A kind of old circuit board method for innocent treatment and device
Technical field
The present invention relates to old circuit board recovery technology fields, and in particular to a kind of old circuit board method for innocent treatment
And device.
Background technique
On the one hand significant components of the waste and old printed circuit board as electron wastes both contain lead, cadmium, polyvinyl chloride plastic
The various heavies such as material, brominated flame retardant and harmful substance, there are potential environmental pollutions;On the other hand contain copper, gold, silver again
Etc. a variety of common metals and rare precious metal, recycling value with higher.
With the implementation of China's strategy of sustainable development, to environmental protection, more stringent requirements are proposed, and electronic waste returns
The thorny problem received and faced using majority state is become.China has become the production and consumption big country of household electrical appliance at present, only
2% calculating is updated to scrap in year, 4 superseded major class household electrical appliance use just up to 20,000,000 in addition popularizing in the whole society every year
Update cycle there was only the high-tech electronics product such as the computer of 2-4, mobile phone, and continue to bring out super quality and competitive price novel family
Electric product, so that the update of scrapping in practical year of China's household electrical appliance has been up to 25,000,000 or more.Printed circuit board (PCB) conduct
Critical component in waste household appliances, recycling and recycling problem have become hot issue urgently to be solved.In addition, by mesh
Before, Nei Diyou printed circuit board manufacturing enterprise, China 1000 or so, PCB in China yield in 2006 is 129,640,000 m2, annual value of production
12800000000 dollars, have become the first mass production of PCB state, a large amount of leftover pieces in production process, the recycling for scrapping plate also face weight
Hang-up.
Waste and old printed circuit board is the mixture of glass fiber reinforced plastics and various metals, belongs to typical electronic waste
Object, a large amount of leftover bits that old circuit board growing day by day is generated plus production circuit board, if not dealing carefully with and disposing,
It not only will cause being largely lost for useful resources, and serious harm can be generated to environment.Tradition is stacked or the method for landfill,
A large amount of spaces are not only taken up, and contained heavy metal such as mercury, chromium, cadmium etc. and macromolecule organic are difficult to drop under field conditions (factors)
Solution, harmful components can enter environment by water, atmosphere, soil, can cause to human health and ecological environment potential, long-term
With expendable harm, lead contained therein is the second largest source of lead in municipal waste." old circuit board " is not " useless
Object ", but untapped " Secondary resource " have very high recycling value.Metal content in circuit board is equivalent to
Tens times of metal content to hundreds of times, the content of metal are up to 40% in common mineral, and most is copper, in addition there are gold,
Aluminium, nickel, lead, silicon metal etc., wherein being no lack of rare metal;And rich ore tenor in nature super only 3%~5%.Have
Statistical data shows that 1t useless circuit board can extract the gold of 300g or so.The substances such as scolding tin and plastics on printed circuit board,
And the valuable source that can be recycled.Therefore, research and development harmless treatment useless circuit board technology has become regeneration
The key subjects of resources domain.
Effective processing is implemented to the wiring board scrapped and resource utilization utilizes, can be slowed down significantly to Resources
Consumption mitigates environmental pollution, and to resource-conserving and environment-friendly society is established, developing a circular economy, it is positive to have the function of
With important meaning.
The main processing technique of old circuit board at present: pyrometallurgy, hydrometallurgy, physical method.
Noble metal is extracted in pyrometallurgy has the characteristics that simple, the convenient and rate of recovery is high, but since there are organic matters to exist
The disadvantages of pernicious gas causes secondary pollution, other metal recovery rates are low, processing equipment is expensive is generated in burning process;
It is more common, the extraction noble metal from Waste ammunition technology that wet process, which controls technology for gold, and wet process controls technology for gold
Basic principle be mainly the feature of nitric acid and chloroazotic acid etc. of capable of being dissolved in using noble metal, it is removed from Waste ammunition
And it is recycled from liquid phase.Compared with pyrogenic process, wet process control technology for gold discharge exhaust gas it is relatively fewer, extract noble metal after it is residual
Object is stayed to be also easy to handle, but the waste liquid generated is more, the complex treatment process of waste liquid, cost is very high.Environment is caused certain
Potential threat
Physical treatment method mainly includes the multiple technologies such as Mechanical Crushing, elutriation and magnetic absorption.Currently, physics
Processing method is mainly used for the recycling of metal such as aluminium, copper, as the U.S. is returned from the PCB of PC using strength rotational flow sorting machine
Aluminium is received, by controlling charging rate, the purity of gained aluminium concentrate is 85%, and the rate of recovery is 90% or more;Sweden utilizes electronic rolling
Cylinder electrostatic separator recycles copper, and by design and operation parameter optimization, the grade of gained copper concentrate is 93%~99%, the rate of recovery
Up to 95%~99%.The country is mainly come the metal and Fei Jin in separating waste, worn electronic product using physical treatment method at present
Belong to.But above-mentioned physical method can only handle the circuit board without component.For the circuit board with component because it has above
Various electronic components, the currently used method by melting the method handling components of tin, belong to manual operations, working efficiency
Low, the molten tin exhaust gas of generation, complex treatment process, processing cost is higher, and very big potential threat is generated to environment.
Summary of the invention
For overcome the deficiencies in the prior art, the purpose of the present invention is intended to provide a kind of old circuit board processing method and dress
It sets, to solve existing old circuit board poor recovery effect, seriously polluted problem.
Technical scheme is as follows:
A kind of old circuit board method for innocent treatment is provided, comprising the following steps:
Step 1: broken: old circuit board is crushed;
Step 2: screening: broken old circuit board being sieved, filters out particle diameter less than 20mm~40mm
Broken material;
Step 3: cracking: broken material feeding pyrolysis oven being cracked, broken material obtains mixed metal after cracking
Slag and exhaust gas;
Step 4: metal recovery: mixed metal slag being cooled down, sieves, filters out mixed metal product;
Step 5: exhaust-gas treatment: the exhaust gas of the generation of step 3 being burnt, is purified, dedusting, makes its qualified discharge.
Wherein, in the step 3, after broken material enters pyrolysis oven, pass through six layers of cracking room from top to bottom in burner hearth
It cracks, under the raking for the rake arms being arranged by every layer, makes the motion profile helically formula decline of broken material.
Wherein, the temperature in six layers of cracking room from top to bottom be respectively 480~500 DEG C, 450~480 DEG C, 430~
450 DEG C, 400~430 DEG C, 350~400 DEG C, 300~350 DEG C.
Wherein, it in the step 5, burns for exhaust gas through dual firing chamber's second-time burning, temperature is 900~1150 DEG C, when burning
Between 2~5s.
It wherein, further include dilution step in the step 5, it is dilute to air blast is carried out by the burned exhaust gas of dual firing chamber
It releases.
Wherein, urea is sprayed to the exhaust gas after air blast dilution, specially sprays the urea of mass percent 28%~35%
Solution.
Wherein, the waste gas recovery heat for having sprayed urea liquid is cooled down, exhaust gas temperature is made to be down to 180~220 DEG C.
It wherein, further include that NaHCO is sprayed into exhaust gas in the step 53Powder.
Wherein, the step 5 further includes that active carbon is sprayed into exhaust gas.
Wherein, in the step 5, dedusting is that exhaust gas is sent into bag filter dedusting, is then discharged out.
Another goal of the invention of the invention is:
A kind of old circuit board processing unit, including feeding machanism, pyrolysis oven, metal recovery mechanism and exhaust gas processor
Structure, the feeding machanism include crushing mechanism and vibrating screen, and the crushing mechanism is used to be fed to the vibrating screen, the vibration
For sieve for being fed to the pyrolysis oven, the mixed metal slag of the pyrolysis oven is sent into metal recovery mechanism, and the pyrolysis oven gives up
Pneumatic transmission enters waste gas recovery mechanism.
Wherein, the pyrolysis oven includes feed inlet, furnace body, rake arms, main shaft, six layers of cracking room and discharge port, and described six layers
Cracking room is from top to bottom arranged and is set in furnace body, and the feed inlet is set to the top of furnace body, and the discharge port is set to institute
The lower part of furnace body is stated, every layer of cracking room is provided with rake arms, and main shaft and the rake arms are drivingly connected, and the rake arms is used for will
The conveying of material downward spiral, passes sequentially through six layers of cracking room, the feeding machanism is fed to the feed inlet, the pyrolysis oven
Discharge port is fed to the metal recovery mechanism.
Wherein, the metal recovery mechanism includes the first screw feeding device and the second screw feeding device, first screw rod
Feed appliance, the second screw feeding device are provided with the cooling spiral for coolant liquid, and the cooling spiral is provided with for air-cooled
The air cooling mechanism of coolant liquid.
Wherein, the waste gas recovery mechanism includes diluting for burning waste gas dual firing chamber, for air blast, spraying urea
Exhaust steam passage, is provided with sodium bicarbonate powder spraying mechanism and active carbon spraying mechanism at the waste heat boiler for recycling heat
Exhaust gases passes, bag filter and chimney, the exhaust gas successively pass through dual firing chamber, exhaust steam passage, waste heat boiler, exhaust gases passes and
Bag filter is discharged through chimney.
Beneficial effects of the present invention are as follows:
It sub-elects short grained material by the way that circuit board to be crushed and screen using treatment process of the invention and is sent into heat
Solution furnace is cracked, and the recyclable metal component of old circuit board is decomposited, and by cooling and screening, metal is separated, is obtained
To metal recovery product, the exhaust gas in cracking process makes its qualified discharge by burning, dilution, dedusting, and recovery efficiency is high,
Cracking temperature can effectively separate the resin of low melting point and dystectic metal, and the exhaust gas for cracking generation is also located
Reason, good separating effect are environment friendly and pollution-free.
Detailed description of the invention
Fig. 1 is a kind of flow diagram of old circuit board method for innocent treatment of the invention.
Fig. 2 is a kind of structural schematic diagram of old circuit board processing unit of the invention.
Appended drawing reference is as follows:
1 level-one crushing mechanism, 2 two-stage crushing mechanisms, 3 pyrolysis ovens, 4 dual firing chamber,
5 urea spraying mechanisms, 6 emergency chimneys, 7 waste heat boilers,
8 exhaust gases passes, 801 sodium bicarbonate powder spraying mechanisms, 802 active carbon spraying mechanisms,
9 bag-type dust mechanisms, 10 blowers, 11 chimneys.
Specific embodiment
In order to make the objectives, technical solutions, and advantages of the present invention clearer, with reference to the accompanying drawings and embodiments, right
The present invention is further elaborated.It should be appreciated that the specific embodiments described herein are merely illustrative of the present invention, and
It is not used in the restriction present invention.
Embodiment one,
A kind of old circuit board method for innocent treatment, comprising the following steps:
Step 1: being crushed, being crushed old circuit board;Step 2: screening, being sent into broken old circuit board
Vibrating screen is sieved, and the broken material that particle diameter is less than 20mm is filtered out;Step 3: by broken material be sent into pyrolysis oven into
Row cracking, 350~500 DEG C of cracking temperature, pyrolysis time 20~40 minutes, broken material obtained after cracking mixed metal slag and
Exhaust gas;Step 4: mixed metal slag is cooled down, it is sent into rotary screen, is sieved, filters out oversize and minus mesh;Step
Rapid five, the exhaust gas of the generation of step 3 burnt, diluted, dedusting, make its qualified discharge.
Crushing process in the present invention is to improve lysis efficiency to make the more thorough of material cracking, is crushed and screens
It is divided into two parts, precrushing and primary screening, old circuit board is decomposed in fine broken and postsearch screening, precrushing, once
40mm material below is sifted out, the material that then will be greater than 40mm or more carries out repeating to be crushed, and fine be crushed will once sieve
The 40mm selected material below is crushed, and is then fed into postsearch screening device and is sieved, and 20mm object below is filtered out
Material is sent into pyrolysis oven and carries out Pintsch process.
Cracking is completed in pyrolysis oven, and specifically in the case where oxygen supply is insufficient, (old circuit board is from furnace roof
Portion is added in burner hearth, and main shaft drives every layer of rake arms to move, and conveys material successively from top to bottom;In described six layers by up to
Under temperature be respectively 480~500 DEG C, 450~480 DEG C, 430~450 DEG C, 400~430 DEG C, 350~400 DEG C, 300~350
DEG C, first layer is provided with 4 heating points, is distributed in the surrounding of first layer cracking room, and the second layer is provided with two to every layer of layer 6
A heating point, it is symmetrical.
The setting mode that temperature is successively decreased step by step from top to bottom in burner hearth, so that negative pressure is formed in burner hearth from top to bottom, due to
Upper layer temperature is high, and hot gas moves upwards output, and underlying gas receives the heat on upper layer since negative pressure also moves upwards
Transmitting successively rises, so that furnace gas will not reunite, and prevent gather qi together in furnace, generate the danger of explosion.
In cracking technology, following variation is mainly had occurred in old circuit board in pyrolysis oven: under the conditions of high temperature anaerobic
CO, CO are generated by the resin cracking of bigger molecule2, hydro carbons and derivative, aromatic compound and its derivative, ethers, phenols
Equal small-molecule substances, in addition the catalytic action for the metal being precipitated in old circuit board, occurs C-Cl, C-Br, C-C, N-CH2、O-
CH2The fracture of key, these small molecules all have lower boiling point, are discharged in gaseous form out of burner hearth.
The mode for the transmission of laminar from top to bottom being arranged in furnace makes the reaction time in burner hearth of the old circuit board after sieving
Increasing, under the raking of each layer rake arms, material is pushed constantly to be moved, the resin in old circuit board is constantly broken up,
It cannot reunite, be heated evenly, reaction thoroughly, it is hardened to be not easy accumulation generation.
Waste gas treatment process is as follows:
Old circuit board contains a large amount of dioxin in cracking in the exhaust gas of generation, dioxin is carcinogen, first will
Exhaust gas is sent into dual firing chamber and burns, and 900~1150 DEG C of ignition temperature, high temperature makes inflammable and explosive and toxic gas burn
Completely;In addition, the burning of this portion gas can maintain the temperature of dual firing chamber, the usage amount of natural gas is reduced;
High-temp combustion eliminates the dioxin in exhaust gas, and then the flue gas of high temperature makes the temperature of exhaust gas by carry out air blast dilution
Degree is down to 900 DEG C of optimal reaction temperature of urea spray denitrification, while also reducing nitrogen oxides, the hydrogen halides in exhaust gas
The concentration of equal substances sprays urea liquid into exhaust gas, and the concentration of urea liquid is 28%~35%, reacts more thorough, has
Effect eliminate nitrogen oxides in exhaust gas, it is sprayed after, exhaust gas, which is sent into waste heat boiler recycling heat, can also reduce by two evils
The generation of English avoids generating load to subsequent exhaust-gas treatment, and the conveying of high-temperature flue gas has strict requirements, carries out waste heat herein
After recycling, flue-gas temperature is made to be reduced to 180-220 DEG C, is the optimal reaction temperature that sodium bicarbonate injection removes HCl.It can effectively save
About subsequent piping cost, continues with convenient for exhaust gas, and after exhaust gas cooling, sodium bicarbonate powder and active powdered carbon are sprayed to it
End, neutralizes the pollutants such as the hydrogen halides in exhaust gas, while active carbon powder also two evils imperfect combustion in adsorbable exhaust gas
Heroic spirit body, dioxin gas that is unburned complete or regenerating at waste heat boiler are then fed into cloth bag with deodorization
After deduster dedusting, qualified discharge.
The flue-gas temperature of dual firing chamber's discharge is at 1100 degree or more first, and temperature is higher, from flue material thermal resistance side
Face considers, must carry out air blast first and be diluted, to reduce flue-gas temperature;After air blast dilution, flue-gas temperature is reduced to 900 degree of left sides
The right side is based on NH3The considerations of in terms of the kinetics of nitrogen oxides reduction, urea is sprayed under the conditions of this temperature, facilitated anti-
Should carry out.
Under the high temperature conditions, the NH generated is decomposed using urea3To NOXSelective catalytic reduction is carried out, by NOxIt is reduced to
N2And H2O, main chemical reactions are as follows:
CO(NH2)2→NH3+HNCO
HNCO+H2O→NH3+CO2
NH3+NO+O2→N2+H2O
NH3+NO2→N2+H2O
Present invention uses two kinds of techniques of metal recovery and exhaust-gas treatment, are used in combination, greatly improve waste and old route
The active principle of plate recycles, i.e., precious metal recycles, and efficiently solves Pintsch process circuit board by waste gas treatment process and is produced
Raw exhaust gas, can be up to state standards discharge.
Embodiment 2
A kind of old circuit board processing unit, as shown in Fig. 2, including crushing mechanism, vibrating screen, pyrolysis oven 3, metal recovery
Mechanism and waste gas treatment mechanism, the crushing mechanism are used to be fed to the vibrating screen, and the crushing mechanism includes that level-one is broken
Mechanism 1 and two-stage crushing mechanism 2 are provided with vibrating screen below the level-one crushing mechanism 1, set below the second-time breakage mechanism
It is equipped with vibrating screen, the used by oscillating screen is fed in the pyrolysis oven 3, and the mixed metal slag of the pyrolysis oven 3 is sent into metal and is returned
Mechanism is received, the exhaust gas of the pyrolysis oven 3 is sent into waste gas recovery mechanism.
Using processing unit of the invention, can effectively be recycled by old circuit board Pintsch process, and by metal mixture,
Exhaust gas feeding waste gas recovery mechanism is handled, its qualified discharge is made.
Urea liquid of the invention can also be 28%, 29%, 32%, 32.5%, 35%, and the content of urea liquid is root
It is adjusted according to the content of nitrogen oxides, halide in exhaust gas, the fluid reservoir of allotment solution is equipped in urea spraying mechanism,
By nitrogen oxides, the hydrogen halide content in detection exhaust gas, the concentration of urea liquid is adjusted in time according to content.
It is provided with the vibrating screen that aperture is 50mm below the level-one crushing mechanism 1, is provided with below two-stage crushing mechanism 2
The vibrating screen of aperture 20mm.Feeding speed is effectively increased by recursher screening, it is less to avoid primary screening discharging,
Consume energy big problem.
Specifically, the pyrolysis oven 3 include feed inlet, furnace body, rake arms, main shaft, six layers of cracking room and discharge port, described six
Layer cracking room, which is from top to bottom arranged, to be set in furnace body, and the feed inlet is set to the top of furnace body, and the discharge port is set to
The lower part of the furnace body, every layer of cracking room are provided with rake arms, and main shaft and the rake arms are drivingly connected, and the rake arms is used for
Material downward spiral is conveyed, six layers of cracking room are passed sequentially through.
The metal recovery mechanism includes the first screw feeding device and the second screw feeding device, first screw feeding
Device, the second screw feeding device are provided with the cooling spiral for coolant liquid, and the cooling spiral is provided with for air-cooled cooling
The air cooling mechanism of liquid.
There are one urgent discharge ports after cooling, when downstream system equipment failure, from urgent discharge hole for discharge.
The waste gas recovery mechanism include for burning waste gas dual firing chamber 4, for the diluted dilution chamber of air blast, be provided with urine
Plain spraying mechanism 5, waste heat boiler 7, the flue gas for being provided with sodium bicarbonate powder spraying mechanism 801 and active carbon spraying mechanism 802
Channel, dedusting mechanism, the exhaust gas successively pass through dual firing chamber 4, dilution chamber, urea spraying mechanism 5, waste heat boiler 7, exhaust gases passes
It is discharged with bag-type dust mechanism 9.
Nozzle, connected also charging, pressurization, conveying device are set on exhaust piping wall.
Sodium bicarbonate powder spraying mechanism 801 of the invention, active carbon spraying mechanism 802 can be using in exhaust pipings
Upper installation nozzle realizes that sprinkling process, structure are simply easily achieved and safeguard.
The present invention can also be provided with emergency chimney 6 between urea spraying mechanism 5 and waste heat boiler 7, due to dual firing chamber
High-temperature flue gas out still has high temperature, can all generate biggish pressure to subsequent mechanism after dilution, when
When subsequent 8 part of exhaust gases passes is broken down, high-temperature flue gas can be discharged by emergency chimney 6, avoid production development thing
Therefore.
Expect platform, level-one crushing mechanism 1, two-stage crushing mechanism 2, between pyrolysis oven 3 by spiral conveyor connection, spiral transferring
Band is sent to be provided with cover board;Cover board is installed additional on first screw feeding device and the second screw feeding device, and the position of feeding, which is sealed, to be set
Meter makes material from when entering workshop, and to being finally recovered out mixed metal slag, whole process sealing, without dust pollution is avoided pair
In the pollution of production environment.
Depression dust-removing mechanism can also be arranged in the present invention, and depression dust-removing mechanism is set to screw rod transmission band, absorb dust.
The foregoing is only a preferred embodiment of the present invention, but scope of protection of the present invention is not limited thereto,
In the technical scope disclosed by the present invention, any changes or substitutions that can be easily thought of by anyone skilled in the art,
It should be covered by the protection scope of the present invention.Therefore, protection scope of the present invention should be with scope of protection of the claims
Subject to.