JP4274067B2 - Method for removing impurity metal from copper alloy and slag fuming method using the same - Google Patents

Description

  The present invention relates to a method for removing an impurity metal from a copper alloy and a slag fuming method using the same, and more particularly, a slag produced from a zinc and / or lead smelting furnace is used as a copper melt. In order to reduce the copper source cost by reusing a copper alloy containing iron, lead, arsenic and other impurity metals formed by coexisting slag fuming as a copper source of the copper melt, The present invention relates to a method for removing impurity metals from an alloy.

  In zinc and / or lead smelting, a blast furnace method for simultaneously smelting zinc and lead called Imperial Melting Process is widely used. As a method for treating the slag generated in the blast furnace, generally, the slag is led to the front floor of the blast furnace to roughly separate the copper-containing crude lead and the furnace iron, and then this is granulated and used for cement raw materials, etc. Product slag is being used. In addition, the slag generally has a high zinc content and contains arsenic, antimony and other metals as components of spices together with lead, so that metals such as zinc, lead, arsenic and antimony in the slag are lowered to a lower level. In order to remove the slag, the slag after the rough separation is subjected to slag fuming, and then granulated to produce a product.

  The slag fuming is to volatilize and remove metals such as zinc, lead, arsenic, and antimony contained in the slag by heating and reducing the molten slag. As a result, zinc and lead can be recovered from the slag and the impurity metal can be removed, thereby obtaining a purified slag. Here, the slag fuming process is performed by reducing and smelting the slag using a lance for gas blowing or a heating furnace having tuyeres at the lower part of the furnace. For example, in the operation of a slag fuming furnace equipped with a lance for gas injection, carbonaceous fuels such as heavy oil, natural gas, pulverized coal, etc. are immersed from the lance tip by immersing the lance in a molten slag charged in the furnace. And reducing air by blowing out air to reduce and volatilize the metal in the slag. And the slag after a process is extracted from the furnace lower part, and the volatilized metal is oxidized by adding air in the middle of the movement to a furnace top part, and is collect | recovered as dust containing zinc and lead.

  However, in general slag fuming treatment, group V elements such as arsenic and antimony having a low boiling point and high vapor pressure are volatilized together with zinc and lead, which are the main target elements of recovery. Concentrate in. When the dust containing these group V elements is repeated in the sintering process of the blast furnace method in order to recover zinc and lead, the group V elements are volatilized in the sintering process and are discharged into the exhaust gas treatment system. There was a problem of increasing the load. Furthermore, when charged into the blast furnace as a sintered ingot, there is a problem that the V group element generates spices that are high melting point metal compounds and makes the blast furnace operation difficult.

  If harmful elements such as lead or arsenic remain in the slag due to fluctuations in the operation of the slag fuming treatment, in the slag elution test after the treatment, the soil environment standard (according to Notification No. 46 of the Environment Agency) Since the problem that the Pb and As elution amounts in the dissolution test cannot be satisfied (each 0.01 mg / L or less) cannot be satisfied, a method that stably satisfies the soil environment standard has been desired.

  As countermeasures for this, a slag reforming method has been proposed. As a typical example, after the slag produced in the blast furnace is led to the front floor to roughly separate copper-containing crude lead and furnace iron, There is a two-stage process (for example, refer to Patent Document 1) in which the copper-containing crude lead and the furnace iron are precipitated and separated by heating and then processed in a slag fuming furnace. However, this method reduces the zinc, lead and arsenic content of the slag and satisfies the slag soil environmental standards, but the fundamental solution is that arsenic and antimony volatilize with zinc and lead. There was a problem that could not be obtained.

  As a solution to this problem, the present applicant previously described in Japanese Patent Application No. 2004-10348 a slag melt containing arsenic and antimony together with zinc and lead produced from a zinc and / or lead smelting furnace. A slag fuming method in which a Cu-Fe-Pb-As-based copper alloy homogeneous melt is formed by reacting the copper melt with arsenic and antimony contained in the slag while coexisting the body and the copper melt ( Hereinafter, it may be referred to as a slag fuming method in the presence of copper. If this method is used, dust containing zinc and lead with low arsenic and antimony contents can be obtained, slag that can stably satisfy the soil environmental standards can be obtained, and the cost can be reduced by one-stage treatment. It is disclosed. However, in this method, if a large amount of copper is used as the copper melt, the cost increases, so the reduction of the cost of the copper source is a problem.

JP-A-11-269567 (first page, second page)

  In view of the problems of the prior art described above, the object of the present invention is to allow slag produced from a zinc and / or lead smelting furnace to coexist with a copper melt in a slag fuming process in the presence of copper. In order to reduce the copper source cost by reusing a copper alloy containing iron, lead, arsenic and other impurity metals formed by slag fuming as a copper source of the copper melt, impurities from the copper alloy are reduced. The object is to provide a method for removing metal.

  In order to achieve the above object, the present inventors have earnestly studied a method of reusing a copper alloy containing iron, lead, arsenic and other impurity metals formed in a slag fuming method in the presence of copper as a copper source. As a result of adding a flux and oxidizing it, an impurity metal is removed from the copper alloy, and a copper alloy that can be reused as a copper source for a copper melt during slag fuming is obtained. The headline and the present invention were completed.

  That is, according to the first aspect of the present invention, iron and lead formed by slag fuming in the presence of slag produced from a zinc and / or lead smelting furnace coexisting with a copper melt. There is provided a method for removing an impurity metal from a copper alloy, which comprises adding a flux to a copper alloy containing arsenic and other impurity metals and then oxidizing the copper alloy.

  According to a second aspect of the present invention, there is provided a method for removing an impurity metal from a copper alloy according to the first aspect, wherein the flux is an acidic oxide or a basic oxide. The

According to a third aspect of the present invention, there is provided the method for removing an impurity metal from a copper alloy according to the second aspect, wherein the basic oxide is CaO and / or Na ₂ O. Provided.

  According to a fourth aspect of the present invention, the copper alloy from which the impurity metal has been removed by the method according to any one of the first to third aspects is reused as a copper source of the copper melt. A slag fuming method is provided.

  A method for removing an impurity metal from a copper alloy of the present invention and a slag fuming method using the same include a copper alloy containing iron, lead, arsenic and other impurity metals formed in a slag fuming method in the presence of copper. It is a method capable of obtaining a copper alloy having a composition suitable for removing an impurity metal and reusing it as a copper source of a copper melt. According to the method of the present invention, zinc with a low content of arsenic and antimony It is possible to obtain lead-containing dust and slag that stably satisfies the soil environmental standards, and the copper source cost in slag fuming is reduced, so that its industrial value is extremely large.

Hereinafter, a method for removing an impurity metal from a copper alloy of the present invention and a slag fuming method using the same will be described in detail.
A method for removing impurity metals from a copper alloy of the present invention and a slag fuming method using the same include a slag fuming process in which slag produced from a zinc and / or lead smelting furnace coexists with a copper melt. A copper alloy containing iron, lead, arsenic and other impurity metals formed by adding a flux and then oxidizing the copper alloy, wherein the impurity metal is removed by the method The alloy is reused as a copper source of the copper melt.

First, a method for producing a copper alloy obtained by the slag fuming method in the presence of copper used in the present invention will be described.
The copper alloy used in the present invention is a Cu-Fe-Pb-As-based copper alloy containing a group V element such as arsenic, antimony, and bismuth as an impurity metal together with iron and lead obtained by a slag fuming method in the presence of copper. . The slag fuming method in the presence of copper can be performed, for example, as follows.

  In the slag fuming method in the presence of copper, the slag melt and the copper melt coexist and subjected to reduction blowing, and the copper melt and the arsenic and antimony contained in the slag are maintained at a predetermined temperature. A uniform melt of copper alloy is formed by reaction. As a result, it is possible to obtain dust containing zinc and lead with low arsenic and antimony contents and slag that stably satisfies the soil environmental standards. That is, volatilization is suppressed by distributing arsenic and antimony in the homogeneous melt of the copper alloy that stably contains them, and the distribution of arsenic and antimony in dust and slag is reduced.

As the slag used in the slag fuming process in the presence of copper, slag produced from a zinc and / or lead smelting furnace and formed in a reducing atmosphere containing arsenic and antimony together with zinc and lead is used. . This slag is a relatively low melting point FeO—SiO ₂ —Al ₂ O ₃ — prepared by mixing zinc and / or lead smelting raw materials and flux so that it can be operated at a slag temperature of 1200 to 1350 ° C. The slag composition is CaO—ZnO—PbO.

  The slag contains arsenic and antimony as a spice phase in a turbid state in the slag. That is, spice is a high melting point intermetallic compound containing arsenic and antimony. For example, in the smelting furnace method of simultaneously smelting zinc and lead called the Imperial Melting Process, it is localized in the slag in a reducing atmosphere. Metallic iron produced by the strong reductive properties reacts with arsenic or antimony to form spices. It is known that arsenic and antimony in this spice have a significantly reduced activity and are in a very stable state. Therefore, arsenic and antimony exist in a turbid state in the slag as an iron spice phase even though the slag temperature is 1200 to 1350 ° C., which is higher than the boiling point of those metals.

  The copper source of the copper melt used in the slag fuming method in the presence of copper is not particularly limited, and a uniform melt is formed with iron at a temperature of 1200 to 1500 ° C. in a reducing atmosphere during reducing blowing. It is preferable to use a metal or oxide-containing copper-containing material that can be melted and used, for example, by melting an intermediate such as copper scrap or crude copper (copper grade 98 to 99% by weight) obtained from a copper smelting process. .

  In the reduction blowing of the slag fuming method in the presence of copper, for example, a slag fuming furnace equipped with a lance for gas blowing is used to lance the mixture of slag melt and copper melt charged in the furnace. Immerse and blow out heavy oil, natural gas, pulverized coal, etc. and oxygen-containing gas from the tip of the lance, mix and agitate them, and make the melt a reducing atmosphere, zinc, lead, arsenic, antimony, etc. Is reduced to the metallic state. Here, most of the metallized zinc and a part of lead are volatilized and recovered as dust.

  On the other hand, metallized arsenic and antimony have a property of high affinity for iron and copper while having a property of high vapor pressure. Therefore, when the copper melt coexists, arsenic and antimony react with copper. If arsenic melts or dissolves in copper due to this reaction, the activity of arsenic in copper is extremely small when the arsenic concentration is low, so the vapor pressure is low, and the arsenic does not volatilize and the copper alloy To be contained in the uniform melt of the copper alloy. Antimony also exhibits the same behavior as arsenic and is contained in the homogeneous melt of the copper alloy.

  The melt temperature of the reduction blowing is 1200 to 1500 ° C, preferably 1200 to 1400 ° C. That is, the above temperature range is appropriate for reacting the copper melt with spices containing arsenic, antimony and the like contained in the slag to form a uniform melt of the copper alloy. When the melt temperature is less than 1200 ° C., there is a problem that the viscosity of the slag is too high or solidifies. On the other hand, when the melt temperature exceeds 1500 ° C., there is a problem that the amount of damage to the refractory increases or the required thermal energy increases.

  The generation of the uniform melt of the copper alloy will be described in more detail with reference to FIG. FIG. 1 shows a copper-iron binary system phase diagram. Here, it can be seen from FIG. 1 that at 1350 ° C., iron melts up to about 15% in copper to form a uniform melt. For example, when iron spice coexists with metallic copper, the iron spice melts in copper and forms a copper-based Cu-Fe-Pb-As-based homogeneous melt together with some lead. In the high copper grade region, the amount of iron dissolved in copper forming a uniform melt varies with temperature, and the amount of dissolution increases as the temperature increases. Therefore, the melt temperature of reduction blowing has the merit that the absorption treatment of spices can be efficiently performed even with a small amount of copper as the temperature is increased.

  The amount of copper used relative to the amount of slag treated in the slag fuming method in the presence of copper is not particularly limited, and Cu reacts with the spices in the slag, and Cu—Fe—Pb in a temperature range of 1200 to 1500 ° C. A condition capable of forming a uniform melt of the As-based copper alloy is selected. For example, in the temperature range of 1200 to 1500 ° C., the amount of iron dissolved in the uniform melt varies from 5 to 50% by weight with respect to copper depending on the temperature. Therefore, the amount of copper required is determined according to the temperature used and the amount of iron in the spices contained in the slag.

  Here, it is desirable that the amount of copper used be equal to or greater than the required amount of copper. Specifically, the uniform melt can be stably formed by changing the amount of copper according to the amount of iron in the spice contained in the slag, or changing the amount of slag to be processed with a constant amount of copper. can do. In addition, in the formation of the homogeneous melt, there is a concern about the formation of a copper spice phase, but the formation of a copper spice phase does not occur under the excessive copper amount addition conditions selected based on the amount of iron dissolved, In effect, it is prepared based on the amount of iron dissolved as described above.

However, since the use of a large amount of copper leads to an increase in the cost of the copper source, it is desired to use the formed copper alloy (uniform melt) repeatedly to minimize the amount of copper used.
In general, since the reaction between copper and spices in the slag depends on the contact degree between the slag melt and the copper melt, it is preferable that the amount of copper relative to the amount of slag per batch is larger. Therefore, as the amount of copper relative to the amount of slag per batch, the amount of iron dissolved in copper is preferably the iron grade of the copper alloy, using the amount of copper per batch obtained from the amount of iron dissolved in copper as described above. Is preferably a method of treating multiple batches of new slag by repeatedly using the copper alloy until saturation is reached in a concentration range of 5 to 50 wt%, more preferably 5 to 35 wt%.

  The limit of the repeated use of the copper alloy is not particularly limited, and can be performed until arsenic or iron does not dissolve or a uniform melt cannot be formed. At this time, the arsenic content in the slag is usually 0. Since it is as low as n% by weight or less, the amount of iron is actually a major factor limiting the repeated use of the copper alloy rather than the amount of arsenic. However, with respect to lead, arsenic, and antimony, if the content in the copper alloy is excessive, the absorption capacity of these impurity metals is reduced.

  In the method for removing impurity metals of the present invention, it is important to add iron, lead, arsenic and other impurity metals by adding flux to the copper alloy and oxidizing the copper alloy. Thereby, a copper alloy having a composition that can be reused as a copper source of the copper melt can be obtained. In particular, it is effective for removing impurity metals from a uniform melt of a copper alloy after a predetermined repeated use.

  In the present invention, in the oxidation treatment of the copper alloy, iron is first oxidized, reacts with the flux and slags and is separated due to the difference in affinity for oxygen, and a deironed copper alloy is generated. Furthermore, a copper alloy from which lead, arsenic and antimony are removed and separated can be obtained by proceeding with the oxidation treatment. In addition, removal of lead, arsenic and antimony has a large effect by volatile separation in an oxidizing atmosphere as well as slag. Any of the obtained copper alloys is a copper alloy having a low impurity metal content that can be reused as a copper source of a copper melt.

  The method of the oxidation treatment is not particularly limited, and a method that can preferentially oxidize iron, lead, arsenic, and antimony in a copper alloy can be used. A method in which an oxygen-containing gas such as air, oxygen-enriched air, pure oxygen, or the like is blown into the melt through a lance or tuyere while adding and melting with heating is preferable.

  Equipment for performing these operations is not particularly limited, and may be carried out in the furnace after removing the slag after reduction blowing in the slag fuming furnace, and a copper alloy is placed outside the furnace. It may be extracted and carried out using another furnace, and the obtained copper alloy may be repeated in the slag fuming furnace.

  The melting temperature of the oxidation treatment is not particularly limited, and is preferably 1150 to 1500 ° C. That is, if the melting temperature is less than 1150 ° C., it is close to the melting point of the alloy, and the viscosity is too low, making the operation extremely difficult. On the other hand, when the melting temperature exceeds 1500 ° C., not only the energy cost increases, but also the refractory is damaged, and the cost required for repairing the furnace and the period of shutdown of the furnace accompanying the repair increase.

The flux used in the present invention is not particularly limited, and can form SiO ₂ , P ₂ O ₅ , B ₂ that can form fluid slag with FeO or Fe ₃ O ₄ produced by oxidation. An acidic oxide such as O ₃ or a basic oxide such as CaO, MgO, or Na ₂ O can be selected. For example, for iron slag, as an acidic oxide, siliceous stone containing SiO ₂ that generates firelite (2FeO · SiO ₂ ) slag, or as a basic oxide, calcium ferrite (CaO—Fe ₂ O ₃ ) Limestone containing CaO that generates slag can be used. Moreover, the compound which melts an iron oxide like various slags, such as slag fuming slag, can also be used.

The addition amount of the flux is not particularly limited. In the case of SiO ₂ , 1 to 20% by weight is preferable with respect to the copper alloy, and in the case of CaO, 1 to 2% with respect to the copper alloy. 15% by weight is preferred. In either case, if it is less than the above range, the effect is insufficient, and if it is too much, the cost increases.

Also, when removing and separating arsenic and antimony by oxidation treatment, if an alkali such as Na ₂ O or CaO or an oxide of an alkaline earth metal is used as the flux, the amount of distribution in the formed oxide increases. preferable. In particular, in the oxidation treatment of a copper alloy enriched in arsenic, antimony and lead, for example, as a flux, the addition ratio of 1 to 15 wt% CaO and 0.2 to 3 wt% Na ₂ O to the copper alloy It is preferable that the mixture is allowed to coexist. Thereby, arsenic and antimony in the copper alloy can be further reduced. That is, when the added amount of CaO and Na ₂ O is out of these ranges, if the amount is too small, the effect is not sufficiently exhibited. If the amount is too large, the cost increases or the erosion amount of the refractory increases.

  In addition, in the oxidation treatment of arsenic and antimony, a large amount of arsenic and antimony is distributed in the exhaust gas. Therefore, an exhaust gas treatment system different from that during reduction blowing is provided for treatment to suppress contamination of dust containing zinc and lead. It is important.

    As described above, in the slag fuming method in the presence of copper, after removing slag in the slag fuming furnace, the copper alloy enriched with iron, lead, arsenic, antimony, etc. is oxidized to thereby produce iron, lead, arsenic. The copper alloy is reused as a copper source for the copper melt by a simple operation method of removing antimony and the like, and then introducing new slag onto the obtained copper alloy and performing a slag fuming operation. be able to.

EXAMPLES The present invention will be described in more detail below with reference to examples of the present invention, but the present invention is not limited to these examples. The metal used in the examples was analyzed by ICP emission analysis.
Moreover, the slag produced from the blast furnace was used for the raw material slag used in the examples. Table 1 shows the chemical composition.

Moreover, the reduction blowing method of the slag used in the Example is as follows.
[Slag reduction blowing method]
The slag fuming device of FIG. 2 was used. The slag fuming device is heated by an externally heated electric furnace 9, and the temperature and the atmosphere in the electric furnace are controlled by the temperature control thermocouple 6 and the atmosphere-supporting nitrogen blowing tube 1. First, the raw material preparation is charged into the alumina crucible 7 used for the reaction, and the alumina crucible 7 is charged into the ceramic outer crucible 5 installed on the crucible holding brick 8. Next, nitrogen is blown into the melt that has been heated and melted through the stirring nitrogen blowing tube 3, and reduction blowing is performed while measuring the reaction temperature with the thermocouple 4 for temperature measurement. The generated dust is recovered through the dust recovery ceramic tube 2.

(Example 1)
A slag fuming treatment was performed using the slag to obtain a copper alloy, and a slag fuming treatment using a post-oxidation copper alloy obtained by an oxidation treatment using the copper alloy was performed.

(1) Slag fuming treatment in the presence of copper In an alumina crucible, the above-mentioned raw material slag 2000 g, metallic copper (copper grade 99.99 wt%) 400 g, and coke in consideration of the oxidation due to oxygen mixed in the furnace (total carbon 87.5% by weight) was added. Next, in accordance with the above [slag reduction blowing method], heated to 1350 ° C. in a nitrogen atmosphere, held for 30 minutes after melting, then stirred in the bath for 120 minutes with nitrogen gas, and held for 60 minutes after completion of stirring. Thus, the first slag fuming was performed. Thereafter, slag and copper alloy were sampled and analyzed for chemical composition. In addition, the volatilized dust was collected and analyzed for chemical composition. The results are shown in Table 2. In addition, the obtained slag was subjected to a dissolution test according to Environment Agency Notification No. 46, and the amounts of lead and arsenic eluted were measured. The results are shown in Table 3. In addition, the production amounts of slag and copper alloy were 1795 g and 305 g, respectively.

  Next, 2000 g of the raw material slag was newly charged in another alumina crucible, and almost the entire amount of the copper alloy obtained by the first slag fuming, a predetermined amount of metallic copper (copper quality 99.99 weight). %) And 40 g of coke taking into account the oxygen content in the furnace, and reduction blowing operation was performed under the same conditions as in the first slag fuming to form dust, slag and copper alloy. The total amount of copper charged was 400 g. Thereafter, slag and copper alloy were sampled and analyzed for chemical composition. In addition, the volatilized dust was collected and analyzed for chemical composition. In addition, this operation was performed 4 times (2nd-5th times) continuously. The results of each slag fuming are shown in Table 2. In addition, the obtained slag was subjected to a dissolution test according to Environment Agency Notification No. 46, and the amounts of lead and arsenic eluted were measured. The results are shown in Table 3.

  From Table 2, arsenic and antimony are concentrated in the copper alloy at any number of operations, and even if the copper alloy is used repeatedly, lead, arsenic and antimony in the slag are reduced, and arsenic and antimony are dust. It turns out that it does not distribute.

  From Table 3, it can be seen that the elution amounts of lead and arsenic stably satisfy the soil environment standard.

(2) Oxidation treatment of copper alloy The slag fuming device shown in FIG. 2 was used. After 300 g of the copper alloy obtained by the fifth slag fuming treatment in the coexistence of copper and 20 g of meteorite (SiO ₂ grade 97 wt%) were placed in an alumina crucible and heated and melted at 1350 ° C., Oxygen was fed into the melt through an alumina tube to oxidize, hold for 60 minutes, and then cooled. Thereafter, the post-oxidation slag and post-oxidation copper alloy were sampled and analyzed for chemical composition. The weights of the obtained oxidized slag and the oxidized copper alloy were 75 g and 250 g, respectively. The results are shown in Table 4.

  From Table 4, since the oxidation process of the copper alloy obtained by the said slag fuming process was performed according to the method of this invention, it turns out that the lead and iron in a copper alloy can be reduced.

(3) Slag fuming treatment using post-oxidation copper alloy In the alumina crucible, 2,000 g of the above raw material slag, 235 g of post-oxidation copper alloy, 165 g of copper metal (copper quality 99.99 wt%) and oxygen mixed in the furnace 40 g of coke (87.5% by weight of total carbon) considering the oxidation content was added. Next, in accordance with the above [slag reduction blowing method], heated to 1350 ° C. in a nitrogen atmosphere, held for 30 minutes after melting, then stirred in the bath for 120 minutes with nitrogen gas, and held for 60 minutes after completion of stirring. Then, slag fuming was performed. Thereafter, slag and copper alloy were sampled and analyzed for chemical composition. In addition, the volatilized dust was collected and analyzed for chemical composition. The results are shown in Table 5. In addition, the obtained slag was subjected to a dissolution test according to Environment Agency Notification No. 46, and the amounts of lead and arsenic eluted were measured. The results are shown in Table 6. In addition, the production amounts of slag and copper alloy were 1680 g and 312 g, respectively.

  From Table 5, the copper alloy obtained after the copper alloy obtained by the slag fuming treatment in the presence of copper according to the method of the present invention can be reused as the copper source of the copper melt of the slag fuming treatment. I understand.

  From Table 6, it can be seen that the amount of lead and arsenic eluted in the obtained slag remains low, and the soil environmental standards are satisfied even after repeated use of the copper alloy after oxidation.

(Example 2)
A slag fuming process was performed using the slag to obtain a copper alloy, and an oxidation process was performed using the copper alloy.
(1) Slag fuming treatment in the presence of copper In the slag fuming treatment in the presence of copper, the same procedure as in Example 1 was conducted except that the number of reduction blowing operations was three (first to third). An alloy was obtained. The chemical composition of the obtained copper alloy was almost the same as that of the copper alloy having the third operation shown in Table 2.
(2) Oxidation treatment of copper alloy The same analysis was performed as in Example 1 except that 310 g of the copper alloy was used as the copper alloy and a mixture containing 20 g of CaO and Na ₂ O was used as the flux. The resulting oxidized copper alloy was chemically analyzed. did. In addition, the weight of the obtained copper alloy after oxidation was 230 g. The results are shown in Table 7.

  From Table 7, it can be seen that since the oxidation treatment of the copper alloy obtained by the slag fuming treatment was performed according to the method of the present invention, lead, arsenic and antimony in the copper alloy can be reduced.

  As is clear from the above, the method for removing impurity metals from the copper alloy obtained by the slag fuming method of the present invention uses slag produced from a zinc and / or lead smelting furnace as a copper melt. It is used as a method for removing impurity metals from copper alloys containing iron, lead, arsenic and other impurity metals formed by co-existing slag fuming, especially iron, lead, arsenic and other high concentrations by repeated use. It is suitably used when obtaining a copper source of a copper melt from a copper alloy containing an impurity metal.

It is a copper-iron binary system phase diagram. It is a conceptual diagram of the slag fuming apparatus used for the Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nitrogen blowing tube for atmosphere protection 2 Ceramic tube for dust collection 3 Stirring nitrogen blowing tube 4 Thermocouple for temperature measurement 5 Ceramic outer crucible 6 Thermocouple for temperature control 7 Alumina crucible 8 Brick for crucible holding 9 Electric furnace

Claims (4)

  Flux to copper alloy containing iron, lead, arsenic and other impurity metals formed by slag fuming in the presence of slag produced from zinc and / or lead smelting furnace coexisting with copper melt A method for removing an impurity metal from a copper alloy, which comprises adding an oxygen, followed by an oxidation treatment.   The method for removing an impurity metal from a copper alloy according to claim 1, wherein the flux is an acidic oxide or a basic oxide. The method for removing an impurity metal from a copper alloy according to claim 2, wherein the basic oxide is CaO and / or Na ₂ O.   The slag fuming method characterized by reusing the copper alloy from which the impurity metal was removed by the method according to any one of claims 1 to 3 as a copper source of the copper melt.

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