ABSTRACT Quicklime quality emerges from coupled thermal history and feed attributes. Temperature, residence time, particle size, and composition govern decarbonation kinetics, pore evolution, and sintering, with direct consequences for reactivity and durability. This review synthesises evidence from X-ray diffraction, scanning electron microscopy, BET surface area, ICP-OES chemistry, and thermogravimetric analysis, linking laboratory indicators to standard reactivity tests and plant performance. We benchmark preparation, calibration, acquisition settings, and quantification practices; identify typical bias sources; and propose harmonised reporting to enable cross-study comparisons. A PRISMA-guided synthesis of 42 full-text studies defines safe operating windows that achieve completion without excessive densification. Figures and tables provide a concept map, PRISMA flow, technique essentials, bias countermeasures, an evidence map organising temperature–time–size–composition effects, and a plant translation checklist. The review concludes with actionable recommendations for kiln set-points, residence-time corridors, and feed conditioning to minimise energy use while meeting product specifications.