Serpentinitic waste materials from the dimension stone industry: Characterization, possible reuses and critical issues

Serpentinites, ultramafic rocks with a peculiar chemical and mineralogical composition, can be used as dimension stones, but there are no significant re-uses of waste materials deriving from quarrying and processing. This paper presents the example from Valmalenco (central Alps, northern Italy), with a detailed mineralogical, chemical, physical and microstructural characterization of waste materials, ranging from shapeless blocks to residual sludge. The mineralogical composition is characterized by abundant antigorite and olivine, with minor chlorite, clinopyroxene and magnetite, and the chemical composition by high MgO grades. The preliminary results suggest interesting applications in the ceramic industry, especially in high-MgO ceramics and forsterite refractories materials, as well as alternative uses as filler for plastic and rubber materials, up to carbon dioxide sequestration. Special care must be taken to avoid chrysotile asbestos contamination. •Serpentinitic rock materials have a peculiar mineralogical and chemical composition.•The waste materials are suitable for the ceramic industry.•From filler for plastic and rubber, up to CO2 sequestration.•Traces of asbestos represent a critical issue.