A method and apparatus are defined for coating a particulate material. The apparatus includes a mixer having a mixing chamber. A quantity of particulate material is fed into an inlet of the mixing chamber. An agitator is provided for mixing and conveying the particulate material. A feed system is also provided for delivery of a coating into the mixing chamber. The coating is delivered as an atomized spray directed at the mixing particulate material within the mixing chamber. A controller is provided for adjusting the flow of the coating into the mixing chamber based on the volumetric feed rate of the particulate material.