Abstract: Iron-containing refractory balls, in a retorting process for oil shale, permit effective magnetic separation of the balls from the spent shale. These ceramic balls can be made by a process such as admixing powdered alumina and water to form an extrudable mixture, extruding to form cylinders, reshaping cylinders into balls, overcoating with iron particles, further overcoating with alumina, and firing.

Abstract: Iron-containing refractory balls, in a retorting process for oil shale, permit effective magnetic separation of the balls from the spent shale. These ceramic balls can be made by a process such as admixing powdered alumina and water to form an extrudable mixture, extruding to form cylinders, reshaping cylinders into balls, overcoating with iron particles, further overcoating with alumina, and firing.

Abstract: Iron-containing refractory balls, in a retorting process for oil shale, permit effective magnetic separation of the balls from the spent shale. These ceramic balls can be made by a process such as admixing powdered alumina and water to form an extrudable mixture, extruding to form cylinders, reshaping cylinders into balls, overcoating with iron particles, further overcoating with alumina, and firing.

Abstract: Iron-containing refractory balls, in a retorting process for oil shale, permit effective magnetic separation of the balls from the spent shale. These ceramic balls can be made by a process such as admixing powdered alumina and water to form an extrudable mixture, extruding to form cylinders, reshaping cylinders into balls, overcoating with iron particles, further overcoating with alumina, and firing.

Abstract: Iron-containing refractory balls, in a retorting process for oil shale, permit effective magnetic separation of the balls from the spent shale. These ceramic balls can be made by a process such as admixing powdered alumina and water to form an extrudable mixture, extruding to form cylinders, reshaping cylinders into balls, overcoating with iron particles, further overcoating with alumina, and firing.

Abstract: Iron-containing refractory balls, in a retorting process for oil shale, permit effective magnetic separation of the balls from the spent shale.

Abstract: Iron-containing refractory balls, in a retorting process for oil shale, permit effective magnetic separation of the balls from the spent shale.

Abstract: An apparatus for recovering vapors expelled from a tank during filling. The apparatus includes a conduit arrangement for selectively conducting vapor to one of a storage tank or a vapor liquefying means. Vapor conducted to the liquefying means is contacted with refrigerated liquid for liquefaction by condensation and/or absorption. Periodically, liquid and liquefied condensable portions of the vapor are discharged from the liquefying means and are replaced with fresh liquid. A pressure controller determines the flow path of the vapor to the storage tank or the vapor liquefying means wherein only a portion of the vapor is conducted to the vapor liquefying means.