LANDFILL MINING POTENTIAL OF CLOSED MSW LANDFILLS IN FINLAND. Tommi Kaartinen VTT, Kai Sormunen Ramboll Finland Oy & Jukka Rintala TUT

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1 LANDFILL MINING POTENTIAL OF CLOSED MSW LANDFILLS IN FINLAND Tommi Kaartinen VTT, Kai Sormunen Ramboll Finland Oy & Jukka Rintala TUT

2 Background Presented studies were conducted as part of two separate research projects Current research project ( ) is concentrating on potentials for landfill mining Main interest of the first project on landfill process control ( ) was to assess emission potential at closed landfills 2

3 Finnish research project on landfill mining Research project (KAIVANTO) on the potentials for landfill mining in Finland 1/2012 6/2014 Contains desk studies and two case-studies on MSW landfills material potential as well as processability Funded by Tekes the Finnish Funding Agency for Technology and Innovation (Green Growth Technology Programme), companies and research institutes Research carried out by VTT Technical Research Centre of Finland, Tampere University of Technology and Ramboll Finland Oy Participating companies Ekokem Oy Ab, BMH Technolgy Oy, Lassila & Tikanoja Oyj, Rosk n Roll Oy Ab 3

4 Research project KAIVANTO - objectives Hands-on experiences and development of novel approaches for surveying material contents of landfills Estimation of material potential in landfills Preliminary estimates on business opportunities related to landfill mining in Finland (and abroad) To create abilities for company driven pilot- or demonstration projects 4

5 Case study 2012, Kuopio Finland MSW landfilled during 2001 and 2011 Area 3,5 ha, max. height 30 m Samples for the project were obtained in connection with drilling of gas collection wells Hand-sorting of samples Full scale trial runs with a chain of mechanical pretreatment unit processes Characterization of sorted fractions 5

6 Sampling and sorting of samples in Kuopio 2012 Samples from drilling of gas wells (3 pc) to skips (6 pc.) Samples (6 pc. à 600 l) from skips to manual sorting Sieving 42 tons of waste to full-scale mechanical sorting Shredder Magnet Magn. metals <20 mm mm mm Manual sorting >100 mm Drum-sieve <30 mm mm >70 mm Plastics Paper and cardboard Textiles Wood Metals Soil Other Light fraction >70 mm Wind sieve Heavy fraction <70 mm

7 Results from manual sorting at Kuopio % Manual sorting of samples (average) 6 % 7 % 7 % 6 % 4 % 24 % 1 % Soil Wood Textiles Paper/Cardboard Metals Plastics Other <20 mm

8 Summary of results from Kuopio 2012 (manual sorting) Mass fraction of fines (<20 mm) %, classified as soil or waste? Varying concentrations and leaching (DOC, SO 4 2- ) of contaminants Low share of recyclable materials Combustible fractions m-% Good heating value (SRF II) High chlorine content (SRF IV/V) Metals 3-4 m-%, typically impure fractions Coarser soil 6-7 m-% High mass fraction of plastics (23-24 %), on other parts results in accordance with previous findings Fines <1 mm Finess 4-10 mm Fines 1-4 mm Fines mm 8

9 Results from full-scale mechanical sorting at Kuopio 2012 Magnetic metals 1,2 % Feed 100 % Shredder Magnet Wind sieve >70 mm Drum sieve Light fraction >70 mm 28 % Heavy fraction >70 mm 4,0 % <30 mm 44 % mm 24 % 9

10 Drill hole 4 Drill hole 3 Case study 2013, Lohja Finland MSW and wastes from local industries landfilled between 1960 s and 1980 s Non-existent documentation of the deposited wastes Geo-electrical measurements preceding the drillings Four drill holes with depths of 10 to 13 meters, locations chosen based on geo-electrical measurements Manual sorting of drill hole samples, similar to case study 2012 Correlations between geo-electrical data and material contents to be further elaborated 10

11 Case studies in Ämmässuo landfill in Helsinki region Large MSW landfill (54 ha) Samples taken as part of a research project on landfill process control in connection with drilling of gas collection wells Sampled waste landfilled between 1987 and 2003 Manual sorting to plastics, paper and cardboard, wood, metals, inert materials, textiles and residuals Kujala landfill in southern Finland Relatively large landfill (27 ha) Samples taken as part of a research project on landfill process control in connection with drilling of leachate inspection wells Sampled waste landfilled between 1960 and 2003 Manual sorting to plastics, paper and cardboard, wood, inert materials and residuals. Textiles were included in the residuals and metals in the inert materials. 11

12 Comparison of results from different landfills Kuopio landfill ( ), average composition Lohja landfill (1960's-80's), average composition 7 % 1 % 43 % 45 % <20 mm Metals Combustibles 20 % 19 % 1 % 58 % <20 mm Metals Combustibles Soil Soil 4 % Others 2 % Others Ämmässuo landfill ( ), average composition Kujala landfill ( ), average composition 42 % 16 % 12 % Fines Metals 30 % Combustibles Inert 23 % 12 % 65 % Residuals Combustibles Inert 12

13 Concluding remarks Case studies on MSW landfills require a large scale Costs Case-specific results There are 2600 closed MSW landfills in Finland alone Essential reasons for excavating MSW landills are likely to be other than mining driven also in the near future A need exists to further develop more cost efficient methods for characterizing material contents of MSW landfills 13