Step 1 – Cold Feed Bins
Aggregate cold feed bins hold the necessary aggregates to produce asphalt. At this point the aggregates are cold and wet. Then, aggregates are conveyed to the dryer.
Step 2 – Drying
The drying process is designed for three purposes:
- To take moisture away from the aggregates.
- To heat up the aggregates. This is important when all the ingredients are put together as the high temperature will give workability to the mix.
- Take very fine aggregate through the air and reuse it as filler in the final mix.
Step 3 – Hot Elevator
After the aggregates are heated up, they are transported through an elevator. It also helps to transfer the heat throughout the aggregate.
Step 4 – Screening
At the top of the plant, the aggregate is divided by size. Each screen has holes of different sizes, allowing the aggregate to filter properly. The rocks that are too big are sent down through the right side elevator.
Step 5 – Mixer
The aggregate has been divided in four sizes. The sizes of aggregate used in the mix will depend on the type of asphalt to be prepared. Recycled Asphalt is conveyed into the mixer. Bitumen is added to the mix from the tanks. Reclaimed Filler from the dryer is used instead of new filler when possible. (Allowing the discharge of dust-free, clean air into the atmosphere)
Step 6 – Transport to Site or Hot Storage
The asphalt is now ready to be transported to the working site or hot storage.