Case Study on Enhanced Landfill Mining at Mont-Saint-Guibert Landfill in Belgium: Characterization and Potential of Fine Fractions

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Fine fractions obtained by mechanical processing of excavated waste constitute a challenge for (enhanced) landfill mining projects. These fractions are mainly composed of humified organic and weathered inorganic compounds, whereas metals and calorific fractions are depleted. In this study we present data on the chemical composition and grain size distribution of the fine fractions <4.5 mm, as well as on the mineralogical composition of the two finest subfractions (0.18 to 0.5 mm and <0.18 mm). Chemical analyses indicate no trend regarding the enrichment or depletion of heavy metals in the different particle size ranges. Leaching from the finer fractions is somewhat higher than from the coarser fractions (i.e. 1.6 to 4.5 mm and 0.5 to 1.6 mm), although the fraction 0.18 to 0.5 mm shows the lowest overall leaching. Pseudo-total contents of Cu, Zn, Cd, Hg and Pb and leachable contents of Ni exceed Austrian limit values for the production of soil substitutes from wastes. Electron microprobe analyses indicate that Zn and Pb, which exceed limit values for pseudo-total content, are present as Fe-Zn alloy, ZnS and ZnSO4, and metallic Pb and Pb-Ca phosphate, respectively. In summary, dry-mechanical processing, which is a feasible method in the particle size range >4.5 mm, showed a limited effect in the range <4.5 mm. Removal of Pb- and Zn-containing phases is highly challenging due to the diverse mineralogy and fine grain size of few µm. Consequently, it seems unlikely that the Austrian limit values for soil substitutes can be met.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

CASE STUDY ON ENHANCED LANDFILL MINING AT MONT-SAINT-GUIBERT LANDFILL IN BELGIUM: MECHANICAL PROCESSING, PHYSICO-CHEMICAL AND MINERALOGICAL CHARACTERIZATION OF FINE FRACTIONS <4.5 MM

Vollprecht

Parrodi²,

Lucas

et al. 2020

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“…44 ha, which has been in operation since 1937 as a sand quarry and was transformed in 1958 into a disposal site for MSW, C&D waste and non-hazardous industrial waste (ISSeP, 2011). The excavation took place in the oldest part (red delimited area in Figure 1a) which covers a surface of 14 ha, storing circa 5.7 million m 3 of waste (Hernández Parrodi et al, 2019;IGRETEC, 1994).…”

Section: Site Descriptionmentioning

confidence: 99%

Quality Assessment of Nonferrous Metals Recovered From Landfill Mining: A Case Study in Belgium

Lucas

López

Parrodi³

et al. 2019

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Nonferrous metals (NFMs) provide a major contribution to potential revenues generated by the implementation of landfill mining (LFM). However, metals present in landfills undergo stronger degradation than during regular use, likely resulting in a lower quality compared to conventional scrap. Nowadays, information relating to the most common metals found in LFM projects is readily available, although no consistent quality data can be attained. In general, excavated landfill material is processed mechanically through a series of different steps, including screening and metal separation by magnetic and eddy current separators. This study focuses on the characterisation of NFMs recovered from a specific landfill site in Belgium, with the aim of assessing the quality of each NFM for marketing purposes. The study also addresses the issue of metal concentration and defilements detected, with a preliminary evaluation indicating a total of 5 kg of NFMs per ton of excavated material processed at the Mont-Saint-Guibert landfill. In addition, the application of thermal treatment enabled the observation that, on average, only 70 wt% of the nonferrous fraction is metallic. The majority of surface defilements (30 wt%) are represented by a combination of organic and inorganic impurities that are strongly bound to NFMs. Consequently, the different scraps extracted and the eventual destination of each were technically assessed using two separate approaches. The first approach facilitated the potential recovery of seven types of scraps from NFMs, including two different qualities of Al scrap, two of Cu, one of Pb, one of Zn, and one of stainless steel. In line with the second, and perhaps more realistic approach, NFMs may be directly marketable from the landfill as mixed nonferrous scrap. FIGURE 9: Concentration of metal and defilements in marketable NFMs [wt%].

“…Nevertheless, taking into account that relevant amounts of grouped material fractions other than "Agglomerated fines <10 mm" (i.e. "Combustibles", "Inert", "Fe metals", "Non-Fe metals" and "Others") were not identified below a particle size of 3.15 mm during the material characterization of the fine fractions (Hernández Parrodi et al, 2019a), the sorting of the fine fractions into "Combustibles + Others", "Inert", "Fe metals" and "Non-Fe metals" would only make sense above 3 mm. Thus, given that the curve for 10 wt.% water content could be expected to be very close to the one in dry state, it was concluded that a reduction of the original water content (median of 27 wt.%) to around 15 wt.% would suffice to allow an adequate mechanical processing of the fine fractions above 3 mm.…”

Section: Optimal Water Contentmentioning

confidence: 99%

“…These grouped ma- terial fractions are also in agreement with those of the material characterization presented in Table 1, except for the fraction "Fine fractions <4.5 mm (Soil-like material)", which has a particle size <4.5 mm and, hence, corresponds partially to fraction "Fine fractions <10 mm (Mixed materials)" and fraction "Others" of the material characterization, from which most part ended up in the fraction "Combustibles" of the mechanical processing due to its characteristics. Unlike material characterization, which was performed by hand down to a particle size of 10 mm, the mechanical processing was implemented down to 4.5 mm, since small amounts of recoverable materials were still visually identified below 10 mm and above 3.15 mm in the material characterization (Hernández Parrodi et al, 2019a). Thus, most of the fraction "Fine fractions <10 mm (Mixed materials)" is composed of the "Fine fractions <4.5 mm (Soil-like material)" fraction, whereas the remainder is expected to be distributed among the rest of the grouped material fractions (i.e.…”

Section: Mass Balance Of Grouped Materials Fractions Per Particle Sizementioning

confidence: 99%

Case Study on Enhanced Landfill Mining at MSG Landfill in Belgium: Mechanical Processing of Fine Fractions for Material and Energy Recovery

Parrodi¹,

Raulf

Vollprecht

et al. 2019

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(Enhanced) landfill mining ((E)LFM) projects have been mainly driven by land reclamation, environmental pollution mitigation and remediation of old landfills and dumpsites, among others. However, previous studies have also shown that these sites may be a relevant source of secondary raw materials. In this respect and within the framework of the "EU Training Network for Resource Recovery through Enhanced Landfill Mining-NEW-MINE", around 374 Mg of waste was excavated from a landfill site in the municipality of Mont-Saint-Guibert, Belgium, as part of a case study to evaluate the full implementation of ELFM. The excavated landfilled material was pre-processed with a ballistic separator onsite directly after excavation, with which the fine fractions (material <90 mm) were obtained. Subsequently, samples of the fine fractions were characterized in order to determine their main properties and material composition, which in turn were used to define the material and energy recovery strategies to be followed. According to these strategies a chain of mechanical processing steps was selected and tested in the processing of the fine fractions in the optimal water content (15 wt.% WC) and dry states. The mechanical processing consisted of particle size classification, ferrous and non-ferrous metals extraction, density separation and sensor-based sorting steps. For the recovery of materials (waste-to-material), fractions of a soil-like material (fine fractions <4.5 mm), inert, ferrous and non-ferrous metals were targeted. These fractions might be suitable for replacing soil in construction applications (e.g. embankments), substituting construction aggregates (e.g. construction gravel) and recycling, respectively. For the recovery of energy (waste-to-energy), a fraction composed of combustible materials was aimed for, which might be suitable for the production of an alternative fuel (e.g. refuse derived fuel). The mechanical processing in the dry state yielded total amounts of 41.9-43.9 wt.% DM fine fractions <4.5 mm, 35.9-39.0 wt.% DM inert materials, 7.4-10.0 wt.% DM combustible materials, 1.2-1.8 wt.% DM ferrous metals and 0.2-0.4 wt.% DM non-ferrous metals. These figures suggest that a significant share of the fine fractions could be recovered through the tested mechanical processing approach, which might contribute to the overall economic and environmental feasibility of the project in case of implementing full scale (E)LFM at the studied landfill site. AKNOWLEDGEMENTS This research has been funded by the European Union´s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 721185 "NEW-MINE" (EU Training Network for Resource Recovery through Enhanced Landfill Mining; www. new-mine.eu). The authors wish to express their special gratitude to Renewi Belgium SA/NV, Stadler Anlagenbau GmbH, Department of Processing and Recycling (IAR) of the RWTH Aachen University and Chair of Waste Processing Technologies and Waste Management (AVAW) of the Montanuniversität Leoben for their straig...