Did you know how asphalt is produced?

asphalt-drum-plant-diagram

The first step in the process for making asphalt is having a stockpile of aggregate. Aggregate comes in multiple forms of crushed stone, gravel, and sand. The blending of these aggregates is the next step in the manufacturing process. Each aggregate is sorted into cold feed bins that adjust the proper amount for the desired mixture. The aggregates run through a conveyor belt system that will transport them to the drying drum. Inside the dryer drum the aggregates are tumbled though a heated air stream. In this step asphalt cement or bitumen is added. Bitumen is the black tar type substance that is a form of crude oil extracted from oilsands. The fourth step is the emission control system. As the drying process takes place fine particles of sand and dust collect. The ECS (emission control system) removes these particles before the air goes back into the atmosphere. The primary collection chamber allows for these particles to be added back to the aggregate mix.

What is the difference from an asphalt batch plant and drum plant?
A batch plant mixes asphalt one batch at a time. This type of manufacturing plant does not incorporate the drying drum. Instead, the aggregates are moved to a tower where they are separated and stored in heated bins. Once all of the aggregates are collected and proportioned out each bin is discharged into a pugmill. A pugmill is the machine that works to mix the aggregates together. After being blended in the pugmill the asphalt is ready to be poured into dump trucks or transferred into storage silos.
Now you have a better idea how asphalt is produced.