Abstract: An improved method for retorting oil shale with heat-carrying bodies comprising relatively coarse attrition resistant, non-oil sorbing, shale ash particles wherein oil recovery is maximized. After retorting, the spent oil shale and heat-carrying bodies are transferred to a reheating vessel or combustor. The reheating vessel contains a dense phase fluidized bed wherein the fixed carbon contained in the spent shale is combusted at temperatures between 1100.degree. F. and 1600.degree. F. to reheat the heat-carrying bodies. The invention is based on the finding that the decomposition of kerogen, which is present as a binder in raw oil shale, leaves pores within kerogen-rich shale which results in relatively large surface areas. Attrition of the kerogen-rich shale in the dense phase fluidized bed at a superificial gas velocity of 7-14 ft/sec reduces the size of this porous, friable material and allows it to be removed in the exit gas stream as fines.