Insight
Orica bulk emulsions - understanding the basics
What are bulk systems?
Bulk Systems are large‑scale explosive solutions used to break rock in mining, quarrying, construction and tunnelling. Unlike packaged explosives, bulk products are manufactured and delivered in large quantities directly into drilled blast holes, using specialised mobile equipment.
This approach allows Orica to adjust the explosive properties at the time of loading, ensuring the energy in each hole matches the ground conditions and blast design.
Understanding bulk emulsion
A bulk emulsion is the most common type of bulk explosive used by Orica. At its simplest, a bulk emulsion is a carefully controlled mixture of water and fuel that is designed to be safe to handle, highly water‑resistant, and extremely effective at breaking rock when detonated.
Think of it like this:
- Oil and water normally don’t mix
- In a bulk emulsion, tiny droplets of water‑based oxidiser are suspended inside oil‑based fuel
- A special ingredient called an emulsifier holds them together, creating a stable, thick liquid
This structure makes bulk emulsions:
- Water resistant (they don’t wash away in wet holes)
- Stable and safer to handle during transport and loading
- Highly efficient at delivering explosive energy when initiated
Testing the viscosity of the bulk emulsion, delivered from a mobile manufacturing unit (MMU™). Each bulk emulsion mixture is designed for specific site applications.
Fortis™ Protect is a bulk emulsion engineered with high-viscosity to resist dynamic water in wet and challenging conditions. The white pellets are known as prill.
What is Prill?
Prill refers to small, round pellets of ammonium nitrate that look similar to tiny white beads. These pellets are a key ingredient used in some bulk explosives, including ANFO and certain bulk emulsion blends.
Why prill is important
Each prill pellet is porous, meaning it contains thousands of microscopic air pockets.
These pores allow the prill to:
- Absorb fuel oil (in ANFO)
- Blend effectively with bulk emulsions
- Help the explosive detonate reliably when initiated
How prill is used in blasting
In ANFO, prill absorbs fuel oil to create a dry blasting explosive for dry holes only.
In bulk emulsion systems, prill may be blended with emulsion to:
- Adjust explosive energy
- Improve gas generation
- Support specific loading or ground conditions
How does a bulk emulsion become an explosive?
On its own, an emulsion contains stored energy but will not detonate.
During loading into the blast hole, the emulsion is sensitised, which is a controlled chemical process that creates tiny gas bubbles throughout the product. These bubbles allow the explosive to detonate reliably when initiated. This is completed through the use of surface delivery systems known as Mobile Manufacturing Units™ (MMU™) or underground delivery systems.
This “manufacture‑in‑the‑hole” approach allows Orica to:
- Control explosive strength
- Adjust energy distribution
- Match performance to geology and hole depth
A hole being loaded with bulk emulsion from a Bulkmaster™ Pro - one of Orica's range of Surface Delivery Systems
Choosing the Right Bulk Emulsion for the Job
There is no single "one‑size‑fits‑all" bulk emulsion. Instead, there are many carefully designed emulsion mixtures, each engineered to deliver a specific blasting outcome or to manage challenging site conditions. Small changes in formulation can result in very different blasting experiences, from higher energy for improved fragmentation, to lower energy for vibration control, or enhanced stability for wet, hot, reactive or deep ground conditions.
Orica’s range of Bulk Emulsion brands is designed to simplify this complexity. Each primary brand clearly signals where the product is used and the secondary branding explains what it is designed to do, helping mining, quarrying and construction customers select the right solution for their application with confidence.
To continue exploring Orica’s Bulk Emulsion range and understand how each is applied across different mining environments, continue reading Orica Bulk Systems - Primary Brands and their applications.
Related articles
Insight
Bulk emulsions product range and applications
Related products and services
Blasting Solutions
Bulk Systems
Blasting Solutions
ANFO
Blasting Solutions
Aquacharge™
Blasting Solutions
Centra™
Blasting Solutions
Civec™
Blasting Solutions
Flexigel™
Blasting Solutions
Fortan™
Blasting Solutions
Fortis™
Blasting Solutions
Subtek™ Bulk System
Blasting Solutions
Vistis™
Blasting Solutions
4D™ Bulk System
Blasting Solutions
Vistan™
Blasting Solutions
Delivery Systems
Blasting Solutions
Services
