JP2011174150A - Method for operating copper refining furnace, and copper refining furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for operating a copper refining furnace, in which slag and matte in molten metal are efficiently separated, and magnetite is prevented from being deposited at a furnace wall part and thickly accumulated thereon, and also the trouble caused by deposition of the magnetite is prevented in the post-step, and to provide the copper refining furnace. <P>SOLUTION: In the method for operating the copper refining furnace 10 used when copper mineral concentrate, scrap or the like are subjected to oxidation refinement to produce crude copper, molten metal containing slag and matte is stored in the copper refining furnace 10, and a metal reducing agent is charged to the molten metal, so that the metal reducing agent is made coexistent inside the molten metal, thereby the amount of magnetite in the molten metal is controlled. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to a method for operating a copper smelting furnace and a copper smelting furnace used when producing crude copper by oxidizing and refining copper concentrate, scrap scrap and the like.

Examples of a method for obtaining crude copper by smelting copper concentrate or scrap scraps include a flash smelting furnace method as shown in Patent Document 1, a continuous copper making method as shown in Patent Document 2, and the like.
In the flash smelting furnace method described in Patent Document 1, copper concentrate is oxidized and melted in oxygen-enriched air at a shaft portion, and the resulting melt is held by a lower setler. Separate slag and mat. The separated mat is transferred to a converter, where it is further smelted to produce crude copper.

  Moreover, in the continuous copper manufacturing method described in Patent Document 2, a smelting furnace that smelts copper concentrate to produce a melt containing slag and mat, and a melt transferred from the smelting furnace A separation furnace that holds and separates the slag and the mat, and a copper making furnace that smelts the mat separated in the separation furnace to obtain crude copper. These smelting furnace, separation furnace, and copper making furnace Are connected by a firewood, and it is set as the structure which performs a smelting process continuously.

Here, in the smelting furnace of the shaft portion and continuous made of copper equipment flash furnace, is reacted with SiO ₂ in the flux causes oxidation of Fe components contained in the copper concentrate, the FeO-SiO ₂ Generates slag as the main component. Further, the Cu component contained in the copper concentrate is condensed as a mat which is a melt of copper sulfide.
At this time, it is known that magnetite (Fe ₃ O ₄ ) is generated by excessive oxidation of the Fe component contained in the copper concentrate. This magnetite has a higher melting point than a melt made of slag or mat.

  In the settling machine and the separation furnace of the above-mentioned flash smelting furnace, the slag and the mat are separated using the specific gravity difference by allowing the melt to stand. Therefore, in the setler and the separation furnace, the flow of the melt is suppressed, and the temperature of the melt tends to decrease. When the temperature of the melt decreases, the magnetite in the melt precipitates as a solid phase and deposits on the furnace wall and the bottom of the furnace. When magnetite is deposited thickly on the furnace wall or the furnace bottom, it becomes impossible to stably separate the slag and the mat.

Therefore, conventionally, when a thick magnetite deposit is formed on the furnace wall or the bottom of the furnace, the magnetite deposit is removed by the heat of reaction between the steel pipe and oxygen by performing a lancing on the steel pipe in which oxygen is circulated. It was removed by melting.
Alternatively, iron dust or ferrosilicon (Fe—Si) is introduced at the time of lancing, and the magnetite is reduced and removed by bringing it into contact with the magnetite deposit.

JP 2004-002916 A Japanese Patent Laid-Open No. 04-183827

However, when magnetite deposits are removed by lansing, there is a possibility that the lance will become excessive and the refractories on the furnace wall and the bottom of the furnace may be worn out. When the refractories on the furnace wall and bottom were worn out, it was necessary to stop the operation and repair the furnace.
In addition, in order to prevent wear of the furnace wall and furnace bottom, if the frequency of lansing is reduced, magnetite deposits cannot be removed sufficiently, and the operation can be performed stably. It becomes impossible.

Moreover, since the magnetite existing in the molten state in the melt cannot be removed by lansing or the like, the amount of magnetite in the melt could not be reduced.
Here, when a high melting point magnetite is contained in the melt, the viscosity of the slag increases, and the slag and the mat cannot be separated efficiently. In this case, “slag loss” is generated in which the mat is discharged together with the slag, and the efficiency of the copper smelting is reduced.

Furthermore, when the mat separated by the setler or the separation furnace is transferred to the subsequent process, if the temperature of the mat is lowered, the magnetite in the mat is deposited, which may cause trouble in the subsequent process. .
In particular, in the continuous copper making method described in Patent Document 2, the mat separated in the separation furnace is transferred to the copper making furnace through the cocoon, so that the temperature of the mat (melt) decreases at the cocoon part. Then, there is a problem that magnetite is deposited and the mat cannot be stably transferred. In order to cope with this, conventionally, the soot was heated with a burner or the like to suppress the precipitation of magnetite, or the precipitated magnetite was dissolved or removed using a jet lance or the like. These operations were very complicated, and the copper smelting operation could not be performed efficiently.

  The present invention has been made in view of the above-described situation, and can efficiently separate the slag and the mat in the melt, and deposit magnetite on the furnace wall and deposit thickly. It is an object of the present invention to provide a copper smelting furnace operating method and a copper smelting furnace that can be prevented in advance and that can prevent troubles caused by precipitation of magnetite in a subsequent process.

  In order to solve the above-mentioned problems, the method of operating a copper smelting furnace according to the present invention is an operating method of a copper smelting furnace used when producing copper by oxidizing and smelting copper concentrate or scrap scraps. In the copper smelting furnace, a melt containing the slag and the mat is stored, and a metal reducing agent is introduced into the melt so that the metal reducing agent is mixed in the melt. Thus, the amount of magnetite in the melt is controlled.

In the operation method of the copper smelting furnace configured as described above, a metal reducing agent is introduced into the melt stored in the copper smelting furnace, and the metal reducing agent is mixed in the melt. Therefore, the magnetite (Fe ₃ O ₄ ) present in the melt is reduced by the metal reducing agent to become FeO and discharged into the slag.
Accordingly, the amount of magnetite in the melt is reduced, the increase in viscosity of the slag is suppressed, and the slag and the mat can be efficiently separated by the difference in specific gravity. Furthermore, “slag loss” in which the mat is discharged together with the slag can be suppressed.
Further, it is possible to prevent magnetite from being deposited thickly on the furnace wall and the bottom of the furnace, and the mat and slag can be stably separated. Furthermore, since the amount of magnetite in the mat is reduced, the precipitation of magnetite will be suppressed even in the post-process where the mat is transferred, and it is possible to prevent the occurrence of troubles due to the precipitation of magnetite. it can.

Here, the copper smelting furnace is provided with a melt supply portion to which the melt is supplied, and a turbulent flow region generated in the vicinity of the melt supply portion when the melt is supplied. On the other hand, it is preferable that the metal reducing agent is introduced.
In separation furnaces and setlers, a slag layer is formed on the upper side and a matte layer is formed on the lower side. Therefore, when the metal reducing agent is simply introduced from above, if the specific gravity of the metal reducing agent is light, only the slag layer is formed. When the specific gravity of the metal reducing agent is heavy, it is added only to the matte layer, and it is difficult to disperse the metal reducing agent throughout the melt. Therefore, by introducing the metal reducing agent toward the turbulent flow region generated by supplying the melt, the introduced metal reducing agent is widely dispersed inside the melt, and the magnetite in the melt is Can be efficiently reduced.

Moreover, it is preferable that the said metal reducing agent is the collection | recovery metal obtained by processing a waste material.
Municipal waste and industrial waste are burned and melted in a rotary kiln furnace, for example. At this time, valuable metals and the like contained in the waste are collected. The component of the recovered metal often contains Fe, although it varies depending on the type of waste. Therefore, when this recovered metal is put into the melt, the magnetite can be reduced by the Fe component in the recovered metal. Moreover, valuable metals such as Au, Ag, and Cu contained in the recovered metal are also recovered by the copper smelting process.

Furthermore, it is preferable that the input amount of the metal reducing agent is 0.15 kg / t or more and 0.80 kg / t or less with respect to the unit weight of the melt.
In this case, since the input amount of the metal reducing agent is 0.15 kg / t or more with respect to the unit weight (1 t) of the melt, the amount of magnetite in the melt can be reliably reduced. Further, since the amount of the metal reducing agent introduced is 0.80 kg / t or less with respect to the unit weight (1 t) of the melt, the metal reducing agent introduced into the furnace is transferred to the furnace wall portion or the furnace bottom portion. There is no risk of damaging the refractory, and the life of the copper smelting furnace can be extended. As described above, it is possible to suppress the accumulation of magnetite thick and to prevent the refractory material of the furnace wall and the bottom of the furnace from being worn, so that the operation can be stably performed.

  The copper smelting furnace according to the present invention is a copper smelting furnace used for producing crude copper by oxidizing and smelting copper concentrate, scrap scrap, etc., and the melt containing the slag and the mat is stored. And a reducing agent charging part for charging a metal reducing agent into the furnace body.

  According to the copper smelting furnace configured as described above, a furnace main body in which a melt containing the slag and the mat is stored, and a reducing agent input unit that inputs a metal reducing agent into the furnace main body, Therefore, the magnetite in the melt can be reduced by introducing a metal reducing agent into the melt. Therefore, the amount of magnetite in the melt is reduced, and troubles caused by magnetite can be prevented in advance.

Here, the furnace main body is provided with a melt supply unit to which the melt is supplied, and the reducing agent charging unit is located in the vicinity of the melt supply unit when the melt is supplied. It is preferable that a metal reducing agent is introduced into the generated turbulent flow region.
In this case, the metal reducing agent can be introduced toward a turbulent region generated by supplying the melt, and the introduced metal reducing agent is widely dispersed inside the melt, so that the magnetite in the melt is dispersed. Reduction can be performed efficiently.

  As described above, according to the present invention, it is possible to efficiently separate the slag and the mat in the melt and to prevent the magnetite from being deposited on the furnace wall portion and being deposited thickly. And the operating method and copper smelting furnace of a copper smelting furnace which can prevent the trouble resulting from precipitation of magnetite in a post process can be provided.

It is a schematic explanatory drawing of the continuous copper making equipment provided with the separation furnace used as the object of the operating method of the copper smelting furnace which is embodiment of this invention. It is a schematic explanatory drawing of the separation furnace and copper making furnace with which the continuous copper making equipment shown in FIG. 1 was equipped. It is side surface explanatory drawing of the separation furnace with which the continuous copper making equipment shown in FIG. 1 was equipped. FIG. 5 is a partially enlarged explanatory view of the separation furnace shown in FIG. 4.

Hereinafter, an operation method of a copper smelting furnace and a copper smelting furnace according to an embodiment of the present invention will be described with reference to the accompanying drawings.
The copper smelting furnace which is the target of the method for operating the copper smelting furnace according to the present embodiment is a separation furnace used in a continuous copper making facility as shown in FIG.

  The continuous copper making facility 1 includes a smelting furnace 2 that oxidizes and melts copper concentrate as a raw material to produce a melt having a mat M and a slag S, and a mat M produced in the smelting furnace 2. The separation furnace 10 for separating the slag S, the copper making furnace 4 for further oxidizing the mat M separated in the separation furnace 10 to produce the crude copper C and the slag S, and the copper making furnace 4 A refining furnace 5 for refining crude copper C to produce higher grade copper. The smelting furnace 2, the separation furnace 10, the copper making furnace 4, and the refining furnace 5 are connected to each other by firewood 6A, 6B, and 6C. In order that the copper furnace 4 and the refining furnace 5 can be moved in this order, they are provided with a height difference in this order.

  The smelting furnace 2 includes a plurality of lances 7 for supplying copper concentrate into the furnace together with an oxidizing gas such as oxygen-enriched air and a flux. The lance 7 is provided so as to be movable up and down through the ceiling of the smelting furnace 2. Further, the smelting furnace 2 is provided with an exhaust port for exhausting gas generated from the inside of the furnace, and a waste heat boiler 9 for recovering waste heat of the exhaust gas is provided at the exhaust port. It is connected.

  The separation furnace 10 separates the mat M and the slag S in the melt fed from the smelting furnace 2 using a specific gravity difference, and has a small specific gravity on the layer of the mat M having a large specific gravity. A layer of slag S is formed. A plurality of electrodes 11 are inserted into the separation furnace 10 with the lower ends immersed in the slag. In the separation furnace 10, the three-phase alternating current is input to these electrodes 11 from a transformer to generate Joule heat to keep the temperature of the melt.

  The copper making furnace 4 includes a plurality of lances 8 for supplying cold material and limestone into the furnace together with an oxidizing gas such as oxygen-enriched air. The lance 8 is provided so as to be movable up and down through the ceiling of the copper furnace 4. Further, the copper making furnace 4 is provided with a discharge port for discharging the gas generated from the inside of the furnace, and a waste heat boiler 9 for recovering waste heat of the exhaust gas is provided at the discharge port. It is connected.

  In order to smelt copper with this continuous copper making facility 1, dried copper concentrate and flux (eg, sand, lime, etc.) are blown into the melt of the smelting furnace 2 together with oxygen-enriched air with a lance 7. In the smelting furnace 2, the melting of raw materials and the oxidation reaction proceed, and a mat M composed mainly of a mixture of copper sulfide and iron sulfide, and a slag S composed of gangue, solvent, iron oxide, etc. in copper concentrate. Generated.

Here, in the smelting furnace 2, the Fe component contained in the copper concentrate is oxidized and reacted with SiO ₂ in the flux to generate slag S mainly composed of FeO—SiO ₂ . At this time, magnetite (Fe ₃ O ₄ ) is generated by excessive oxidation of the Fe component contained in the copper concentrate. Thus, magnetite is contained in the melt (slag S and mat M) generated in the smelting furnace 2. Since this magnetite has a higher melting point than a melt made of slag S or mat M, it precipitates as a solid phase when the temperature of the melt decreases.

The melt having the mat M and the slag S is sent to the separation furnace 10 by the rod 6A, where it is separated into the lower layer mat M and the upper layer slag S due to the difference in specific gravity.
The slag S separated in the separation furnace 10 will be collected separately. In addition, the sulfur-containing gas such as SO ₂ gas generated in the smelting furnace 2 or the like is transferred to a sulfuric acid factory (not shown) and recovered as sulfuric acid or gypsum (CaS0 ₄ ).

  On the other hand, the mat M separated in the separation furnace 10 is sent to the copper making furnace 4 through the basket 6B. In the copper making furnace 4, a flux is blown together with air using the lance 8 to oxidize sulfur and iron in the mat M to obtain crude copper C having a purity of 98.5% or more. The crude copper C continuously produced in the copper making furnace 4 is transferred to the refining furnace 5 through the jar 6C. And the refined copper 5 is refine | purified in the refinement | purification furnace 5, and higher quality copper is produced | generated.

  In this process, in the oxidation step in the copper making furnace 4, a part of copper is also oxidized and taken into the slag Sa. That is, the copper making furnace slag Sa contains a considerable amount of copper oxide (14 to 16%) together with iron oxide. For this reason, in a normal process, the copper-making furnace slag Sa is made into a solid powder by water granulation, dried, then sent to the smelting furnace 2, and dissolved again together with the raw material ore to recover copper.

  Next, the separation furnace 10 will be described with reference to FIGS. As shown in FIG. 2, the separation furnace 10 is connected to a furnace body 12 for storing a melt, and one end of a rod 6 </ b> A provided between the smelting furnace 2 and the separation furnace 10. The melt supply part 15 to which the melt generated in step S1 is supplied, the siphon 16 that overflows the mat M located below the furnace body 12, and the slag discharge port that discharges the slag S located in the upper layer of the mat M 17. One end of a cage 6B is connected to the siphon 16, and the other end of the cage 6B is connected to the copper making furnace 4.

In addition, as shown in FIG. 3, the separation furnace 10 is provided with a reducing agent charging device 20 that is disposed above the furnace body 12 and charges the metal reducing agent toward the furnace body 12.
The reducing material charging device 20 includes a charging pipe 24 inserted into the furnace body 12, a hopper portion 21 in which a metal reducing agent is stored, and a belt that transfers the metal reducing agent from the hopper portion 21 to the charging pipe 24. And a feeder 22.
As shown in FIGS. 3 and 4, the charging pipe 24 is disposed in the vicinity of the melt supply unit 15 in the furnace body 12, and the turbulent flow generated when the melt is supplied from the melt supply unit 15. In the region D, a metal reducing agent is introduced.

  In the separation furnace 10, the melt supplied from the smelting furnace 2 is stored in the furnace body 12 and separated into slag S and mats M using a specific gravity difference. At this time, in the separation furnace 10, the three-phase alternating current is input to the electrode 11 to generate Joule heat so that the melt is kept warm, so that the slag S and the mat M It is configured so as to promote separation.

  The separation furnace 10 is continuously charged with a metal reducing agent using a reducing material charging device 20. Here, in the present embodiment, as the metal reducing agent, a recovered metal crush obtained by treating waste is used. Further, the input amount of the recovered metal crushed mass, which is a metal reducing agent, is adjusted to be 0.15 kg / t or more and 0.80 kg / t or less with respect to the unit weight (1 t) of the melt.

  Recovered metal crumbs used as metal reducing agents are used for combusting and melting waste in the city, shredder dust from automobiles that are industrial waste, waste home appliances, printed circuit boards, etc., using a rotary kiln furnace, for example. It is obtained by processing. The waste put into the rotary kiln furnace is combusted and gasified, and incombustible materials containing metal components are melted to form molten slag. The molten slag is water-crushed and subjected to sorting such as sieving, whereby the crushed metal is recovered. The crushed metal collected in this way contains valuable metals such as Fe, Au, Ag and Cu.

  Although the component of the recovered metal varies depending on the type of waste to be treated, it contains a large amount of Fe, so that the recovered metal crumb can be used as a reducing agent for magnetite. Note that the recovered metal used in the present embodiment contains Fe: 50 to 90 wt%. The recovered metal crushed particles are finely sieved to a particle size of less than 3 mm and then charged into the separation furnace 10.

In the operation method of the copper smelting furnace (separation furnace 10) and the copper smelting furnace (separation furnace 10) which are the present embodiment configured as described above, the molten material stored in the furnace body 12 of the separation furnace 10 is used. On the other hand, a crushed metal recovered from the metal, which is a metal reducing agent, is introduced into the melt, so that the magnetite (Fe ₃ O ₄ ) present in the melt is reduced by the recovered metal. FeO can be discharged into the slag.

Since the amount of magnetite in the melt is thus reduced, the viscosity increase of the slag S is suppressed, and the slag S and the mat M can be efficiently separated by the difference in specific gravity. Furthermore, the slag loss which the mat | matte M flows out with the slag S can be suppressed, and copper smelting can be performed efficiently.
In addition, since the amount of magnetite in the melt is small, even if the temperature of the melt is lowered by allowing the melt to stand in the furnace body 12, the magnetite is placed on the furnace wall 12 </ b> A and the furnace bottom 12 </ b> B of the furnace body 12. Is not deposited thick. Therefore, the frequency of removing the magnetite deposits by the lansing can be greatly reduced, the refractory of the furnace body 12 can be worn out, and the life of the furnace body 12 can be extended.

  Furthermore, the amount of magnetite in the mat M separated in the separation furnace 10 will also be reduced, and the precipitation of magnetite will be suppressed also in the soot 6B and the copper making furnace 4 which are the subsequent steps of the separation furnace 10. . Therefore, it is not necessary to heat the basket 6B with a burner, and it is not necessary to use a jet lance or the like to remove the precipitated magnetite. Thereby, the stable operation can be performed.

  In addition, since the recovered metal that is a metal reducing agent is introduced into the turbulent flow region D generated by supplying the melt via the melt supply unit 15, Thus, the magnetite in the melt can be efficiently reduced. That is, the recovered metal is dispersed throughout the furnace main body 12 using the flow of the melt transferred from the smelting furnace 2.

Furthermore, in this embodiment, the recovered metal crushed used as the metal reducing agent is used as waste in the city, shredder dust of automobiles as industrial waste, waste home appliances, printed circuit boards, etc., for example, rotary kiln furnaces It is assumed that it was obtained by burning / melting process. Since this recovered metal crushed material contains valuable metals such as Fe, Au, Ag, and Cu, it is possible to recover valuable metals from waste by using a continuous copper production facility. .
Moreover, since the collection | recovery metal used in this embodiment contains Fe: 50-90 wt%, the magnetite in a melt can be reduced with this Fe component.

  Further, since the input amount of the recovered metal, which is a metal reducing agent, is 0.15 kg / t or more with respect to the unit weight (1 t) of the melt, the magnetite in the melt can be reliably reduced, and the amount of magnetite Can be reduced. In addition, since the input amount of the recovered metal is 0.80 kg / t or less with respect to the unit weight (1 t) of the melt, the recovered metal input into the furnace is the furnace wall 12A of the furnace body 12 or There is no possibility of damaging the refractory of the furnace bottom 12B, and the life of the furnace body 12 can be extended. In this way, the magnetite is prevented from being deposited thickly and the refractories on the furnace wall 12A and the furnace bottom 12B are prevented from being worn, so that the operation can be stably performed.

  Further, since the recovered metal crushed material is finely sieved so as to have a particle size of less than 3 mm and then charged into the separation furnace 10, the recovered metal may directly contact the refractory at the furnace bottom 12 </ b> B. Suppressed and widely dispersed in the melt, the amount of magnetite in the melt can be efficiently reduced.

As described above, the copper smelting furnace operating method and the copper smelting furnace according to the embodiment of the present invention have been described. It is.
For example, although it demonstrated as a thing about the separation furnace of continuous copper making equipment, it is not limited to this, You may apply to other copper smelting furnaces, such as a flash smelting furnace.

In the present embodiment, the metal reducing agent has been described as using a recovered metal crush obtained by treating waste, but the present invention is not limited to this, and ferrosilicon (Fe-Si) is used. Etc.) as long as it can reduce magnetite.
Furthermore, although it demonstrated that the collection | recovery metal contains Fe: 50-90 wt%, it is not limited to this, The component of a collection | recovery metal will not be restrict | limited especially if a magnetite is reduce | restored.

10 Separation furnace (copper smelting furnace)
12 Furnace body 15 Melt supply unit 20 Reducing agent charging device (reducing agent charging unit)

Claims (6)

It is a method of operating a copper smelting furnace used to produce crude copper by oxidizing and refining copper concentrate and scrap scraps,
In the copper smelting furnace, a melt containing the slag and the mat is stored, and a metal reducing agent is introduced into the melt, and the metal reducing agent is mixed in the melt. A method for operating a copper smelting furnace, wherein the amount of magnetite in the melt is controlled.   The copper smelting furnace is provided with a melt supply portion to which the melt is supplied, and when the melt is supplied, against a turbulent flow region generated in the vicinity of the melt supply portion. The method for operating a copper smelting furnace according to claim 1, wherein the metal reducing agent is added.   The method for operating a copper smelting furnace according to claim 1 or 2, wherein the metal reducing agent is a recovered metal obtained by treating waste.   The input amount of the metal reducing agent is 0.15 kg / t or more and 0.80 kg / t or less with respect to a unit weight of the melt. The operation method of the described copper smelting furnace. A copper smelting furnace used to produce crude copper by oxidizing and refining copper concentrate and scrap scrap,
A copper smelting furnace comprising: a furnace main body in which a melt containing the slag and the mat is stored; and a reducing agent charging unit for charging a metal reducing agent into the furnace main body.   The furnace main body is provided with a melt supply section for supplying the melt, and the reducing agent charging section is a turbulence generated in the vicinity of the melt supply section when the melt is supplied. The copper smelting furnace according to claim 5, wherein a metal reducing agent is introduced into the flow region.

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