Mechanism of Sulphation by Atmospheric SO 2 of the Limestone and Marble of Ancient Monuments and Statues: III. Further proofs of the validity of the galvanic cell model

Abstract

This work is a continuation of that published in Parts I and II (BCJ, 1981, 16,63 and 70) under the same title.

In the present paper measurements of the rate of sulphation of powdered pentelic marble at high temperatures (weight gain), of polymer-coated marble at ambient temperature (EPMA), of untreated and polymer-coated marble at ambient temperature (weight gain), and of the rate of attack of sulphuric acid (weight loss) on untreated and polymer-coated marble at ambient temperature, support and provide supplementary evidencefor the validity of the model of a galvanic cellfor the sulphation of marble and its mechanism as presented in our previous work, and of the danger of using ‘protective’ organic films which accelerate the sulphation.