Metal recovery process

A process for recovering a metal in its elemental state by reducing an oxide or salt of the metal with a reducing gas, comprising:

• providing a reaction vessel containing a packed bed of a packing material which is substantially chemically inert under the conditions in the reaction vessel and whose melting point is higher than the temperature at which the packed bed is maintained, the packing material being packed so as to provide void spaces in the bed through which fluid flow of the oxide or salt, reducing gas and any elemental metal formed through the bed and in intimate contact with each other and with the packing material is permitted;
• maintaining the temperature of the packed bed above the melting point of the metal in its elemental state and at a level at which substantial reduction of the metal in its oxide or salt occurs by reaction of the oxide or salt with the reducing gas;
• introducing the metal oxide or salt and the reducing gas into the reaction vessel wherein the metal oxide or salt and reducing gas react to form the metal in its elemental state and passing a reaction mixture comprising the elemental metal formed, any gaseous product formed, any unreacted reducing gas and any unreacted fluid metal oxide or salt downward through the void spaces within the packed bed so as to effect intimate contact between the unreacted fluid metal oxide or salt, the unreacted reducing gas and the packed bed to thereby promote heat transfer therebetween and reaction of the unreacted fluid metal oxide or salt with the unreacted reducing gas, and so as to effect intimate contact of the elemental metal formed and the packed bed to thereby promote coalescence within the packed bed of the elemental metal formed;
• permitting the reaction mixture to remain within the packed bed sufficiently long that reaction between the metal oxide or salt and the reducing gas and coalescence of the elemental metal formed are substantially complete by the time the reaction mixture passes out of the packed bed;
• and
• collecting within the reaction vessel and below the packed bed any coalesced elemental metal passing out of the packed bed.