Job Description: TOBERITE® Shotcrete used in Mining
The mining sector currently uses a Fibrecrete mix design for all shotcrete applications for example:
- Ground support
- In-cycle development
The mining sector requires a minimum re-entry time of 2 hours, accelerants are used in the Fibrecrete mix to help ensure they achieve this.
The mining sector is currently investigating solutions to improve the overall performance of Fibrecrete applications in their operations.
Seels technology achieved great success in the testing of TOBERITE® Shotcrete and believed it would provide suitability for the mining sector. Seels Technology approached the geotechnical team regarding results achieved in commercial shotcrete and were invited to complete a series of in-situ trials on an underground operation to test TOBERITE® in a mining context.
TOBERITE® was sprayed at different locations within the mine with various mix designs tested.
Results demonstrated that the inclusion of TOBERITE® atoms achieved;
- Easy integration to standard batching procedure and equipment: no change to equipment or existing batching standard process was required
- No blockages: no blockages occurred during any of the application despite low slump levels
- Early stabilisation: all mixes compacted well and stabilised on faces and structures
- Workability: maintains adhesion during application in cases even when ground water seepage appeared on the substrate
- Lower rebound: visibly lower rebound
- Reduction of constituent volumes: higher level of compaction and compressive strength using fewer volume of fibres similarly when a lower cement quantity was used
OVERALL FEEDBACK FROM GEOTECHS AND OPERATORS
“No issues with batching process”.
“No issues with TOBERITE® Atoms flowing through nozzle”.
“Mix stabilized well and withstood seepage on rock face, stood up well with and without accelerant, more cohesive mix than normal – bowl was clean, friction proof of concept held true”.
“Noticeably lower rebound, good body, surprised how it sprays given low slump, agi bowl cleans out easier – no residue, and better finish as the Atoms don’t pro/trude from face lining”.
“Mate I would spray this all day every day if you could get it to me”.
“The mix builds up faster than conventional mix and were able to spray thicker passes”.
“When a single TOBERITE® Atom was removed from the mix the Fibres had attached themselves to the single atom, proving an alliance between the Fibres and Atoms”.
FINDINGS TO TAKE AWAY AND ANALYSE
- Spray angle was more critical for TOBERITE® than conventional mix at a low slump
- Noticeable rebound at very low slump (45 slump)
- Couldn’t use probe to test thickness (very compressed)