SSBS offers a range of material property test work including Particle Size Distribution (PSD), solids density, pH, conductivity, freely and maximum settled bed packing volume concentrations and permeability (hydraulic conductivity) tests for characterization of tailings and backfill materials.
Test work capabilities includes unconfined compressive strength (UCS) test work for backfill applications. UCS tests are used to determine the strength development of different backfill mixtures and cementitious materials for different curing periods.
SSBS performs cement mortar compressive strength tests for different curing periods. This is done to test the cement for compliance with the minimum strength requirements.
Once the cement mortar compressive strengths tests are successfully concluded, UCS tests are conducted on different mix designs to optimise the cement content for a plethora of backfill strength requirements and exposures.
SSBS offers pipe loop testing services for tailings and backfill applications. Pipeline friction pressure gradients are measured in a small-scale pipe loop. The pipe loop comprises a tailings receiving and delivery tank, centrifugal tailings pump with variable speed motor, flow meter, differential pressure transmitter, clear viewing section and data logger.
Pipeline friction pressure gradients are measured in 50 NB and 80 NB steel pipes. Pipeline friction pressure gradients are measured over a range of solids concentrations, typically enveloping the design concentration. Clear viewing sections are used to observe the settling characteristics (stationary deposition velocities) of the tailings.
SSBS utilizes the small-scale pipe loop test results to determine the flow and settling characteristics of the material. In conjunction with material properties and rheology test results.
The small-scale pipe loop test results are used to support the hydraulic design of the full scale slurry transportation system.
SSBS offers rheology measurements of tailings and backfill (cemented as well as uncemented) to determine the flow behaviour properties such as yield stress and apparent viscosity. These properties form the basis for hydraulic design and modelling.
Rheology tests are conducted with a rotational viscometer with concentric cylinder measuring geometries. Rheology tests can be conducted in SSBS’ laboratory or on-site with the portable rotational viscometer.
Rheological properties are determined over a range of solids concentrations, typically enveloping the design concentration to support the hydraulic design of slurry systems. Rheology tests and analysis methodology are conducted in accordance with international test standards.
SSBS uses a falling head permeameter to determine the coefficient of permeability of backfill. The permeability of backfill is a measure of its capacity to allow the flow of a liquid through it. Tailings consist of solid particles with voids between them. In general, the voids are interconnected which enables water to pass through them. The permeability of the tailings or backfill is directly proportional to the percentage fines.
The coefficient of permeability is an important parameter which is used to design barricade drainage systems.
SSBS conducts slump tests using a standard 300 mm height slump cone and a Boger slump cylinder. The slump tests provide a visual indication of the yield stress of the tailings or backfill. The slump tests are typically done in conjunction with pipe loop and rheology tests, where applicable.
SSBS offers flow table tests to determine the workability of tailings or backfill. The average spread is measured in two directions parallel to the table edges.
SSBS offers custom-made solutions to meet client specific needs. One such example is the humidity and temperature monitor and control cabinet that SSBS developed for a client. This unit is used externally to measure and control the humidity and temperature of a curing cabinet.