WO2018233382A1

WO2018233382A1 - Dry separation and recovery process for recovering valuable constituent from waste circuit board

Info

Publication number: WO2018233382A1
Application number: PCT/CN2018/085435
Authority: WO
Inventors: 贺靖峰; 赵跃民; 何亚群; 段晨龙; 王海锋; 姚亚科
Original assignee: 中国矿业大学
Priority date: 2017-06-23
Filing date: 2018-05-03
Publication date: 2018-12-27
Also published as: CN107442549A; CN107442549B

Abstract

A dry separation and recovery process for recovering a valuable constituent from a waste circuit board comprises: step 1. dismantling a waste circuit board to obtain a bare waste circuit board; step 2. removing a solder from the bare waste circuit board; step 3. sequentially performing coarse crushing and fine crushing on the bare waste circuit board from which the solder has been removed to obtain granulated particles of the waste circuit board; step 4. performing sieving and classification of the granulated particles of the waste circuit board to obtain materials having grain sizes of -2+1 mm, -1+0.5 mm, -0.5+0.3 mm, -0.3+0.125 mm, -0.125+0.074 mm and -0.074 mm; step 5. respectively supplying the materials to different dry physical separation apparatuses to undergo separation operations; and step 6. respectively recovering a metal concentrate and a non-metal concentrate obtained by the separation operations performed by the respective apparatus. The present invention employs several physical separation techniques to separate metal constituents and non-metal constituents from materials having different grain sizes, thereby obtaining a high-grade metal concentrate product after separation, and achieving a high recovery rate. The separation process causes less environmental contamination.

Description

Dry sorting and recycling process for valuable components in waste circuit boards

Technical field

The invention relates to the technical field of electronic waste resource recycling, in particular to a dry sorting and recycling process for valuable components in a waste circuit board.

Background technique

In recent years, the rapid development of integrated circuit technology and its products has made electronic circuit boards (PCBs) an indispensable and important component in the modern information industry. With the speed and frequency of electronic product development and promotion, and consumers' electronics The demand for product features is getting higher and higher. A large number of discarded circuit boards are produced during the replacement and elimination of various electronic products. The annual growth rate of electronic waste is 16% to 28%. As an important part of electronic products, waste circuit boards are very complicated due to their material composition and bonding methods. The dissociation degree of monomers is small, and metal components and non-metal components are not easy to separate. The comprehensive recycling process has always been a rather complicated problem. .

The Chinese Patent Publication No. CN 102228890A discloses a multi-stage air separation-high-voltage electrostatic sorting method, which uses a multi-stage wind sorting method to sort waste circuit board particles with a particle size ranging from 1.20 to 0.02 mm. The mixed metal and non-metal mixture obtained from the two stages are subjected to high-pressure electrostatic air separation, and the non-metal material obtained by the first or second-stage air separation is used as a non-metal rich collective product; the method uses a wind sorting to reduce the high-voltage electrostatic sorting machine. The content of non-metal in the feed increases the sorting efficiency, but the range of feed size is wider, and the corresponding sorting operation parameters are not easy to adjust, so that the sorting effect is not ideal for sorting narrow-grain materials by a single physical sorting technique.

The Chinese patent of CN 101406861A discloses a multi-roll high-voltage electrostatic separation method for recycling waste printed circuit boards; the method indicates that the multi-roll high-voltage electrostatic separation method is suitable for sorting metals with a particle size of 0.1-0.6 mm. - non-metal mixed particles, the method separates the intermediate product produced by the first separation for a second time, and then can be separated as many times as needed to solve the problem of high yield of the intermediate product, but the particle size range of the feed Wide, resulting in high-voltage electrostatic sorting equipment operating parameters are difficult to adjust, thereby reducing the separation accuracy of metal components and non-metallic components.

Summary of the invention

In view of the above analysis, the present invention aims to provide a dry sorting and recycling process for valuable components in a waste circuit board, which is used to solve the problem of narrow application particle size range and low recovery efficiency caused by the existing single physical recovery technology. The problem.

The object of the present invention is mainly achieved by the following technical solutions:

A dry sorting and recycling process for valuable components in a waste circuit board, comprising the following steps:

Step 1. Disassemble the discarded circuit board to obtain the disassembled bare board of the discarded circuit board;

Step 2: removing the solder from the bare board of the discarded circuit board;

Step 3, the bare board of the discarded circuit board after removing the solder is sequentially subjected to dry coarse crushing and dry fine crushing to obtain waste circuit board particles;

Step 4: feeding the waste circuit board particles into the dry vibration multi-layer grading sieve for sieving and grading, and obtaining the granularity levels of -2+1 mm, -1+0.5 mm, -0.5+0.3 mm, -0.3+0.125 mm, - 0.125+0.074mm and -0.074mm materials;

Step 5: The above-mentioned granular grade materials are separately fed into different dry physical physical sorting equipments for sorting, respectively, to obtain metal rich collectives and non-metal rich collectives;

Step 6. Collect the metal rich group and the non-metal rich group separately sorted by each device.

The process of the invention separates the waste circuit board particles by multi-layer screening and sorting, and has the advantages of two aspects compared with the prior art. First, the present invention can select suitable sorting equipment for materials of different grain sizes. The effect of material size on the sorting precision is reduced, thereby improving the sorting efficiency of materials in each sorting device; secondly, the present invention selects a sorting device that is suitable for narrower-grained materials, and can exert a greater extent The advantages of each sorting device can achieve better sorting effect when the feed size range is the ideal feed size range of the sorting equipment.

Further, in the step 1, the components obtained by disassembling the discarded circuit board are sequentially classified by component classification and component performance detection.

The components obtained by disassembling the discarded circuit board include resistors, capacitors, inductors, diodes, transistors, relays, integrated circuits, etc., by using a multimeter to detect whether the functions of these components are intact, and classifying the functionally intact components as reusable Components; components that are damaged in function and contain harmful substances such as polybrominated biphenyls and polychlorinated biphenyls are classified as toxic and hazardous components; components with functional damage but high metal content are classified as components with high metal content. For example, the content of aluminum and copper in the slot is high; the components obtained by disassembly are divided into reusable components, components with high metal content and toxic and harmful components, wherein reusable components can be used for old equipment. Maintenance and production of new components; smelting and processing of components with high metal content to recover valuable metals; and toxic and hazardous components are handled in accordance with the relevant laws and regulations on solid waste pollution prevention and control.

Further, in the step 2, the tin slag obtained by removing the solder is sequentially subjected to smelting and refining to obtain a solder conforming to the national standard.

Further, in the step 3, the bare board of the discarded circuit board after removing the solder is sequentially subjected to dry coarse crushing and dry fine crushing using a dry double-toothed roller crusher and a dry high-speed impact mill.

Further, the crushing process consisting of the dry coarse crushing and the dry fine crushing is a two-stage dry crushing process.

In the crushing process, the particle size of the material is reduced by one crushing section. The crushing section is composed of: 1) single crushing operation; 2) pre-screening-crushing operation; 3) crushing-checking screening operation; 4) Pre-screening---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- It has the advantages of high crushing efficiency, good product characteristics and high selection index. The product characteristics are better in the uniform particle size and less pulverization.

Further, in the step 3, the particle size of the waste circuit board obtained by the dry crushing is less than 20 mm, and the particle size of the discarded circuit board obtained by the dry crushing is less than 2 mm.

The step 3 of the invention is subjected to dry coarse crushing and then subjected to dry fine crushing, which can narrow the particle size range of the fine crushing equipment, improve the crushing efficiency of the fine crushing equipment, and at the same time reduce the excessive crushing of the material to ensure the metal component in the material. Dissociation from the non-metallic component at the coarsest particle size possible; the present invention reduces the particle size of the waste circuit board to less than 2 mm because of the basic dissociation particle size range of the metal component and the non-metal component in the waste circuit board It is 0.5~1.2mm; the particle of the waste circuit board is broken to 2mm or less in order to dissociate the metal component and the non-metal component as much as possible to improve the sorting index of the crushed product, which is beneficial for subsequent further sorting. condition.

Further, in the step 3, an industrial vacuum cleaner is used for dust removal in the dry coarse crushing and the dry crushing process.

Further, in the step 4, the mesh size of the dry vibrating multi-layer grading sieve is 2 mm, 1 mm, 0.5 mm, 0.3 mm, 0.125 mm, and 0.074 mm from top to bottom; the dry vibration multi-layer grading The vibration vibration motor of the sieve has a suitable adjustment range of 300 to 960 times/min, an appropriate amplitude adjustment range of 4 to 8 mm, and a suitable adjustment range of the vibration direction angle of 45 to 60 degrees.

The invention selects the dry vibration multi-layer grading sieve with the above-mentioned mesh size, which can improve the screening effect and ensure accurate sorting in the next step.

Further, in the step 5, the material with a particle size of -2+1 mm is sorted into a pulsating airflow sorting machine, and the feed granularity of the pulsating airflow sorting machine ranges from 1 to 5 mm, and the gas velocity is The suitable adjustment range is 2~10cm/s, and the pulsation frequency is suitable for the range of 0~2.35Hz.

The pulsating airflow sorting machine of the invention selects the above parameters, and the metal grade of the metal rich group obtained by the sorting is higher than 90%, and the metal recovery rate is higher than 90%.

Further, in the step 5, the material with a particle size level of -1+0.5 mm is fed into a fluidized bed of a dense phase gas-solid medium, and the dense phase gas-solid medium fluidized bed is directed to the circuit. The particle size of the plate particles is in the range of 0.5 to 2 mm, and the gas velocity is suitably adjusted in the range of 6 to 13 cm/s; the separation medium is selected from magnetite ore, and the particle size of the magnetite powder is in the range of 0.06 to 0.3 mm.

The above-mentioned parameters are selected for the fluidized bed of the dense phase gas-solid medium of the present invention, and the metal grade of the metal-rich collective obtained by sorting is higher than 85%, and the metal recovery rate is higher than 85%.

Further, in the step 5, the material with a particle size of -0.5+0.3 mm is fed into a vibrating gas-solid medium fluidized bed for sorting, and the vibrating gas-solid medium fluidized bed is directed to the circuit board particles. The feeding particle size range is 0.125~1mm, the gas velocity is suitable for the adjustment range of 4~10cm/s; the amplitude is suitable for the adjustment range of 0~4mm, the vibration frequency is suitable for the adjustment range of 0~40Hz; the separation medium is magnetite powder. The magnetite powder has a particle size ranging from 0.06 to 0.3 mm.

The vibrating gas solid medium fluidized bed of the invention selects the above parameters, and the metal grade of the metal rich group obtained by the sorting is higher than 85%, and the metal recovery rate is higher than 75%.

Further, in the step 5, the material with a particle size of -0.3+0.125 mm is sorted into a high-voltage electrostatic sorting machine, and the high-pressure electrostatic sorting machine has a particle size range of 0.04 for the board particles. ~3mm, the sorting voltage is suitable for the range of 15~30kV, the roller speed is suitable for the range of 60~120rpm, the corona electrode deflection angle is suitable for the range of 20°~35°, and the distance between the corona electrode and the roller is adjusted. The range is 60-75mm, and the deflection angle of the high-pressure static electrode is suitably adjusted from 60° to 80°. The distance between the high-pressure static electrode and the roller is suitably adjusted to be 80-95mm.

The high-voltage electrostatic sorting machine of the invention selects the above parameters, and the metal grade of the metal rich group obtained by sorting is higher than 85%, and the metal recovery rate is higher than 85%.

Further, in the step 5, the material with a particle size level of -0.125+0.074 mm is fed into a friction electric separator for sorting, and the feeding particle size range of the friction electric separator is 0 to 0.2 mm, and the voltage is suitable. The adjustment range is 0~40kV, and the suitable airflow range is 10~90m ³ /h.

The friction electric separator of the invention selects the above parameters, and the metal grade of the metal rich group obtained by sorting is higher than 85%, and the metal recovery rate is higher than 70%.

Further, in the step 5, the material with a particle size of -0.074 mm is sorted into a cyclone separator, and the inlet particle size range of the cyclone separator is 0-0.1 mm, and the inlet wind speed is appropriately adjusted. 12 to 18 m/s.

The cyclone separator of the present invention selects the above parameters, and the metal grade of the metal rich group obtained by sorting is higher than 90%, and the metal recovery rate is higher than 80%.

Further, for the metal rich group sorted in the step 6, the magnetic material is recovered by a dry magnetic separator; the copper and silver in the metal rich group are recovered by the acid leaching method and the electrolytic method; the aqua regia method and the extraction are adopted. The method recovers gold, platinum and palladium in the metal rich group.

Further, the magnetic substance is mainly iron, cobalt and nickel.

Further, the non-metal rich group sorted in the step 6 can be used for preparing modified asphalt, filling material as a composite material, and heat treatment to prepare activated carbon and porous silicate.

The beneficial effects of the present invention are as follows:

(1) The method of the invention adopts manual dismantling, mechanical crushing and various physical sorting techniques to separately process waste circuit board materials of different granularity levels, which is a metal component of the waste circuit board particles of each granularity after crushing. The recovery of non-metallic components provides good sorting conditions, improves the grade and recovery of metals such as copper, iron, tin, aluminum, etc. in the metal rich group, and reduces the metals such as copper, iron and tin in the non-metallic rich group. The residual amount improves the quality of the non-metallic rich group products, thereby achieving efficient sorting and recovery of metal components and non-metal components in the waste circuit board;

(2) The method of the present invention separates metal components and non-metal components in materials of different size grades by using various physical sorting techniques according to physical properties, chemical composition and metal enrichment of the discarded circuit boards, and sorts the obtained metals. Rich collective products have higher grades, higher metal recovery rates, and less environmental pollution throughout the sorting process.

DRAWINGS

Figure 1 is a process flow diagram of the method of the present invention;

2 is a schematic view of a system of a pulsating airflow sorting machine in the present invention;

3 is a schematic view of a fluidized bed sorting system for a dense phase gas solid medium in the present invention;

4 is a schematic view showing a fluidized bed solidification fluidized bed sorting system according to the present invention;

Figure 5 is a schematic view of a high voltage static electricity sorting machine of the present invention;

6 is a schematic view of a sorting system of a friction electric separator according to the present invention;

Figure 7 is a schematic view of a cyclone separator sorting system of the present invention.

In the figure, the fan in the 1-pulsating airflow sorter system; the wind pack in the 2-pulsating airflow sorter system; the airflow valve in the 3-pulsating airflow sorter system; the 4-pulsating airflow sorter system Rotor flowmeter; pulsating valve in 5-pulsed airflow sorter system; 6-pulse airflow sorter system in the inverter; 7-pulsating airflow sorter system feeding device; 8-pulsating airflow sorting The feed port of the machine system; the heavy component discharge port of the 9-pulsating airflow sorter system; the discharge valve of the 10-pulsed airflow sorter system; the air distribution chamber of the 11-pulsating airflow sorter system; The air distribution plate of the pulsating airflow sorting machine system; the sorting column of the 13-pulsating airflow sorting system; the heavy component particles separated by the 14-pulsating airflow sorting system; and the 15-pulse airflow sorting system Light component granules; light component discharge port of 16-pulsating airflow sorter system; cyclone dust collector in 17-pulsating airflow sorter system; dust outlet of cyclone dust collector in 18-pulsating airflow sorter system 19-Dense phase gas-solid medium fluidized bed sorting system fan; 20-dense phase gas-solid medium flow Wind pack of bed sorting system; main damper of 21-dense phase gas solid medium fluidized bed sorting system; rotameter of 22-dense phase gas solid medium fluidized bed sorting system; 23-dense phase Bypass damper for gas-solid heavy medium fluidized bed sorting system; base of 24-dense phase gas-solid medium fluidized bed; 25-dense phase gas-solid medium fluidized bed plenum; 26-dense phase The air distribution plate of the gas-solid heavy medium fluidized bed; the separation bed of the 27-dense phase gas-solid medium fluidized bed; the heavy component particles separated by the 28-dense phase gas-solid medium fluidized bed sorting system; Light-weight particles separated by 29-dense phase gas-solid medium fluidized bed sorting system; weighted particles of 30-dense phase gas-solid medium fluidized bed sorting system; 31-vibration gas-solid medium fluidization Fan of bed sorting system; wind pack of 32-vibrating gas-solid heavy medium fluidized bed sorting system; main damper of 33-vibrating gas-solid heavy medium fluidized bed sorting system; 34-vibrating gas-solid heavy medium flow Rotor flowmeter of chemical bed sorting system; bypass damper of 35-vibrating gas-solid heavy medium fluidized bed sorting system; 36-vibration table of vibrating gas-solid heavy medium fluidized bed sorting system; 37-vibration Vibration control system of solid-weight fluidized bed sorting system; base of 38-vibrating gas-solid heavy medium fluidized bed; air chamber of 39-vibrating gas-solid heavy medium fluidized bed; 40-vibrating gas-solid heavy medium flow The air distribution plate of the chemical bed; the separation bed of the 41-vibrating gas-solid heavy medium fluidized bed; the heavy component particles separated by the 42-vibrating gas-solid heavy medium fluidized bed sorting system; 43-vibrating gas-solid heavy medium Light component particles separated by fluidized bed sorting system; weighted particles of 44-vibrating gas-solid heavy medium fluidized bed sorting system; 45-high-pressure electrostatic sorter feeding device; 46-high-voltage electrostatic sorting Grounding electrode of the machine; 47-charged area of high-voltage electrostatic sorting machine; 48-corona electrode of high-voltage electrostatic sorting machine; 49-high-voltage static electrode of high-voltage electrostatic sorting machine; rolling of 50-high-voltage electrostatic sorting machine Brush; 51-high-pressure electrostatic sorter product collection tank; 52-high-pressure electrostatic separator separation of non-metallic particles; 53-high-pressure electrostatic separator separation of metal particles; 54-high-voltage electrostatic separator metal Particle collection tank; 55-high-pressure electrostatic separator intermediate product collection tank 1; 56- middle of high-voltage electrostatic separator Material collection tank 2; 57-intermediate product collection tank 3 of high-voltage electrostatic separator; 58-non-metallic particle collection tank of high-voltage electrostatic separator; 59-fan of friction electric separator; air volume of 60-friction electric separator Controller; 61-friction electric separator feeding device; 62-friction electric separator feeding port; 63-friction electric separator friction chamber; 64-friction electric separator nozzle; 65-friction electric separator High-pressure sorting chamber; 66-separated metal particles by friction electric separator; 67-triboelectric separator discharge port; 68-friction electric separator non-metal component discharge port; 69-triboelectric Non-metallic particles separated by machine; 70-cyclone feeder; 71- cyclone feed port; 72-cyclone light component discharge port; 73-cyclone separator Room; 74-light component particles separated by a cyclone; 75-heavy component particles separated by a cyclone; 76-heavy component discharge port of a cyclone.

Detailed ways

The preferred embodiments of the present invention are described in detail below with reference to the accompanying drawings, in which FIG.

Example 1

The invention relates to a dry sorting and recycling process for valuable components in a waste circuit board, and the specific process is shown in FIG. 1. The dry sorting and recycling process of the valuable components in the discarded circuit board of the computer is as follows :

Step 1. Disassemble the discarded circuit board of the computer to obtain the bare board of the discarded circuit board of the disassembled 5kg computer, and disassemble the discarded circuit board of the computer through the component classification and performance testing procedures. Reusable components, components with high metal content and toxic and harmful components; in this embodiment, the discarded circuit boards of the computer are disassembled to obtain components on the discarded circuit board: resistors, capacitors, inductors, diodes, and triodes. , relays, integrated circuits, etc., with the help of a multimeter to check whether the functions of these components are intact, classify the functionally intact components as reusable components; components that are functionally damaged and contain harmful substances such as polybrominated biphenyls and polychlorinated biphenyls. Classified as toxic and hazardous components; classify some components with damaged function but high metal content as components with high metal content. If the content of aluminum and copper in the slot is high, it is classified as high metal content. Components

Step 2: removing the soldering process from the bare board of the discarded circuit board of the computer; then, the tin slag obtained by removing the solder is sequentially subjected to smelting and refining to obtain a solder conforming to the national standard; in this embodiment, the solder is removed by using a heated sanding method;

Step 3: using a dry double-toothed roller crusher and a dry high-speed impact pulverizer to perform dry coarse crushing and dry fine crushing on the bare board of the discarded circuit board after removing the solder to obtain waste circuit board particles; The particle size of the discarded circuit board particles after the coarse crushing is 10mm-20mm, and the particle size of the waste circuit board particles after dry crushing is less than 2mm, and finally the waste circuit board particles with particle size less than 2mm are obtained after two stages of crushing; the crushing process is adsorbed by industrial vacuum cleaner. Dust to reduce the pollution of dust to the environment;

Step 4. The dry circuit board waste granules are sent to a dry vibrating multi-layer sieving sieve for sieving and grading, and the obtained size fraction is -2+1 mm, -1+0.5 mm, -0.5+0.3 mm, -0.3. The materials of +0.125mm, -0.125+0.074mm and -0.074mm have mass ratios of 39.08%, 25.24%, 16.52%, 8.9%, 7.21% and 3.05%, respectively;

Step 5. The graded materials of -2+1mm, -1+0.5mm, -0.5+0.3mm, -0.3+0.125mm, -0.125+0.074mm and -0.074mm are sequentially fed into the pulsating airflow sorting machine. , dense phase gas solid medium fluidized bed, vibrating gas solid medium fluidized bed, high pressure electrostatic sorting machine, friction electric separator and cyclone separator are sorted to obtain metal rich collective and non-metal rich collective respectively;

Step 6. Collect the metal rich group and the non-metal rich group obtained by each device for recycling.

It is worth noting that the dry coarse crushing equipment used is a dry double-toothed roller crusher with a feed size range of 80-200 mm, a discharge size range of 15 to 50 mm, and a discharge size range adjusted by a double-toothed roll pitch; The dry crushing equipment used is a dry high-speed impact pulverizer with a feed size range of 10 to 40 mm, a discharge size range of 0 to 5 mm, and a discharge size range controlled by adjusting the discharge opening size; The crushing efficiency can be improved, and the particle size of the discarded circuit board particles of 88% to 94% after the crushing is concentrated at the level of -2+0.125 mm.

It is worth noting that the suction diameter of the industrial vacuum cleaner is 50mm, the filtration area is 2.4m ² , the collection barrel volume is 65L, the highest vacuum is 23036Pa, the dust removal efficiency is higher than 99.95%, and the processing capacity is 100～265m ³ /h. The length x width x height of the outer dimensions is 1180 x 670 x 1320 mm.

It is worth noting that the mesh size of the multi-layer screen in the dry vibrating multi-layer grading sieve is 2mm, 1mm, 0.5mm, 0.3mm, 0.125mm and 0.074mm from top to bottom; the vibration vibration motor is suitable for adjustment range. 300 to 960 times / min, the appropriate range of amplitude adjustment is 4 ~ 8mm, the vibration direction angle is suitable to adjust the range of 45 ° ~ 60 °; the screen material is a wire woven mesh;

It is worth noting that the pulsating airflow sorting machine sorts the materials of -2+1mm grain size, and the schematic diagram of the pulsating airflow sorting machine sorting system is shown in Figure 2, mainly by the air supply system, the flow control system, the pulsating airflow generator, The material device, the sorting column 13, the heavy product discharging device and the cyclone dust collector 17 are composed of components; the pulsating airflow converter is composed of a pulsating valve 5, a motor for controlling the pulsating valve and a frequency converter 6, and the pulsating frequency of the pulsating airflow is controlled by the frequency converter. Control; when the pulsating airflow sorting machine sorts the material of -2+1mm size grade, the material is fed into the sorting column 13 through the feeding device, the air is blown into the wind pack 2 by the blower 1, and after passing through the main damper after being stabilized The bypass damper adjusts the wind pressure and the air volume, and then converts it into a pulsating airflow of a desired waveform through a pulsating airflow converter; the pulsating airflow is uniformly fed into the sorting column 13 through the air blowing chamber 11 and the air distribution plate 12; an appropriate airflow At the pulsating frequency, the material in the sorting column 13 is stratified by density under the action of the pulsating airflow, and the particles with high density will continue to settle to the bottom of the sorting column due to the action of gravity and inertia; and the particles with low density are subjected to the airflow. Role The work rises and is finally taken out of the sorting column 13 by the airflow to achieve separation of high and low density materials. The feed size range of the equipment is 1 to 5 mm, the processing capacity is 10 to 50 kg/h, and the inner diameter of the sorting column is 100 mm. The height is 1000mm; the air distribution plate is composed of thick cotton fabric sandwiched between two layers of 5mm thick sponge-like filling material; the frequency range of the inverter output is 0-550Hz, and the precision is 0.01Hz;

/ power factor is greater than 0.95 / 0.72; control mode is V / f, V ² / f and FCC; rated power is 0.75kW, the length of the device dimensions × width × height is 68 × 142 × 127.8mm; working, pulsating airflow The speed is suitable for the adjustment range of 2~10cm/s, and the pulsation frequency is suitable for the range of 0~2.35Hz; the feed metal content of this embodiment is 34.57%, the pulsating airflow velocity is 8.5cm/s, and the pulsation frequency is 2.02Hz; After sorting, the metal grade of the metal rich group was 96.54%, and the metal recovery rate was 92.63%.

It is worth noting that the dense phase gas solid medium fluidized bed sorting -1 + 0.5mm size grade material, the dense phase gas solid weight medium fluidized bed sorting system is shown in Figure 3, mainly by fan, fluidized bed The bed body, the rotameter and the like are composed of components, wherein the fluidized bed body is mainly composed of a sorting bed body, an air distribution plate, an air distribution room and a base; the sorting room is made of plexiglass to observe the particles in the bed. The fluidized state is composed of a porous steel plate and a double-layer multifilament filter cloth, and the porous steel plate is covered with a multifilament filter cloth having a thickness of 0.5 to 1.5 mm, and the steel plate and the multifilament filter cloth are connected by a rubber pad and a bolt. The porous steel plate has a hole diameter of 3 mm and an opening ratio of 32.65%; the air distribution chamber is welded by a steel plate; a height scale is fixed on the side of the bed body, which can be used to calibrate the fluidized bed height and the sampling height; Lamination change, a pressure measurement point is set every 30~40mm on the side wall of the bed, and the pressure drop inside the bed is measured by the plug-in pressure measuring probe; the fluidized bed is sorted by dense phase gas solid medium - When 1+0.5mm grain size material, it will be heavier In the bed, the weight of the weight is 2/3 of the size of the bed, the air is blown into the wind bag by the blower, and after adjusting, the wind pressure and air volume are adjusted through the main damper and the bypass damper, and the airflow enters the air chamber. After evenly distributing the air, it enters the bed through the air distribution plate; by selecting a suitable air flow speed, the bed is subjected to heavy fluidization until the gas-solid contact is sufficient, and the fluidized bed has no good or fluidized state of fluidization, forming a good fluidization state. a sorting medium having a certain density and uniform stability; the feed material is fed into the fluidized bed layer from the top of the sorting bed body, and under the action of the gas stream, the feed material is gradually dispersed in the fluidized bed layer after entering the bed layer. And layered according to the density of the fluidized bed, the high density particles sink to the bottom of the bed, the low density particles float to the bed surface, and the high and low density materials are separated by the discharge device respectively; the device is for the circuit board The particle size range of the particles is 0.5-2 mm, the treatment capacity is 30-100 kg/h; the diameter of the sorting bed is 100 mm, the height is 300 mm, the experimental wind pressure is fixed at 0.02 MPa, and the gas velocity is suitable for the adjustment range of 6-13 cm/ s, the separation medium uses magnetite powder, particle size range 0.06 ~ 0.3mm. In this embodiment, the metal content of the feed is 54.14%; when sorting, the gas flow rate is 8.2 cm/s, and the weight quality is 15 kg; the metal grade of the metal rich group is 92.57%, and the metal recovery rate is 85.08%.

It is worth noting that the vibrating gas-solid heavy medium fluidized bed sorting -0.5+0.3mm granular grade material, vibrating gas-solid heavy medium fluidized bed sorting system is shown in Figure 4, mainly by fan 19, fluidized bed The body, the rotameter 22, the vibration table and the control system are composed of components, wherein the fluidized bed body is mainly composed of the sorting bed body 27, the air distribution plate 26, the air distribution room 25 and the base 24; the sorting room adopts organic The glass is processed to observe the fluidized state of the particles in the bed; the air distribution plate 26 is composed of a porous steel plate and a double-layer multifilament filter cloth, and the porous steel plate is covered with a multifilament filter cloth having a thickness of 0.5 to 1.5 mm, respectively. The multifilament filter cloth is connected by a rubber pad and a bolt, wherein the porous steel plate has a hole diameter of 3 mm and an opening ratio of 32.65%; the air distribution chamber 25 is welded by a steel plate; the height of the separation bed body 27 is fixed with a height scale, which can be used for calibrating the flow. Bed height and sampling height; in order to facilitate the measurement of bed lamination drop during fluidization, a pressure measuring point is set every 30 to 40 mm on the side wall of the bed, and the pressure drop inside the bed is measured by means of a plug-in pressure measuring probe. Change; when working, add 10kg weighting In the fluidized bed, the air is blown into the wind pack 20 by the blower 19, and after being regulated, the wind pressure and the air volume are adjusted through the main damper 21 and the bypass damper 23, and the airflow enters the air distribution chamber 25 and is uniformly ventilated and then passed through the air distribution plate. 26 enters the bed; by selecting the appropriate vibration parameters (amplitude, vibration frequency) and airflow velocity to make the aggravated mass fluidization until the gas-solid contact is sufficient, and there is no bubble or less bubble in the fluidized bed, forming a good fluidization state. A sorting medium having a certain density and uniform stability. The feed is fed into the fluidized bed from the top of the sorting bed. Under the action of vibration and gas flow, the feed is gradually dispersed in the fluidized bed after entering the bed, and according to the fluidized bed. The density is stratified, the high-density particles sink to the bottom of the bed, and the low-density particles float to the bed surface, and the high-low density materials are separated by the discharging device respectively; the feeding granularity of the device for the circuit board particles is 0.125. ~1mm, processing capacity is 30 ~ 80kg / h; sorting bed diameter is 110mm, height is 400mm, experimental wind pressure is fixed at 0.02MPa, gas speed is suitable for adjustment range is 4 ~ 10cm / s; amplitude suitable adjustment range is 0 ~4mm, the vibration frequency is suitable for the adjustment range of 0 ~ 40Hz; the separation medium is magnetite powder, the particle size range is 0.06 ~ 0.3mm; the feed metal content of this embodiment is 36.58% at a gas velocity of 6.8cm / s, Under the condition of amplitude of 3 mm and vibration frequency of 30 Hz, the metal grade of the metal-rich group was 90.24%, and the metal recovery rate was 79.06%.

It is worth noting that the high-voltage electrostatic sorting machine of the invention sorts the material of -0.3+0.125mm size grade, and the schematic diagram of the sorting system of the high-voltage electrostatic sorting machine is shown in Fig. 5, mainly by the feeding device 45, the corona electrode 48, the high voltage The static electrode 49, the roller and the product collection tank 51 are composed of components. When sorting is carried out using a high-voltage electrostatic sorting machine, the material is fed by the feeding device 45 at a certain rate, and is laid on the surface of the roller electrode which rotates clockwise at a certain rotation speed, and rotates therewith; the feed rate needs to be with the roller The rotation speed of the cylinder is adapted to ensure a single layer, uniform mixed particle layer is formed on the surface of the roller electrode; when the material enters the ionization region generated by the corona electrode 48, both the conductor particles and the non-conductor particles are charged; The difference in electrical properties, the negative charge obtained by the conductor particles is quickly transferred away by the charging roller; at the same time, the conductor particles are inductively induced by the electrostatic field generated by the high-voltage static electrode, and a positive charge is induced near one side thereof. Aside from the other side of it, a negative charge is induced, and the negative charge is quickly transferred away from the roller, so that only a positive charge remains on the conductor particles; for a non-conducting particle having a good dielectric property, the negative charge obtained is difficult. Passing away through the roller; when the charging process is completed, the conductor particles and non-conductor particles exhibit different motion trajectories under the electrostatic field generated by the high-voltage static electrode; the conductor particles are positively charged while the static electrode is negative. Electric, so the conductor particles are attracted by the static electrode due to the electrostatic force; at the same time, the conductor particles are also subjected to the centrifugal force of the roller movement and the tangential component of the gravity. Under the combined action of these forces, the conductor particles are fixed. The angle is detached from the surface of the roller and falls into the conductor product collection area; the non-conductor particles are tightly adsorbed on the surface of the roller due to the negative charge, and then rotateed, and finally removed by the roller brush to fall into the non-conductor product collection area, thereby realizing the conductor Separation of particulate and non-conducting particles. The equipment has a feeding particle size range of 0.04~3mm for the board particles, a processing capacity of 500-800kg/h, and a sorting precision higher than 90%; the sorting voltage is suitable for the range of 15~30kV, and the roller speed is suitable for adjustment. The range is 60-120 rpm, the deflection angle of the corona electrode is suitable for the range of 20°-35°, the distance between the corona electrode and the roller is suitably adjusted to 60-75mm, and the deflection angle of the high-voltage static electrode is suitable for the range of 60°-80. °, the distance between the high-pressure static electrode and the roller is suitably adjusted to be 80-95 mm; the content of the incoming metal in this embodiment is 34.57%; when the sorting voltage is 25 kV, the rotational speed of the roller is 80 rpm, and the deflection angle of the corona electrode is 25°. The distance between the corona electrode and the roller is 65mm, the deflection angle of the high-voltage static electrode is 75°, the distance between the high-pressure static electrode and the roller is 85mm; the metal grade of the metal-rich group obtained by sorting is 96.12%, and the metal recovery rate is 89.75%.

It is worth noting that the friction electric separator sorts -0.125+0.074mm grain size materials. The schematic diagram of the friction electric separator sorting system is shown in Fig. 6. It is mainly composed of a fan, an air volume controller 60, a feeding device 61, and a friction chamber 63. And high-pressure sorting room 65 and other components; when using a friction electric separator to sort -0.125 + 0.074mm size material, the air is blown in by the blower, the material is fed by the feeding device 61, under the appropriate air volume control, suitable The air volume refers to the feed air volume, and the air that is blown in forms a stable gas-solid two-phase flow with the feed material; the material and air form a uniform gas-solid two-phase flow into the friction chamber; through the particles and particles or between the particles and the friction chamber The mutual contact, friction and collision between the walls of the conductor, the conductor particles and the non-conductor particles are charged with opposite polarity and electric quantity due to the difference in dielectric properties. The final conductor particles are positively charged, and the non-conductor particles are negatively charged; The charged particles coming out of the chamber enter the high-pressure sorting chamber through the nozzle. Under the combined action of the electric field force, the particle's own gravity and the wind, the conductor particles and the non-conductor particles exhibit different motion trajectories and are positively charged. The conductor particles move toward the negative plate, and the negatively charged non-conductor particles move toward the positive plate, thereby separating the conductor particles and the non-conductor particles; the feeding size of the device ranges from 0 to 0.2 mm, and the processing capacity is 80 to 120 kg. /h, the sorting precision is higher than 85%, the experimental voltage is suitable for the adjustment range of 0 to 40kV, and the air volume is suitable for the operation range of 10 to 90m ³ /h; the feed metal content of this embodiment is 18.56%, when the sorting voltage is 8kV When the air volume is 22m ³ /h, the metal grade of the metal-rich group obtained by sorting is 89.77%, and the metal recovery rate is 73.90%.

It is worth noting that the cyclone separator sorts -0.074mm size grade material. The schematic diagram of the cyclone separator sorting system is shown in Figure 7. It is mainly composed of the feeding device 70, the sorting chamber 73, the discharge port 72 and the like; When the cyclone separator sorts the material of -0.074 mm size, the material is fed into the sorting chamber 73 by the feeding device 70. Under the action of the inertial centrifugal force, the heavy component particles enter the downward moving outer swirl due to the high density. Moving toward the wall and moving with the external swirl to the heavy component discharge port 76; the light component particles enter the upwardly moving internal swirl due to the low density, and are discharged through the light component discharge port 72, thereby achieving light reorganization The separation of the particles; the feeding size range of the equipment is 0-0.1mm, the processing capacity is 400-800kg/h, the sorting precision is higher than 95%; the inlet wind speed is suitable for the adjustment range of 12-18m/s; the diameter of the cylindrical section 300mm, height 500mm, cone height 550mm; inlet height 162mm, width 77mm; light component discharge opening diameter 145mm, light component discharge tube inserted into the cylindrical section depth 410mm, heavy component The discharge opening has a diameter of 115 mm. The feed metal content of the present embodiment is 3.92%; at the time of sorting, the inlet wind speed is 15 m/s; the metal grade of the metal rich group is 94.52%, and the metal recovery rate is 83.18%.

It is worth noting that the present invention recovers the recovered metal rich group, and uses a dry magnetic separator to recover the magnetic substances iron, cobalt and nickel in the metal rich group; the acid leaching method and the electrolytic method are used to recover the metal rich group. Copper and silver; gold, platinum and palladium in the metal rich group are recovered by aqua regia dissolution method and extraction method;

It is worth noting that the present invention uses the recovered non-metal rich group for preparing modified asphalt, filling material as composite material, heat treatment to prepare activated carbon and porous silicate.

The invention discloses a dry sorting and recycling process for valuable components in a waste circuit board, first disassembling the discarded circuit board, and then crushing and sifting the disassembled bare board of the discarded circuit board, and then using the combined use Different sorting equipment can sort the materials of different size grades, which can give full play to the advantages of each sorting equipment, improve the sorting effect, and improve the quality of metal rich collective products and metal recovery rate.

The above is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or within the technical scope disclosed by the present invention. Alternatives are intended to be covered by the scope of the present invention.

Claims

A dry sorting and recycling process for valuable components in a waste circuit board, characterized in that it mainly comprises the following steps:

Step 1. Disassemble the discarded circuit board to obtain the disassembled bare board of the discarded circuit board;

Step 2: removing the solder from the bare board of the discarded circuit board;

Step 3: performing dry coarse crushing and dry fine crushing on the bare board of the discarded circuit board after removing the solder to obtain the waste circuit board particles;

Step 4: feeding the waste circuit board particles into the dry vibration multi-layer grading sieve for sieving and grading, and obtaining the granularity levels of -2+1 mm, -1+0.5 mm, -0.5+0.3 mm, -0.3+0.125 mm, - 0.125+0.074mm and -0.074mm materials;

Step 5: The above-mentioned granular grade materials are separately fed into different dry physical physical sorting equipments for sorting, respectively, to obtain metal rich collectives and non-metal rich collectives;

Step 6. Collect the metal rich group and the non-metal rich group separately sorted by each device.
The dry sorting and recycling process for a valuable component in a waste circuit board according to claim 1, wherein in the step 1, the components obtained by disassembling the discarded circuit board are sequentially passed through the components. Classification and component performance testing are classified; in the second step, the tin slag obtained by removing the solder is sequentially subjected to smelting and refining to obtain a solder conforming to national standards.
A dry sorting and recycling process for a valuable component in a waste circuit board according to claim 1 or 2, wherein in the step 3, a dry double-toothed roller crusher and a dry high speed are used. The impact pulverizer performs dry coarse smashing and dry smashing on the bare board of the discarded circuit board after removing the solder.
A dry sorting and recycling process for a valuable component in a waste circuit board according to claim 3, wherein in the step 3, the particle size of the discarded circuit board obtained by the dry crushing Less than 20 mm, the dry circuit board obtained after the dry crushing has a particle size of less than 2 mm.
A dry sorting and recycling process for a valuable component in a waste circuit board according to claim 4, wherein in the step 3, an industrial vacuum cleaner is used in the dry coarse crushing and the dry crushing process. Dust removal.
A dry sorting and recycling process for a valuable component in a waste circuit board according to claim 5, wherein in the step 4, the sieve size of the dry vibrating multi-layered sieve is from top to bottom 2mm, 1mm, 0.5mm, 0.3mm, 0.125mm and 0.074mm in sequence; the vibrating motor of the dry vibration multi-layer grading screen has a suitable adjustment range of 300-960 times/min, and the amplitude is suitably adjusted to 4 ~ 8mm, the vibration direction angle is suitable for the adjustment range of 45 ° ~ 60 °.
A dry sorting and recycling process for a valuable component in a waste circuit board according to claim 6, wherein in the step 5, the material having a grain size of -2+1 mm is fed into the pulsating airflow. Sorting machine for sorting, the pulsating airflow sorting machine has a feeding particle size ranging from 1 to 5 mm, a suitable gas velocity adjusting range of 2 to 10 cm/s, and a suitable pulsating frequency of 0 to 2.35 Hz;

The material having a particle size level of -1+0.5 mm is subjected to sorting into a fluidized bed of a dense phase gas-solid medium medium, and the particle size range of the dense phase gas-solid medium fluidized bed for the circuit board particles is 0.5 ～2mm, suitable gas velocity adjustment range is 6～13cm/s; magnetization ore powder is used for sorting medium, and the particle size range of the magnetite powder is 0.06～0.3mm;

The material with a particle size of -0.5+0.3 mm is fed into a vibrating gas-solid medium fluidized bed for sorting, and the vibrating gas-solid medium fluidized bed has a particle size range of 0.125 to 1 mm for the circuit board particles. The gas velocity is suitable for the adjustment range of 4 to 10 cm/s; the amplitude is suitable for the adjustment range of 0 to 4 mm, and the vibration frequency is suitable for the adjustment range of 0 to 40 Hz; the separation medium is selected from magnetite ore, and the size range of the magnetite powder is selected. 0.06 to 0.3 mm;

The material with a particle size of -0.3+0.125 mm is sorted into a high-voltage electrostatic sorting machine, and the high-pressure electrostatic sorting machine has a feeding particle size range of 0.04 to 3 mm for the circuit board particles, and the sorting voltage is appropriately adjusted. The range is 15 ~ 30kV, the roller speed is suitable for the range of 60 ~ 120rpm, the corona electrode deflection angle is suitable for the range of 20 ° ~ 35 °, the distance between the corona electrode and the roller is suitable for the range of 60 ~ 75mm, high voltage static The range of the polar deflection angle is suitably adjusted from 60° to 80°, and the distance between the high-pressure static electrode and the roller is suitably adjusted to be 80-95 mm;

The material with the particle size level of -0.125+0.074mm is fed into the friction electric separator for sorting. The particle size range of the friction electric separator is 0-0.2 mm, and the suitable voltage range is 0-40 kV, and the air volume is suitable. The operating range is 10 to 90 m3/h;

The material with a particle size of -0.074 mm is sorted into a cyclone separator. The particle size range of the cyclone separator is 0-0.1 mm, and the inlet wind speed is suitably adjusted to be 12-18 m/s.
A dry sorting and recycling process for a valuable component in a waste circuit board according to claim 7, wherein the metal rich group sorted in the step 6 is recovered by a dry magnetic separator Magnetic substance; copper and silver in the metal rich group are recovered by acid leaching method and electrolytic method; gold, platinum and palladium in the metal rich group are recovered by aqua regia dissolution method and extraction method.
A dry sorting recovery process for valuable components in a waste circuit board according to claim 8, wherein said magnetic substance is mainly iron, cobalt and nickel.
A dry sorting and recycling process for valuable components in a waste circuit board according to claim 9, wherein the non-metal rich group sorted in the step 6 can be used for preparing modified asphalt, as Activated carbon and porous silicate are prepared by filling materials and heat treatment of composite materials.