An improved, energy efficient method and apparatus for conditioning of fracturing sand provides an elongated, rotatable drying/cooling shell with co-current flow of heated air and sand through the shell. Structure operable to deliver additional quantities of wet sand into the shell is provided at a zone between the shell inlet and outlet, and downstream of the point where the initial quantity of wet sand is substantially dry. The additional quantities of wet sand mix with the initial quantities of substantially dry sand in order to evaporatively dry the additional quantity of wet sand, and to cool the initial and additional quantities of wet sand.