oreblocks: License-Free Synthetic Ore-Body Block Models with a Stamped Exact Ultimate-Pit Optimum

Benchmarking an open-pit optimiser, a mine-dispatch simulator, or a teaching tool needs realistic ore-body block models with a known answer, but the standard public instances (the MineLib library) are granted for academic download only and cannot be redistributed, and real mine models are proprietary. This software note presents oreblocks, a small pure-Python package that generates synthetic three-dimensional ore-body block models of the same nature as the public instances (seeded deposit archetypes with per-block grades, bench structure, slope precedence and net-value economics) and stamps each one with its exact ultimate-pit optimum. The optimum is computed by the classical reduction of the ultimate-pit problem to a maximum closure and thence to a minimum s-t cut (Picard's theorem), solved by a Dinic max-flow with self-verifying closure and value-identity checks, and every instance is emitted in exact MineLib .blocks/.prec/.upit format with a sidecar carrying the stamped optimum, so any solver can be validated against a known-by-construction answer without touching licensed data. The solver is validated independently: on all four deposit archetypes its pit value agrees with a totally-unimodular linear program solved by a separate method (SciPy HiGHS) to relative 1e-15, i.e. to machine precision, and the exact solve runs in under a second up to 32,000 blocks. The package is deterministic, MIT-licensed, and consumed by downstream pit, dispatch and haulage tools; every number and figure regenerates from the committed artifacts. Source and reproducible artifacts (MIT): https://github.com/fsantibanezleal/CAOS_OreBlocks .