Particle beds exhibit a wide range of temporal scales from short-lived micromechanics to slow, macroscopic heat transfer. Our data-assisted approach decouples fast from slow degrees of freedom under steady conditions of the bed dynamics. After the granular velocity has been obtained from short simulations with computational fluid dynamics coupled to the discrete element method (CFD-DEM), particle motion takes place on this prescribed field with the interstitial fluid phase and heat transfer governed by their usual equations of motion (EOMs). We validated the approach on a small-scale, moving bed, where we compared CFD-DEM and data-assisted CFD with tracers. Then, we proceeded to a blast furnace (BF) slot model with about 28 m height and 15 m width. Using our novel technique, we simulated particle motion through the BF including heat transfer from the hot blast for 24 h process time to obtain a thermal steady state. (C) 2019 Elsevier B.V. All rights reserved.