Apparatus and method for refining a process liquor by gravity settling

A method for refining a process liquor that includes solids by gravity settling the solids in a vessel having a base and side wall that define an internal volume, the method comprising:

• (a) allowing solids in the process liquor to settle under gravity toward the base, thereby forming (i) a high solids-content slurry and a build-up of settled solids in a lower region of the internal volume and (ii) a refined liquor in an upper region of the internal volume;
• (b) extracting the high solids-content slurry and the refined liquor from separate extraction points in the vessel, the separate extraction points comprising a refined liquor outlet at or near the top of the internal volume for extracting the refined liquor and a slurry outlet at or near the bottom of the internal volume for extracting the slurry, wherein the slurry outlet is unrestrictedly open to said internal volume;
• and
• (c) operating solids displacement elements extending across and fixed relative to the vessel, for directing settled solids and/or settling solids in the vicinity of the side wall or of the base toward a flow path of high solids-content slurry being extracted from the vessel through the slurry outlet.

An apparatus for refining a process liquor that includes solids, which apparatus includes:

• (a) a vessel having a side wall and a base extending downwardly and inwardly from the side wall to a bottom of the vessel, the side wall and the base defining an internal volume for containing the process liquor and for allowing gravity settling of the solids in the liquor, whereby to produce a refined liquor toward a top of the internal volume and a slurry toward the bottom of the internal volume;
• (b) a refined liquor outlet at or near the top of the internal volume for extracting the refined liquor;
• (c) a slurry outlet at or near the bottom of the internal volume for extracting the slurry, unrestrictedly open to said internal volume, wherein the apparatus is configured such that the slurry follows a downward flow path through the internal volume to the slurry outlet;
• and
• (d) solids displacement elements connected to at least one of the side wall and the base and extending across and fixed relative to the vessel, wherein the solids displacement elements are disposed within the internal volume and spaced upwardly from the bottom of the internal volume, for directing settled solids and/or settling solids in the vicinity of the side wall or of the base toward the flow path of the slurry being extracted from the slurry outlet.