A laboratory simulation of desalting on calcareous building stone with wet sepiolite

In the present study a new laboratory method for the extraction of salts using wet sepiolite in closed cubic boxes has been developed. The methodology involved three successive applications of sepiolite, which were applied to four different types of calcareous building stone, previously subjected to artificial aging by salt crystallization (chlorides, nitrates and sulfates) that had been introduced through their pore network. Data revealed that the amounts of these anions extracted in the first two extractions, depended on the free porosity of each of the building stones. It was determined that by using this non-aggressive method, it was possible to remove nearly all of the salts upon the third extraction (more than the 95 % of the chlorides and nitrates and up to 88 % of the sulfates).