JP3535381B2 - Collection of valuable metals - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to copper (Cu), zinc (Zn), lead (Pb), iron (Fe) generated from various industries.
Suppress the deterioration of valuable metals due to oxidation while suppressing the generation of harmful substances by using metal slag containing valuable metals such as etc., shredder dust containing valuable metals generated from automobiles, electric appliances, etc., and industrial waste such as waste plastics as raw materials. A method for recovering valuable metals is provided.

[0002]

To obtain a metal from the ore of the Prior Art nonferrous smelting, hydrometallurgical, also requires a seed s of steps in either pyrometallurgical, residue, sure metal debris generated therebetween. In particular, in copper smelting, a large amount of copper scrap is generated in a mat smelting such as a reverberatory furnace and a converter for producing blister copper. This copper scrap is obtained by recovering the target metal, copper, as the target metal material, but contains a large amount of copper.
Have. Therefore, in order to effectively use resources or improve production yield, copper scrap is refined again to recover copper. On the other hand, a large amount of shredder dust and waste plastics generated from the living environment are generated as industrial waste due to the current popularization of automobiles and home appliances. These industrial wastes contain a large amount of waste plastics such as epoxy resin and valuable metals such as copper and iron, and valuable metals are collected from these. In addition to this, general wastes include waste liquid and sludge, which are generated by general sewage and wastewater from the mining industry. A small amount of metals and organic substances remain in these waste liquids and sludges, and it is desirable to recover valuable metals and incinerate them by heat treatment in order not to adversely affect the environment.

Therefore, as a method for recovering valuable metal by reprocessing from a metal slag, for example, JP-A-4-218627 has been proposed. Here, as a method for reprocessing zinc- and lead-containing residues in a metallurgical plant, residues are produced at various stages during the production of iron and steel, and zinc, lead and alkali contained in these are reprocessed under reducing conditions. A continuous method of processing is provided. However, this method is mainly composed of zinc or the like having a high vapor pressure, and has a problem that it is difficult to recover a metal having a low vapor pressure. On the other hand, as a method of recovering valuable metals from industrial waste, for example, Japanese Patent Laid-Open No. 6-
Japanese Patent No. 136458 has been proposed. Here, calcium chloride is added as needed to plastic containing a large amount of high melting point metal compound and a small amount of low melting point metal compound in industrial waste, and the low melting point metal is converted to chloride gas under a reducing atmosphere. The method of separating, cooling, and recovering is provided. However, this method also has a problem that it is difficult to recover a metal having a low vapor pressure similarly to the above. Furthermore, no method has been proposed for simultaneously recovering metals from both metal slags and other industrial wastes generated during smelting and refining.

[0004]

However, there are the following problems in recovering metal from both the metal slag and the industrial waste at the same time. If it is carried out together with the incineration of industrial waste, the dry method will be used, but if the temperature is raised to incinerate, there is the problem that the valuable metal of interest is oxidized and must be reduced again later. . Further, when incineration of industrial waste is carried out at a low temperature, there is a problem that harmful substances such as dioxin and NOx are generated. Therefore, in view of the above problems, the present invention has a problem that, as a raw material, an industrial waste containing a copper slag (including copper scrap) and a valuable metal and a plastic as a metal slag,
(EN) A method for recovering valuable metals of good quality by treating both of them at the same time to suppress the generation of harmful substances and preventing metal oxidation. Further provided is a method for simultaneously recovering valuable metals such as copper and iron, which are difficult to recover due to high melting point and low vapor pressure, and valuable metals such as zinc and lead, which have low melting point and high vapor pressure. Further, it provides a method for simultaneously incinerating waste such as sludge and waste liquid.

[0005]

In order to solve the above-mentioned problems, the invention according to claim 1 provides copper (Cu), zinc (industrial wastes containing copper slag and metal generated from various industries). A method for recovering a valuable metal selected from Zn), lead (Pb), iron (Fe), and aluminum (Al), in which a copper slag and industrial waste are put into a fluidized bed gasification furnace to lower the gasification furnace. Air is blown from the above to form a fluidized bed to gasify the industrial waste, and Fe, Cu, or Al is fed from the gasification furnace .
A step of recovering the first incombustible material containing one or more valuable metals selected from the group, and one or more kinds selected from Zn, Pb and Cu which are elevated by the air from the lower part of the gasification furnace into the melting furnace. > while swirling the second incombustible and pyrolysis gas produced in the gasification furnace containing valuable metals were charged, Cu in the molten furnace
Generating a slag containing, separating and collecting, and charging the slag to be collected in the melting furnace into an electric holding furnace,
A method of recovering valuable metal, including a step of recovering black copper (crude copper). The invention according to claim 2 is the method for recovering valuable metal according to claim 1, wherein a step of returning a part of the first incombustible material to the gasification furnace and a remaining portion of the first incombustible material, And a step of recovering Fe with a magnetic separator. The invention according to claim 3 is the method for recovering valuable metals according to claim 1 or 2, wherein fly ash generated from the melting furnace and / or the electric holding furnace is recovered and dissolved in an aqueous solution solvent for neutralization. Or sulfurized to Zn and
It is a method of recovering a valuable metal including a step of depositing and recovering a salt containing at least one valuable metal selected from Pb . The invention according to claim 4 is the method for recovering valuable metal according to any one of claims 1 to 3, further comprising the step of spraying and decomposing the waste liquid into a waste liquid decomposing tower provided after the melting furnace. It is a collection method.

According to a fifth aspect of the present invention, in the method for recovering valuable metals according to the first aspect, the fluidized bed gasification furnace is heated to a temperature of 400 to 600 ° C., and an air ratio is 0.1 to 0.3.
Is a method for recovering valuable metals by gasifying the industrial waste in a reducing atmosphere. The invention according to claim 6 is the method for recovering valuable metal according to claim 5, wherein the temperature is adjusted by spraying and introducing waste liquid into the fluidized bed gasification furnace. The invention according to claim 7 is the method for recovering valuable metals according to claim 1, wherein the melting furnace is set to a temperature of 1300 to 1500 ° C., and an air ratio is 0.9 to
This is a valuable metal recovery method of producing the slag in an oxidizing atmosphere of 1.3, separating and recovering it. The invention according to claim 8 is the method for recovering valuable metal according to claim 2, wherein the residual amount of the first incombustible material is retained by a magnetic separator.
The process of recovering the valent metal includes iron (Fe) -containing material and copper (C).
u) and aluminum (Al) inclusions are selected by magnetic force
And a step of recovering iron (Fe) -containing material, further comprising:
From the recovered residue, a copper (C
u) and aluminum (Al) sorting and recovery process
It is a method of recovering valuable metals including . The invention according to claim 9 is the method for recovering valuable metal according to claim 1, wherein the electric holding furnace is set to a temperature of 1300 to 1500 ° C, and a reducing agent is used to remove the black copper (crude copper) from the slag. Is a method of recovering valuable metals.

Further, since the melting furnace and the electric holding furnace process at a high temperature, it is possible to suppress the generation of harmful substances such as dioxins. Further, in order to remove a trace amount of harmful substances in the exhaust gas, activated carbon is blown into the transfer path of the exhaust gas, whereby harmful substances such as dioxins can be adsorbed to the activated carbon and removed. Furthermore, the amount of harmful substances can be reduced and removed by performing neutralization cleaning and electrostatic precipitating treatment with a cleaning tower or mist cotrel in the exhaust gas transfer route.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. The present invention is represented in FIGS. Figure 1 shows copper slag and industrial waste as exhaust gas and slag,
It is a schematic block diagram which showed the process until a valuable metal is collect | recovered. FIG. 2 is a diagram showing the structure of a fluidized bed gasification furnace for separating copper slag and industrial waste into pyrolysis gas and incombustible particles. FIG. 3 is a diagram showing the structure of a melting furnace that combusts a pyrolysis gas containing second incombustible particles and produces slag.

As shown in the schematic diagram of FIG. 1, copper slag A1
Is stored in the first storage 1 and the industrial waste A2 containing metal is stored.
Etc. are stored in another second store 2. The first reservoir 1, can be stored at the same time low ores of other quality, such as copper-bearing pyrite, sulfide ores of chalcopyrite such, the oxide ores. As a copper slag, brass wrought copper factory, slag generated from bronze factory,
Dust, shavings, and copper hydroxide and precipitated copper from chemical plants. In addition, sludge generated by neutralization treatment and the like can be stored at the same time, and silica sand and limestone for forming slag and coke for reduction may be stored at the same time. Etc. Dokasu A1 from the first reservoir 1 finely crushing over the crusher (not shown), simultaneously supplied to the supplying feeder 4 more supply conveyor 3 and crushing the industrial wastes A2, and the like. At this time, a step of removing large iron scraps by hanging on a magnetic sorter (not shown) may be provided. Next, to introduce a certain amount from the supply feeder 4 to the fluidized-bed gasification furnace 11. Here, the sludge B can be introduced into the fluidized gasification furnace 11 by a supply feeder (not shown) separately from the copper slag A1 and the like. The sludge B includes sewage sludge generated from general sewage, night soil sludge, and neutralization sludge generated from wastewater treatment. Here, the copper slag A1 is
A slag having a copper quality of 20 to 80% is preferable. Copper grade 2
If it is less than 0%, the variable cost becomes large and the copper grade is 80%.
This is because if it is more than%, it is advantageous to solidify it by some means and put it into the copper smelting converter plant. For the above reason, the copper grade is more preferably in the range of 30 to 50%. Further, the industrial waste A2 includes shredder dust containing valuable metals and plastics obtained by shredding automobiles, home electric appliances and the like, and household and industrial waste plastics.

[0010] In fluidized-bed gasification furnace 11, as further shown in FIG. 2, the entered industrial waste A2 and Dokasu like A1
However, the air C pushed from the fluidized bed 12 forms a fluidized bed in the gasification furnace 11 and is circulated. Gasification furnace 11
The inside temperature is 400 to 600 ° C., and the air ratio is 0.1 to 0.
By setting the reducing atmosphere of 3 to prevent combustion of the waste plastic in the industrial waste A2, the waste plastic is thermally decomposed and gasified. At this time, in the gasification furnace 11, while preventing the oxidation of valuable metals such as copper (Cu), iron (Fe), and aluminum (Al), cuprous oxide (Cu ₂ O) that is the main component of the copper slag is removed. This is because the effect of being reduced can also be expected. When the temperature in the gasification furnace 11 is 400 ° C. or lower, the waste plastic is difficult to gasify, and when it is 600 ° C. or higher, it burns, and more preferably 500 to 550 ° C. This is because it is suitable for gasifying waste plastics and preventing oxidation of valuable metals. Air C is 0.5 to 2.0 m / sec.
Send it in the speed range of. Preferably 1.5
m / sec. The degree is good. Within this velocity range, the copper slag particles float in the fluidized bed 13, and the particles collide with each other to gradually become spherical, and are crushed into fine particles. Copper slag that is not atomized in the gasification furnace 11 and C that has a low vapor pressure
The first incombustible material D1 containing valuable metals such as u, Fe and Al is recovered from the side of the fluidized bed 12 to the outside of the gasification furnace 11. Further, the pyrolysis gas E generated in the gasification furnace 11, a copper slag having a diameter of 100 to 250 μm containing crushed Cu ₂ O, and a second incombustible substance of valuable metal having a high vapor pressure separated from waste plastics D2 is directly transferred to the melting furnace 21. At this time, the waste liquid L can be sprayed into the gasification furnace 11 from the furnace top by a spraying water pump (not shown). Gasification furnace 1
This is for maintaining the atmosphere in 1 at a predetermined temperature. The waste liquid includes ordinary waste acid and waste alkali.

Further, in the melting furnace 21, as shown in FIG. 3, at the same time when the pyrolysis gas E and the like are transferred, air is supplied to make the air ratio 0.9 to 1.3 and the atmosphere is made oxidative and burned. . Combustion is performed at a temperature of 1200 to 1500 ° C. If the combustion temperature is 1200 ° C or lower, the fluidity of the slag deteriorates and
If the temperature is 500 ° C. or higher, the wall of the melting furnace 21 may be damaged. The temperature range of 1300 to 1400 ° C. is preferable. This is because the temperature is suitable for suppressing the generation of harmful substances and converting the copper slag A1 into slag. The combustion temperature can be adjusted by the amount of industrial waste A2 such as waste plastic, the amount of sludge B supplied, and the amount of air input. The combustion air is preferably blown from the side wall of the melting furnace 21. This is to promote the formation of the swirling flow 25. The pyrolysis gas E is combusted to form the exhaust gas F, which is discharged from the exhaust gas discharge port 22. In addition, Zn, P in incombustibles
b is oxidized to fly ash H and is discharged together with the exhaust gas F. Copper slag melts at high temperature and turns into slag, whirling flow 25
It will come into contact with the inside of the car and become bigger, and will fall down due to gravity,
Or, it hits the side wall of the melting furnace 21 by centrifugal force and falls.
The dropped slag G is collected in the slag collecting port 23 and collected outside. The recovered slag G contains a large amount of Cu ₂ O.

FIG. 4 shows the slag G recovered from the melting furnace 21.
3 is a flowchart showing a method of recovering valuable metal, including a step of refining the metal in an electric holding furnace 31. The slag G recovered from the melting furnace 21 is put into the electric holding furnace 31, and the graphite electrode is inserted from the upper part. Passing a current between the electrodes,
It melts by the resistance heat of slag G. In the electric holding furnace 31,
Furthermore, untreated sulfide ore and copper slag can be newly added. This is for adjusting the viscosity, basicity, etc. of the generated slag for proper operation of the electric holding furnace 31. Moreover, coke M for reduction can be charged. Carbon C, which is a component of coke M, directly reduces Cu ₂ O to form C
produce u and CO. Here, examples of the reducing agent include coke M, pulverized coal, and LPG, and coke M is preferable. This is because the loading device is simple and easy to operate. 1250 to 140 in the electric holding furnace 31
A temperature range of 0 ° C. is preferred. This is because the melting point of Cu ₂ O is 1230 ° C., the melting point of copper is 1080 ° C., and it is necessary to be at least higher than the melting point of Cu ₂ O. 0.
The copper grade is about 70 to 8 by refining for 5 to 1.0 hours.
It is possible to obtain 0% black copper (crude copper) I. Further, since the waste slag J contains almost no metal and is composed of a homogeneous vitreous component of silica sand, it can be used as a cement material for a roadbed or the like.

FIG. 5 shows a melting furnace 21 or an electric holding furnace 31.
3 is a flowchart showing a valuable metal recovery method for recovering zinc, lead, etc. from the fly ash H generated from the same in the form of a salt.
The fly ash H generated together with the exhaust gas F from the melting furnace 21 and the like can be cooled by cooling water and recovered, and the cooled exhaust gas F can be transferred to the bag filter 51 to recover the fly ash H. In addition, fly ash H generated during refining in the electric holding furnace 31
Collect. Harmful substances in exhaust gas F that dioxin adsorbed removed it can then collect the fly ash H by the bag filter 51, Zn in fly ash H, a wet process because it contains Pb, Metal Zn, and Pb to recover.
The fly ash H recovered in each step is put into a slurry tank, then leached with an aqueous sulfuric acid solution, and lead is precipitated as a sulfate. The precipitated lead sulfate is made into a mud ore using a thickener,
Next, lead sulfate having a quality of 50 to 60% is recovered as a slag with a filter. Zinc is dissolved in the slurry tank, and slaked lime (Ca (OH) ₂ ) is added to neutralize it, and zinc is precipitated as a hydroxide salt. Similarly, zinc hydroxide of 50-60% grade is slag. Collect as. It is easy for the industry to purify the recovered lead sulfate and the like by other refining methods to obtain metal Zn and Pb. The drainage sludge at this time can be reintroduced into the fluidized bed gasification furnace 11.

FIGS. 6 and 7 show the first produced in the fluidized bed gasification furnace.
It is the flowchart which showed the method of collect | recovering valuable metals from the incombustible material D1. Put the first incombustible material D1 on a sieving machine,
The incombustible material under the sieve is charged again into the fluidized bed gasification furnace 11.
At this time, an incombustible material under the sieve passed through using a sieve having a size of 2 to 4 mm is preferable. The metal scraps on the sieve sorted by the sieve sorter are Fe scraps and other Cu scraps by the magnetic sorter.
Sorted into scrap, Al scrap, and copper slag containing Cu ₂ O. The magnetic sorter may be of a static magnetic field type, an AC magnetic field type or a belt type or a drum type, but the belt type is preferable. The Fe scraps are collected as they are for practical use. Since the fluidized bed gasification furnace 11 has a low temperature and oxidation is suppressed, Fe scraps can be used as they are. On the other hand, Cu etc. is passed through a sieving machine again to remove Cu scraps and Al.
Sort into scrap and copper slag. Cu and Al scraps are sorted and collected by a vortex sorter or by hand, and the copper slag is crushed and put into the fluidized bed gasification furnace again. As described above, industrial waste, copper slag, etc. are put into a fluidized bed gasification furnace and treated to produce Fe, Cu,
Valuable metals such as Al can be recovered. In addition, when the industrial waste includes a circuit board using gold (Au) or the like, the industrial waste can be recovered by the same process. It is easy for the industry to change the method of recovering valuable metals contained depending on the type of industrial waste.

Next, the waste liquid L is sprayed on the exhaust gas F from the melting furnace 21 in the waste liquid decomposition tower 26, and further cooling water is sprayed in the quenching tower 41 to cool the exhaust gas F, and the exhaust gas F is discharged into the atmosphere. Can be cooled until ready. This waste liquid decomposition tower 2
A step of incinerating the waste liquid L in 6 can be included. The waste liquid generated by smelting contains metal ions and acids, and the waste liquid generated by general sewage contains inorganic substances, organic substances and the like. It is desirable to incinerate these. By exposing the waste liquid L to a high temperature, organic substances, acids, etc. are decomposed, and inorganic substances, metal ions, etc. are converted into oxides and can be collected by the bag filter 51. The cooled exhaust gas F generated in the electric holding furnace 31 is burned in the secondary combustion furnace to decompose harmful substances, and is similarly cooled by cooling water in the quenching tower 41. When the exhaust gas F is rapidly cooled in the range of 250 to 500 ° C., harmful substances such as dioxins are resynthesized. Therefore, the time in this temperature range is shortened to prevent the generation of harmful substances again. Is. The activated carbon K is blown into the bag filter 51 while the rapidly cooled exhaust gas F is being transferred. It is treated by blowing activated carbon K having an average particle size of 10 to 20 μm together with air into the exhaust gas passage. Although high-temperature combustion in the melting furnace 21 suppresses the generation of dioxins and the like, it is difficult to always suppress them completely. Therefore, the harmful substances can be removed by blowing the activated carbon K during the discharge of the exhaust gas F. Actually, the exhaust gas F discharged from the quenching tower 41 contains 1 ng-TEQ / Nm ³ or less of dioxin, but by spraying activated carbon K, the dioxin concentration can be made 0.1 ng-TEQ / Nm ³ or less. it can.

(Examples) The contents of the present invention will be described below by giving specific numerical values based on the embodiments of the present invention. The copper slag after leaching the copper oxide ore with sulfuric acid was carried into the first storage 1. This copper slag contains valuable metals shown in Table 1 below.

[Table 1] Further, shredder dust of household appliances crushed to 150 mm or less and waste plastic containing no metal were carried into the second storage. This shredder dust contains valuable metals shown in Table 2 below.

[Table 2] The fluidized bed gasification furnace 1 is fed through the feed feeder 4 while weighing these from each storage by the weighing conveyor.
I put it in 1. January, 500t copper slag (dry weight 400
t), Shredder dust 500t, waste plastic 2
When 00t is treated at the same time, the valuable metals contained in them are in the amounts shown in Table 3 below.

[Table 3]

Next, the size of the fluidized bed gasification furnace 11 thus implemented has an inner diameter of 1.4 m and a height of 7 m. From the fluidized bed 12 in the furnace to 1.5 m / sec. By blowing air, the temperature in the furnace is set to 550 ° C., and the air ratio is set to 0.3, the styrene-acrylic resin, polyethylene resin, etc. takes 5 to 25 minutes.
It can be pyrolyzed and gasified in 90 minutes. In the process of the fluidized bed gasification furnace 11, the first recovered from the side of the fluidized bed 12
The amount of incombustibles D1 is 877t per month including fluidized sand
become. Second incombustibles pyrolyzed gas E and refinement of such waste plastics D2 is, 7936Nm ³ per hour is transferred to the melting furnace 21.

Next, in the melting furnace 21, the temperature inside the furnace is 135
The air ratio is set to about 1.0 at 0 ° C. As a result, Zn and Pb having high vapor pressure are discharged together with the exhaust gas F into the waste liquid decomposition tower 2
6. Transfer to the quenching tower 41. In the melting furnace 21, copper is oxidized at high temperature to form slag G, which is collected in the electric holding furnace 31. The collected amount is 466t per month.

Next, in the electric holding furnace 31, a graphite electrode was used to bring the temperature to 1300 ° C., and the coke M was fed at 15.6 in January.
Add t to reduce. In the electric holding furnace 31, 2 in January
It produced 03t of black copper (crude copper) and 263t of slag.
The copper grade of black copper (crude copper) is 75%, and the copper grade of slag is 2.5%. Therefore, by refining the black copper (crude copper) , 152 t of copper can be recovered per month.

Next, Z oxidized by the bag filter 51
52 tons of fly ash H containing n and Pb is collected per month. The analytical values of valuable metals contained in Fly Ash H are shown in Table 4 below.

[Table 4] 47 t sulfuric acid and 20 leachates per month for this fly ash H
Leach with sulfuric acid using 8 m ³ . Next, solid-liquid separation was performed with a thickener to collect 13.4 t of lead sulfate per month. Since the lead quality of the recovered lead sulfate is 50%, 6.7 tons of lead can be recovered per month. Furthermore, 33 t of slaked lime was used per month in the separated leachate, and 48.8 t of zinc hydroxide was recovered per month. The zinc quality of the recovered zinc hydroxide is 60%, and 29.3 tons of zinc can be recovered per month. The amount of valuable metal recovered is shown in Table 5 below.

[Table 5]

On the other hand, the recovered first incombustible material D1 contains copper scraps and metal scraps such as Cu, Fe, and Al that have become single substances by thermal decomposition of waste plastics in the fluidized bed gasification furnace 11. Has been. This is sieved with a mesh of 4.0 mm, and the size under the sieve (including fluidized sand) is 74 per month.
3.6 t is again charged into the fluidized bed gasification furnace 11. The amount of metal scraps on the sieve is 133.4t per month, and the magnetic scraper first collects 30t of iron scraps per month. Other Cu scrap, Al scrap and copper slag 103.4t per month
It is recovered and again passed through a 15-mesh mesh sieving machine to collect 80 t of copper slag under the sieve per month, which is then crushed by a crusher and charged again into the feed feeder 4. The amount of Cu scraps and the like on the sieve is 23.4 tons per month, and this is separated by a vortex sorter. 6.4t of Cu scrap per month,
Collect 17 tons of Al scrap. Therefore, Table 6 shows the amount of valuable metal recovered from the first incombustible material D1.

[Table 6]

Next, the exhaust gas F has a temperature of 1350 ° C.
Then, the waste liquid L is sprayed in the waste liquid decomposition tower 26, and the waste liquid L is incinerated by 500 t per month. The temperature of the exhaust gas F after spraying the waste liquid L is 850 ° C., which is 10151 per hour.
Nm ³ is discharged. Therefore, 2316 tons of industrial water is sprayed per month in the quenching tower 41 to cool the exhaust gas F to 200 ° C. By spraying industrial water, the exhaust gas F is 14955 Nm ³ per hour and the quenching tower 4
Emitted from 1. Here, the dioxin concentration is 1.0
Since it contains about ng-TEQ / Nm ³ , the exhaust gas F
When the temperature of dioxin became lower than the temperature for synthesizing dioxin, activated carbon K was blown into the transportation route of 572 kg per month to obtain a dioxin concentration of 0.1 ng-T.
It can be made equal to or less than EQ / Nm ³ . Next, the washing tower 6
In step 1, the exhaust gas F is converted to SO with an aqueous solution of caustic soda (NaOH).
After neutralizing x, HCl, etc., the mist and dust are removed by the mist cotrel 71, and the mist and dust are discharged to the outside through the discharge protrusion 81. The waste liquid containing dust collected by the mist cotrel 71 is discharged after the waste water treatment. Here, the exhaust gas F is activated carbon K
Blow write caustic soda solution 19067Nm ³ next washing tower 61 per hour by only by spraying of, recovered by the mist Cottrell 71 to neutralize the SOx and the like. Finally, the exhaust gas F releases 12966 Nm ³ per hour from the exhaust 81 into the air.

By the above steps, valuable metals in the amounts shown in Table 7 below can be recovered.

[Table 7] From these, Cu is 95% or more of the total input and Al is 10%.
0% and other Zn and Pb can be recovered by 50% or more. Furthermore, the waste liquid L can be treated for 500 t per month.

[0024]

As described above, according to the method for recovering valuable metals of the present invention, the plastic etc. in the industrial waste is pyrolyzed and gasified in the fluidized bed gasification furnace and separated from the valuable metal parts. The valuable metal part can be recovered as an incombustible material. Since the gasification is performed at a relatively low temperature, the valuable metal can be recovered without being oxidized. In addition, valuable metals that cannot be recovered in the fluidized bed gasification furnace can be recovered as slag by high-temperature treatment in the melting furnace, and harmful substances generated in the fluidized bed gasification furnace can be decomposed. Further, by subjecting the recovered slag to a reduction treatment in an electric holding furnace, black copper (crude copper) of high copper quality can be recovered. Furthermore, zinc and lead can be recovered by recovering and treating the fly ash generated in the melting furnace and the electric holding furnace. Furthermore, by sorting the incombustibles recovered in the fluidized bed gasification furnace, unoxidized iron, copper, and aluminum can be recovered. As a result, incineration of industrial waste and recovery of valuable metals from industrial waste and copper slag can be performed at the same time, and generation of harmful substances can be suppressed.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a valuable metal recovery method according to an embodiment of the present invention.

FIG. 2 is a diagram showing the structure of a fluidized bed gasification furnace used in the method for recovering valuable metals.

FIG. 3 is a diagram showing a structure of a melting furnace used in the method for recovering valuable metal.

FIG. 4 is a flow chart showing a step of purifying black copper in an electric holding furnace in the method for recovering valuable metal.

FIG. 5 is a flowchart showing a process of recovering zinc and lead from fly ash generated in a melting furnace or an electric holding furnace.

FIG. 6 is a flow chart showing a process of recovering contents such as iron and copper from incombustibles recovered in a fluidized bed gasification furnace.

FIG. 7 is a flowchart showing a process of recovering iron, copper, and other contents from incombustibles recovered in a fluidized bed gasification furnace.

[Explanation of symbols]

1 1st store 2 2nd store 3 Supply conveyor 4 Supply feeder 11 Fluidized bed type gasification furnace 12 Fluidized bed 13 Fluidized bed 21 Melting furnace 22 Exhaust gas discharge port 23 Slag recovery port 24 Auxiliary burner 25 Swirling flow 26 Waste liquid Decomposition tower 31 Electric holding furnace 41 Quenching tower 51 Bag filter 52 Activated carbon blowing device 61 Cleaning tower 71 Mist cotrel 81 Exhaust collision 91 Fly ash treatment device A1 Copper slag A2 Industrial waste A Raw material B Sludge C Air D1 First incombustible D2 Second incombustible material E Pyrolysis gas F Exhaust gas G Slag H Fly ash I Black copper (crude copper) J Waste slag K Activated carbon L Waste liquid M Coke

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI C22B 15/00 102 C22B 19/04 19/04 19/30 19/30 13/04 (56) Reference JP-A-9-323076 (JP, A) JP 3-150322 (JP, A) JP 4-218627 (JP, A) JP 56-238 (JP, A) JP 9-87762 (JP, A) Kaihei 7-214029 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) C22B 1/00-61/00 B09B 3/00

Claims (9)

(57) [Claims] 1. A method of recovering a valuable metal selected from copper (Cu), zinc (Zn), lead (Pb), iron (Fe) and aluminum (Al) from industrial waste containing copper slag and metal. So, we put copper slag and industrial waste into a fluidized bed gasification furnace, blow air from the lower part of the gasification furnace to form a fluidized bed, and gasify a part of the industrial waste by thermal decomposition. From the chemical furnace
A step of recovering the first incombustible material containing at least one valuable metal selected from Fe, Cu, and Al , and Zn, Pb, and Cu rising in the melting furnace by the air from the lower part of the gasification furnace.
The second incombustible containing one or more valuable metals selected and the pyrolysis gas generated in the gasification furnace are swirlingly charged to generate a slag containing Cu, and the slag is separated and recovered, and the melting. And a step of charging the slag recovered in the furnace into an electric holding furnace to recover black copper (crude copper). 2. The method for recovering valuable metal according to claim 1, wherein a step of returning a part of the first incombustible material to the gasification furnace and a remaining portion of the first incombustible material by a magnetic separator. And a step of recovering Fe . 3. The method for recovering valuable metals according to claim 1, wherein fly ash generated from the melting furnace and / or the electric holding furnace is recovered, dissolved in an aqueous solvent and neutralized or sulfurized. Zn
And a method of recovering a valuable metal, comprising a step of precipitating and recovering a salt containing at least one valuable metal selected from Pb and Pb . 4. The valuable metal recovery method according to claim 1, further comprising a step of spraying and decomposing the waste liquid into a waste liquid decomposing tower provided after the melting furnace. Recovery method. 5. The method for recovering valuable metals according to claim 1, wherein the fluidized bed gasification furnace is heated to a temperature of 400 to 600 ° C.
A method for recovering valuable metals, characterized in that a part of the industrial waste is gasified by thermal decomposition in a reducing atmosphere with an air ratio of 0.1 to 0.3. 6. The method for recovering valuable metals according to claim 5, wherein waste fluid is sprayed and charged into the fluidized bed gasification furnace. 7. The method for recovering valuable metals according to claim 1, wherein the melting furnace is heated to a temperature of 1300 to 1500 ° C., and slag is generated in an oxidizing atmosphere with an air ratio of 0.9 to 1.3, A method for recovering valuable metals, characterized by separating and recovering. 8. The method for recovering valuable metal according to claim 2, wherein the step of recovering valuable metal from the rest of the first incombustible material by a magnetic separator is iron (Fe) -containing material and copper (Cu). , Aluminum (Al) inclusions are sorted by magnetic force to produce iron (F
e) a step of recovering the inclusion, further comprising a step of selectively recovering copper (Cu) and aluminum (Al) from the recovered residue by a vortex sorter or manual selection Recovery method. 9. The method for recovering valuable metal according to claim 1, wherein the step of recovering the black copper (crude copper) is performed by using the holding furnace.
A method of recovering valuable metal, which is a step of recovering the black copper (crude copper) from the slag by using a reducing agent at a temperature of 0 to 1500 ° C.