JP2012211381A - Method for removing deposit on furnace bottom in iron and tin-containing copper treatment furnace - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for efficiently removing a residue deposited on the furnace bottom of a recycling furnace with no slag layer and no matte layer.SOLUTION: A method for removing a deposit on the furnace bottom in an iron and tin-containing copper treatment furnace is executed as follows: the temperature in the iron and tin-containing copper treatment furnace, on the furnace bottom of which an iron compound is deposited, is raised to a temperature between 1,300°C and 1,400°C, and a slag part and a metal part are removed from the furnace; then metal grains, which have a grain size of 2-30 mm, a metallic Fe content of 50-95 mass%, a C content of 1-5 mass%, and a Cu content of ≤35 mass%, and which are obtained by smelting reduction treatment of general waste or industrial waste, are thrown on to a furnace bottom deposit, which is formed on the furnace bottom and contains FeOas a main component, from above the furnace bottom; so that the furnace bottom deposit that is formed on the furnace bottom and contains FeOas a main component is efficiently dissolved and removed.

Description

  The present invention relates to a method for removing bottom deposits of iron and tin-containing copper processing furnaces.

In a copper smelting furnace, generally, a sulfide concentrate is oxidized, a mat in which valuable metals such as copper (Cu) are concentrated, iron oxide (FeO) in which iron reacts with oxygen (O ₂ ), and silicon dioxide (SiO ₂ ). ₂ ) A slag produced by a reaction of forming can be obtained as a melt, and settling in a holding container is performed to separate them by a specific gravity difference.

In this oxidation reaction, oxidation of iron in the raw material proceeds, and a part of iron (Fe) is excessively oxidized from FeO to triiron tetroxide (magnetite, Fe ₃ O ₄ ). Since this Fe ₃ O ₄ has a high melting point, it solidifies when it reaches the bottom of the holding container, resulting in build-up 18 as shown in FIG. Increasing the build-up 18 is known not only to reduce the effective volume in the holding vessel, but also to disturb the solution flow in the holding vessel and inhibit the specific gravity separation of the mat and slag in the holding vessel. Yes.

Conventionally, a buildup mainly composed of Fe ₃ O ₄ at the bottom of the holding container is made of a pig iron block (general type 280 mmL × 80 mmW × 50 mmH, ingot having a weight of about 5 kg) as a reducing agent. 20), a means for reducing the amount of Fe ₃ O ₄ by reducing it with pig iron is generally used.

But,
1) With this method, only the buildup 18 immediately below the ingot inlet 20 is melted, and it is impossible to melt the buildup 18 at a portion, for example, about 1 m away from just below the inlet.
In order to dissolve a wide range of build-ups 18, it is necessary to provide a large number of inlets. However, if provided, leakage of high-temperature gas containing SO ₂ gas from the inlets, mechanical in the vicinity of the inlets There was a problem of strength reduction.

2) In this method, it is necessary to transport and throw ingots having a weight of 2 to 5 kg. However, mechanization is difficult, and manual feeding and throwing are common. However, this work is a work near the smelting furnace having a furnace temperature of about 1300 ° C., and the working environment was poor.
In order to solve the above problems, Japanese Patent No. 4096825 (Patent Document 1) has been disclosed.
However, as shown in FIG. 1, these include a slag layer 14 and a mat layer 16, and a buildup 18 therebelow, and a furnace for improving the quality of the recycled product of the present invention. In contrast, it could not be immediately used to solve problems related to the treatment of bottom deposits in recycling furnaces.

Japanese Patent No. 4096825

  An object of the present invention is to provide a method that efficiently removes deposits that are free from slag layers and mat layers and that accumulate on the bottom of a recycling furnace.

Therefore, the following invention is proposed.
(1) In an iron and tin-containing copper treatment furnace, the furnace in which the iron compound is deposited on the furnace bottom is heated to a temperature between 1300 ° C. and 1400 ° C., and then slag and metal are removed from the furnace. After that, the particle size is 2 to 30 mm, the metallic Fe grade is 50 to 95 mass%, the C grade is 1 to 5 mass%, the Cu grade is 35 mass% or less, and general waste or industrial waste is melted. The metal particles obtained by the reduction treatment are formed on the bottom of the furnace by throwing them into the bottom of the furnace bottom deposit mainly composed of Fe ₃ O ₄ formed on the bottom of the furnace. A method for removing a bottom deposit in an iron- and tin-containing copper treatment furnace, which efficiently dissolves and removes the bottom deposit composed mainly of Fe ₃ O ₄ .
(2) the composition of the furnace bottom sediments of (1), iron: 20 40 mass% of copper: 15 25 mass% from _SiO 2: 7 13 mass% from CaO: iron are those containing from 3 8mass% Sukunakumo, A method for removing bottom deposits of a tin-containing copper processing furnace.
(3) In any of the above (1) or (2), in order to protect the refractory in the furnace, not all of the bottom deposit is removed, and a part of the bottom deposit is removed from the bottom of the furnace. For removing bottom deposits of iron and tin containing copper processing furnaces.

(4) In any of the above (1) to (3), when at least two batches of the iron and copper-containing copper treatment steps are performed, the furnace of the iron and tin-containing copper treatment furnace that treats the bottom deposit A method for removing bottom deposits.
(5) In any one of the above (1) to (4), the method for removing the bottom deposit of an iron- and tin-containing copper processing furnace, wherein the bottom deposit is treated after the deironing and tinning steps.
(6) In any one of the above (1) to (5), a method for removing a bottom deposit in an iron- and tin-containing copper treatment furnace in which the metal particles are introduced from a furnace inlet of the furnace.
(7) In any one of the above (3) to (6), a part of the furnace bottom deposit remaining on the furnace bottom is an iron and tin-containing copper processing furnace having a thickness of 2 cm to 20 cm from the furnace bottom. Method for removing bottom deposits.

By implementing the present invention, the following effects are obtained.
(1) A wide range of iron and tin-containing copper treatment furnace bottom deposits can be efficiently dissolved and removed. Moreover, if the particle size, bulk specific gravity, charging speed, etc. of the metal particles are set as appropriate conditions, the removal method of the bottom deposit of the iron and tin-containing copper processing furnace can be efficiently dissolved and removed. Furthermore, it is possible to prevent the work environment from deteriorating.
(2) Deposits can be removed efficiently.
(3) The shortening of the furnace life can be suppressed.
(4) The copper contained in the bottom deposit of the iron and tin-containing copper treatment furnace can be efficiently recovered.
(5) The copper contained in the bottom deposit of the iron and tin-containing copper processing furnace can be efficiently recovered.
(6) Deposits can be efficiently removed.
(7) The shortening of the furnace life can be suppressed.

It is the schematic which shows the removal of the deposit of the smelting furnace which is a copper smelting furnace different from this invention. It is a flowchart which shows the processing method of iron and tin containing copper. It is a figure showing the elapsed time in a deironing process, and the density | concentration change of each component. It is a figure showing the elapsed time in a deironing process, and the density | concentration change of each component. It is one aspect | mode of this invention, and the dissolution condition of the bottom deposit of an iron and tin containing copper processing furnace is shown.

Hereinafter, the configuration of the present invention will be described in detail.
In the present invention, the target furnace is a furnace for treating iron and tin-containing copper. The furnace is, for example, a processing furnace related to recycling, and is a furnace in which an iron compound is deposited on the bottom of the furnace. Iron and tin-containing copper are copper containing iron and tin.

  First, the content of the processing method of iron and tin containing copper is demonstrated. The purpose of this treatment method is to efficiently remove iron and tin from iron and tin-containing copper. As an example, the iron / tin-containing copper to be used in the present embodiment contains 5 mass% to 25 mass% of iron, 1 mass% to 8 mass% of tin, and 50 mass% to 80 mass% of copper. The iron / tin-containing copper processing method according to this embodiment will be described along the processing flow shown in FIG.

(Deironing process (Iron oxidation process))
First, as a first step, a deironing step of oxidizing and removing iron is performed. In the iron removal step, the above-mentioned iron / tin-containing copper is introduced into the furnace and a solvent is introduced. As the solvent, for example, silica sand (SiO ₂ ) and limestone (CaCO ₃ ) are added. For example, 2.5 to 3 tons of dredged sand and 3.5 to 4.5 tons of limestone are added to 25 to 30 tons of iron / tin-containing copper.

  The furnace in which the iron / tin-containing copper is charged is not particularly limited. As an example, a converter, an upper blowing furnace, or the like can be used. After the iron / tin-containing copper and solvent are added, the iron / tin-containing copper is melted by heating the furnace using combustion heat such as propane gas or heavy oil to form a molten metal. Since propane gas has a low sulfur content, it is preferable to use propane gas from the viewpoint of reducing processing of exhaust gas. The temperature of the molten metal in the furnace is preferably maintained at 1300 ° C to 1400 ° C. This is because iron can be efficiently oxidized and removed while suppressing the oxidation of copper. In order to further suppress copper oxidation, the temperature of the molten metal in the furnace is preferably maintained at 1300 ° C to 1350 ° C.

Next, an oxygen-containing gas (for example, air) is blown into the molten metal. As an example, it is blown about 4 hours to 5 hours of air at a flow rate of 300Nm ³ / h~400Nm ³ / h from the tuyere. For example, the tuyere is preferably provided at about 2 to 6 locations on the side wall of the furnace. The amount of air blown is, for example, 5000 Nm ³ / batch to 7000 Nm ³ / batch. By blowing the oxygen-containing gas, iron in the molten metal is oxidized and moves to the slag. Thereby, iron is removed from the molten metal.

  Oxidation heat is generated when iron is oxidized. Therefore, in order to suppress the temperature of the molten metal from rising excessively, a cold material is introduced into the molten metal. However, it is preferable to adjust the oxygen concentration in the molten metal to be 2 mass% or less when the cold material is added. This is to suppress copper loss. In order to further suppress the copper loss, it is preferable to adjust the oxygen concentration in the molten metal to be 1 mass% or less.

  The cold material is not particularly limited. As an example, it is preferable to use late copper as a cooling material. This is because impurities in the late copper can be removed. For example, it is preferable to use late copper containing at least one of iron and tin as the cooling material. Alternatively, low-quality recycled products such as plating scraps may be used as the late copper. Although high quality waste copper may be used, it is more economical to use low quality waste copper.

  When using late copper as a cold material, it is preferable that the amount of the cold material to be introduced is a little smaller than the starting iron-tin-containing copper. For example, it is preferable that the input amount of the cooling material is 20 to 30 tons with respect to 25 to 30 tons of iron / tin-containing copper. As an example, a copper containing 5 mass% to 10 mass% of iron, 1 mass% to 10 mass% of tin, and 70 mass% to 90 mass% of copper is used as the late copper.

  Table 1, Table 2, FIG. 3 and FIG. 4 are diagrams showing elapsed time and concentration change of each component in the deironing process. 3 and 4, the horizontal axis represents the elapsed time. The vertical axis | shaft of FIG. 3 shows the iron concentration in the metal in a deironing process, the tin concentration in slag, and the copper concentration in slag. The vertical axis in FIG. 4 indicates the tin concentration in the metal, the oxygen concentration in the metal, and the iron concentration in the metal.

  As shown in Table 1, Table 2, FIG. 3, and FIG. 4, the iron concentration in the iron / tin-containing copper decreases with time. Therefore, it can be seen that iron is oxidized and removed by blowing the oxygen-containing gas. After iron has been oxidized and removed to some extent, tin is oxidized and removed.

(Slag discharge / casting process)
After the iron removal process, slag is discharged from the furnace. Further, casting is performed by pouring molten metal into a mold and cooling. In this case, since the tin removal slag described below is generated after the iron removal slag is removed, mixing of the iron removal slag and the tin removal slag is suppressed. Thereby, the tin removal efficiency fall in the below-mentioned tin removal process can be suppressed.

  The slag components discharged after the iron removal step are, for example, 25 mass% to 45 mass% for iron, 0.5 mass% to 2 mass% for tin, and 5 mass% or less (for example, 1 mass% to 5 mass%) for copper. Moreover, the metal (copper ingot) obtained by casting is, for example, 0.2 mass% to 2 mass% for iron, 2 mass% to 4 mass% for tin, and 90 mass% to 95 mass% for copper. Thus, the iron concentration in the iron / tin-containing copper can be significantly reduced by passing through the iron removal step. Moreover, the slag containing high concentration iron can be discharged | emitted by passing through a slag discharge process and a casting process.

(Tin removal process (tin oxidation process))
Next, a tin removal step is performed. First, the copper metal and the solvent are again put into the furnace. As a solvent in the tin removal process, for example, silica sand and limestone are added. For example, 0.8 to 1.5 tons of dredged sand and 1 to 2 tons of limestone are added to 25 to 27 tons of copper containing iron and tin. Further, sodium carbonate (Na ₂ CO ₃ ) is added as a tin removal agent for efficiently removing tin. For example, 2 to 3 tons of sodium carbonate is added to 25 to 27 tons of iron / tin-containing copper.

  The furnace in which the iron / tin-containing copper is charged is not particularly limited. As an example, a converter, an upper blowing furnace, or the like can be used. After charging the copper ingot, the solvent, and the tin removal agent, the copper ingot is melted to form a molten metal by heating the furnace using combustion heat such as heavy oil and propane gas. The temperature of the molten metal in the furnace is preferably maintained at 1200 to 1270 ° C. This is because tin can be efficiently removed by oxidation while suppressing oxidation of copper.

Next, an oxygen-containing gas (for example, air) is blown into the molten metal. As an example, blown 300Nm ³ / h~400Nm ³ / 1.5 hours to 2.5 hours at a flow rate of h air from tuyere. For example, the tuyere is preferably provided at about 2 to 6 locations on the side wall of the furnace. In order to suppress the oxidation of copper, the number of tuyere used in the tin removal step may be reduced from the number of tuyere used in the iron removal step. The amount of air blown is, for example, 5000 Nm ³ / batch to 7000 Nm ³ / batch. The oxygen in the molten metal is oxidized by the oxygen-containing gas and the tin removal agent and moves to the slag. Thereby, tin is removed.

  In the tin removal step, it is preferable to put a cold material into the furnace in order to adjust the molten metal temperature. For example, the copper ingot obtained in the casting process and the late copper having the same grade of iron and tin may be used as the cooling material. Moreover, you may use late copper (iron is 0.2 mass% to 2 mass%, tin is 0 mass% to 4 mass%, copper is 90 mass% to 98 mass%) as a cooling material, which is higher quality than copper bullion. As high-quality waste copper, an unelectrolyzed portion of the anode (turned anode) or the like may be used. This is because the contamination of the molten metal can be suppressed by introducing high-quality waste copper. Moreover, it is because it can be used for melt | dissolution of a cast-back anode simultaneously.

  Each component of the copper ingot obtained through the tin removal step is, for example, 0.05 mass% to 0.25 mass% for iron, 0.2 mass% to 1.0 mass% for tin, and 96 mass% to 99 mass% for copper. is there. Moreover, each component of the slag obtained by the tin removal process is, for example, 10 mass% to 25 mass% for iron, 3 mass% to 15 mass% for tin, and 8 mass% to 15 mass% for copper. Thus, iron and tin can be efficiently removed by carrying out the iron removal step, the slag discharge step, the casting step, and the tin removal step.

After the iron and tin-containing copper treatment steps as described above, deposits may accumulate on the furnace bottom. The composition of the furnace bottom sediments of the furnace, the iron: 20~40mass%, copper _{(Cu): 15~25mass%, SiO} 2: 7~13mass%, calcium oxide (CaO): the 3～8Mass%, at least containing It is a waste.
Iron is in the state of magnetite (Fe ₃ O ₄ ).
These deposits are generated, for example, in a furnace in which copper containing iron and tin (Sn) is oxidized to 96 to 99 mass%.

In particular, deposition occurs when the copper treatment process is performed more than once in a batch, which significantly reduces furnace deposition.
For example, when 200 tons of 150 tons of iron and tin containing copper collected in a recycling treatment furnace are treated twice, 7 to 10 tons of things are deposited at the bottom of the furnace.

If these deposits are left unattended, the throughput of the furnace will be drastically reduced and the efficiency of operation will be impaired.
On the other hand, accumulation to some extent has the effect of not damaging the brick inside the furnace body, and has the effect of extending the furnace life. Therefore, it is preferable to leave a part of the deposition part at the furnace bottom. For example, a deposit having a thickness of about 2 cm to 20 cm from the furnace bottom may be left on the furnace bottom.
As a guide for removal, removal is performed when the deposit occupies 15 to 16% by volume of the furnace space.
Therefore, in the present invention, for example, when the treatment is performed twice or more with the iron removal step, the casting step, and the tin removal step as one step, it is desirable to perform the treatment of the present invention. Thereby, copper can be efficiently recovered and deposits can be removed.

The deposit deposited in the furnace is heated from 1300 ° C. to 1400 ° C., and then an iron-containing material having a particle size of 2 to 30 mm is introduced into the deposit that does not melt. Heating is performed with a gas burner or the like. Heavy oil or propane gas is used as the fuel.
The metal particles used preferably have a particle size of 2 to 30 mm. With this particle shape, the reactivity and diffusivity are good, and mechanization of transportation and charging becomes easy. As a result, deposits can be removed efficiently and the working environment is improved.
The iron-containing material forming the metal particles preferably contains 50 to 95 mass% of metallic Fe, 1 to 5 mass% of C, and 35 mass% or less of Cu. Moreover, it is preferable that it is a metal particle obtained by melt-reducing a general waste or an industrial waste.
This is because the composition within this range is excellent in reactivity with the deposit. The reason why carbon is essential here is that the melting point of the iron alloy is lowered when carbon is added, and the reactivity in a furnace for treating iron and tin-containing copper is increased.
A thing containing valuables, such as Cu, will lead to recovery of valuables, and is more suitable.
However, it is desirable that the Cu quality is 35 mass% or less. This is because when it is 35 mass% or more, the iron component and the carbon component are reduced, and the reduction effect on the bottom deposit is weakened. More preferably, it is 20 mass% or less. This is to increase the reduction effect on the furnace bottom deposit.

By introducing the metal grains toward the bottom deposit from the top of the furnace, the bottom deposit composed mainly of Fe ₃ O ₄ formed on the bottom can be reduced and efficiently dissolved and removed. .

The metal particles are introduced at 150 to 250 kg / time for 7 to 10 tons of furnace bottom deposits. The speed is, for example, 0.15 cm ² or more per second.
This is because if more than the required amount of metal particles is added, the bottom of the furnace may be damaged. Usually, charging is performed from the raw material charging port (furnace inlet). The part where the bottom deposit is formed is widened, and the metal particles are introduced so that the appropriate part is covered with the metal particles. This is because it is desirable to cause the reaction in a wide range and efficiently remove the bottom deposit.
After removing the slag and metal components from the furnace, the metal particles are uniformly introduced into the deposit surface at the bottom of the furnace. After the charging, the furnace is heated to a temperature between 1300 ° C. and 1400 ° C. by using a gas burner, for example, to dissolve the deposit and discharge the dissolved component outside the furnace. The above operation is performed several times. However, removing all deposits can reduce the life of the bottom refractory. For this reason, it is preferable to leave a part of the deposit on the furnace bottom. For example, the deposit may be left to have a thickness of about 2 to 20 cm from the furnace bottom. Thereby, shortening of the lifetime of a furnace can be suppressed. The thickness of the remaining deposit may be about 5 to 10 cm, for example. The temperature of the furnace may be, for example, a temperature between 1300 ° C. and 1350 ° C., or a temperature between 1350 ° C. and 1400 ° C.

According to the present invention, it becomes possible to efficiently dissolve the bottom deposit mainly composed of Fe ₃ O ₄ formed at the bottom of the iron and tin-containing copper processing furnace, and the effective volume in the holding container is reduced. It is possible to maintain, stabilize the solution flow in the holding container, and efficiently perform the specific gravity separation of the metallic copper solution and the slag.

In this example, iron and tin-containing copper were processed by a converter having a brick inner diameter of 2 m and a length of 3 m. FIG. 5A and FIG. 5B are examples of converters. The inlet of the converter 10 is closed by a lid 22. By removing the lid 22, it becomes possible to throw things into the converter 10 from the charging port (furnace inlet). A buildup 21 (furnace bottom deposit) is deposited in the converter 10. The converter 10 is provided with, for example, four tuyere 24.
Iron and tin-containing copper are blown from the four tuyere 24 in the iron removal process to oxidize the iron in the solution, turn the iron into slag, separate the slag and solution, cast the solution, The cast ingot was put into the converter 10 and air was blown from the two tuyere 24 to remove tin, and the tin was slagged and separated and recovered from the solution to obtain 96 to 99% crude copper.
When this treatment was performed twice, a build-up 21 as a deposit was generated at the bottom of the converter 10, and an undesired reduction in volume occurred in operation. Moreover, it was not a favorable state for fluidity and discharge of solution and slag.

The furnace deposit of iron and tin containing copper processing furnace produced 8 tons. Table 3 is a table showing the composition and quality of the furnace deposit. As shown in Table 3, grade _{Cu: 21mass%, Fe / Fe} 3 O 4: 35mass%, SiO 2: 9.0mass%, CaO: 5.7mass%, Al 2 O 3: met 2.3 mass% It was.
As metal particles for melting and removing such furnace deposits, pig iron particles generated from “general waste direct melting / resource plant” are used.
The particle size of the pig iron particles is 2 to 30 mm, and the composition is metallic Fe: 75 mass%, C: 2.5 mass%, Cu: 3.5 mass%. The pig iron particles were intermittently charged at a rate of 200 kg for 60 minutes. The pig iron particles can be charged from the charging port from which the lid 22 is removed. The pig iron grain charging speed is 400 to 700 g per second, for example, but can be changed.
After the iron slag is removed from the converter 10 from the slag and the metal, it is charged uniformly over the surface of the deposit. After the charging, the converter 10 was heated to, for example, a temperature between 1300 ° C. and 1400 ° C., for example, with a gas burner, etc., the deposit was dissolved, and the dissolved component was discharged out of the converter 10. The above operation was performed several times. However, since removing all the deposits could shorten the life of the furnace bottom refractory, a portion of the deposits were left to have a thickness of, for example, 2 to 20 cm from the furnace bottom.

In the buildup 21 (furnace bottom deposit), the magnetite was reduced to form a solution and could be easily removed.
In addition, the recovered material was abundant in copper and was put into a copper smelting furnace to recover copper.
The copper at the bottom of the furnace was also effectively recovered.

10 Converter 21 Build-up

Claims (7)

In the iron and tin-containing copper treatment furnace, the furnace in which the iron compound is deposited on the furnace bottom is heated to a temperature between 1300 ° C. and 1400 ° C.,
After removing slag and metal from the furnace, the particle size is 2 to 30 mm, the metallic Fe grade is 50 to 95 mass%, the C grade is 1 to 5 mass%, and the Cu grade is 35 mass% or less. Then, metal particles obtained by smelting reduction treatment of general waste or industrial waste are thrown into the furnace bottom deposit mainly composed of Fe ₃ O ₄ formed on the furnace bottom from above. Thus, the bottom deposit of an iron and tin-containing copper treatment furnace, which efficiently dissolves and removes the bottom deposit mainly composed of Fe ₃ O ₄ formed on the bottom of the furnace. Removal method. The composition of the furnace bottom sediments of claim 1, iron: 20 40 mass% of copper: 15 25 mass% of, _SiO 2: 7 13mass% from CaO: characterized in that those containing from 3 8mass% Sukunakumo A method for removing bottom deposits of iron and tin-containing copper processing furnaces.   In order to protect the refractory in the furnace according to any one of claims 1 and 2, not all of the bottom deposit is removed but a part of the bottom deposit is left on the bottom. A method for removing bottom deposits of an iron and tin-containing copper treatment furnace.   The furnace for an iron and tin-containing copper treatment furnace according to any one of claims 1 to 3, wherein the furnace bottom deposit is treated when at least two batches of the iron and tin-containing copper treatment process are performed. A method for removing bottom deposits.   5. The method for removing a bottom deposit in an iron- and tin-containing copper processing furnace according to claim 1, wherein the bottom deposit is treated after the deironing and detinning steps.   6. The method for removing a bottom deposit in an iron- and tin-containing copper processing furnace according to claim 1, wherein the metal particles are introduced from a furnace charging inlet of the furnace.   The iron or tin-containing copper treatment furnace according to any one of claims 3 to 6, wherein a part of the bottom deposit left on the bottom has a thickness of 2 cm to 20 cm from the bottom. A method for removing the bottom deposit.

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