JP7020883B2 - Metal-containing waste treatment equipment and treatment method - Google Patents

Description

The present invention relates to the treatment of waste containing metals, and in particular, appropriately treats waste clothes and shredder dust (SR) such as automobile shredder dust (ASR). The present invention relates to a device and a method for recovering valuable metals and reusing them as fuel.

Currently, about 940,000 tons of unnecessary clothes are discharged annually in Japan, and about 75% of them are disposed of by incineration or landfill. Various types of recycling are being carried out in order to reduce the amount of such waste clothes disposed of. For example, waste clothes are reused as waste cloth used in factories, etc., used clothes are reused domestically, and they are exported overseas.

However, in recent years, domestic demand for waste cloth has decreased due to the overseas relocation of factories. In addition, the demand for used clothing is decreasing at home and abroad due to the decline in clothing prices. Therefore, it is difficult to expand the recycling of waste clothes such as waste clothes and used clothes in the future.

Therefore, attention is being paid to thermal recycling of waste clothes. Thermal recycling is not simply incinerating waste, but recovering and effectively utilizing the heat energy generated during incineration, and is being promoted for various types of waste.

On the other hand, shredder dust (SR), which is a mixture of debris that is discarded as industrial waste after crushing waste home appliances and waste automobiles with an industrial shredder and collecting metals, is a technology / facility and waste for the shredder process. Since the composition changes depending on the pre-sorting situation, the main constituent phase is resin, urethane foam, fiber, rubber, etc., and some metal or glass, although it is not always constant.

Among the above SRs, those that need to be disposed of at a controlled disposal site are required to be recycled, and the development of recycling technology is being promoted mainly in both the thermal and chemical fields. For example, as described in Patent Document 1, utilization as a fuel substitute is being studied in the cement industry as well. Further, the SR contains valuable metals such as iron, non-ferrous metals, and rare metals, and it is preferable that the SR can be easily recovered in order to reuse them.

Japanese Unexamined Patent Publication No. 2014-205091

In the thermal recycling of waste clothes, the waste clothes are crushed and then burned in order to improve combustibility. However, when the waste clothes are crushed by the crusher, the fibers of the waste clothes fluff and expand, or the fibers of the waste clothes get entangled inside the crusher, which makes it difficult to operate the crusher stably. In some cases.

Further, when waste clothes are crushed as they are and converted into fuel, decorative parts such as fasteners and fibers are in a state of being entangled, so that copper (Cu), aluminum (Al), etc. contained in the decorative parts are used. It is also difficult to recover valuable metals.

On the other hand, when using SR as fuel, the resin content (plastic, urethane, rubber, synthetic fiber scraps, harness coating, etc.) in SR is soft (high viscoelasticity) and is intricately entangled with metal, so the resin as it is. It is difficult to crush the portion and separate and recover the metal, and it is also difficult to use it as a fuel substitute.

Therefore, the present invention has been made in view of the above-mentioned problems in the prior art, in which valuable metals and the like are recovered from metal-containing waste such as waste clothes and shredder dust, and combustible substances such as organic substances and carbon are recovered. The purpose is to promote thermal recycling.

In order to achieve the above object, the present invention is a metal-containing waste treatment apparatus, in which a clinker cooler for cooling a cement clinker and a part of the exhaust gas of the clinker cooler are used as combustion air through a cooler bleed duct. From the calcination furnace to be introduced, the charging section for charging the metal-containing waste into the cooler bleeding duct, and the metal-containing waste provided between the charging section and the calcination furnace in the cooler bleeding duct. It is characterized by including a collection unit for collecting separated metal waste.

According to the present invention, by heating the metal-containing waste with the exhaust gas of the cleaner cooler, the combustibles contained in the metal-containing wastes are burned, and the metal wastes and combustibles are formed by carbonization or brittleness of the combustibles. The entanglement of the metal-containing waste is eliminated, and the heated metal-containing waste is separated into metal waste and non-metal waste mainly composed of combustibles and inorganic substances. It is possible to efficiently recover combustibles and thermally recycle combustibles. In addition, it is more efficient than installing a new dedicated processing facility because it only needs to install a facility to recover metal by utilizing the heat and wind power existing in the cooler bleed air duct using the existing cement firing device. , Cost can also be reduced. Further, since the harmful gas generated when combustibles are burned, carbonized or embrittled is also treated by the cement manufacturing equipment, there is no need to newly install an exhaust gas treatment equipment.

In the metal-containing waste treatment apparatus, the collector is connected to the inlet side opening to be connected to the cleaner cooler side portion of the cooler bleed air duct, and the outlet side opening is connected to the temporary combustion furnace side portion of the cooler bleed air duct. The cross-sectional area is formed larger than that of the cooler bleed duct, and the metal waste can be collected at the bottom of the gravitational dust collecting device. As a result, the metal waste can be recovered by utilizing the gravity of the metal waste contained in the metal-containing waste flowing in the recovery unit.

In the metal-containing waste treatment apparatus, the collector is connected to the inlet side opening to be connected to the cleaner cooler side portion of the cooler bleed duct, and the outlet side opening is connected to the tentative burner side portion of the cooler bleed duct. It can be an inertial dust collecting device that directs the gas flow flowing from the inlet side opening to the outlet side opening toward the bottom side and collects the metal waste at the bottom side. As a result, the metal waste can be recovered by utilizing the difference in mass of the metal-containing waste flowing in the recovery unit.

In the metal-containing waste treatment apparatus, the recovery unit is connected to the cleaner side portion of the cooler air extraction duct at the gas inlet side opening, and the calciner side portion of the cooler air extraction duct is connected to the gas outlet side opening. The metal waste separated from the metal-containing waste can be discharged from the solid outlet portion as a cyclone to which the metal-containing waste is connected. As a result, the metal waste can be recovered by utilizing the difference in mass of the metal-containing waste flowing in the recovery unit.

Further, the present invention is a method for treating metal-containing waste, in which a clinker cooler for cooling a cement clinker and a part of the exhaust gas of the clinker cooler are introduced as combustion air through a cooler extraction duct. A method of treating metal-containing waste using a cement firing device equipped with a furnace, in which the metal-containing waste is put into the cooler bleed duct and separated from the metal-containing waste in the cooler bleed duct. The metal waste is collected from the cooler bleeding duct, and the non-metal waste not collected from the cooler bleeding duct is introduced into the calcining furnace as fuel through the cooler bleeding duct.

According to the present invention, by heating the metal-containing waste with the exhaust gas of the cleaner cooler, the combustibles contained in the metal-containing wastes are burned, and the metal wastes and combustibles are formed by carbonization or brittleness of the combustibles. The entanglement of the metal-containing waste is eliminated, and the heated metal-containing waste is separated into metal waste and non-metal waste mainly composed of combustibles and inorganic substances. It is possible to efficiently recover combustibles and thermally recycle combustibles. Further, since the existing cement firing device is used to utilize the heat and wind power existing in the cooler bleed air duct to recover the metal, the efficiency is high and the cost can be reduced. Further, harmful gases generated when combustibles are burned, carbonized or embrittled can also be treated by the cement manufacturing equipment.

In the method for treating metal-containing waste, the metal-containing waste can be used as waste clothes and / or shredder dust.

As described above, according to the present invention, it is possible to recover valuable metals and the like from metal-containing waste such as waste clothes and shredder dust, and to achieve thermal recycling of combustible substances such as organic substances and carbon.

It is a schematic diagram which shows the 1st Embodiment of the metal-containing waste processing apparatus which concerns on this invention. It is an enlarged view of the part A of FIG. It is a schematic diagram which shows the 2nd Embodiment of the metal-containing waste processing apparatus which concerns on this invention. It is a schematic diagram which shows the 3rd Embodiment of the metal-containing waste processing apparatus which concerns on this invention.

Next, a mode for carrying out the present invention will be described in detail with reference to the drawings.

FIG. 1 shows a first embodiment of a metal-containing waste treatment apparatus according to the present invention, in which the treatment apparatus 1 utilizes a cement firing apparatus and has a clinker cooler 3 for cooling a cement clinker. , A part of the exhaust gas of the clinker cooler 3 (tertiary air, hereinafter simply referred to as "cooler exhaust gas") G is introduced as combustion air through the cooler bleeding duct 7 and metal in the cooler bleeding duct 7. A collection unit 7a for charging the contained waste W and a recovery unit 7b provided between the charging unit 7a and the calciner 4 in the cooler bleeding duct 7 to collect the metal waste W1 separated from the metal-containing waste W. Etc. are provided. Here, the metal-containing waste W is a waste in which at least a metal and a combustible substance are mixed, and is, for example, waste clothes, SR, and the like.

The processing apparatus 1 further includes a preheater 5 for preheating the cement raw material M, a cement kiln 2 for firing the raw material calcined in the calcining furnace 4, and the like. Here, the components other than the cooler bleed duct 7 including the charging section 7a and the collecting section 7b are provided in a normal cement firing device.

The preheater 5 is usually composed of cyclones arranged in four stages, but only two stages are omitted and are indicated by reference numerals 5a and 5b. The preheater 5 preheats the cement raw material M supplied from the raw material chute (not shown).

The calcining furnace 4 is provided with a burner (not shown) for calcining, and calcins the cement raw material M supplied from the second-stage cyclone 5b of the preheater 5.

The cement kiln 2 includes a main burner 2a and fires the cement raw material M supplied from the lowermost cyclone 5a of the preheater 5 to the kiln tail 2b.

The charging section 7a of the cooler bleed duct 7 is provided on the clinker cooler 3 side of the cooler bleed duct 7 to charge the metal-containing waste W into the cooler bleed duct 7. By providing, for example, flap dampers in a plurality of stages in the charging section 7a, even when treating waste clothes as metal-containing waste W, for example, it is stable while preventing air from entering the cooler bleed duct 7. Can be thrown in. It is preferable that the charging portion 7a is provided in a horizontal portion rather than a rising portion from the cooler 3 so that the metal-containing waste W is not mixed with the clinker. The metal-containing waste W charged into the cooler bleed duct 7 is carried to the downstream side by a wind speed of about 10 m / s, but the cooler bleed duct 7 may be inclined to the downstream side so as not to stay.

The recovery unit 7b is provided on the calciner 4 side of the charging unit 7a to collect the metal waste W1 separated from the metal-containing waste W.

The collection unit 7b is a gravity-type dust collecting device. For example, as shown in FIG. 2, a cooler bleed duct 7 is connected to a cooler bleed duct 7 on the inlet side opening 7h, and a cooler bleed duct is connected to the outlet side opening 7i. The part of the calciner side of the calciner 7 is connected, and is formed in the shape of a cylinder or a rectangular chamber having a larger cross-sectional area than the cooler bleed duct 7. Since the metal waste W1 has a high specific density, the cross-sectional area of the recovery unit 7b can be separated by more than twice that of the cooler bleed duct 7, and the combustibles are transported to the downstream side, and the heat loss is 10 times or less so as not to increase. It is preferable to do. The length of the recovery unit 7b may be appropriately determined in consideration of the wind speed and the sedimentation speed obtained from the specific gravity of the metal, but it is set to about 5 to 30 m in consideration of the recovery efficiency and the heat loss from the surface. .. Since the cross section of the recovery section 7b is circular or square and the cross section of the cooler bleed air duct 7 is usually circular, tapered or rounded corner connection duct sections 7c and 7d are provided to connect the two.

At the bottom of the recovery unit 7b, a plate-shaped member 7e having a slit through which the metal waste W1 having a large specific density separated from the metal-containing waste W can pass and an opening 7f formed in a grid pattern is provided. The size of the slits and lattices of the opening 7f is preferably 5 to 50 mm in diameter or opening so that the metal concentration in the metal waste W1 is increased and the metal is not washed away in the calcination furnace 4. Combustibles are lightweight and are carried downstream by the gas stream. Those that have landed on the opening 7f are also carried downstream by the gas flow, and since the cooler bleed duct 7 on the side of the calciner is horizontal, they are smoothly transported to the calciner. The lower part of the opening 7f is formed in a pot shape, and the metal waste W1 on the pot is discharged.

Further, the collecting portion 7b is provided with a baffle plate 7g formed in the shape of a rectangular plate. One side of the baffle plate 7g is fixed to the cooler side end portion (right end portion in FIG. 2) or the ceiling portion of the recovery portion 7b, and the entire baffle plate 7g is temporarily provided from a surface perpendicular to the extending direction of the cooler bleed duct 7. It tilts to the furnace side (left side in Fig. 2). The baffle plate 7g may be one or more, and may have holes or the like.

Next, the operation of the metal-containing waste treatment apparatus 1 having the above configuration will be described with reference to FIGS. 1 and 2.

As shown in FIG. 1, the cement raw material M is preheated by the preheater 5. The cement raw material M preheated by the second stage cyclone 5b is supplied to the calcining furnace 4 to be calcined, and then supplied to the kiln tail 2b of the cement kiln 2 via the lowermost stage cyclone 5a and the raw material chute 6. The cement raw material M supplied to the kiln butt 2b is fired in the cement kiln 2 with the combustion heat of pulverized coal or the like blown from the main burner 2a, and the generated cement clinker is supplied to the clinker cooler 3 to be cooled.

Along with the above operation, the cooler exhaust gas G is introduced into the calciner 4 via the cooler bleed duct 7. Here, the metal-containing waste W is charged into the cooler bleed duct 7 through which the cooler exhaust gas G flows through the charging unit 7a, and the metal-containing waste W is heated.

As shown in FIG. 2, the combustible material of the metal-containing waste W is used as a heat source of the calcining furnace even if it is completely burned in the cooler bleed duct 7, and the metal waste W1 is separated and collected. It can be recovered in 7b. In this case, it is not necessary to separate combustibles and inorganic substances from the metal waste W1. Even when the combustible material of the metal-containing waste W is carbonized or embrittled, the metal-containing waste W is separated from the metal-containing waste W1 by eliminating the entanglement between the metal-containing waste W1 and the combustible material. Drops in the collection unit 7b, passes through the opening 7f, and is collected on the pot. Even if the non-metal waste W2 is mixed with the metal waste W1, the entanglement between them is eliminated, so that the metal can be easily separated by the separation method described later. On the other hand, the non-metal waste W2 not recovered by the recovery unit 7b flows out from the cooler bleed duct 7 to the calcining furnace 4 and is introduced as fuel.

The metal-containing waste W is a cooler exhaust gas having a temperature of 500 ° C. or higher so that the resin does not fuse and accumulate in the duct, and 800 ° C. or lower so that the temperature becomes too high due to combustion of combustibles and the cooler bleed air duct 7 is not damaged. It is preferable to put it in G. When the metal-containing waste W contains metallic aluminum, it is put into a place where the temperature of the cooler exhaust gas G is 700 ° C. or lower so as not to melt in the cooler bleed air duct 7, or directly to the recovery part 7b or the duct part. It is preferable to put it in 7c. If the temperature of the cooler exhaust gas G cannot be changed, the temperature is adjusted by changing the charging position (residence time) in the cooler bleed duct 7 or in the recovery unit 7b, and the combustible material of the desired grade is supplied to the calcining furnace 4. It may be done so that the metal aluminum does not melt.

Here, since the baffle plate 7g is provided in the recovery unit 7b, it is possible to prevent the metal from being introduced into the calcination furnace 4 together with the non-metal waste W2, and more reliably put the metal on the pot below the opening 7f. Can be recovered.

As described above, according to the present embodiment, the injection section 7a and the recovery section 7b are provided in the cooler extraction duct 7 of the cement firing device, and the metal from the metal-containing waste W to the metal while maintaining the normal operation of the cement firing device. It is possible to recover the waste W1 and utilize the non-metal waste W2 as fuel in the calciner 4.

Next, a second embodiment of the metal-containing waste treatment apparatus according to the present invention will be described with reference to FIG.

The metal-containing waste treatment device 11 uses a recovery unit 12 different from the collection unit 7b of the treatment device 1. The collection unit 12 is an inertial dust collector, and the cleaner cooler side portion of the cooler air extraction duct 7 is connected to the gas inlet side opening 12a, and the calciner side of the cooler air extraction duct 7 is connected to the gas outlet side opening 12b. The portions are connected, and the upper center is curved so that the gas flow flowing from the gas inlet side opening 12a to the gas outlet side opening 12b is directed toward the bottom side.

By using the recovery unit 12, the metal waste W1 separated from the metal-containing waste W by heating in the cooler extraction duct 7 is guided to the bottom by using inertial force, and is discharged from the recovery solid outlet unit 12c and collected. At the same time, the non-metal waste W2 discharged together with the cooler exhaust gas G from the gas outlet side opening 12b can be introduced into the calcination furnace 4 and used as fuel.

As the recovery unit 12, in addition to the inertial dust collector having the above configuration, a type that guides the flow of the cooler exhaust gas G to the bottom by using a louver or the like can also be used.

Next, a third embodiment of the metal-containing waste treatment apparatus according to the present invention will be described with reference to FIG.

The metal-containing waste treatment device 21 uses a cyclone 22 instead of the recovery unit 7b of the treatment device 1. In the cyclone 22, the clinker cooler side portion of the cooler bleed duct 7 is connected to the gas inlet side opening 22a, and the calciner side portion of the cooler bleed duct 7 is connected to the gas outlet side opening 22b.

By using the cyclone 22, the metal waste W1 separated from the metal-containing waste W by heating in the cooler extraction duct 7 is guided to the cone portion 22c by using the inertial force, and is discharged from the solid outlet portion 22d and recovered. At the same time, the non-metal waste W2 discharged together with the cooler exhaust gas G from the gas outlet side opening 22b can be introduced into the calcination furnace 4 and used as fuel.

Since the metal waste W1 recovered in the above embodiment may contain combustibles (carbide, brittle material) and inorganic substances such as ceramics and earth and sand, adjust the particle size as necessary. Then, the metal is recovered by sorting with a wind power sorter, a vertical mill, an air table, etc. Further, since the metal contains iron contained in shredder dust and valuable metals such as copper and aluminum contained in decorative parts of clothes, these valuable metals are recovered by magnetic force sorting and eddy current sorting. Further, if an air table equipped with a vibrating table and a blower blower is used, various metals can be sorted from the metal waste W1 at once. The recovered combustibles may be effectively used as fuel, and the inorganic substances may be effectively used as a raw material for cement.

Further, in the above embodiment, in collecting the metal waste W1 separated from the metal-containing waste W in the cooler extraction duct 7, the gravity type or inertial type collection units 7b, 12 and the cyclone 22 are used. Not limited to these, other structures and devices can be used as long as the metal waste W1 can be recovered.

1 Metal-containing waste treatment equipment 2 Cement kiln 2a Main burner 2b Kiln bottom 3 Cleaner cooler 4 Temporary firing furnace 5 Preheater 5a Bottom cyclone 5b Second stage cyclone 6 Raw material chute 7 Cooler extraction duct 7a Input section 7b Recovery section 7c, 7d Duct 7e Plate-shaped member 7f Opening 7g Interfering plate 7h Inlet side opening 7i Outlet side opening 11 Metal-containing waste treatment device 12 Recovery unit 12a Gas inlet side opening 12b Gas outlet side opening 12c Solid outlet 21 Metal-containing waste treatment equipment 22 Cyclone 22a Gas inlet side opening 22b Gas outlet side opening 22c Cone 22d Solid outlet G Cooler exhaust gas M Cement raw material W Metal-containing waste W1 Metal waste W2 Non-metal waste

Claims (6)

A clinker cooler that cools the cement clinker,
A calciner in which a part of the exhaust gas of the clinker cooler is introduced as combustion air through a cooler bleed duct, and
A charging section for charging metal-containing waste into the cooler bleed duct,
The cooler bleed air duct is provided between the charging unit and the calcining furnace, and is provided with a collection unit for collecting the metal waste separated from the metal-containing waste. Device. In the collection section, the cleaner cooler side portion of the cooler bleed duct is connected to the inlet side opening, the calciner side portion of the cooler bleed air duct is connected to the outlet side opening, and the cross-sectional area is larger than that of the cooler bleed duct. The metal-containing waste treatment device according to claim 1, wherein the device is a gravity-type dust collector that is formed large and collects the metal waste at the bottom. In the collection section, the cleaner cooler side portion of the cooler bleed duct is connected to the inlet side opening, the calciner side portion of the cooler bleed duct is connected to the outlet side opening, and the outlet is connected to the inlet side opening. The metal-containing waste treatment device according to claim 1, wherein the device is an inertial dust collecting device that collects the metal waste at the bottom so that the gas flow flowing to the side opening is directed toward the bottom side. The recovery unit is a cyclone in which the cleaner cooler side portion of the cooler bleeding duct is connected to the gas inlet side opening, and the calciner side portion of the cooler bleeding duct is connected to the gas outlet side opening. The metal-containing waste treatment apparatus according to claim 1, wherein the metal waste separated from the metal-containing waste is discharged from the solid outlet portion. Metal-containing waste is treated using a cement calcination apparatus equipped with a clinker cooler for cooling the cement clinker and a calcining furnace in which a part of the exhaust gas of the clinker cooler is introduced as combustion air through a cooler bleed duct. It ’s a method,
The metal-containing waste is put into the cooler bleed duct, and the metal-containing waste is put into the cooler bleed duct.
The metal waste separated from the metal-containing waste in the cooler bleed duct is collected from the cooler bleed duct.
A method for treating metal-containing waste, which comprises introducing non-metal waste not recovered from the cooler bleed duct into the calcination furnace as fuel through the cooler bleed duct. The method for treating metal-containing waste according to claim 5, wherein the metal-containing waste is waste clothing and / or shredder dust.

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