Cemented Paste Backfill Engineering for Mining Applications

Cemented paste backfill (CPB) engineering has emerged as a pivotal solution for the sustainable management of mining voids, transforming fine tailings into structural support within underground excavations. By blending mine tailings, water and a binder—often Portland cement or alternative pozzolans—CPB achieves a controllable yield stress that enables safe pumping through pipelines and layer‐wise deposition in stopes. On curing, hydration products such as calcium silicate hydrates and ettringite bind particles into a cohesive matrix, delivering uniaxial compressive strengths sufficient to stabilise adjacent ore pillars and limit subsidence. Mix design parameters—including solid content, binder‐to‐tailings ratio and additive selection—govern both the fresh‐state rheology and hardened mechanical performance. Modern CPB practice balances operational cost, waste valorisation and geotechnical safety, with an increasing focus on low‐carbon binders and real‐time monitoring to ensure global applicability and environmental compliance.

Research from Nature Portfolio

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Research from all publishers

Recent studies have advanced our understanding of CPB flow dynamics, strength development and microstructural evolution. A 2023 investigation employed a thin‐film lubrication model to capture the confined yield‐stress flows of paste within stopes, revealing two distinct filling regimes controlled by dimensionless parameters; laboratory trials using realistic lead–zinc and nickel tailings confirmed the model’s predictive power. Work on alkali‐activated slag binders demonstrated that such mixes follow a Bingham rheology, with higher binder contents and specific silicate moduli accelerating the gain in yield stress and plastic viscosity; comparative tests showed these systems to outperform conventional Portland‐cement CPB in pumpability, especially under varying temperature conditions. Foundational experiments on gold mine tailings examined the relationships among solid content, cement‐to‐tailings ratio and curing time, linking increases in solid fraction to steeper viscosity curves and greater uniaxial compressive strength; scanning electron microscopy revealed the formation of ettringite and calcium silicate hydrates as key to long‐term performance, guiding efficient mix designs that reduce binder consumption and operational expense.

Cemented Paste Backfill Engineering for Mining Applications publication trend

The graph below shows the total number of articles in cemented paste backfill engineering for mining applications across all publications each year (not limited to Nature Index journals).

Technical terms

Cemented paste backfill (CPB): A mixture of mine tailings, water and cementitious binder used to refill underground voids.

Yield stress: The minimum shear stress required to initiate flow in a non‐Newtonian slurry.

Rheology: The study of flow and deformation of fresh CPB mixtures, including yield stress and viscosity.

Uniaxial compressive strength (UCS): The maximum axial load a cured CPB specimen can sustain under one‐dimensional compression.

Hydration products: Solid compounds (e.g. calcium silicate hydrates, ettringite) formed during binder hydration that impart strength to CPB.

References

1. Confined yield stress lubrication flows for cement paste backfill in underground stopes. Cement and Concrete Research (2023).
2. Influence of Solid Content, Cement/Tailings Ratio, and Curing Time on Rheology and Strength of Cemented Tailings Backfill. Minerals (2020).
3. Rheological Properties of Cemented Paste Backfill with Alkali-Activated Slag. Minerals (2020).
4. Evaluation of Viscosity, Strength and Microstructural Properties of Cemented Tailings Backfill. Minerals (2018).