Thermal Analysis of Minerals

the investigation of mineral systems by means of thermal analysis. Thermal analysis was first applied to the study of minerals and rocks by the French scientist H. L. Le Chátelier in 1886. It is usually performed in conjunction with other methods; for example, combined thermal and thermogravimetric analysis makes it possible both to record heating and cooling curves and to detect changes in the weight of a substance during heating.

Thermal analysis is a reliable and convenient method for identifying many minerals. It is especially valuable in determining the composition of finely dispersed mechanical mixtures of minerals, for example, clays, bauxites, iron and manganese ores, cement materials, carbonate rocks, soils, and silts. The mineral content of a rock is estimated quantitatively by comparing the areas or heights corresponding to heat effects, the temperature peaks, and other features on thermograms of a specimen and a standard.

Thermal analysis is widely used for studying the mechanism and kinetics of phase transformations and chemical reactions that occur in minerals during heating. In such studies, particular attention is given to determining the heat effects and activation energies of chemical reactions involving minerals. Thermal analysis is also of use in solving more general geological problems, such as correlating sedimentary rocks in the construction of composite geologic sections, ascertaining the facies patterns with which minerals are associated, and establishing regional paragenesis.