Storing Asphalt Emulsions

Asphalt emulsion is a dispersion of fine droplets of asphalt in water and has special storage requirements. Storage tanks should be insulated for protection from freezing and efficient use of heat. A skin of asphalt can form on the surface of emulsions when exposed to air. Therefore, it is best to use tall, vertical tanks that expose the least amount of surface area to the air. Most fixed storage tanks are vertical, but horizontal tanks are often used for short-term field storage. Skin formation can be reduced by keeping horizontal tanks full to minimize the area exposed to air.

Side entering propellers located about 3 feet (1 meter) from the tank bottom may be used to prevent surface skin formation. These propellers should be large in diameter and turned slowly (approximately 60 RPM) to gently circulate the material. Propellers should only be utilized when there is sufficient emulsion for proper mixing.