Variable perforation liquid-liquid extraction column

Liquid-liquid extraction column (1) comprising the following elements:

• a first injection point for a first phase (2) located at an intermediate position between the top and the bottom of the column (1);
• a second injection point for a second phase (3) and a third injection point for a backwash liquid (4), one being located at the top of the column (1) and the other being located at the bottom of the column (1);
• a first withdrawal point for an extract (5) and a second withdrawal point for a raffinate (6), one being located at the bottom of the column (1) and the other being located at the top of the column (1);
• a plurality of trays (Pi) located from the top of the column (1) to the bottom of the column (1) and defining n zones, each zone comprising at least two trays (Pi), n being between 2 and 30;
• in which the n zones comprise:
• at least one extraction zone Zi located between a zone Zi comprising the second injection point for the second phase (3), and a feed zone Zx comprising the first injection point for the first phase (2), x being greater than or equal to 1;
• and
• at least one backwash zone located between a zone Zx+1 and a zone Zn comprising the third injection point for the backwash liquid (4), n being greater than x;
• in which the trays (Pi) of the same zone have the same number of holes (9);
• and
• in which:
• when x is greater than 1, the number of holes (9) per perforated tray (Pi) of the zones Zi increases as the value i increases;
• and
• when x is equal to 1, the number of holes (9) per perforated tray (Pi) of the at least one backwash zone is less than or greater than than the number of holes (9) per perforated tray (Pi) of the zone Zi.