Fixing of gypsum layers formed on the surface of limestone building materials of monuments or new buildings, sculptural decoration and statues by the effect of atmospheric SOx and damp by converting them back to calcium carbonate at the same time cleaning the surface of the suspended particles that have settled on it

摘要

This invention fixes gypsum layers, which have been formed by the effect of atmospheric SOx and damp on surfaces of limestone building materials of monuments, sculptural decorations and statues or new buildings by converting them back to calcium carbonate and saving details preserved on the surface but which have been obliterated from the surface of the original authentic materials. At the same time the surface is cleaned of the suspended particles, mainly soot, which have settled on it. The invention consists in daily (in the morning or at some other time) spraying of the gypsum surfaces with a 0.003 - 0.3 M solution of potassium carbonate saturated in Ca2+SO42- and converting them to calcium carbonate and in air blasting with a blow pipe (in the afternoon or at some other time) to remove settled suspended particles (mainly soot) which have already been loosened by the reduction in the volume of CaSO4.2H2O - CaCO3 during the conversion. After it has been fully converted back, the surface is washed with deionized water using absorbent paper to remove the by-product K22+SO42-: CaSO4.2H2O + K2CO32---> CaCo3 + K22+SO42- + 2H2O.