Medium temperature asphalt is used to make linoleum, building waterproof layer, high-grade asphalt paint, etc. It is also a raw material for making asphalt coke or delayed coke and modified asphalt. It can be used to make electrode paste, anode paste binder, carbon products, refractory material binder, roof coating and anti-humidity agent for construction, and it is also the main raw material for road construction industry.
Modified asphalt is made from medium temperature asphalt. The benzene insoluble content BI of ordinary medium temperature asphalt is about 18%, and the quinoline insoluble content QI is about 6%. When this kind of asphalt is heat-treated, the aromatic molecules in the asphalt produce hydrogen, methane and water during the thermal polycondensation process. At the same time, a part of the original β resin in the asphalt is converted into a secondary α resin, and a part of the benzene soluble substance is converted into a β resin. The α component increases, the cohesiveness increases, and the asphalt is modified. This kind of asphalt is called modified asphalt.
The modified asphalt is a black solid at room temperature, with a softening point of 110°C.
Medium temperature asphalt
1. Different concepts
Thermal insulation asphalt pump is suitable for conveying medium temperature of 350℃, material is cast steel, viscosity is not more than 40mm2/s, and does not contain solid particles, such as asphalt and paraffin, which are solidified at room temperature and during outdoor installation and process in high-cold areas. Where heat preservation is required. Heat transfer oil, hot water, steam, etc. can be introduced to heat and keep the conveying medium.
The medium temperature asphalt is the residual liquid part of tar distillation, and the yield accounts for 54 to 56% of the tar. It is composed of aromatic compounds with more than three rings, oxygen-containing, nitrogen-containing, and sulfur-containing heterocyclic compounds, and a small amount of high-molecular carbon materials. The molecular weight of the bituminous component is between 200-2000 and can reach 3000. Medium temperature asphalt is classified according to different softening points. The softening point is 65～90℃ for medium temperature asphalt.
2. Different softening points
Coal tar pitch is a black solid with a bulk density of 1.25 to 1.35g/cm3 at room temperature. It becomes soft when heated to a certain temperature: medium temperature pitch has a ring and ball softening point of 75 to 95°C. For high-temperature asphalt (hard asphalt), the ring and ball method has a softening point of 95-120°C; in addition, the coking plant can produce ultra-high-temperature asphalt with a softening point of 120-250°C according to user requirements.