Municipal solid waste incineration (MSWI) bottom ash‐Characterization, treatments, application 

P. TANG

M.V.A. Florea

H.J.H. Brouwers Eindhoven University of Technology

1. MSWI bottom ash Wednesday, 29 June 2016

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Waste‐to‐energy plant Waste storage before incineration

Scheme  of  the incineration system

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Municipal solid waste incineration 

1) Reduction of solid waste2) Generation of energy3) Production of combustion residues 4) Poor physical and chemical properties 

Building material development

1) Consumption of raw materials2) Environmental pollution 3) Energy consumption4) Reuse and recycling of materials

??Environment Economy

Sustainable development

2. Motivation

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3. Characterization Wednesday, 29 June 2016

General treatments 

• Separation – clean coarse aggregate

• Fine fraction – higher amount of 

contaminants 

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Influence on cement hydration (binder substitute)

3. Characterization

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Influence on mortar strength (sand replacement)

3. Characterization

7 Wednesday, 29 June 20164. Treatment

8 Wednesday, 29 June 20164. Treatment

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9 4. Treatments

Washing 

Remove of soluble salts (chloride, sulphate) 

Thermal treatment 

Reduction of heavy metals leaching (Cu, Sb, etc.) 

Chemical extraction

Extraction and recycle of metals 

Pelletization

Recycle and reuse of fine bottom ash to produce artificial aggregate  

10 5. Cold bonded pelletizing technique

Pelletizing technique ‐ agglomerating of powdery material into a shape of pellet

Application field :

Mining ‐ iron ore 

Agriculture ‐ Fertilizer 

Biomedical field ‐medicine production

Recycling powder wastes to produce lightweight 

aggregate – sludge and dust, coal/MSWI fly ash, GGBS, etc. 

MSWI bottom ash fines (new)

Disc/pan pelletizer

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MSWI bottom ash fines properties ‐ negative

Highly porous material

Containing contaminants (heavy metals and salts)

Metallic aluminum (expansion risk)

High costs for general treatment 

Cold bonded pelletization with binders ‐ positive

Controlling size for application in concrete

Density control

Pellet strength

Spherical particle size for better flowability

Immobilization by binders (S/S)

Pre‐reaction of metallic aluminum 

Low cost 

5. Cold bonded pelletizing technique

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WasteMSWI bottom ash fines

ValuesArtificial aggregates

Application in concrete

Cold bond technique

Stage 1

Characterization

Stage 2

Technique study

Recipe design

Stage 3

Properties of pellet

Optimization of recipe according to 

requirement

Stage 4

Properties of concrete

Environmental impact of artificial 

aggregate application

Recycling 

5. Cold bonded pelletizing technique

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1 2 3

5. Cold bonded pelletizing technique

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Properties of the artificial aggregates 

Specific density 2.5 g/cm3

Loos bulk density 980 kg/m3

belong to lightweight aggregate according to EN standards    

Crushing resistance 7.5 N/mm2

higher than other artificial aggregate in literature 

The leaching of the sulphate, copper and antimony is well under limit value. 

5. Cold bonded pelletizing technique

15 5. Cold bonded pelletizing technique Wednesday, 29 June 2016

16 5. Cold bonded pelletizing technique

• Bulk density‐decreased by 10%

• Crushing resistance‐increased by 12‐22%

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Thank you for your attention!