WO2012048462A1

WO2012048462A1 - Method for recovering valuable resource from waste gfrp and waste circuit board

Info

Publication number: WO2012048462A1
Application number: PCT/CN2010/077697
Authority: WO
Inventors: 宋金有
Original assignee: Song Jinyou
Priority date: 2010-10-13
Filing date: 2010-10-13
Publication date: 2012-04-19

Abstract

A method for recovering valuable resources from waste GFRP (glass-fiber-reinforced plastic) and waste circuit boards includes the following steps: (1) microwave heat cracking: placing the waste GFRP and waste circuit boards in a high frequency microwave oven, switching on the high frequency microwave oven, and heating the material to a high temperature of 500-600℃ under microwave action to decompose and crack the thermoset high polymer materials to obtain a heat cracked gas and a solid residue; (2) condensing: collecting the heat cracked gas in the oven from step (1) and condensing to obtain an aromatic hydrocarbon mixed organic matter; (3) residue smelting: collecting the solid residue from step (1), smelting at a high temperature in a smelting furnace, and separating to obtain non-ferrous metals and a carbonaceous residue. The method has simple treating process, no pollution, low cost and high recovering efficiency.

Description

Recycling method for valuable resources of discarded FRP and waste circuit boards

Technical field

The invention relates to the technical field of waste electrical and electronic products and industrial waste recycling, and particularly relates to a method for recovering valuable resources by microwave thermal cracking from waste glass steel and waste electronic wires. Background technique

With the rapid development of the economic and electronic information industry, the upgrading of electronic and electrical products has intensified, and the service life of products has been shortened, resulting in the abandonment of a large number of electronic products. Disposable printed circuit boards are a major component of electronic waste, and its recycling has become a global problem that needs to be addressed. Abandoned circuit board is different from ordinary solid waste. In addition to precious metals and other valuable metals, it also contains lead, cadmium, mercury, hexavalent chromium, polyvinyl chloride and surface-containing flame retardants. Improper handling will cause environmental damage. Serious pollution. At present, the most commonly used technologies for recycling waste circuit boards are mechanical crushing, hydrometallurgy, pyrometallurgy or a combination of several technologies, but there is no pollution-free, high-efficiency, low-cost technology for the recycling of waste circuit boards. .

Domestically, Application No. 98101834.3 discloses a method and apparatus for recycling a printed circuit board with molten tin metal. The invention firstly puts the waste printed circuit board into a tin liquid treatment furnace, and carbonizes and crushes and stirs it by a burner installed in the tin liquid treatment furnace, a plurality of sets of crushing and stirring devices, a scum scraping device and a copper foil separating device. Separation, using the copper foil, thermosetting plastic and glass fiber in the printed circuit board, the specific gravity is different, separately separated and collected, to achieve the purpose of recycling the waste circuit board. The method uses expensive tin metal as a heating medium to process the circuit board, and the cost is high; tin is easily oxidized during the treatment process, and the molten tin has strong adhesion, which makes separation of components of the waste circuit board difficult; metal tin can be combined with gold and silver , platinum and palladium form metal compounds, so this method is easy to cause difficulties and loss of recovery of these precious metals; in addition, the gas generated during the treatment will still pollute the environment after burning.

Application No. 99119731.3 discloses a method of treating a printed circuit board with molten inorganic salts. First, the waste circuit board is put into the molten inorganic salt, and after being crushed and stirred, it is a copper foil self-printing circuit. Peel off the board. At the same time, the thermosetting plastic is pyrolyzed, thereby separating the glass fiber and other substances therein, and the other generated is discharged after being burned. In this method, the molten inorganic salt is used as the heat medium, and the waste circuit board floats on the upper portion of the molten metal due to the relatively small density during the treatment, which makes it difficult to stir and crush in the next step. Therefore, the method of dealing with waste circuit boards is very low, and the problem of gas pollution environment is not solved.

Application No. 99102862.7 discloses a pulverization separation and recovery process for waste printed circuit boards and equipment therefor. The invention first pulverizes the printed circuit board into scraps and further finely pulverizes them. At the same time of fine pulverization, the powdery discharge is separated by air separation, and the non-metal is separated first, and then the remaining metal and non-metal powder are separated from the air. The separator is separated, and the coarse powder is returned to the fine pulverizer to continue pulverization. This method of mechanical pulverization has many steps, long process, and large equipment investment. The recycling process requires a large amount of energy, high recovery cost, and not only the metal substance adheres seriously during the crushing and grinding process, but also toxic gas is easily generated. polluted environment.

Application No. 200310103403.0 discloses a method of recycling valuable resources in a waste printed circuit board. The method firstly dismantles the components of the waste circuit board, separately performs coarse crushing, and then uses a dry magnetic separator to select a ferromagnetic substance, a high frequency vibrating pneumatic sorting machine, and sorts metal materials and non-metal materials, and adopts a wet method. The magnetic separator extracts the ferromagnetic material, and the selected ferromagnetic material is sorted by a flotation column to finally produce ferromagnetic materials, copper, alloys, and plastics and resins. This method is mostly manual disassembly in the step of removing components, which is time consuming and inefficient. The pulverization method also has the disadvantages of long process, high energy consumption, high cost, and the like, and toxic gases are also generated during the pulverization process.

Application No. 200410013482.5 discloses a physical recovery process for a metal rich group in a waste circuit board. The whole process of the process adopts mechanical and physical sorting methods. The waste circuit board is subjected to shearing, crushing, sieving and sorting by double-tooth roll shearing machine and high-efficiency centrifugal sorting machine to finally separate various components. The metal rich and non-metallic rich collective. This mechanical crushing method also has disadvantages such as high energy consumption, high cost, and environmental pollution, and the process does not fully consider the problem of non-metal recycling.

Application No. 200510084196.8 discloses a method for recycling waste printed circuit board resources. The first material is pyrolyzed by a normal pressure pyrolysis system in nitrogen, and the solid is finely divided by a shearing and crushing machine after pyrolysis. Broken, separating metal from non-metal: Selecting ferromagnetic material from finely divided product by magnetic separator: For magnetic residue, use high-frequency pneumatic separator to separate metal and non-metal by density. After mechanical crushing, it is further pyrolyzed and further pulverized and separated. The energy consumption in the treatment process is high: The pyrolysis circuit board is prone to secondary cracking under nitrogen atmosphere, and a large amount of halogen-containing gas is generated. The environmental conditions on the site are poor, and toxic during the early coarse crushing. Gas pollutes the environment.

Application No. 200610002019.5 discloses a method of recycling a waste printed circuit board. The invention first heats the waste circuit board and removes the electronic components used: the surface solder is removed by a vacuum suction device, and then the waste circuit board from which the surface solder has been removed is soaked with a nitric acid stripping solution to recover the solder of the inner layer of the circuit board: Dissolving the circuit board with a strong acid to dissolve the copper foil on the circuit board in the molten metal: The treated waste circuit board is put into a molten state of sodium nitrate melt for thermal cracking to separate the glass fiber from the organic matter and other components. This method handles the long process flow of the board and is costly. A large amount of harmful gases and waste acid are generated during the treatment, causing secondary pollution to the environment.

Germany Daimler-Benz Ulm Research Centre has developed a four-stage process: to break, to freeze and then pulverize liquid nitrogen, to separate the metal from the non-metal after electrostatic separation. The company's electric sorting equipment can separate particles smaller than 0.1mm in size. The low-temperature crushing method reduces the generation of harmful gases and makes the waste circuit board more fragile, and solves the problem of the traditional mechanical crushing to generate toxic gas, but the process flow is long, and the equipment is extremely demanding, and the refrigeration process consumes a large amount of energy. , high cost.

The processing technology used by Kamet Recycling Gmbh in Germany is to obtain several components such as iron, aluminum, precious metals and organic matter by means of crushing, re-election, magnetic separation and vortex separation. The treatment of Trischler und Partner Gmbh in Germany is basically the same. These two methods are the most commonly used mechanical treatment processes. After such treatment, 90% of the metal and plastic in the waste circuit board can be recycled, and about 10% of the remaining materials (including fine materials that are difficult to further process, Dust, etc.) is landfilled or incinerated depending on the nature of the ingredients, causing environmental pollution.

Japanese EC Corporation has developed a waste circuit board processing process. The process first uses infrared heating and two-stage removal (using vertical and horizontal impact forces, respectively) to detach the perforated elements without causing any damage. Then combined with heating, impact and surface ablation techniques, 96% of the solder on the board is desoldered, and the board is separated and separated by a two-stage crushing method. Use shear crusher and special The mill has a shearing and impact action, and the slab is pulverized into pieces of about 0.1-0.3 mm. A special grinding rotor is used in the special grinding machine, and special ceramics are used as the grinding material. This and the technology use air as a heating medium to remove solder and components, and the heat utilization rate is relatively low, and heating the circuit board in the air will cause some toxic elements to volatilize, thereby causing environmental pollution, requiring sealing treatment and treatment of toxic substances: In addition, through two-stage crushing separation and non-metal, in this process, harmful gases are easily generated to cause environmental pollution, and the recovery cost is also high.

Sweden's Scandinavian Recycling AB (SR) has developed a rotary crusher with a freely rotatable crush ring around the intermediate turn, which relies on the shearing action between the crush ring and the inner wall of the device to break the material. The use of such a crusher can reduce the entanglement of the metal after dissociation. Swiss Result Technologies has developed a new device for breaking multi-layer composite parts such as coated circuit boards at supersonic speeds. It utilizes the different impact and centrifugal properties of the various laminates to separate the multilayer composites from one another. The deformation of different materials is different, the brittle material is broken into powder, and the metal forms a multi-layered ball. These two devices rely on shearing, impact and centrifugation to break the waste circuit board. Although the crushing efficiency is improved, it still has the disadvantages of high energy consumption and environmental pollution.

The above method separates and recycles the components of the waste circuit board, and the recycling process has the disadvantages of high energy consumption and easy pollution environment. The recycling of waste circuit boards should fully consider the harmless and efficient recovery of metals and organic materials. The early recovery of solder can create favorable conditions for the efficient separation of other metals. Therefore, the existing technology needs to be further improved to improve recovery efficiency and recovery. Purity: At the same time, new processing technologies and equipment need to be developed to find a low-cost, more efficient resource recycling method for large-scale waste circuit boards. Summary of the invention

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for recovering aromatic hydrocarbon-based organic components from cracking of non-contaminated microwave radiation from waste glass steel and waste circuit boards by overcoming the deficiencies of the prior art. The recycling method has simple processing, no pollution, low cost and high recycling efficiency.

The object of the present invention can be achieved by the following technical measures: A method for recovering valuable resources from waste glass steel and waste circuit boards, the method comprising the following steps:

(1) Microwave thermal cracking: Put waste glass steel and waste circuit board in high frequency microwave oven, open high Frequency microwave oven, the material generates high temperature of 500 °C-600 °C under the action of microwave, and the thermosetting polymer material is decomposed and cracked to obtain thermal cracking gas and solid residue;

(2) Collecting condensation: Collection step (1) The pyrolysis gas in the furnace is condensed to obtain an aromatic hydrocarbon mixed organic matter;

(3) Residue smelting: The solid residue of step (1) is collected, and then smelted by high temperature in a smelting furnace to separate non-ferrous metals and carbon residue. As a preferred embodiment of the method for recovering valuable resources of the waste glass reinforced plastic and the waste circuit board of the present invention, in the step (1), 1 wt% to 2 wt% of alumina is used as the cracking catalyst. As a preferred embodiment of the method for recovering valuable resources of waste glass fiber reinforced plastics and waste circuit boards of the present invention, before step (1) microwave thermal cracking, step (la) is further included: the waste glass reinforced plastic and the waste circuit board are put into the pulverizer for milling. Made into 30~60 mesh fine 'j, powder. As a preferred embodiment of the method for recovering valuable resources of the waste glass reinforced plastic and the waste circuit board of the present invention, the condensation temperature in the step (2) is 10 to 30 °C. As a preferred embodiment of the method for recovering valuable resources of the waste glass reinforced plastic and the waste circuit board of the present invention, the recovery method further includes

Step (4) Carbon residue reuse: The carbon residue obtained in the step (3) is used as a cement sintered material of a cement plant. The invention uses microwave high-temperature pyrolysis waste circuit board and waste glass steel to recover valuable resources therefrom, and the advantages thereof are as follows:

1. High-temperature cracking of waste circuits and waste glass steel by microwave technology can eliminate environmental pollution caused by coal incineration. The cracking requirement can be achieved by using microwave high-frequency radiation to bring the temperature in the furnace within several tens of seconds. The use of microwaves with a suitable amount of catalyst to stabilize the cracking temperature, easy to operate and control, easy The volatile matter distillation range is low, and the dry distillation organic matter is mostly aromatic hydrocarbon organic matter with recovery value.

2. Waste electronic circuit boards and FRP wastes enter the smelting furnace after microwave high-frequency radiation, which can make non-ferrous metals separate relatively pure metal in the melting point of each phase, which was not possible with other physical separations in the past. .

3. Due to the use of microwave high-frequency cracking instead of the traditional soil extraction, it is beneficial to the recovery of organic components, and the recovery rate of non-ferrous metals can be significantly improved. The invention has the advantages in the recovery of organic components or the recovery of non-ferrous metals. High economic efficiency, the equipment required for each procedure is simple, the conditions are easy to control, and the recycling cost and equipment investment can be significantly reduced.

4. High recovery efficiency and low energy consumption, suitable for large-scale recycling of waste electronic circuit boards and FRP waste.

In summary, the present invention optimizes the processing conditions and processes of the waste thermosetting resin according to the material characteristics of the waste circuit board and the waste glass fiber reinforced by microwave high-frequency radiation, and the method is simple in the thermal cracking process, so that the waste electronic circuit board is discarded. The recycling cost is lower, the efficiency is higher, and it is more in line with the requirements of industrial recycling treatment. It is suitable for large-scale recycling of waste circuit boards and waste glass steel. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to make the present invention easier to understand, specific embodiments of the present invention will be further described below.

Example 1

In this embodiment, a microwave, carbon furnace integrated heating cracking waste circuit board and a waste glass steel valuable resource recycling method are as follows:

<1> Using microwave high-frequency radiation: The waste electronic circuit board is placed in a microwave cracking furnace, and a suitable catalyst is added to raise the temperature in the microwave oven to 500 ° C to 600 ° C for 5 to 6 minutes under microwave irradiation. Thermal cracking

<2> Collecting the pyrolysis distillate product and condensing it into an aromatic hydrocarbon organic compound (liquid oil) at 10 °C ~ 30 °C; <3> Microwave high-frequency thermal cracking: further smelting the solid product after cracking at 130 0 °C ~ 1500 °C, its role is to separate the non-ferrous metals from the residue, according to the melting point of each non-ferrous metal Set the temperature in the furnace, and extract and separate it from 500 °C to 1500 °C;

< 4 > The metal component in the residue is collected and the remaining glass fiber inorganic material is used as a cement sintered material of the cement plant.

The method can completely solve the problem of waste electronic circuit board and waste glass steel pollution. Example 2

The recycling method for the valuable resources of the waste glass steel and the waste circuit board in the present embodiment includes the following processes: Microwave high-frequency cracking: the waste circuit board and the waste glass fiber reinforced plastic are crushed by the crusher and then sent to the microwave high-frequency cracking furnace through the screw feeder. Increased to 500 °C ~ 600 °C, adding 1%~2% alumina in the furnace as a catalyst during the cracking process. The purpose of using the catalyst is to increase the yield of aromatic organic compounds, reduce the reaction process, and reduce energy consumption. save costs);

When the temperature rises to 250 ° C, the thermosetting material in the furnace begins to depolymerize, and some of the low-fraction volatiles are retorted. When the temperature is continuously increased, the output of the reaction product increases sharply; when the temperature rises to 500 : ~ 600 ° C, collecting thermal cracking gas and condensation to obtain aromatic organic compounds; the furnace abandoned electronic circuit board and waste glass steel has also become a metal-containing residue, and then heated and smelted in a high-temperature smelting furnace until various colored The metal is completely separated.

The final carbon residue is collected and used as an industrial raw material in cement plants as a raw material for burning cement. Example 3

- After breaking, pass through the screw feeder and enter the high-frequency microwave oven. Add 1%~2% alumina to the furnace, and heat the furnace to distill the pyrolysis at 500 °C~600 °C. The organic components are collected, and the condensation temperature of the heat exchanger is 20 ° C ~ 30 ° C. The distillate components are mostly aromatic hydrocarbons. The solid matter after dry distillation contains 15% to 20% of metal and 80% to 85% of residue, and is then separated into a variety of pure non-ferrous metals by a high-temperature smelting furnace, and the final carbon residue is used as a material of sintered cement.

Conclusion: (1) In the microwave oven, high temperature of several hundred degrees will be generated in the furnace, which will cause the thermosetting resin to be quickly broken into aromatic hydrocarbons, and the dry distillation accounts for about 16%. (2) The recovered solid residue is separated by high temperature smelting to separate 15%~20% of metal materials, and the final carbon residue can be used for sintering materials in cement plants. Example 4 The foam was passed through a high-frequency microwave oven. The microwave oven was a tubular pyrolysis furnace. The cracking method was continuous cracking. The catalyst was not used, and the temperature in the furnace was also free of catalytic dry distillation at 500 °C - 600 °C.

Conclusions: (1) Although no catalyst is used in the thermal cracking process, the particle size of waste electronic circuit board and glass steel waste can be effectively cracked by 30~60 mesh.

(2) Since the waste electronic circuit board has been broken into fine d and fine particles, the metal component can be separated by static electricity. Example 5

The waste electronic circuit board and FRP waste are broken into pieces by the crusher and then mixed with 1%~2% aluminum powder as catalyst. The cracking temperature of the microwave oven is 500 °C~600 °C, and the condenser water temperature is 10 °C. The ~20 ° C cracking product is an aromatic hydrocarbon.

Conclusions: (1) In high frequency microwave cracking, the aromatics organic matter yield is 16.5%.

(2) Various non-ferrous metals can be completely recycled and will not pollute the environment.

(3) The final solid residue can also be recycled, which truly achieves the purpose of recycling resources. It should be noted that the above embodiments are only intended to illustrate the technical solutions of the present invention, and are not intended to limit the scope of the present invention. The technical solutions of the present invention may be modified or equivalently substituted without departing from the spirit and scope of the technical solutions of the present invention.

Claims

Rights request

A method for recovering valuable resources of waste fiberglass and waste circuit boards, characterized in that the method comprises the following steps:

(1) Microwave thermal cracking: The waste glass fiber reinforced plastics and waste circuit board are placed in a high-frequency microwave oven, and the high-frequency microwave oven is turned on. The material generates a high temperature of 500 ° C to 600 ° C under the action of microwave, and the thermosetting polymer material is decomposed and cracked. , obtaining pyrolysis gas and solid residue;

(2) Collecting condensation: Collecting step (1) The pyrolysis gas in the furnace is condensed to obtain an aromatic hydrocarbon mixed organic matter;

(3) Residue smelting: The solid residue of step (1) is collected, and then smelted by high temperature in a smelting furnace to separate non-ferrous metals and carbon slag.

A method for recovering valuable resources of waste glass reinforced plastics and waste circuit boards according to claim 1, wherein in the step (1), lwt% to 2% by weight of alumina is used as a cracking catalyst.

3. The method for recovering valuable resources of waste fiberglass and waste circuit boards according to claim 1, characterized in that, before step (1) microwave thermal cracking, step (la) is further included: putting waste fiberglass and waste circuit boards into The powder is ground into a fine powder of 30-60 mesh in a pulverizer.

A method of recovering valuable resources of waste fiberglass and waste circuit boards according to claim 1, wherein the condensation temperature in said step (2) is 10 to 30 °C.

5. The method for recovering valuable resources of waste fiberglass and waste circuit boards according to claim 1, wherein said recycling method further comprises

Step (4) Carbon residue reuse: The carbon residue obtained in the step (3) is used as a cement sintered material of a cement plant.