evolved moisture through the illustrated stage drying operations however deep beds of pellets can be applied to enhance the reduction reactions of gasification recycled warm low btu gas and medium btu gas can be used as a drying medium as indicated in fig2 a series of bins 72 74 and 76 respectively contain high carbon 1 4 inch returns 1 4 inch shale and 2 inch 1 4 inch shale as the primary feed the 1 4 inch portions are fed to a ball mill 78 for fine grinding to 65 mesh and this material is fed to three balling machines 80 82 and 84 where the material is balled to about 1 inch 1 4 inch green pellets with moisture additions a hearth layer of 2 inch 1 4 inch recycle material with a high carbon content is applied directly to a traveling grate 86 through a bin 88 pellets formed by the balling machine 80 are fed to a bin 90 and are layered onto the hearth layer at a depth of about 12 inches recycled 2 inch 1 4 inch material is applied to the first layer of green pellets through a bin 92 and is struck off by a wall 94 of the bin the thus far deposited material passes through a hood 96 where the green pellets are dried by low btu gas from a gasifying zone 98 green pellets from the balling machine 84 are deposited onto the layered material through a bin 100 a further layer of 2 inch 1 4 inch recycle material is deposited on the green pellets through a bin 102 and the recycle material is struck off by a.