What is bitumen emulsion?
What are its uses and features? Bitumen is one of the most practical materials that is used in many industries today and has received special attention due to its unique properties such as excellent adhesion and high water impermeability. In general, there are different types of bitumen and each of them has many characteristics, capabilities and applications. In the meantime, one of their types is emulsion bitumen, in which various materials such as alkaline salt, organic acids or ammonium salt are used as emulsifiers.
bitumen emulsion
Emulsion bitumen is actually a mixture of bitumen and water which is immiscible and bitumen is suspended in the form of very fine particles. In this mixture, bitumen is known as internal or non-continuous phase and water as external or continuous phase. This type of bitumen is combined with a substance called an emulsifier or emulsifier, and finally it makes up about 0.3 to 0.5% of the weight of the bitumen.
“It might be interesting to know that the diameter of the bitumen grains is between 0.001 and 0.002 mm, and the smaller this diameter, the higher the quality of the emulsion.”
In general, the emulsion consists of various materials, which include:
Water
Acid
bitumen
Emulsifier
calcium chloride (calcium chlorideCacl2)
The materials that we mentioned are the main ingredients of bitumen, but in many cases, to increase the quality of emulsion bitumen, various substances such as solvent, stabilizer and polymer are added.
The most important substances used as emulsifiers in bitumen emulsion are alkaline salt, organic acids or ammonium salt, which make its particles charged. Finally, this impregnation causes the bitumen particles to repel each other and float in the water in the form of spheres with a small diameter.
Characteristics of bitumen emulsion
Emulsion bitumen, like other types of bitumen, can have unique features, the most important of which can be summarized as follows:
High adhesiveness
Can be used at ambient temperature
Easy transportation in bulk and…
Excellent permeability due to high fluidity
High compatibility with the environment and non-toxicity
No need for heating during storage, transportation and spraying
Having a lower risk of ignition due to having different amounts of water
The low level of pollution compared to petroleum bitumen, blown bitumen, soluble bitumen, etc.
And…
Emulsion bitumen production process
In general, emulsion bitumen are produced by two main methods: colloidal milling and quick mixing. Their main difference is that in the colloidal milling method, the emulsion is prepared continuously. In contrast to the rapid mixer method, the emulsion is prepared in a number of separate containers.
Colloidal grinding method
The colloidal mill consists of a rod inside a cylinder, the distance between the rod and the inner wall of the cylinder is 0.3-0.5 mm. Also, this rod rotates at a speed of 10,000 feet per minute.
To produce bitumen with this method, hot emulsifier solution and hot bitumen are poured into water in specific proportions and rotated at a specific speed.
Quick mixer method
In this method, hot bitumen is introduced into a dilute alkaline solution and finally, the emulsification process takes place due to the interaction between the organic acids in the bitumen and the alkaline solution. The way to produce bitumen with this method is that a certain amount of water whose temperature has reached near the boiling point must be entered in a mixer equipped with a stirring device and then some alkali is added to it.
In the next step, hot bitumen, which has a temperature of about 100 degrees Celsius, is slowly and continuously added to the mixer to produce a high-quality emulsion bitumen. You should note that the mixer should not be in the center of the mixer; Because it creates a vortex.
Quick mixer method
Application of bitumen emulsion
As we said, bitumen has many uses due to its special and unique properties such as impermeability to water and excellent adhesion. In the meantime, emulsion bitumen can be divided into three categories, anionic, cationic, and nonionic, according to their ionic structure, and provide you with special advantages. Among the most important applications of bitumen emulsion are the following:
Widely used in cold asphalt mixtures
Use for asphalt repairs and staining
Use for purposes such as dusting and mulching
Use in fugsil, sealcoat, single coat, prime coat, etc.
Multiple applications in single-layer or multi-layer surface asphalts
The price of bitumen emulsion
Emulsion bitumen, like other types of bitumen, can have many features, capabilities and applications, and its price can be influenced by various factors and parameters. Among the most important factors affecting the price of emulsion bitumen, the following can be mentioned:
Method and method of production
Supply, demand and…
Type of emulsifier
Applications and purpose of use
Packaging method and volume purchased
Brand and manufacturer or extracting company
Exchange rate and its fluctuations and the amount of import and export
Bitumen type (anionic, cationic and nonionic) and its technical specifications
