But How about the heat launched in the course of clinker cooling or even the drying processes? Industry reports estimate that just about 40% of all energy inputs in cement manufacturing are wasted as a result of heat loss, largely by way of outdated cooling methods and poorly insulated kilns. https://purethermal.co.uk/media-news/november-launch-waste-heat-recycling-design-support-service-from-pure-thermal-and-oilon/