The reaction mechanisms in As and As-S systems during their oxidation and/or thermal decomposition are complex to describe due to the physicochemical characteristics of arsenic and its sulfides; the information highlighted in the literature was analyzed and correlated to determinate the predominant phases and reaction mechanisms during the thermal decomposition and oxidation of arsenic, in its elemental form and in sulfurate phases. As a result of this analysis, it was determined that the predominant phases are mainly composed of allotropies of arsenic, sulfides, and dimers. In addition, reaction mechanisms are provided that describe the behavior of arsenic and its sulfides during its thermal decomposition and oxidation.

Keywords: reaction mechanismsarsenic sulfidethermal decompositionoxidationroasting