Life prediction of dump reactivity caused by slags from lead production

• Claudia A. Möller
• Srecko Stopic
• Bernd Friedrich

A slag landfill site for slags from secondary lead production was operated by the BSB Recycling GmbH in Braubach, Germany until 1990. Due to the closure in 1990 it is necessary to provide the landfill with a surface cover according to German legislation. To build such a surface cover profiling of the landfill is necessary up to a depth of 11 m. Previous investigations of the dump however revealed temperatures up to 400 °C inside of the pile. Therefore an investigation was started to identify possible risks during profiling under this conditions and to predict the remaining reaction period. Three wells were drilled through the landfill, showing that the reaction inside is proceeding from bottom to top and that this reaction is/can be independent of water and/or air admission. Identified hazards were especially a high arsenic concentration appearing in the water vapours even during the drilling process. By analysing the chemical reactions inside the landfill the reaction progress was assessed. The thermochemical analysis between 150 °C and 450 °C offered the possible chemical reactions inside of the pile. Together with the assumed constraints the remaining reaction period was evaluated to be approximately 66 years.