Thermogravimetric analysis of the thermal decomposition process of calcium oxalate

Calcium oxalate, as an important intermediate compound, has a wide range of applications in pharmaceuticals, chemical production, and biomineralization. Understanding its thermal decomposition behavior is of great significance for process optimization and product quality control. Thermogravimetric analysis has become one of the effective methods for studying the thermal stability of solid materials due to its ability to continuously monitor the changes in sample quality with temperature.

1、 Operation steps of the experiment

1. Measuring instruments:DZ-TGA201 Thermogravimetric Analyzer

2. Sampling: Take about 5mg of calcium oxalate sample and place it in a pre treated crucible, as flat as possible to ensure uniform heating.

3. At a heating rate of 10 ° C/min, under a nitrogen atmosphere, raise the temperature to 1000 ° C and collect and store real-time test spectra of the percentage of mass loss over time or temperature.

4. Measurement spectrum analysis:

Calcium oxalate will undergo three stages of significant weight loss at RT-1000 ℃. One stage represents the loss of water molecules, the second stage represents the decomposition of CaC2Q4 into CaCQ3, and the third stage represents the decomposition of CaCO3 into Ca0. From the above figure, it can be concluded that calcium oxalate loses 12.31% of water molecules at RT-300 ℃. In the second stage of 350 ℃ -550 ℃, calcium oxalate begins to decompose and lose 19.14% weight, resulting in a mass proportion of CaCQ3 of -12.31% -19.14%=68.55%. In the third stage of 600 ℃ -850 ℃, the weight loss is 30.74%, resulting in a mass proportion of calcium oxide of 68.55% -30.74%=37.81%.

2、 Conclusion of the experiment

We can further expand our research direction in the study of calcium oxalate thermal decomposition. On the one hand, it is possible to explore in depth the effects of different atmospheres (such as oxygen, hydrogen, inert gases, etc.) on the thermal decomposition process of calcium oxalate, understand the interaction mechanism between gas molecules in the atmosphere and calcium oxalate, and how this interaction changes the temperature, products, and reaction rate of thermal decomposition. On the other hand, studying the thermal decomposition behavior of calcium oxalate under different pressure conditions is also a meaningful direction. Changes in pressure may affect the structure of calcium oxalate crystals and the stability of chemical bonds, leading to differences in the thermal decomposition process. In addition, by combining other analytical techniques such as infrared spectroscopy (FT-IR), mass spectrometry (MS), etc., a more comprehensive and in-depth analysis of the intermediate and final products in the thermal decomposition process of calcium oxalate will help us to better understand the microscopic mechanisms of the thermal decomposition reaction.