What a bitumen emulsion plant does
Bitumen does not mix with water on its own. A bitumen emulsion plant mills hot bitumen into a soap solution of water and emulsifier. The product is bitumen emulsion (also called emulsion bitumen): fine droplets of bitumen suspended in water.
It is used in cold mix road building, which cuts the heating and pollution of working with hot bitumen.
For what bitumen emulsion is, its types and each step in making it, see our guide to the bitumen emulsion process.
Inside a Wahal bitumen emulsion plant
A plant has four main sections.
| Section | What it does |
|---|---|
| Soap tank | Water, emulsifier and chemical agents are mixed to the recipe, at about 50 °C |
| Bitumen tank and heating | Brings the bitumen to about 150 °C; thermic fluid or electric heating |
| Multi-stage homogenizer | Mills the bitumen into the soap solution, with droplets as fine as 0.5 micron |
| Emulsion storage | Holds the finished emulsion for loading into tankers |
The homogenizer at the heart of the plant
Every plant is built around a Wahal inline homogenizer. It has several rotor-stator stages, so the bitumen is sheared again and again in a single pass. This brings the emulsion droplets down to as fine as 0.5 micron and gives a fine, stable emulsion. The stators can be changed to suit the droplet size required.
See also our colloid mill for bitumen emulsion.
Containerised and delivered assembled
Each plant is designed to the dimensions of a 20 ft or 40 ft ISO container, so it can be shipped or airlifted.
It arrives on site fully assembled and can be connected and switched on without special requirements. Our team installs it, and the design allows easy installation and fast commissioning.
Options and automation
Every plant is tailor-made to the client’s requirements. It can include:
- load cells for weighing bitumen and soap solution
- actuated valves
- a PLC/HMI control system
- thermic fluid or electric heating
- tank filling pumps for bitumen and water
- a cooling system for the emulsion
- a dosing station for precise dosing of emulsifiers and additives into the soap tank
With PLC/HMI control the plant runs with a high degree of automation. That makes the process more efficient and reduces the chance of human error.
Turnkey bitumen emulsion production
Wahal bitumen emulsion plants have been on the market since 1990, and the design has been updated over the years. As well as the plant itself, we offer turnkey packages that include recipe formulation and storage tanks.
Tell us the emulsion type and output you need, and we will size a plant around it.
Emulsion types and uses
The soap solution recipe sets the type of emulsion: cationic or anionic by surface charge, and rapid, medium or slow setting. Cationic emulsions are the type mostly used in India. The types of bitumen emulsion are explained on our process page.
Bitumen emulsion is used for:
- road surfaces and pavement work, including in wet weather
- premixing with coarse aggregate and uniform mixing with fine aggregate
- soil stabilisation in desert areas
- under seals and waterproofing compounds
Other bitumen plants we build
- Polymer modified bitumen plants blend polymers such as SBS, APP, EVA or PVC into bitumen for road surfaces and roofing felt.
- Cutback bitumen plants use an inline homogenizer to mix hot bitumen with solvents such as naphtha or kerosene.
- Bitumen decanting unit: if your bitumen arrives in drums, it melts and empties them on site.
Frequently asked questions
What is a bitumen emulsion plant?
It is a plant that makes bitumen emulsion by milling hot bitumen into a soap solution of water and emulsifier. It is also called an emulsion plant or asphalt emulsion plant. Wahal plants are containerised and built around a multi-stage homogenizer.
How does a bitumen emulsion plant work?
The soap solution is mixed in one tank and the bitumen is heated in another. Both are fed together into the homogenizer, which shears the bitumen into fine droplets that the emulsifier keeps suspended in water. The emulsion then goes to storage tanks for loading.
How fine is the emulsion from a Wahal plant?
The multi-stage homogenizer shears the bitumen several times in one pass and brings the droplets down to as fine as 0.5 micron, which gives a stable emulsion.
Can the plant be shipped or airlifted?
Yes. Each plant is designed to the dimensions of a 20 ft or 40 ft ISO container. It arrives fully assembled and can be connected and switched on without special requirements.
Can the plant be automated?
Yes. Options include a PLC/HMI control system, actuated valves, load cells for weighing bitumen and soap solution, and a dosing station for emulsifiers and additives.
Which bitumen emulsions can the plant make?
The type of emulsion depends on the soap solution recipe: cationic or anionic, and rapid, medium or slow setting. Tell us the type you need and we will size the plant around it. We can also help with recipe formulation.
Do you supply a complete, turnkey plant?
Yes. Besides the plant, we can supply storage tanks and help with recipe formulation, and our team installs the plant on site.
What does a bitumen emulsion plant cost?
It depends on the output you need and the options you choose, such as automation, heating and cooling. Send us your emulsion type and output and we will quote for a plant sized to it.
