Ore Competence, Mineral Texture and Feed Variability: Screening Criteria for HPGR Applicability

High-pressure grinding rolls (HPGR) are evaluated as a potential energy-efficient comminution option, but ore competence indices alone cannot establish their suitability across variable geological domains. This critical narrative review organizes a supplied, non-systematically assembled bibliography of 131 records around ore texture, confined-bed response, feed conditioning, representative sampling, circuit boundaries, and industrial transferability. The contribution is a proposed FEL-1 decision framework combining a staged evidence-gated workflow, a qualitative feed-sensitivity matrix, a source-traceability register, and a risk envelope that distinguishes tested from untested feed conditions. Published examples with identifiable methodological detail are differentiated from metadata-only bibliographic context and author-proposed engineering criteria. No new experiments, pooled performance estimates, universal acceptance thresholds, or validated prediction of plant performance are reported. The framework is intended to make outstanding risks and evidence requirements explicit before circuit selection.