Characterization of Mined Metals from a Brazilian Sanitary Landfill

Sanitary landfills are a disposal method of municipal solid wastes (MSW) to reduce the environmental impacts and the human health risks. MSW originate from domestic activities, including garden wastes, being a material extremely heterogeneous. These landfills are the most used form of MSW disposal in Brazil receiving several recyclable materials. The lower efficiency of selective collection experienced, the higher potential for energy, civil construction, and industry reuse for these materials can be achieved. Metals disposed of in landfills are considered secondary raw materials, which can be economically and technologically evaluated for future reuse. This research aims to analyze metals mined from a sanitary landfill in Southeastern Brazil by physical and chemical analysis to propose their commercialization in the regional market. Magnetic and non-magnetic metals were obtained from a representative sample of landfilled waste (with 248.23 kg) aged 8 years and subjected to particle-size distribution tests, and to X-ray fluorescence and X-ray diffraction analyses. Magnetic metals were predominant and presented 0.905% of the representative sample, with 2.25 kg, and non-magnetic 0.269%, with 0.67 kg. Iron was the predominant chemical element (~ 98.6%) in magnetic metals, and aluminum (~ 92.3%) in non-magnetic metals. Currently, it is estimated that 31.16 thousand tons of magnetic metals and 9.4 thousand tons of non-magnetic metals could be recovered from the sanitary landfill, that is, US$ 3.5 million and US$ 8 million, respectively. The determination of the mined metals characteristics is useful for an economically feasible recovery of metals disposed of in sanitary landfills. Graphical Abstract