According to the test results, the purity of coal pitch is judged mainly by the following indicators:
1.Relative density: The relative density of coal pitch is generally 10~1.2, the relative density of coal pitch with higher purity will be greater. Therefore, by determining the relative density of coal pitch, its purity can be preliminarily judged.
2.Bulk density: The bulk density of coal pitch should not be less than 06g/cm³。The higher the purity of the coal pitch, the greater the bulk density. Therefore, the purity of coal pitch can also be judged by determining its bulk density.
3.Ash: Ash is the non-burning part of coal pitch, mainly including minerals, ash and other inorganic substances. By determining the ash content, the purity of the coal pitch can be determined. In general, the lower the ash content, the higher the purity of the coal pitch.
4.Volatile matter: Volatile matter is the total amount of water vapor, organic matter, and other volatile substances produced during the heating process of coal pitch. By determining the volatile content, it is possible to know the amount of volatile substances in the coal pitch. The lower the volatile content, the higher the purity of the coal pitch.
5.Chemical composition: The chemical composition of coal pitch is one of the important factors that determine its purity. Through laboratory analysis, the content of various elements in coal pitch can be understood, especially the content of aromatic hydrocarbons, aliphatic hydrocarbons, carbohydrates, proteins and inorganic substances. The ratio and content of these components determine the chemical properties and stability of coal pitch and thus its purity.
It should be noted that the above indicators can only be used as a reference basis for judging the purity of coal asphalt, and the specific judgment needs to be comprehensively considered in combination with the actual situation and application field. At the same time, in order to ensure the accuracy of the test results, it is necessary to adopt standard laboratory methods and equipment, and operate in strict accordance with the operating procedures.