Use of emanation thermal analysis to characterize thermal reactivity of brannerite mineral

Emanation thermal analysis (ETA) was used to characterize the thermal reactivity of amorphous brannerite mineral of general formula U1-xTi2+xO6 (locality El Cabril, near Cordoba, Spain). It was demonstrated that on sample heating up to 880 degrees C microstructure changes taking place in the sample were accompanied by the formation of new radon diffusion paths, followed by their closing up during the final transformation of amorphous to crystalline brannerite in the range 900-1020 degrees C. Relative changes in structure irregularities that served as radon diffusion paths during heating and subsequent cooling of the sample to temperatures of 300, 550, 750, 880, 1020 and 1130 degrees C, respectively, were determined from the ETA results. Mass losses in temperature ranges of 230-315, 570-760 and 840-1040 degrees C were observed by thermogravimetry. Mass spectrometry indicated the release of CO2 mainly due to the decomposition of minor carbon amount in the brannerite mineral sample.