Recipe optimisation ensures operating cost efficiency while meeting the minimum required backfill strength underground and ultimately satisfies the current and future production profiles of a mine. The key to recipe optimisation is to limit the amount of binding agent necessary to meet both the short and long-term strength requirements, while maintaining a flowable backfill product. Cement screening and quality tests are key to ensuring an optimised backfill recipe. Determination of the type of fill suitable for the specific application (hydraulic, paste, rock/aggregate) is key to ensure long term sustainability of a mine’s backfill system.
Flowsheet development of the backfill preparation process from trade-off level to detailed design, incorporating the optimised backfill recipe design, mass balance, binder addition and trim water requirements.
Backfill and Grout systems are designed to offer solutions suitable to the type of fill (hydraulic, paste, rock/aggregate). SSBS provides optimal designs to ensure safety and limit wear during long term operation. Solutions include hydraulic, mechanical and structural designs.
SSBS has extensive experience in the design and field monitoring of shotcrete barricades and fill fences. An integrated design process is followed when designing barricades or fill fences by considering the construction methodology, backfill procedure employed by the mine, fill type and stope drainage requirements. The expected stresses developed in the barricade, due to various loading conditions are determined by considering the backfill properties, stope dimensions and placement strategy. Preliminary barricade dimensions are determined and the capacity of the barricade is confirmed for various design loading conditions using 3D analysis structural software.
A suitably designed drainage system forms part of the barricade design process, when required. The size and type of drainage system depends on the fill type, seepage water and backfill permeability properties.
SSBS has a fully equipped laboratory where standard and custom drainage tests are undertaken to determine the permeability and drainage properties of the backfill. SSBS has designed and implemented a number of underground pressure monitoring systems which range from basic field monitoring to state of the art data logging and monitoring systems with live data available on-line.
On site audits of backfill or grout systems are provided to identify system bottlenecks, confirm actual plant throughputs and determine the required throughputs to meet production profiles. Through a systematic audit procedure, areas of non-conformance are identified, processes are optimised and downtime is reduced in order to meet the required current and future production profiles.
SSBS provide suitably experienced staff to assist in bringing the backfill plant to full production while confirming the correct backfill product is produced and placed underground.