Quantitative determination of certain minerals in natural and artificial mixtures by DTA

Differential thermal analysis has been used in identifying individual minerals successfully; however, the use of DTA in identification of individual minerals in a mixture is not well accepted. This paper is divided into: introduction, terminology, history, derivation of the basic formula and thermograph. The various methods of determination are outlined and the advantages and disadvantages of each method discussed. Under separate-standard method the author considers the calibration curve method, the proportional method and the dilution method; the combined-standard method and the compensation-standard method are also treated. Piloyan concludes that the most reliable method is that of the calibration curve for quantitative analysis in a mixture, but this is contingent upon knowing the contained minerals to begin with. For poorly controlled experimental conditions the best results are obtained by using the combined-standard method. Advantages of DTA are the low cost of the apparatus, the fact that chemical analyses will not determine the minerals present. He also points out that DTA will not substitute for X-ray or chemical analyses but the three should be used in conjunction.—M.A. Klugman