In this paper, the chemical composition detection method of asphalt is introduced in detail, and the composition analysis of road petroleum asphalt is carried out by using the four-component method. The method accurately determined the contents of asphaltene, saturated, aromatic and colloidal by solvent precipitation and column method. The experimental procedure includes specimen preparation, activated alumina, solvent removal of aromatic hydrocarbons, component separation, and final mass determination to ensure complete separation of components and reliable results.
This method is designed to analyze the four-component composition of road petroleum asphalt by solvent precipitation and chromatographic column method, and is suitable for the chemical composition detection of various asphalt samples.
Glass adsorption column - jacketed and equipped with hot water circulation system.
High-temperature furnace - temperature range 0~1000°C, with automatic temperature control function.
Vacuum Drying Oven – temperature controlled at 105°C±5°C.
Chemical reagents - petroleum ether, n-heptane, toluene, absolute ethanol and other analytical pure reagents.
Alumina - particle size 0.15~0.075mm, used for chromatography.
Analytical balance - inductance not more than 0.1mg.
Preparation
Wash and dry the equipment to ensure that it is free of impurities.
The alumina is activated, heated in a high-temperature furnace at 500 °C for 6 hours, followed by cooling and activated by the addition of distilled water.
Determination of asphaltene content
The asphalt sample is accurately weighed, n-heptane is added, and heated and refluxed to dissolve asphaltene.
Filter and wash the residue, recover the solvent and dry.
Determination of saturation, aromatic and colloidal content
N-heptane was recovered, the solution was concentrated to about 10 mL, and heated in a Thermostatic Water Bath.
Activated alumina was used for separation, and the components were sequentially washed with solvents such as n-heptane and toluene, and each component was separated.
Calculation of gum content
According to the results of asphaltene, saturated and aromatic content, the gum content was calculated by the difference subtraction method.
Calculation and reporting of results
The mass of each component was recorded and the recovery rate was calculated to ensure that the experimental results were within the allowable error range.
Submit a detailed report, including component content and recovery.
Precautions
During the experiment, keep the temperature and environmental conditions of the equipment stable to avoid affecting the test results.
Experiments should be repeated at least twice to ensure the reliability of the results.
Through the above methods, the four components of asphalt can be effectively and accurately detected, which provides important data support for the quality control and application of asphalt.
The four-component analysis method of asphalt provides an important basis for evaluating its performance, and can effectively reveal the chemical characteristics of asphalt through scientific experimental procedures and accurate instrumentation. This analytical method is not only suitable for asphalt quality control, but also provides basic data for the research and development and application of new materials, which is of great significance for promoting the development of the asphalt industry.