Rheology of Paste in Mine Backfilling: Mechanisms, Models, and Key Influencing Factors

The rheological behavior of paste in mine backfilling systems is governed by multiple coupled mechanisms, including particulate structure evolution, time-dependent effects, spatially heterogeneous flow, and scale dependence. As a result, its macroscopic response cannot be adequately described by a single material parameter or purely local constitutive relations. Although significant progress has been made in experimental characterization and empirical modeling, rheological parameters reported under different conditions remain difficult to reconcile, highlighting the limitations of existing models in capturing structural evolution and nonlocal effects. This review provides a concise synthesis of current advances in paste rheology for mine backfilling applications, with emphasis on yield behavior, shear-rate-dependent nonlinear flow response, thixotropy, and shear history effects. The applicability and limitations of commonly used rheological models, including the Bingham and Herschel–Bulkley models, are critically examined. Key factors influencing paste rheology—such as particle gradation, temperature, and chemical additives—are discussed from a structure-controlled perspective. Finally, physics-constrained data-driven approaches are highlighted as a promising direction for improving the description and prediction of complex rheological behavior. Overall, this review emphasizes the need to balance experimental observability, model simplicity, and physical consistency, and highlights the importance of linking microstructural mechanisms, scale effects, and macroscopic rheological response to establish more unified and engineering-relevant frameworks for paste rheology in mine backfilling systems.