Ash testing in coal pitch is usually done to determine the amount of inorganic matter in coal pitch, which helps to understand the quality and performance of coal pitch. There are several methods for ash detection:
Slow ashing method (arbitration law):
This method is suitable for the accurate determination of ash content in coal pitch. First, the coal pitch sample is placed in an ash dish and then slowly heated to a certain temperature (usually around 500 °C) in a muffle furnace and held for a certain period of time (usually 30 minutes) to allow the organic matter in the coal pitch to volatilize. After that, continue to warm to a higher temperature (usually around 850°C) and burn at this temperature for 1 hour until the mass change is less than 00010g。Finally, the ash content is calculated by weighing the mass of the residue.
2 Rapid ashing method:
The rapid ashing method is a relatively simple detection method that is suitable for routine analysis. In this method, a coal pitch sample is rapidly burned at a higher temperature (typically around 800°C) to rapidly remove organic matter, and then the ash content is determined by weighing the mass of the residue.
3. High temperature ashing method:
In the high-temperature ashing method, a sample of coal pitch is burned at a high temperature (usually above 900°C) to completely remove organic matter, and then the ash content is determined by weighing the mass of the residue. This method ensures that the organic matter in the coal pitch is completely burned, but it may lead to the melting or volatilization of some inorganic mineral components.
4Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES):
This is a modern analytical method that enables the rapid and accurate determination of the inorganic element content in coal pitch by means of inductively coupled plasma emission spectrometry to calculate the ash content. This method allows the determination of multiple elements at the same time with high accuracy and sensitivity.
During ash detection, experimental conditions need to be tightly controlled, including temperature, time, and how the sample is placed, to ensure the accuracy and reproducibility of the test results. In addition, due to the complex composition of coal pitch, there may be some special ash composition, so the specific characteristics of the sample and the purpose of the test need to be taken into account when selecting the ash detection method.