Process and apparatus are disclosed for recovering liquid and gaseous fuel from solid hydrocarbon-containing mineral material such as bitumen-containing mineral materials exemplified by tar sands or oil-bearing diatomites, without expensive pretreatment to separate the hydrocarbon containing material from material containing no hydrocarbon. The hydrocarbon-containing material is agglomerated into discrete pieces that are treated on a traveling grate such as a circular traveling grate and subjected to sequential treatments in which hot gases are passed upwardly or downwardly through a relatively deep permeable bed of the pieces on the grate, in several treating zones separated by transverse gas seals and sealed at the side edges by suitable gas seals. All, or essentially all, of the heat required is obtained in a coke burn-off zone from combustion of coke that remains in the material on the grate after the volatile hydrocarbons have been removed by distillation in an earlier distillation zone. Part of the gas from the distillation zone is continually recycled to pass through the hot material on the grate in a zone following the coke burn-off zone to transfer heat by the gas to the distillation zone and to cool the spent material on the grate before it leaves the grate. Water gas may be produced by passing steam through material containing residual coke, in a treating zone following and preferably near or adjacent the coke burn-off zone. Because of high temperatures in the coke burn-off zone the agglomerated pieces are sintered, and may be glazed, to provide spent pieces that are useful and of economic value.