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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

O

H2

O

Principle of electrodynamic fragmentation

� Use streamer field increases as signposts along phase boundaries

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H2

O

H2

O

� 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)