JPH0523328B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for recovering metals from a workpiece containing at least a solid combustible organic substance and metals in a mixed state.

[Prior art and problems to be solved] Many discarded electric wires are insulated with plastics, and the number of scraps used as raw materials for steel that are coated with plastics is increasing.
For example, the current situation is that it accounts for 1/4 to 1/5 of the total weight of scrapped passenger cars, and in addition, recently,
The amount of discarded electronic components that are made of plastic substrates with gold, platinum, etc. as contact members is increasing.

When recovering metals such as gold, platinum, silver, copper, and iron from materials that contain a mixture of solid combustible organic substances and metals, mechanical recovery methods are used rather than recovery methods that use incinerators. Collection methods such as scraping and extraction or, in rare cases, pulverization separation after cryogenic treatment are taken, but in addition to the high cost, the plastics after separation must ultimately be disposed of by landfilling or incineration. There are many problems, such as:

Of course, it may be incinerated and separated in an incinerator, but
In that case, the quality of the metal changes due to overfiring, the oxidation of the metal, etc., resulting in a decrease in the value of the recovered product and a decrease in yield. In addition, it is not possible to completely burn combustible materials in the primary combustion chamber of an incinerator, and the method of afterburning the smoky waste gas with burners using general fuel in the secondary and tertiary combustion chambers has been proposed. There are many incinerators, and in addition to afterburning in the secondary and tertiary combustion chambers, it is often necessary to perform auxiliary combustion with a burner using general fuel in the primary combustion chamber as well. Therefore, in any case, high costs cannot be avoided, and furthermore,
Even when the above-mentioned combustion and incineration are carried out, a large amount of soot and dust is generated, and a dust collector becomes an indispensable auxiliary equipment, which causes a rise in the cost of the device and the operating cost.

The present invention has been made in view of the above-mentioned problems existing in the prior art, and its purpose is to remove at least a material to be treated containing a mixed state of a solid combustible organic substance and a metal. A metal recovery method and gas for metal recovery using gasification combustion that can recover valuable metals in good quality at a high recovery rate at low cost, efficiently utilize exhaust gas heat, and purify exhaust gas. The purpose of the present invention is to provide a chemical combustion device.

[Means for Solving the Problems] In order to achieve the above object, the metal recovery method by gasification combustion of the present invention collects metals from a material to be treated containing at least a solid combustible organic substance and a metal in a mixed state. A recovery method, which comprises placing the material to be treated in a primary reaction chamber, igniting it, and then controllingly sending air into the primary reaction chamber so as to cause incomplete combustion and thermal decomposition of the organic substances in the material to be treated. The water vapor is controlled in the primary reaction chamber so that a flammable gas is generated by entering the water vapor, and a water gas reaction occurs with the carbon produced from the organic substances in the material to be treated through incomplete combustion and thermal decomposition. By supplying water gas, water gas is generated, and the temperature rise is suppressed to the extent that deterioration of the quality of the metal to be recovered in the material to be treated can be prevented. The flammable gas generated by decomposition and the water gas generated by the water gas reaction are guided into a gas combustion chamber, and air or air and water vapor are introduced into the gas combustion chamber, and temporarily auxiliary combustion is performed using an auxiliary combustion burner using general fuel. By doing so, continuous self-combustion of the flammable gas and water gas is performed.

Further, the gasification combustion apparatus for metal recovery of the present invention is an apparatus for recovering metals from a workpiece containing at least a solid combustible organic substance and a metal in a mixed state, and contains the workpiece. a primary reaction chamber; an air control supply means for controllingly supplying air to the primary reaction chamber to cause incomplete combustion and thermal decomposition of the organic material in the material to be treated to generate flammable gas; A water gas reaction occurs between the carbon content generated from the organic substances in the material to be treated through complete combustion and thermal decomposition, generating water gas and preventing quality deterioration of the metals to be recovered in the material to be treated. a steam control supply means for controlling and supplying steam to the primary reaction chamber so as to suppress the temperature increase to a certain degree; a gas combustion chamber to which water gas generated by the gas reaction is introduced; a feeding means for feeding air or air and water vapor into the gas combustion chamber; It is equipped with an auxiliary combustion burner using general fuel for continuous self-combustion.

[Function] After the material to be treated is stored in the primary reaction chamber and ignited, air is controlled to be fed into the primary reaction chamber so that incomplete combustion and thermal decomposition of the organic substances in the material to be treated occur. Complete combustion suppresses the conversion of carbon content in organic substances into carbon dioxide, increases the tendency to convert them into carbon monoxide, and enriches combustible components. Incomplete combustion of the organic substance promotes thermal decomposition of the organic substance due to the reaction heat, and as a result, hydrocarbon gas, hydrogen gas, etc. are generated.

Incomplete combustion and thermal decomposition of organic substances, on the one hand, promotes carbonization, and the resulting coal becomes a kindling state. By controlling the feeding, it is possible to generate water gas while digesting the charcoal, and since the water gas reaction is an endothermic reaction, it prevents quality deterioration of the metals to be recovered in the material to be treated. It is possible to suppress the increase in temperature to the extent possible. Moreover, it also halves the generation of thermal NO _x .

Furthermore, carbon monoxide gas due to incomplete combustion, hydrogen gas due to thermal decomposition, and hydrogen gas and carbon monoxide gas due to water gas reaction exhibit a reducing effect, so in the primary reaction chamber, the Metal oxidation is prevented.

As described above, flammable gas generated by incomplete combustion and thermal decomposition of organic substances in the primary reaction chamber and water gas generated by water gas reaction are introduced into the gas combustion chamber, and air or air and By introducing steam and temporarily auxiliary combustion using an auxiliary combustion burner using general fuel,
Continuous self-combustion of the flammable gas and water gas can be performed.

Then, in the primary reaction chamber, carbon monoxide gas,
The combination of the highly efficient production of combustible gases such as hydrocarbon gases and hydrogen gas, and the fact that these gases are sufficiently preheated in the primary reaction chamber, results in Ideal complete combustion conditions are continuously achieved, and the dust concentration in the exhaust gas is extremely low.

[Example] An example of the present invention will be described with reference to the drawings.

Reference numeral 1 denotes a primary reaction chamber that accommodates a processed material containing at least a solid combustible organic substance and a metal in a mixed state. Specifically, the objects to be treated include coated electric wires, circuit boards, electrical or electronic equipment containing them, various types of equipment or parts thereof in which plastic and metal are integrated, or these and other combustible materials. Examples include mixtures with organic substances or nonflammable substances.

2 is an air supply machine that communicates with the bottom floor 5 of the primary reaction chamber via a control valve 3 and an air supply pipe 4. By operating the control valve 3, the amount of air fed into the first cavity of the primary reaction chamber through the numerous air jet ports 6...6 opened in the bottom floor 5 of the primary reaction chamber is controlled. Incomplete combustion and thermal decomposition due to the heat of the incomplete combustion occur in the organic substances contained in the material to be treated stored in the container.

7 is a water vapor supply pipe that communicates with the air supply pipe 4 . The steam generated in the steam boiler (not shown) causes a water gas reaction with the generated coal in the primary reaction chamber 1 to generate water gas and prevent quality deterioration of the metal to be recovered. In order to suppress the rise in temperature to the extent that it is possible to obtain the desired temperature, the mixture is mixed with feed air in the air supply pipe 4 and controlled to be fed into the primary reaction chamber 1.

8 is a gas combustion chamber to which combustible gas generated in the primary reaction chamber 1 is fed via a flammable gas outlet 9, and includes only the air supply device 10 or the air supply device 10 and the steam supply pipe. In the presence of air or a mixture of air and water vapor supplied from both of the primary reaction chamber 1 and 11, the combustible gas supplied from the primary reaction chamber 1 continuously self-combusts due to temporary auxiliary combustion of the auxiliary combustion burner 12 using general fuel. It is structured in such a way that it can be obtained.

In the above-described apparatus, first, the primary reaction chamber 1
A solid combustible substance or metal waste containing the solid combustible substance is contained in the chamber through the canopy 13, the recovery door 14 provided in front of the primary reaction chamber 1 is closed, and then general fuel, especially heavy oil An auxiliary combustion burner 12 using
ignition is started to create a combustion flame in the gas combustion chamber 8.

The flame heats the inner wall of the gas combustion chamber 8 and is discharged into the atmosphere through the exhaust gas port 15 as waste gas. The exhaust gas port 15 may be connected to a chimney (not shown) as appropriate depending on the environmental conditions of the equipment location.
It is convenient if you connect it with

Immediately after the ignition of the auxiliary burner 12 is started, the air supply device 10 is started to supply air to the gas combustion chamber 8 via the air supply pipe 16, and the supplied air is generated by the auxiliary burner 12. The exhaust gas is discharged into the atmosphere through the exhaust gas port 15 together with the waste gas.

Next, the vicinity of the bottom floor 5 of the primary reaction chamber in the material to be treated stored in the primary reaction chamber 1 is ignited, and the collection door 14 is ignited.
Immediately after the door is closed, the air supply machine 2 is started, and a controlled amount of air is sent to the bottom floor 5 of the primary reaction chamber from the air outlet 6...6 via the control valve 3...3. do.

In this way, the combustion of the combustible organic substance in the primary reaction chamber 1 becomes incomplete combustion by controlling the amount of air introduced by the control valves 3...3, and as a result, the carbon content in the combustible organic substance becomes Carbonization is suppressed, increasing the tendency to convert to carbon monoxide (CO), and flammable components become abundant.

Furthermore, the incomplete combustion of the combustible organic substances mentioned above
The heat of reaction promotes thermal decomposition of the solid combustible material, and as a result, hydrocarbon gas (C _n H _o ), hydrogen (H ₂ ), etc. are generated.

By the way, the incomplete combustion and thermal decomposition of the combustible organic substance in the primary reaction chamber 1 described above, on the one hand, promotes carbonization and increases the high temperature in the bonfire state due to the continuation of air supply by the air supplier 2. However, there is a problem in that the quality of metals in the object to be treated, such as copper and iron, deteriorates or melts, making them unrecoverable.

However, in this device, water vapor is mixed with the air in the air supply pipe 4 via the steam supply pipe 7 and is controlled to be sent to the bottom floor 5 of the primary reaction chamber, so that the following water gas reaction of the produced coal is carried out. This occurs, producing the water gases carbon monoxide (CO) and hydrogen (H ₂ ).

C+H ₂ O→CO+H ₂ The above water gas reaction is, as is well known, an endothermic reaction in which carbon (C) is digested into carbon monoxide (CO) gas.

Therefore, in this device, the temperature inside the primary reaction chamber 1 can be easily and freely adjusted by adjusting the amount of air and water vapor to be fed, thereby preventing over-firing of the metal, and the carbon (C) can be effectively digested. However, since carbon monoxide gas due to incomplete combustion, hydrogen gas due to thermal decomposition, and hydrogen gas and carbon monoxide gas due to water gas reaction exhibit a reducing effect, the oxidation of valuable metals to be recovered is performed in the primary reaction chamber 1. is prevented.

As described above, highly combustible gases such as carbon monoxide gas, hydrocarbon gas, and hydrogen gas efficiently generated through incomplete combustion, thermal decomposition, and water gas reaction of combustible organic substances are transferred to the primary reaction chamber. The gas is sent to the gas combustion chamber 8 in a state that has been sufficiently preheated in step 1, so that ideal complete combustion conditions are continuously obtained, the dust concentration in the exhaust gas is extremely low, and exhaust gas heat is efficiently utilized. be able to.

The relationship between the position of the combustible gas outlet 9 that supplies flammable gas from the primary reaction chamber 1 to the gas combustion chamber 8 and the position of the air supply pipe 16 to the gas combustion chamber 8 is as follows.
It is desirable that the structure is such that an ejecting effect such as combustible gas is sucked from the primary reaction chamber 1 into the gas combustion chamber 8 can be obtained.

Alternatively, instead of leading the heated waste gas generated in the gas combustion chamber 8 to the exhaust gas port 15, it may be introduced into a heat utilization device such as a boiler, dryer, or heater through the hot gas supply port 17. It is effective if configured.

[Effects of the Invention] In the present invention, by controlling the supply of air and the controlled supply of water vapor to the primary reaction chamber, incomplete combustion and thermal decomposition are caused in the organic substances in the material to be treated, and the organic substances are generated from the organic substances. By generating water gas between the carbon monoxide and water vapor, the temperature increase can be suppressed to an extent that can prevent quality deterioration of the metal to be recovered in the treated material, and carbon monoxide gas and The reducing action of hydrogen gas prevents oxidation of metals, making it possible to improve the quality of recovered valuable metals and increase the recovery rate. That is, for example, in terms of the recovery rate of discarded electric wires, it is possible to achieve a recovery rate of 95% or more, compared to 80% with conventional devices. Moreover, by digesting the charcoal, metals can be easily recovered and the labor required to process the charcoal can be saved.

In addition, exhaust gas heat can be used efficiently due to the ideal complete combustion state in the gas combustion chamber, which is achieved through incomplete combustion, thermal decomposition, and efficient generation of flammable gas through water gas reactions. At the same time, the dust concentration in the exhaust gas is extremely low, so there is almost no need for accessories such as dust collectors.

Furthermore, the generation of thermal NO _x can also be reduced, and by supplying steam together with air to the gas combustion chamber, if necessary, the thermal NO _x in the gas combustion chamber can be reduced to half that of conventional devices.

[Brief explanation of the drawing]

The drawings are all about one embodiment of the present invention, and FIG. 1 is a longitudinal sectional view of the device, FIG. 2 is a cross-sectional plan view thereof, and FIG. 3 is a longitudinal sectional view taken along the line AA in FIG. 1. It is. In the drawing, 1 is the primary reaction chamber, 2 is the supply aircraft, 3...
3 is a control valve, 4 is an air supply pipe, 5 is a bottom floor of the primary reaction chamber, 6...6 is an air outlet, 7 is a steam supply pipe, 8 is a gas combustion chamber, 9 is a combustible gas outlet, 1
0 is an air supply machine, 11 is a steam supply pipe, 12 is an auxiliary combustion burner, 13 is a canopy, 14 is a recovery door, 15 is an exhaust gas port, 16 is an air supply pipe, and 17 is a hot gas supply port.

Claims (1)

[Scope of Claims] 1. A method for recovering metal from a workpiece containing at least a solid combustible organic substance and a metal in a mixed state, the method comprising: storing the workpiece in a primary reaction chamber and igniting the workpiece; Combustible gas is generated by controlling air flow into the primary reaction chamber to cause incomplete combustion and thermal decomposition of the organic substances in the material to be treated, and the material to be treated is destroyed by incomplete combustion and thermal decomposition. By controllingly feeding water vapor into the primary reaction chamber so as to cause a water gas reaction with the carbon produced from the organic materials in the material, water gas is generated and the metal to be recovered in the material to be treated is removed. flammable gas generated by incomplete combustion and thermal decomposition of organic substances in the primary reaction chamber and water gas generated by water gas reaction are guided to the gas combustion chamber. A gas characterized in that air or air and water vapor are introduced into the gas combustion chamber, and the combustible gas and water gas are caused to continuously self-combust by temporarily auxiliary combustion using an auxiliary combustion burner using a general fuel. Metal recovery method by chemical combustion. 2. An apparatus for recovering metals from a workpiece containing at least a solid combustible organic substance and a metal in a mixed state, comprising: a primary reaction chamber containing the workpiece; and an organic substance in the workpiece. air control feeding means for controllingly feeding air into the primary reaction chamber so that incomplete combustion and thermal decomposition occur to generate flammable gas; and A water gas reaction occurs with the carbon produced from the substance to generate water gas, and the primary reaction is performed so that the temperature rise is suppressed to an extent that can prevent quality deterioration of the metal to be recovered in the material to be treated. a steam control feed means for controlling steam to be fed into the chamber; and a gas combustion system in which flammable gases generated by incomplete combustion and thermal decomposition of organic substances and water gases generated by water gas reactions are introduced into the primary reaction chamber. a feeding means for feeding air or air and water vapor into the gas combustion chamber; and auxiliary combustion with general fuel to cause continuous self-combustion of the flammable gas and water gas by temporarily auxiliary combustion. A gasification combustion device for metal recovery, characterized by comprising a burner. 3. The gasification and combustion apparatus for metal recovery according to claim 2, wherein the gas combustion chamber has a hot gas supply port communicating with a heat utilization device such as a boiler, dryer, or heating furnace. 4. Gasification and combustion for metal recovery according to claim 2, wherein the primary reaction chamber is equipped with a recovery door that can be opened and closed to recover residual metal after gasification and combustion of flammable substances in the object to be treated. Device.