Why do the crucibles used for SO3 and loss on ignition experiments crack?
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Hello everyone, I have a question: for use in determining SO3 and loss on ignition, which type of crucible is better – a regular porcelain crucible or a higher-quality corundum crucible? Or something else? Because we are currently using ordinary porcelain crucibles, but they crack; I don’t know why Please be informed, thank you
If anyone knows, please let me know. Thank you
If it is possible to determine mechanistically whether the intermediate crack occurs during the heating phase or the cooling phase, this will **reduce the number of tests required. Place the crucible in the area of the furnace where the temperature is most uniform, and reduce the heating and cooling rates significantly to see if it still cracks. If it doesn’t crack, then the rate of temperature change is too fast. Otherwise, it might be a quality issue with the crucible.
I wonder if you are using graphite, corundum, ceramic, or metal?
There are several possibilities: 1. Quality issues with the crucible itself ； 2. The rate of temperature increase/decrease is too high ； 3. After the sample is melted, a large amount of molten material adheres to the crucible; upon cooling, due to the significant difference in shrinkage rates between the sample and the crucible, it may be advisable to reduce the amount of sample used.
1. The heating speed is too fast, 2. Quality issue with the crucible, 3. The heating temperature exceeds the crucible’s tolerance limit