Although commercial processes for the manufacture of alkaline earth metal carbonates date from the nineteenth century, the control of precipitate morphology had become regarded as an art, rather than a science. Many of the processing stages took place in empirically designed, but largely outdated, equipment operated under heavily prescribed conditions. Apprehension about changes to an existing product, unfavourable customer reaction and the demands of continuous production inhibited progress. Recently an experimental investigation of the gas-liquid-solid contacting stage has been carried out. Scale-up experiments from a 5 litre laboratory vessel, through pilot scale, to a 5 m(3) plant reactor has confirmed that morphology, particle size and distribution can be improved using modern proprietary, or in-house designed, reactors run using relatively simple operating procedures. On a laboratory scale, the latest design gives better than 75% utilization of carbon dioxide during the carbonatation stage and promises very significant cost savings. A complete process featuring this gas-liquid-solid reactor, currently undergoing pilot scale assessment for commercial exploitation inside one year, is outlined.