lest means for solidifying the molten phase an for melting the solidified molten phase, and means for bringing the arrangement in the vicinity of the taphole; the arrangement includes at least one thermally conductive element (5) that can be cooled when closing the taphole (3) and heated when opening the taphole. In addition, the invention relates to a method for opening and closing the taphole (3) of a molten phase (2) tapped out of a metallurgic smelting reactor.

Description

ARRANGEMENT AND METHOD FOR OPENING AND CLOSING THE TAPHOLE OF A SMELTING REACTOR

The invention relates to an arrangement and method defined in the independent claims for opening and closing the taphole of a metallurgic smelting reactor.

In smelting reactors that belong in the smelting process, molten phases such as metallic sulfide matte and slag are settled as separate layers on the bottom of the smelting reactor. Owing to the periodic nature of the next process step, the molten phase is tapped from the reactor from time to time, although the feed into the reactor is continuously operated. Generally a metallurgic reactor may have several melt tapping holes, all of which are not necessarily used simultaneously. A desired quantity of the molten phase, such as sulphidic matte, slag or metal is tapped from the melt tapping hole, whereafter the hole is closed for a required time and opened when needed.

According to the prior art, the melt tapping hole of a metallurgic smelting reactor is often opened and closed manually. When opening, there is used a metal tube that is inserted in the taphole. Oxygen is blasted through the tube in the material solidified in the taphole, so that the melt is made to flow out of the hole. In the closing of the taphole, it is known to use clay that is solidified in the taphole in order to prevent the melt from flowing. Manual opening and closing is risky for the safety at work, and it also brings forth drawbacks connected to the efficiency and accuracy of the job. In the prior art, there also is used a device for detaching the solidified clay off the hole.

From the patent US 5,820,815 there is known a device and method for plugging the taphole of a metallurgic furnace. According to the invention, the molten material is frozen by means of an elongate and conical, threaded device in order to stop the flowing of the material. In the device, there circulates a cooling fluid whereby the molten material is frozen. When unplugging the taphole, the flowing of the cooling fluid in the device is interrupted, and the device is removed from the taphole by rotating. The device does not include any other element designed for opening the taphole, and in the method it is assumed that the heat of the molten material contained in the furnace suffices to melt the material frozen in the taphole. In many cases, however - and particularly in copper production - this does not happen.

From the patent US 3,973,761 there is known a method and arrangement for stopping the flow of molten metal in connection with the tapping of a furnace. The device includes a pipe that can be inserted in the taphole, through which pipe there is blown a desired quantity of air at a given pressure into the melt in order to reverse the flowing direction back towards the furnace, and for holding the molten metal inside the furnace.

The solutions according to the prior art do not mention anything about the suitability of the arrangements for both closing and opening tapholes. Moreover, the solutions of the prior art arrangements are complicated in their practical applications.

The object of the present invention is to introduce a novel solution for opening and closing the taphole for a molten phase tapped out of a metallurgic smelting reactor.

The invention is characterized by what is set forth in the preambles of the independent claims. Other preferred embodiments of the invention are characterized by what is set forth in the other claims.

Remarkable advantages are achieved by using the arrangement and method according to the invention. The invention relates to an arrangement for opening and closing the taphole of a molten phase tapped out of a metallurgic smelting reactor, said arrangement comprising at least means for solidifying the molten phase and for melting the solidified molten phase, and means for bringing the arrangement in the vicinity of the taphole, so that the arrangement includes at least one thermally conductive element that can be cooled when closing the taphole and heated when opening the taphole. By means of the thermally conductive element provided in the arrangement, the taphole of a metallurgic smelting reactor can be both closed and opened by using one and the same arrangement. According to a preferred embodiment of the invention, the thermally conductive element is tubular. When closing the taphole, the thermally conductive element can be filled with a cooling medium, such as water and air, in order to solidify the molten phase by cooling. When the thermally conductive element is cooled owing to the effect of the cooling medium, the thermally conductive element advantageously also cools the melt contained in the vicinity of said element, which melt is solidified at the orifice of the taphole and thus plugs the taphole. After plugging the taphole, the thermally conductive element can be left in the taphole. This means that it is not necessary to separately remove the thermally conductive element from the taphole.

According to a preferred embodiment of the invention, when opening the taphole, the thermally conductive element can be filled by oxygen in order to melt the solidified phase. Thus the thermally conductive element, when heated, melts the solidified molten phase, and the taphole is opened. After the taphole has been opened, the thermally conductive element can be removed from the taphole along with the molten phase.

According to a preferred embodiment, the outer diameter of the thermally conductive element is advantageously 20 - 50 millimeters. According to a preferred embodiment, the thermally conductive element is made of iron. According to another preferred embodiment, the thermally conductive element is made of steel. According to another preferred embodiment of the invention, the thermally conductive element is made of graphite. According to yet another preferred embodiment, the thermally conductive element is made of copper or a copper-based alloy.

According to the invention, the arrangement includes a movable supply system for the cooling medium and oxygen. The supply system comprises a feed pipe for feeding cooling medium in the taphole when closing it, and for feeding oxygen in the taphole when opening it, and at least two control elements, such as rollers, in order to define the position of the feed pipe. According to the invention, the quantity of the cooling medium and oxygen can be adjusted. According to a preferred embodiment, the feed pipe is arranged in a coil around the support axis belonging in the arrangement. In order to move the arrangement according to the invention, the arrangement includes at least one support arm that can be turned with respect to the support axis. Now the arrangement can advantageously be moved in the vicinity of the taphole and shifted for instance completely away from the taphole. The thermally conductive element can be arranged at the reactor-side end of the feed pipe. According to a preferred embodiment, the outer diameter of the feed pipe is essentially shorter than the outer diameter of the thermally conductive element, i.e. advantageously less than 20 millimeters. According to a preferred embodiment of the invention, the feed pipe is made of aluminum. According to another preferred embodiment of the invention, the feed pipe is made of steel.

According to the invention, the taphole edges can be sealed by a sealing element, such as clay. Sealing prevents the melt from possibly extruding at the taphole edges during the solidification. The sealing element extends substantially around the whole thermally conductive element. In the sealing element, there is connected a detaching element, by means of which the sealing element can be detached after the taphole is closed. The molten phase is slag, sulfide matte or metal.

The invention also relates to a method for opening and closing the taphole of the molten phase to be tapped out of a metallurgic smelting reactor by an arrangement comprising at least means for solidifying the molten phase and for melting the solidified molten phase, means for bringing the arrangement in the vicinity of the taphole, in which case the arrangement includes at least one thermally conductive element, which is cooled when closing the taphole and heated when opening the taphole. According to the method of the invention, when closing the taphole, in the thermally conductive element there is fed cooling medium, such as water and air a, in order to cool the molten phase. According to the method, when the taphole is closed, the thermally conductive element is left in the taphole. When opening the taphole, oxygen is fed in the thermally conductive element in order to melt the solidified molten phase. After the taphole has been opened, the thermally conductive element is discharged from the taphole along with the molten phase. By means of the feed pipe of the arrangement included in movable cooling medium and oxygen supply system, cooling medium is brought in the taphole when closing it, and oxygen is brought in the taphole when opening it.

The invention is described in more detail below with reference to the appended drawing.

Figure 1 An arrangement according to the invention

Figure 1 illustrates an arrangement 1 according to the invention for opening and closing the taphole 3 of a molten phase 2, such as matte, tapped from a metallurgic smelting reactor, such as a flash smelting furnace, said arrangement comprising at least means for solidifying the molten phase and for melting the solidified melt, and means for bringing the arrangement in the vicinity of the taphole. The arrangement is placed in the vicinity of the taphole 3 arranged in the wall structure 4 of the metallurgic smelting reactor. The closing of the taphole is carried out by solidifying the molten phase in the hole, and opening is carried out by burning the solidified melt in the hole. The arrangement also includes a tubular, thermally conductive element 5 installed inside the taphole, for example an iron tube that serves as a cooler when closing the taphole, and as fuel when opening the taphole.

When closing the taphole 3, the thermally conductive element 5 is brought in the taphole by means of the movable supply system 6 of cooling medium, for example air and water, and oxygen included in the arrangement. The supply system 6 comprises a feed pipe 7, made of for example steel, which feed pipe is coiled in a coil 18 around the support axis 14, for bringing the cooling medium and oxygen 11 in the taphole, as well as three control elements 8, 9 and 10, such as rollers, for defining the position of the feed pipe 7. In addition, according to the example the arrangement includes support arms 16 and 17 for moving the arrangement, by means of which support arms the feed pipe and iron tube are shifted to the taphole and away therefrom. The iron tube is connected to the end of the feed pipe 15, so that it surrounds the feed pipe. The outer diameter of the iron tube is preferably 20 - 50 millimeters, in which case the outer diameter of the feed pipe 7 is preferably less than 20 millimeters. When closing the taphole, in the feed pipe 7 reeled off the coil 18, there is fed a desired quantity of cooling medium by means of the provided control arrangement 19, which cooling medium is then conducted in the iron tube 5 arranged in the taphole. As the cooling medium, there is first fed water and air, and in the end air. The iron tube 5 is cooled off and solidifies the molten phase 2 contained in the taphole 3 to form a plug that plugs the orifice of the taphole. When the melt is solidified, the cooling medium supply is cut down. When the taphole has been closed, the iron tube 5 is left in the taphole, and the arrangement is left in the same position where it was during the closing step. When the support arms 16 and 17 are moved with respect to the support axis 14 for instance by means of a pneumatic cylinder, the arrangement can be turned to the taphole and away therefrom. The feed pipe moves as controlled by the control elements 8, 9 and 10 attached to the support arm 17. Around the iron tube, there is provided a sealing element 12 made for example of clay, and its detaching element 13. The sealing element seals the orifice of the taphole 3 on the exterior surface thereof in order to prevent the melt from flowing during the solidification step. The sealing element is always replaced before a new closing operation of the taphole.

When opening the taphole, the cooling medium supply is completely terminated. Before opening the taphole, the sealing element 12 typically made of clay is detached from the taphole orifice by moving the detaching element 13. The iron tube 5 left in the taphole is heated owing to the warm melt located around it. When opening the taphole, the employed fuel is the material of the thermally conductive element or the feed pipe, typically iron or aluminum. When opening the taphole, oxygen is blown along the feed pipe 7 belonging in the supply system 6 into the heated iron tube 5, which initiates a combustion reaction when feeding in oxygen. The solidified melt contained in the taphole melts, and as the melt starts to flow out of the reactor, the taphole obtains its original size. When the taphole has been opened, the arrangement 1 is turned in relation to the support axis 14, for example by means of a pneumatic cylinder, so that the feed pipe is lifted in its top position, away from the taphole. The flowing melt carries the residues of the iron tube 5 away from the taphole.

The next closing operation of the taphole is prepared by installing in the arrangement a new thermally conductive element and by inserting the feed pipe 7, controlled by rollers 8, 9 and 10, inside the thermally conductive element from the coil located on the support axis 14. A new sealing element 12 is installed in the device.

For a man skilled in the art, it is clear that the various preferred embodiments of the invention are not restricted to the above described examples only, but may vary within the scope of the appended claims.

Claims

1. An arrangement (1) for opening and closing the taphole (3) of a molten phase (2) tapped out of a metallurgic smelting reactor, said arrangement comprising at least means for solidifying the molten phase and for melting the solidified molten phase, and means for bringing the arrangement in the vicinity of the taphole, characterized in that the arrangement includes at least one thermally conductive element (5) that can be cooled when closing the taphole (3) and heated when opening the taphole.

2. An arrangement according to claim 1 , characterized in that the thermally conductive element (5) is tubular.

3. An arrangement according to claim 1 or 2, characterized in that when closing the taphole (3), the thermally conductive element (5) can be filled with a cooling medium (11), such as water and air, in order to solidify the molten phase by cooling.

4. An arrangement according to claim 1 , 2 or 3, characterized in that after the taphole (3) has been closed, the thermally conductive element (5) can be left in the taphole.

5. An arrangement according to any of the preceding claims, characterized in that when opening the taphole (3), the thermally conductive element (5) can be filled by oxygen in order to melt the solidified molten phase.

6. An arrangement according to claim 5, characterized in that when the taphole (3) has been opened, the thermally conductive element (5) can be removed from the taphole along with the molten phase.

7. An arrangement according to any of the preceding claims, characterized in that the outer diameter of the thermally conductive element (5) is advantageously 20 - 50 millimeters.

8. An arrangement according to any of the preceding claims, characterized in that the thermally conductive element (5) is made of iron.

9. An arrangement according to claim 1 - 7, characterized in that the thermally conductive element (5) is made of steel.

10. An arrangement according to claim 1 - 7, characterized in that the thermally conductive element (5) is made of graphite.

11. An arrangement according to claim 1 - 7, characterized in that the thermally conductive element (5) is made of copper or a copper-based alloy.

12. An arrangement according to any of the preceding claims, characterized in that the arrangement includes a movable supply system (6) for the cooling medium and oxygen.

13. An arrangement according to claim 12, characterized in that the supply system (6) includes a feed pipe (7) in order to feed cooling medium in the taphole (3) when closing the taphole and in order to feed oxygen in the taphole (3) when opening the taphole, as well as at least two control elements (8, 9, 10) for defining the position of the feed pipe.

14. An arrangement according to claim 12 or 13, characterized in that the quantities of the cooling medium and oxygen can be adjusted.

15. An arrangement according to claim 13, characterized in that the feed pipe is arranged in a coil (18) around the support axis (14).

16. An arrangement according to claim 15, characterized in that in order to move the arrangement, it comprises at least one support arm (16, 17) that can be turned with respect to the support axis (14).

17. An arrangement according to claim 13 or 15, characterized in that the thermally conductive element (5) can be arranged at the reactor-side end (15) of the feed pipe (7).

18. An arrangement according to claim 13, 15 or 17, characterized in that the outer diameter of the feed pipe (7) is essentially shorter than the outer diameter of the thermally conductive element (5), advantageously less than 20 millimeters.

19. An arrangement according to claim 13, 15, 17 or 18, characterized in that the feed pipe (7) is made of aluminum.

20. An arrangement according to claim 13, 15, 17 or 18, characterized in that the feed pipe (7) is made of steel.

21.An arrangement according to any of the preceding claims, characterized in that the edges of the taphole (3) can be sealed by a sealing element (12), such as clay.

22. An arrangement according to claim 21 , characterized in that the sealing element (12) extends essentially completely around the thermally conductive element (5).

23. An arrangement according to claim 21 or 22, characterized in that to the sealing element (12), there is connected a detaching element (13).

24. An arrangement according to any of the preceding claims, characterized in that the molten phase (2) is slag, sulfide matte or metal.

25. A method for opening and closing the taphole (3) of a molten phase (2) tapped out of a metallurgic smelting reactor by an arrangement comprising at least means for solidifying the molten phase and for melting the solidified molten phase, and means for bringing the arrangement in the vicinity of the taphole, characterized in that the arrangement includes at least one thermally conductive element (5) that is cooled when closing the taphole (3) and heated when opening the taphole.

A method according to claim 25, characterized in that when closing the taphole (3), in the thermally conductive element (5) there is fed cooling medium (11), such as water and air, in order to cool the molten phase.

A method according to claim 25, characterized in that after the taphole (3) has been closed, the thermally conductive element (5) is left in the taphole.

A method according to any of the preceding claims, characterized in that when opening the taphole (3), in the thermally conductive element (5) there is fed oxygen in order to melt the solidified molten phase.

A method according to claim 28, characterized in that after the taphole (3) has been opened, the thermally conductive element (5) is discharged out of the taphole along with the molten phase.

A method according to any of the preceding claims, characterized in that by means of the feed pipe (7) of the movable supply system (6) included in the arrangement for the cooling medium and oxygen, in the taphole (3) there is brought cooling medium when closing the taphole, and oxygen when opening the taphole.