As an important chemical raw material, medium-temperature coal asphalt has a wide range of applications in many fields. In order to better understand and grasp the properties and characteristics of medium-temperature coal asphalt, it is necessary to conduct in-depth research and analysis of its physical and chemical indicators.
1. Appearance and color.
The appearance of medium-temperature coal pitch is black or dark brown with a certain luster. Its color varies depending on the origin, processing method and raw material. High-quality medium-temperature coal pitch should have a more consistent color, without obvious impurities and particles.
2. Density. The density of medium-temperature coal pitch is generally 115～1.25g cm. Generally speaking, the denser medium-temperature coal pitch has better bonding properties, while the less dense medium-temperature coal pitch has better permeability.
3. Viscosity and fluidity.
The viscosity of medium-temperature coal pitch is a manifestation of its fluidity. The viscosity directly affects the performance of medium-temperature coal asphalt. Generally speaking, the viscosity of medium-temperature coal pitch is between 100 and 3000 pa·s. Medium-temperature coal pitch with high viscosity has better adhesion properties, while medium-temperature coal pitch with lower viscosity has better permeability and wettability.
Fourth, the softening point.
The softening point is an important index to measure the heat resistance of medium-temperature coal asphalt. The softening point directly affects the temperature range of medium-temperature coal asphalt. Generally speaking, the softening point of medium-temperature coal pitch is between 65 and 95. Medium-temperature coal asphalt with a high softening point has better heat resistance, while medium-temperature coal asphalt with a lower softening point has better flexibility and plasticity.
5. Ash and volatile.
Ash and volatile matter are also important physical and chemical indexes of medium-temperature coal asphalt. Ash refers to the mineral powder left after the combustion of medium-temperature coal asphalt at high temperature, and volatile matter is the gas and vapor released during the heating process of medium-temperature coal asphalt. Generally speaking, the volatile content of medium-temperature coal pitch is between 50% and 70%, and the ash content is 03%～0.6%. The content of ash and volatile matter will directly affect the quality and performance of medium-temperature coal asphalt, so its content needs to be strictly controlled.
6. Chemical composition.
The chemical composition of medium-temperature coal pitch is also one of its important physical and chemical indicators. Its main components include aromatic hydrocarbons, naphthenes, gums and resins. The ratio of these components will directly affect the performance and use of medium temperature coal asphalt. For example, medium-temperature coal pitch with higher aromatic hydrocarbon content has better adhesion properties and corrosion resistance, while medium-temperature coal pitch with higher naphthenic content has better elasticity and plasticity.
7. Stability and durability.
Stability and durability are one of the important indicators to measure the quality of medium-temperature coal asphalt. High-quality medium-temperature coal pitch should have good stability and be able to maintain its stable performance in different temperatures and environments. At the same time, medium-temperature coal asphalt should also have good durability and be able to maintain a long service life during use.
To sum up, the physical and chemical indexes of medium-temperature coal asphalt mainly include appearance and color, density, viscosity and fluidity, softening point, ash and volatile, chemical composition, stability and durability. In order to better understand and grasp the performance and characteristics of medium-temperature coal asphalt, it is necessary to conduct comprehensive research and testing on various physical and chemical indicators, so as to provide strong technical support and basis for practical application.