The production process includes: heating temperature of bitumen and soap solution, adjustment of soap solution pH value, and control of flow rate of each pipeline during production.
(1) Heating temperature of bitumen and soap solution
Bitumen needs to have a high temperature to achieve a good flow state. The dissolution of emulsifier in water, the increase of emulsifier soap solution activity, and the reduction of water-bitumen interfacial tension require the soap solution to be at a certain temperature. At the same time, the temperature of emulsified bitumen after production cannot be higher than 100℃, otherwise it will cause water boiling. Taking these factors into consideration, the bitumen heating temperature is selected to be 120~140℃, the soap solution temperature is 55~75℃, and the emulsified bitumen outlet temperature is not higher than 85℃.
(2) Adjustment of soap solution pH value
The emulsifier itself has a certain acidity and alkalinity due to its chemical structure. Ionic emulsifiers dissolve in water to form soap solution. The pH value affects the activity of the emulsifier. Adjusting to a suitable pH value enhances the activity of the soap solution. Some emulsifiers cannot be dissolved without adjusting the pH value of the soap solution. Acidity enhances the activity of cationic emulsifiers, alkalinity enhances the activity of anionic emulsifiers, and the activity of nonionic emulsifiers has nothing to do with the pH value. When using emulsifiers, the pH value should be adjusted according to the specific product instructions. Commonly used acids and alkalis are: hydrochloric acid, nitric acid, formic acid, acetic acid, sodium hydroxide, soda ash, and water glass.
(3) Control of pipeline flow
The pipeline flow of bitumen and soap solution determines the bitumen content in the emulsified bitumen product. After the emulsification equipment is fixed, the production volume is basically fixed. The flow of each pipeline should be calculated and adjusted according to the type of emulsified bitumen produced. It should be noted that the sum of the flow of each pipeline should be equal to the emulsified bitumen production volume.