Paste Technology / Paste Backfill
Backfill materials are used to fill voids in the mine which have been created by the mining excavation process. The materials normally used for backfill can either be traditional hydraulic fill materials such as tailings, sand, rock or cement or they can be a technologically progressive fill material such as paste which uses the same base materials but in a different way.
With a reduced need for barricades, drainage systems or cleanup of water slimes, and a quick setting consistency and minimal segregation, the application of a paste backfill could result in increased mining productivity and reduced operating costs as compared to traditional hydraulic fill methods.
The design of any paste backfill plant is driven by such factors as tailings material property, compressive strength required of the backfill, location of the plant with respect to targeted stopes, available static heads and horizontal distances between the plant and current and future mine workings.
The potential advantages of paste backfill over hydraulic fill include reduced binder consumption, better slimes handling, faster stope piling and curing cycle time, as well as a reduced surface disposal footprint.
Paste backfill applications have been used very successfully in the mining industry as a method of ground control and are a proven method of recovering pillars and increasing reserves. They generally require less cement than hydraulic fill to achieve the target strength, which is usually the primary contributor to the operating cost of placing backfill.
As an underground construction material in the mining industry, a well engineered paste backfill can provide:
- A floor to mine on
- A wall to mine next to
- Head cover to mine under
- Primary ground support
- A major mine waste disposal method
The benefits of utilizing paste technology in a backfill application include:
- Lower cement content
- Lower requirement for drill holes
- Utilization of surplus / waste materials readily available on site
- Complete filling of a void to the back of the opening
- Engineered achieved strengths in the paste mix design
- Flexibility in formula design for different applications
- Reduced stope cycle time
- Reduced mine dewatering costs
- Reduction of in-rush risk in the mine
