JP6772036B2 - Processing method - Google Patents

Description

The present invention relates to a processing method.

The incinerated ash of general household waste is processed by drying, magnetic force sorting, sieving, crushing, eddy current sorting, etc., and the cement raw material extracted from the incinerated ash after processing is used as concrete products and external sawn timber for housing. , The technology used for ready-mixed concrete is known.

In addition, the residue obtained by removing cement raw materials and iron components from the incinerated ash after treatment, crushing and classifying with a roller mill contains valuable metals such as copper, zinc, gold, silver, palladium, and platinum. Therefore, a technique for recovering these is also known (see, for example, Patent Document 1 and the like).

Japanese Unexamined Patent Publication No. 2016-89196

However, it cannot be said that the technique described in Patent Document 1 can properly treat the residue, and there is a possibility that the valuable metal cannot be properly recovered from the residue.

The present invention has been made in view of the above problems, and is capable of appropriately treating the residue obtained by removing the cement raw material from the incineration ash of general household waste, and further efficiently recovering valuable metals from the residue. The purpose is to provide a method.

The inventors have found that aluminum and valuable metals can be appropriately sieved by sieving the residue obtained by removing the cement raw material from the incineration ash of general household waste using two or more types of sieves. Furthermore, they have found that valuable metals can be efficiently concentrated and the valuable metals can be recovered by sorting them to a specific size or smaller.

That is, the treatment method of the present invention includes a first sieving step of sieving the residue obtained by removing the cement raw material from the incineration ash of general household waste using a first sieve having a sieve mesh diameter of 14 to 18 mm. the residue under sieve obtained in the first screening process, a second screening process the diameter of the sieve mesh is sieved using a second sieve 8 to 12 mm, obtained in the second screening process The residue on the sieve is put into the first melting furnace and melted, and the residue under the sieve obtained in the second sieving step is combined with a sieve having a mesh diameter of 3 to 5 mm. The third sieving step of sieving using the sieve of No. 3 and the residue on the sieve and the residue under the sieve of the third sieve are subjected to specific gravity sorting and shape sorting under different conditions to obtain aluminum. The processing step of removing, the residue obtained by removing aluminum from the residue on the sieve of the third sieve, and the residue obtained by removing aluminum from the residue under the sieve of the third sieve are put into a second melting furnace. It includes a second melting step of melting .

The treatment method of the present invention has an effect that the residue obtained by removing the cement raw material from the incineration ash of general household waste can be appropriately treated, and the valuable metal can be efficiently recovered from the residue.

It is a process drawing which shows the processing method which concerns on one Embodiment. It is a table which shows the composition (chemical analysis value) of the residue for each particle size. In addition, in FIG. 2, precious metals mean gold, silver, platinum, palladium and the like.

Hereinafter, one embodiment will be described in detail with reference to FIGS. 1 and 2. FIG. 1 is a process diagram showing a processing method according to an embodiment.

In the present embodiment, the incinerated ash of general household waste is subjected to processing such as drying, magnetic force sorting, sieving, crushing, and eddy current sorting, and the iron component, aluminum component, and cement raw material component in the incinerated ash are added. Except for most, the residue obtained by crushing and classifying with a roller mill is used as a starting material. By this treatment, this raw material (residue) contains valuable metals such as copper, gold, silver, palladium, and platinum.

As shown in FIG. 1, the residue is first sieved using three types of sieves. Here, the three types of sieves include a sieve having a mesh diameter of 14 to 18 mm (16 mm in the present embodiment), a sieve having a sieve diameter of 8 to 12 mm (10 mm in the present embodiment), and a sieve. Includes a sieve having a diameter of 3 to 5 mm (3 mm in this embodiment). By sieving the residue using these three types of sieves, as shown in FIG. 1, on the sieve sieved with a sieve mesh of 16 mm; sieve under the sieve sieved with a sieve size of 16 mm or more and a sieve mesh of 16 mm. On a sieve separated by 10 mm; on a sieve sieved by a sieve mesh of about 10 to 16 mm and a sieve mesh of 10 mm; on a sieve sieved by a sieve mesh of 3 mm; a sieve sieved by a sieve particle of about 3 to 10 mm and a sieve mesh of 3 mm. Bottom: It can be divided into four types with a particle size of about 0 to 3 mm. In the present invention, the notation "degree" in the description of the particle size means the particle size of the residue existing on and under the sieve when sieved according to each mesh size. To do. Further, regarding the notation of "particle size of about 0 to 3 mm", in reality, there is no residue of 0 mm size, but the range of the particle size of the residue under the sieve having a size larger than 0 mm and up to about 3 mm is defined. , For convenience of description, it shall be expressed as "particle size 0 to 3 mm".

The reason why a sieve having a mesh diameter of 16 mm is used is that if the residue is 16 mm or more, the separability of stainless steel (for example, wire chips, spoon, etc.) can be improved. Further, the reason why a sieve having a mesh diameter of 10 mm is used is that a residue smaller than about 10 mm in diameter contains a large amount of valuable metal, so after removing aluminum (Al), it is put into a copper smelting process or the like. This is because the valuable metal can be concentrated and recovered. Further, the upper limit of the processable particle size in the specific gravity sorting and the shape sorting (air table) described later is about 10 mm, which is one of the reasons for using a sieve having a mesh diameter of 10 mm. Further, the reason why a sieve having a mesh diameter of 3 mm is used is that it is preferable to divide the air table into 3 to 10 mm and 0 to 3 mm and treat them under different treatment conditions. Here, FIG. 2 shows the composition (chemical analysis value) of the residue for each particle size. As shown in FIG. 2, the residue of about 0 to 10 mm contains a large amount of valuable metals such as gold (Au), silver (Ag), palladium (Pd), platinum (Pt), and copper (Cu). You can see that. It can be seen that aluminum is contained in a predetermined amount (17 to 21%) in the residue regardless of the particle size.

Next, a method for treating the sieved residue will be described.

(Regarding the treatment of residues with a particle size of 16 mm or more)
For the residue having a particle size of 16 mm or more (on the sieve obtained by sieving using a sieve having a mesh diameter of 16 mm), a picking process is performed as shown in FIG. In this case, for example, by hand sorting, an object having a specific external shape, for example, wire dust and a residue of incineration ash having a plate-like, lump-like, or disc-like shape are selected and excluded. The lumpy incineration ash also includes things such as spoons that retain their original shape before incineration. The picking process is not limited to manual selection, and color selection may be performed. The color selection is a method in which the residue is photographed with a camera, the picking object is automatically identified based on the color, shape, etc., and the identified picking object is selected by a spatula, a pressure wave with increased air pressure, or the like. Stainless steel and the like selected from the residue are sold outside as iron scraps. On the other hand, the residue from which stainless steel or the like has been removed (including aluminum (Al metal) and other metals) is subjected to the same treatment as the residue having a particle size of about 10 to 16 mm.

(Regarding the treatment of residues with a particle size of about 10 to 16 mm)
Residues with a particle size of about 10 to 16 mm (on the sieve obtained by sieving using a sieve with a mesh diameter of 10 mm) are melt-treated, and the solidified product is sold outside or required. Recycle according to the situation. The furnace used for melting is not specified, but a melting furnace capable of melting the residue to form metal and slag and separating them is desirable. Specifically, smelting blister copper (black copper, etc.) is directly smelted, for example, melting furnaces such as tilting reverberatory furnaces, shaft furnaces with hearths, oval furnaces, drum furnaces, and upper blowing converters. Be done. In this case, the aluminum contained in the residue can be removed from the system by slagging treatment.

When the aluminum content (treatment amount) in the residue is large, the treatment amount of the aluminum-containing slag becomes large, and the operation load of the melting furnace becomes large. In this case, as a pretreatment for the residue having a particle size of about 10 to 16 mm, a treatment for selecting aluminum and other pulverized products may be performed. For example, as pretreatment, known treatments such as specific gravity sorting, shape sorting, eddy current sorting, sorter sorting (optical, electromagnetic induction, transmitted X-ray, fluorescent X-ray, etc.), dry dissolution, wet dissolution, and manual selection by appearance are performed. Can be adopted.

(Regarding the treatment of residues with a particle size of about 3 to 10 mm)
The residue under the sieve (particle size is about 0 to 10 mm) sieved using a sieve having a mesh diameter of 10 mm includes gold (Au), silver (Ag), palladium (Pd), and platinum (Pt). , Copper (Cu) and many other valuable metals are contained. It is a feature of the present invention that the valuable metal can be efficiently recovered by treating the residue having a particle size of about 0 to 10 mm in a step in which the valuable metal can be recovered. For example, a residue having a particle size of about 3 to 10 mm (on a sieve obtained by sieving using a sieve having a mesh diameter of 3 mm) is shifted to a step in which valuable metals can be recovered. In the step in which the valuable metal can be recovered, the valuable metal may be recovered by a treatment step including a dry treatment using a melting furnace, or the heavy weight compound is directly dissolved in an acid or alkaline solution to be neutralized and precipitated or treated with an adsorbent. Valuable metals may be recovered by wet treatment such as.

The type of melting furnace used in the dry treatment is not limited, but it is sufficient that the molten metal can be cast. For example, a self-melting furnace used in a copper smelting process, a converter, an electric furnace, and other furnaces that can be used for treating the above-mentioned residue having a particle size of about 10 to 16 mm (tilt type reflection furnace, shaft with hearth) A furnace, an oval furnace, a drum furnace, an upper blowing type converter, etc.) may be used separately to melt and cast a residue having a particle size of about 0 to 10 mm. The cast ingot can recover valuable metals through known methods such as electrolytic refining, electrowinning, and wet treatment of electrolytic ridges.

A typical example of dry processing as a process in which valuable metals can be recovered is copper smelting. In copper smelting, copper is obtained by smelting from copper ore (copper concentrate), and at the same time, other valuable metals contained in the ore are used as electrolysis deposits generated by copper electrolysis, and are recovered in each process. Therefore, if a residue having a particle size of about 0 to 10 mm is put into a flash smelting furnace or converter used for copper smelting, the valuable metal in the residue is recovered together with the valuable metal in the ore.

It is also effective to sift the residue having a particle size of about 0 to 10 mm using a sieve having a mesh diameter of 3 mm. The reason for sieving is that it is preferable to divide the air table into 3 to 10 mm and 0 to 3 mm and treat them under different treatment conditions as the treatment conditions of the air table described later.

(Regarding the treatment of residues with a particle size of about 0 to 3 mm)
Using a sieve with a mesh diameter of 3 mm, the residue is divided into a residue having a particle size of about 3 to 10 mm (on the sieve) and a residue having a particle size of about 0 to 3 mm (below the sieve), and then aluminum is added to each residue. A step of removing may be added. As a step of removing aluminum, it is effective to perform a combination of specific gravity sorting and shape sorting, and specifically, it is desirable to use an air table.

The residue having a particle size of about 3 to 10 mm and the residue having a particle size of about 0 to 3 mm can be used in any of aluminum as a light ratio and copper, gold, silver, etc. as a heavy ratio using an air table. Can also be divided into unsorted residues. Further, for the residue (unsorted product) that is not sorted by any of them, the processing step that combines the above-mentioned specific gravity sorting and shape sorting is repeatedly executed. Each of the heavy weight products (copper, gold, silver, etc.) from which aluminum has been removed from the residue having a particle size of about 3 to 10 mm and the residue having a particle size of about 0 to 3 mm is sent to a step of recovering valuable metals. The step of recovering the valuable metal may be a dry treatment or a wet treatment, but as a specific example of the dry treatment, it is put into a flash smelting furnace or a converter for copper smelting.

In the specific gravity sorting and shape sorting of the residue having a particle size of about 0 to 3 mm, the wind speed of the air blown from the air table is made smaller than in the case of the specific gravity sorting and shape sorting of the residue having a particle size of about 3 to 10 mm. , Increase the frequency of the air table and decrease the inclination angle of the air table. For example, when sorting the specific gravity and shape of a residue having a particle size of about 0 to 3 mm, the air velocity is 2.2 to 2.4 m / s, the frequency is 554 to 586 rpm, and the X-axis direction of the air table ( The inclination angle θ with respect to the horizontal plane in the vibration direction in the upper surface of the air table) is 9 to 11 °, and the inclination angle ψ with respect to the horizontal plane in the Y-axis direction (direction orthogonal to the X-axis direction in the upper surface of the air table) is 6.5 to 8. It may be set to 0 °, more preferably 7.0 to 8.0 °. On the other hand, when selecting the specific gravity and shape of the residue having a particle size of about 3 to 10 mm, the air velocity is 2.7 to 2.9 m / s, the frequency is 500 to 540 rpm, and the inclination with respect to the horizontal plane in the X-axis direction. The angle θ can be set to 9 to 11 °, and the inclination angle ψ with respect to the horizontal plane in the Y-axis direction can be set to 8.5 to 10 °, more preferably 8.5 to 9.5 °.

In this case as well, the same treatment as for the residue having a particle size of about 10 to 16 mm is performed on the light ratio product (aluminum).

As described in detail above, according to the present embodiment, the residue obtained by removing the cement raw material from the incineration ash of general household waste is sieved using a sieve having a mesh diameter of 16 mm, and the obtained sieve under the sieve. The residue is sieved using a sieve having a mesh diameter of 10 mm, and each of the sieved residues is subjected to a different treatment. This makes it possible to perform an appropriate treatment on the residue according to the particle size. Further, by performing an appropriate treatment according to the particle size, it becomes possible to efficiently recover valuable metals from the residue under the sieve of a sieve having a diameter of 10 mm.

Further, in the present embodiment, the residue on the sieve having a diameter of 10 mm is melted and treated. As described above, the melt-treated lump contains iron and aluminum and is recycled by external sales.

Further, in the present embodiment, the residue having a particle size of about 3 to 10 mm and about 0 to 3 mm is subjected to specific gravity sorting and shape sorting under different conditions to remove aluminum. As a result, specific gravity sorting and shape sorting can be performed under appropriate conditions according to the particle size, so that aluminum can be efficiently removed from the residue.

Further, in the present embodiment, an object having a specific appearance shape is selected and excluded from the residue on the sieve sieved using a sieve having a mesh diameter of 16 mm. Thereby, iron scraps and the like can be excluded from the residue having a particle size of 16 mm or more by an appropriate method.

Further, in the present embodiment, the residue under the sieve sieved using a sieve having a mesh diameter of 16 mm is sieved using a sieve having a sieve mesh diameter of 10 mm, and then the sieve mesh diameter is 3 mm. Sieve using the sieve of. As a result, different treatments can be performed on the residues having a particle size of about 3 to 10 mm and about 0 to 3 mm. Therefore, a residue having a particle size of about 3 to 10 mm and a residue having a particle size of about 0 to 3 mm can be treated by an appropriate method.

Further, in the present embodiment, the residue from which aluminum has been removed by specific gravity sorting and shape sorting is put into a melting furnace (self-melting furnace or converter for copper smelting, electric furnace, tilting reverberatory furnace, etc.), and thus melted. It is possible to suppress an increase in the amount of aluminum-containing slag generated in the furnace and prevent an increase in the operating load of the melting furnace. Further, if the aluminum content (treatment amount) in the residue is large, the aluminum increases the viscosity of the slag, which leads to deterioration of the fluidity of the slag, and it becomes difficult to continuously tap the slag in the melting furnace, which is not preferable. Therefore, selective removal of aluminum in the residue is important.

The embodiments described above are examples of preferred embodiments of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention.

Claims (11)

A first sieving step in which the residue obtained by removing the cement raw material from the incineration ash of general household waste is sieved using a first sieve having a mesh diameter of 14 to 18 mm.
A second sieving step in which the residue under the sieving obtained in the first sieving step is sieved using a second sieve having a mesh diameter of 8 to 12 mm.
In the first melting step, the residue on the sieve obtained in the second sieving step is put into the first melting furnace and melted.
A third sieving step of sieving the residue under the sieve obtained in the second sieving step using a third sieve having a mesh diameter of 3 to 5 mm.
The residue on the sieve and the residue under the sieve of the third sieve are subjected to specific gravity sorting and shape sorting under different conditions to remove aluminum.
The residue obtained by removing aluminum from the residue on the sieve of the third sieve and the residue obtained by removing aluminum from the residue under the sieve of the third sieve are put into a second melting furnace and melted. Melting process and
Processing method including. The processing method according to claim 1, wherein the second melting furnace is a furnace capable of recovering valuable metals in a residue by melting. The processing method according to claim 2, wherein the second melting furnace is any one of an electric furnace, a flash smelting furnace for copper smelting, and a converter. The processing method according to claim 2, wherein the second melting furnace is any one of a tilting reverberatory furnace, a shaft furnace with a hearth, an oval furnace, a drum furnace, and an upper blowing type converter. .. Any of claims 1 to 4, wherein the first melting furnace is any one of a tilting reverberatory furnace, a shaft furnace with a hearth, an oval furnace, a drum furnace, and an upper blowing type converter. The processing method described in item 1. A first sieving step in which the residue obtained by removing the cement raw material from the incineration ash of general household waste is sieved using a first sieve having a mesh diameter of 14 to 18 mm.
A second sieving step in which the residue under the sieving obtained in the first sieving step is sieved using a second sieve having a mesh diameter of 8 to 12 mm.
A melting step in which the residue on the sieve obtained in the second sieving step is put into a melting furnace and melted.
A third sieving step in which the residue under the sieving obtained in the second sieving step is sieved using a third sieve having a mesh diameter of 3 to 5 mm.
The residue on the sieve and the residue under the sieve of the third sieve are subjected to specific gravity sorting and shape sorting under different conditions to remove aluminum.
A dissolution step of dissolving the residue obtained by removing aluminum from the residue on the sieve of the third sieve and the residue obtained by removing aluminum from the residue under the sieve of the third sieve with an acid solution or an alkaline solution.
Processing method including. The processing method according to claim 6, wherein the melting furnace is any one of a tilting reverberatory furnace, a shaft furnace with a hearth, an oval furnace, a drum furnace, and an upper blowing type converter. The treatment method according to any one of claims 1 to 7, further comprising a step of removing aluminum from each of the first sieving step and the residue sifted in the second sieving step. Any one of claims 1 to 8, further comprising a step of selecting and excluding an object having a specific external shape from the residue on the sieve screened in the first sieving step. The processing method described in. The processing method according to claim 9, wherein the object having the specific shape contains at least one of linear, plate-like, lump-like, and disc-like residues. The residue obtained by removing the cement raw material from the incineration ash of general household waste contains at least one element of gold, silver, palladium, platinum, copper, aluminum, and iron, according to any one of claims 1 to 10. Processing method.

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