Innovative recycling of building material (2) 2.4_IBP...MVA slags are hydraulically reactive and...
Transcript of Innovative recycling of building material (2) 2.4_IBP...MVA slags are hydraulically reactive and...
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INNOVATIVE BUILDING MATERIAL RECYCLING
June 25th, 2013
Andreas Kaufmann
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The life cycle as a basis
utilization phaserecycling
precursors productionmanufacturing
disposal
resource extraction
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Wolfgang Staudt
Future issue for the construction industryRecyclability
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Why recycling for the building sector?
� Careful use of limited resources
� Dumping space becomes scarce
� Resources are and will be causes of conflicts
� Redemption Regulation for the building industry is imminent
� The industrial countries are rich in resources (not in the earth but in dumping spaces)
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Facts about concrete
� Most used material worldwide next to water
� 2 billion tonnes of concrete waste worldwide every year
� Problems in re-using secondary aggregate
� No cycle of material for concrete
� The actual recycling rate for concrete is below 4%
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End-of-life usage of concrete until now
Reduction with the Jaw Crusher
No re-cycling but down-cycling
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New recycling method: electrodynamic fragmentation
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Principle of electrodynamic fragmentation
� Pulsed power processing
Voltage:
90 – 200 kV
Amperage:
6 – 20 kA
Energy of pulse:
10 – 100 J
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Principle of electrodynamic fragmentation
� Electro-physical Effect:
� electrical breakdown resistance of solids against a high voltage discharge depends on the pulse length!
� If the pulse length is below 500 nsec, the discharge will preferably run through the solid and not through the water!
Pulse length [nsec]
� Origin of the process:
� The method was developed in the 50s at the University of Tomsk (RUS)
� Developments and patenting at the Researchcenter Karlsruhe (FZK)
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� Preferably the electrical breakdown runs at phase boundaries, the resulting plasma channel T ~ 104 K generates, a pressure wave with about 1010 Pa.
� The pressure wave is reflected by the vascular wall and generates a compression wave, which increases the exposure of the components
inhomogenuous
electric field
generation of
streamersplasma channel
expansion of
plasma channel
compression
shock waves
Principle of electrodynamic fragmentation
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H2O
H2O
Christof Karlstetter Fraunhofer IBP Holzkirchen
Principle of electrodynamic fragmentation
� Polarization caused field enhancement material interfaces
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H2
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H2
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Principle of electrodynamic fragmentation
� Use streamer field increases as signposts along phase boundaries
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H2
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H2
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� Pulsed power processing: Plasma & shock wave weaken and crushes the material
Principle of electrodynamic fragmentation
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Separation of concrete
Old concrete fragments on IBP laboratory plant:
U = 180 kV
f = 5 Hz
Duration: 20 sec
Throughput: 250 g / sec
Old concrete before and after fragmentation; Products were dried and sieved. The fine fraction is derived from process water and consists mostly of limestone.
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Separation of concrete
1st German fragmentation plant (1985)
Modern fragmentation lab plant (2011)
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Through an electrodynamic fragmentation even steel fibers can be exposed from old concrete
Separation of concrete
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Freshconcrete
Cementadditive
Raw material forcement production
Separation of concrete
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Supplier of waste concrete
Electrodynamic Fragmentation & Water processing plant
Fine fraction:Calcite rich fraction
Coarse fraction:Aggregate, gravel
Cement producersReady-mix concrete
construction
Ready-mix concreteplants,Roadconstruction
Separation of concrete: recycling chain
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Upscaling of fragmentation plants
� Goal:
Throughput rate for fragmented waste concrete of approx. 20 tonnes / hour
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Upscaling of fragmentation plants
Frequency:
40 - 60 Hz
Pulse time:
120 nsec
Throughput per module:
3,6 t / h
Throughput in total :
ca. 20 t / h
� Industrial – Plant (expected in 2015)
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Goal of current project:
The combination of bothplants!
Frequency: 20 – 40 Hz
Throughput: 3 t / h
Energy: 3 – 4 kWh / t
Upscaling of fragmentation plants
� Prototype of a continuously running fragmentation plant
� Industrial plant for recyclingfresh concrete
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Domestic waste before incineration Domestic waste after incineration
Fragmentation of waste incineration ashes
� Amount of waste incineration ashes:
� In Germany: 4.5 million t / a, worldwide: 350 million t / a, as estimated in 2015: 420 million t / a
� Approx. 10% of ferrous and non-ferrous metals are removed, the majority remains on the disposal
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Fragmentation of waste incineration ashes
� MVA slags are hydraulically reactive and form resistance forming CSH phases, but there are following problems by a wide use as a building material :
� high content of heavy metals
� Content of chlorides and sulfates
� Content of metallic iron and aluminum
� Content of organics
� Strong fluctuations of the output pockets
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Fragmentation of waste incineration ashes
� Main components all coarse fractions (> 2 mm) are ceramics, glass, enamel products, metals, fine fractions appear to be different
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Fragmentation of waste incineration ashes
� MVA-melting products are also exported to fragmentation still hydraulically active and react similar to cementitious systems. Potential as a cement grinding additive or substitute.
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Fragmentation of metallic coatings
� Metal layers can separate very well from non-ferrous metals
� Other polymers go through the process into dilution, this polymer (ABS) is an exception
� First gropings for electroplating products, chrome plated automotive parts, were conducted
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Current industrial state
� Costs
� running costs 5-13 € / t (depending on material)
� Investments:
� 1-3 tons/hour: about € 1.2 million
� 20-30 tons/hour : approximately € 2.5 million
� to 100 tons/hour : about 9 million €
Plant for 1tons/hour
Plant for 30tons/hour (plannedfor 2014)