[Application of Thermogravimetric-Differential Scanning Calorimetry(TG-DSC)in Quality Control of Limonitum].

Objective: To control the quality of Limonitum by investigating the thermoanalysis curves. Methods: Analysis Limonitum samples from different origins by Thermogravimetric-Differential Scanning Calorimetry( TG-DSC),and the processed samples and fake samples were analyzed to compare the difference of them at the same time. Results: Thermal analysis curves showed that most of Limonitum samples had three weight loss steps in 30 ~ 1 000 ℃,and the process of dehydration weight loss of goethite was obviously in about309 ℃. There was a positive correlation between the weight loss rate of the second step and the content of iron. Conclusion: The Thermal analysis method can provide reference to the identification and quality control of Limonitum.