Abstract for presentation at Chemeca 2007

Carbonate minerals play a significant role in many industries. In mineral related industries, almost all production processes involve in heating the minerals. Therefore, understanding the reactions of carbonate minerals at high temperature is important. Eight industrially useful carbonate minerals, namely calcite CaCO₃, aragonite CaCO₃, azurite Cu₃(CO₃)₂(OH)₂, malachite Cu₂(CO₃)(OH)₂, smithsonite Zn(CO₃), gaspeite Ni_0.6Mg_0.3Fe²⁺_0.1(CO₃), cerrucite Pb(CO₃), and stichtite, Mg₆Cr₂(OH)₁₆(CO₃)•4(H₂O) were analysed using In-situ High Temperature X-ray Diffraction (HTXRD). Samples were heated to the top temperature of 900° C and analyses were conducted at 100° C intervals. Resulting diffraction patterns and their changes with temperature are discussed here with possible reactions. Although similar in chemical composition, calcite and aragonite behave very differently during heating and end up as different products. Some minerals show deviations from the expected trend, especially when associated with another mineral, or heated in a different environment. Reasons for these differences are discussed.