Coarse particles require distinctly different conditions to their fine and intermediate counterparts for successful flotation and recovery to the concentrate launder. These range from simple operational requirements such as shallow froth depth, reduced impeller speed and higher collector dosage to those that must be optimised specifically for the coarser size fractions such as air addition rate and bubble size, as well as the chemical environment (pH). This paper is the first of a series of publications on the topic of flash flotation and reviews many of the factors that affect coarse particle flotation with a view to how they impact the flash flotation process. A review of the current state of knowledge of the flash flotation process is presented and raises a number of issues in regard to both current operational knowledge and modelling practices. (C) 2012 Elsevier Ltd. All rights reserved.