In modern road construction and maintenance projects, the concepts of sustainable development and environmental protection are increasingly deeply rooted in people's hearts. Among them, the recycling and reuse of waste asphalt pavement materials (RAP) has become an industry standard practice. The core key technology of this process is the asphalt mixture separator, whose efficient and precise working principle is the fundamental guarantee for achieving high-quality recycled asphalt mixture (RAP) production.

　　The asphalt mixture separator, as its name suggests, does not "separate" asphalt and aggregate, but is a key equipment based on screening and heating drying principles, specifically designed to crush, screen, and classify agglomerated, cold waste asphalt mixtures according to particle size.Its core mission is to process waste materials of different sizes from milling operations into clean and uniformly sized recycled aggregates, laying the foundation for precise proportioning and mixing of new materials in the future.

Its working principle can be clearly divided into three core stages:

　　Phase 1: Crushing and Preliminary Dispersion

The large pieces of waste asphalt mixture transported from the cold storage bin first enter a low-speed rotating crushing and drying drum. The drum is equipped with specific blades and lifting plates inside. Under the rotation of the drum, the material is repeatedly lifted to a certain height and thrown down, achieving initial crushing and dispersion. At the same time, an appropriate amount of hot air is introduced into the drum, which is not heated vigorously like a regular drying drum to remove all moisture, but for "gentle drying". The main purpose of this process is to soften the asphalt wrapped on the surface of the aggregate, reduce its viscosity, and evaporate some surface moisture, creating favorable conditions for subsequent efficient screening - neither overheating can cause asphalt aging, nor can it bond into clusters due to insufficient temperature.

　　Phase 2: Multi stage precise screening

After initial crushing and gentle drying, the material is transported to the core part of the equipment - the multi-layer vibrating screen. This screening system usually consists of two or more layers of screens with different pore sizes, with the pore size gradually decreasing from top to bottom. Under the high-frequency drive of the vibration motor, the material is evenly distributed on the screen surface and moves forward. Particles smaller than the sieve size fall through the sieve, while those larger than the sieve size continue to move forward until they are discharged from the outlet. Through this process, the material is accurately separated into groups of different particle sizes, such as 0-5mm, 5-10mm, 10-15mm, etc., and stored separately in different thermal storage bins.

　　Phase Three: Measurement and Transportation

Recycled aggregates that have been precisely graded have become a raw material that can be accurately measured. Each hot material bin is equipped with high-precision electronic scales and belt scales below. When producing fresh asphalt mixture, the control system will extract the corresponding quality of recycled material from each hot material bin according to the preset formula in proportion. Through a closed bucket elevator or belt conveyor, it will be accurately fed into the new material drying drum or the mixing tank of the double drum mixer in the main mixing plant, and evenly mixed with the newly added asphalt, new aggregate, and necessary supplementary rejuvenator.

In summary, the asphalt mixture separator successfully converts messy waste materials into controllable quality renewable resources through a coherent process of "mild heating crushing dispersion precise screening precise metering". It not only greatly enhances the blending ratio and value of RAP, but also plays an irreplaceable role in saving natural resources, reducing energy consumption, and minimizing environmental pollution. It is the core equipment for promoting the green cycle of asphalt pavement technology.