Patent ID: 7727384

Claim:
A bitumen recovery process comprising the following steps: (a) providing a bitumen froth or a component derived from the bitumen froth as a feed material, wherein the bitumen froth is produced in a primary separation process from a slurry comprising oil sand and water; and (b) subjecting the feed material to froth flotation in a column flotation cell in order to recover a bitumen product from the feed material, wherein the column flotation cell is comprised of an upper end and a lower end, a feed inlet for introducing the feed material into the column flotation cell, an aeration bubble inlet for introducing a supply of gas bubbles into the column flotation cell, an underflow outlet for removing an underflow stream from the column flotation cell, and an overflow outlet for removing the bitumen product from the column flotation cell, wherein the underflow outlet is located adjacent to the lower end of the column flotation cell, wherein the overflow outlet is located adjacent to the upper end of the column flotation cell, wherein the aeration bubble inlet is located between the underflow outlet and the overflow outlet, wherein the feed inlet is located between the aeration bubble inlet and the overflow outlet, and wherein subjecting the feed material to froth flotation in the column flotation cell is comprised of: (i) introducing the feed material into the column flotation cell at the feed inlet; (ii) introducing the supply of gas bubbles into the column flotation cell at the aeration bubble inlet so that the gas bubbles rise in the column flotation cell toward the overflow outlet; (iii) contacting the feed material with the supply of gas bubbles as the gas bubbles rise in the column flotation cell so that a bitumen-rich fraction of the feed material is assisted in rising in the column flotation cell toward the overflow outlet; (iv) passing the bitumen-rich fraction of the feed material through an underwash zone of the column flotation cell located between the feed inlet and the overflow outlet of the column flotation cell as the bitumen-rich fraction rises toward the overflow outlet, wherein the underwash zone is comprised of a layer of an underwash water contained in the column flotation cell; (v) removing the bitumen-rich fraction of the feed material from the column flotation cell at the overflow outlet as the bitumen product; and (vi) removing the underflow stream from the column flotation cell at the underflow outlet.