Protection of Stone Monuments Using a Brushing Treatment with Ammonium Oxalate

Stone monuments and buildings are susceptible to weathering. Carbonate-based stones especially vulnerable in acidic environments, whereas magmatic more chemical weathering basic environments. To slow down surface corrosion of limestone marble artworks/buildings, protective coatings which inhibit calcite dissolution have been proposed. In this work, samples from two stone types with different porosity were treated ammonium oxalate (AmOx) create a layer calcium (CaOx) using the previously developed brushing method. Two synchrotron microscopy experiments performed determine its capability. X-ray powder diffraction (SR-μ-XRPD) transmission geometry allowed visualization distributions carbonate oxalates along sample depths. second step, fluorescence (SR-μ-XRF) was used check efficiency/integrity coating layer. This done by measuring sulfur distribution on after exposing protected sulfuric acid. XRPD showed formation thickness 5–15 µm less porous stone, while 20–30 thick formed stone. The XRF study that optimal treatment time depends porosity. Increasing 1 3 h resulted decreased efficiency for low We assume is due vertical channels (cracks)