Abstract: A bulk hopper tank assembly which has a bulk hopper tank containing an opening at the top end thereof wherein a lid assembly selectively covers the opening. The lid assembly includes a lid, a generally vertical arm extending along the exterior side of the bulk hopper tank, and a generally horizontal arm connecting the lid and the vertical arm. A lifter connects to the vertical arm and is moveable between a down position in which the lid covers the opening in the bulk hopper tank and an up position in which the lid is vertically above the opening in the bulk hopper tank. A handle connects to the vertical arm and is moveable to a plurality of positions between a first position in which the lid is in the vertical volume of the opening and a second position in which the lid is outside of the vertical volume of the opening.

Abstract: Oil shale is mixed and retorted with hot porous pellets. The porous pellets have a surface area of at least 10 square meters per gram. Iron oxide is deposited or impregnated on the pellet surface area prior to retorting. The iron oxide imparts special properties to the pellets. After retorting, the pellets are separated from the processed oil shale solids, reheated and returned to a retort. At least a portion of the pellets are separated by a magnetic separator.