Patent ID: 7981468

Claim:
A method of treating the surface of particles of a particulate matter with surface treating particles, comprising: providing an airflow chamber and a mixing chamber, the chambers being connected by a plurality of nozzles arranged around the perimeter of the mixing chamber, each of the nozzles being skewed relative to a radial direction; introducing a flow of pressurized process air into the airflow chamber so that process air flows through the nozzles into the mixing chamber to create a centrifugal flow of pressurized process air therein; combining particulate matter and surface treating particles; injecting the combined particulate matter and surface treating particles into the mixing chamber, the mixture being carried by an injection flow of pressurized air; adjusting an outlet means to vary an output gap to have a selected open area, so that the residence time of the combination within the mixing chamber is controlled to achieve a desired level of embedment of the surface treatment particles in the particulate matter.