Patent CA-2317289-A1 (CA)
Inventor: NEUMAN MARK
IPC: C22B15/00
Filed: 2000-09-01
Abstract: A modular solvent extraction plant for extracting metal from a metal ore includes a stage-wise, plug flow contactor that mixes an aqueous solution and an organic solvent solution into a mixed emulsion, a reactor to further mix the solutions, a separator having a first section comprised of coalescing material for breaking up the emulsion and a quiet zone for a further separation by gravitational forces of the aqueous solution and the organic solution, a loaded organic coalescer that removes aqueous entrainment from the organic solution, a raffinate coalescer that removes organic entrainment from the aqueous solution, a second stage-wise, plug flow contactor that mixes an electrolyte solution with the organic solution from the loaded organic coalescer to form a second mixed emulsion, a second reactor that further mixes the solutions, a second separator having a first section comprised of coalescing material for breaking up the second emulsion and a quiet zone for a further separation by gravitational forces of the electrolyte solution and the organic solution, and an electrolyte coalescer that removes organic entrainment from the electrolyte solution. Another aspect of the present invention is a method for making this modular plant. This modular plant can be made by mounting each of the contactors, reactors, separators, and coalescers on a movable structure and then connecting the apparatus with piping. Still another embodiment of the present invention is a process for obtaining metal from its corresponding metal ore using the plant of the present invention. This process involves extracting metal from a pregnant leach solution using an organic solution and then stripping this metal from a loaded organic solution using an electrolyte solution. The extraction step involves feeding a pregnant leach solution and an organic solution through the stage-wise, plug flow contactor, the reactor, the separator, and the loaded organic coalescer, which are connected in series as described above. The stripping step involves feeding the loaded organic solution and an electrolyte solution through the second stage-wise, plug flow contactor, the second reactor, the second separator, and the electrolyte coalescer, which are connected in series as described above.    An organic scrub station may be used in place of the loaded organic coalescer. It is comprised of a stage-wise, plug flow contactor, a separator connected to said contactor having a first section comprised of coalescing material and a quiet zone for a final separation, a coalescer connected to the loaded organic solution that exits from the separator, and a contaminant removal station connected to the scrub solution that exits the separator. The present invention further includes a process for removing contaminants comprising using the organic scrub station described above. More specifically, this process for removing contaminants involves mixing a scrub solution and a contaminant rich loaded organic solution, wherein contaminants are transferred to the scrub solution; separating the solutions; polishing the loaded organic solution by feeding the loaded organic solution through a coalescer so as to remove scrub solution entrainment; removing contaminants from the scrub solution; and recycling the scrub solution so that the scrub solution may be used to pick up additional contaminants.