CCE-MultiContactor™ and Chelation Solvents Applications

Chelation Chemistry
Chelation is the use of a chemical substance to bind molecules, such as metals or minerals, and bring the resulting complex into a state where it will be soluble in water and possibly other solvents. This principle is used in the medical field to remove excess or toxic metals from the blood stream before they can cause damage to the body. It was first used in the 1940's by the Navy to treat lead poisoning.
 
The most common form of chelation therapy uses a man-made amino acid called EDTA (ethylene diamine tetra-acetic acid). EDTA removes heavy metals and minerals from the blood, such as lead, iron, copper, and calcium, and is approved by the U.S. Food and Drug Administration (FDA) for treating lead poisoning and poisoning from other heavy metals.
EDTA is also used in many industrial applications for the “Solublization” of metals so that they can be flushed out or removed from their location using a water solvent.

There are many other compounds that act as chelating agents.

This illustration shows how the EDTA molecule can block up to six reactive sites on a metal ion, completely deactivating the ion. The highly stable ring structures contribute excellent pH, heat, and lightstability to these complexes .
Fig 1 Chelation using EDTA
 

 
PWST supplied a CCE-MultiContactor to the US Department of Energy for development of a process using SelenTec chelation solvent to extract plutonium from canal soil. The test was supervisd by the Argonne National Laboratory.
 
Applications using chelation solvents identified to date include

Treated Waste Wood fibre recovery and CCA recycling
PWST are developing an application of Hogwash™ Technology process to apply chelation chemistry to remove CCA ( Copper-Chromium-Arsenic) preservatives from Treated Waste Wood (TWW).
The recovered CCA may be recycled for further use in wood preservation, or potentially recovered as metals for sale.

This technology has many applications around the world where CCA – TWW is now being removed from service because of environmental and health threats,mainly from arsenic that may be leached out.

Metal ores and tailings waste 
The ™CCE-MultiContactor together with chelation solvents provides a process to recover valuable components from metal ores and tailings. This applucation has been tested on plutonium extraction from canal soil

PWST is seeking a partner from the mining industry to pursue this application