Mining & Mineral Processing
Solvent extraction (SX) has been the predominant method of copper recovery in mining applications. While solvent extraction processes are adequate for high-grade ores, selective ion exchange (IX) has proven more economical, particularly for copper recovery from lower-grade sources of copper (those producing pregnant leach solution grades less than about 1.0 g/L).
Dow has developed a number of selective IX resins for the capture, recovery, and purification of copper. The resins selectively remove copper from a background high in iron or other metals. Using these Dow resins, very high purity cathode copper can be produced even without electro-refining:
DOWEX™ M4195 Chelating Resin is highly-selective for copper in acidic conditions. Elution is accomplished with an ammonium solution.
DOW™ XUS 43605.00 Developmental Chelating Resin is highly-selective for copper and is used when elution with sulfuric acid is desired.
For a description and advantages of the continuous ion exchange process to recover copper with Dow resin, read the pilot test results published in 1998.
NOTICE:If products, such as DOW™ XUS products, are described as “experimental” or “developmental”: (1) product specifications may not be fully determined; (2) analysis of hazards and caution in handling and use are required; (3) there is greater potential for Dow to change specifications and/or discontinue production; and (4) although Dow may from time to time provide samples of such products, Dow is not obligated to supply or otherwise commercialize such products for any use or application whatsoever.
Acid Rock Drainage (ARD)
DOWEX™ M4195 Chelating Resin may be an excellent choice for many ARD applications. This resin has extreme selectivity for copper and high removal efficiency so effluent streams have extremely low concentrations of copper, even at very low pH.
Copper is often a problem metal in precious metal and trivalent chromium plating operations. The distinct ability of DOW™ XUS 43578.00 Developmental Chelating Resin to selectively sorb Cu2+ from strongly acidic media makes it an excellent choice for applications like removal of copper from trivalent chromium baths and from bright-dip rinse applications in aluminum finishing processes. DOW XUS 43578.00 Resin offers exceptional kinetics due to its uniform particle size distribution. In systems requiring lowest pressure drop, DOWEX™ M4195 Chelating Resin will be preferred.
AMBERLITE™ IRC748i Chelating Resin is used to remove copper from copper plating rinse streams.
In some solutions of hydrochloric acid, copper forms anionic complexes that can be captured using a strong base anion exchanger like DOWEX 21K XLT Resin.
NOTICE: If products, such as DOW™ XUS products, are described as “experimental” or “developmental”: (1) product specifications may not be fully determined; (2) analysis of hazards and caution in handling and use are required; (3) there is greater potential for Dow to change specifications and/or discontinue production; and (4) although Dow may from time to time provide samples of such products, Dow is not obligated to supply or otherwise commercialize such products for any use or application whatsoever.
Printed Circuit Board & Electronic Chips
Current technology for high-speed data chips incorporate copper conductors. Several chip manufacturers have already discovered the phenomenal selectivity, capacity, and acid processing capability of DOWEX™ M4195 Chelating Resin, making it well-suited for this application area. Due to its uniform particle size, DOW™ XUS 43578.00 Developmental Chelating Resin should also be considered to take advantage of improved resin operating capacity and more efficient regeneration.
Removal of copper from water and organic solvents is fairly common using strong acid cation resins. For waters with low levels of salt content, a strong acid cation resin such as DOWEX™ G 26 (H) Resin would be a good starting point. In addition, a weakly acidic cation exchange resin like DOWEX MAC 3 Resin is often quite selective for multivalent ions such as Cu2+.
If the wastewater is highly acidic, DOWEX M4195 Chelating Resin should be used.
“Copper Recovery from Leach Liquors Using Continuous Ion Exchange” by Gordon J. Rossiter and Kenneth C. Carey, Proceedings of Copper Hydromet Roundtable 98, Randol, Vancouver.
“Ammoniacal elution of copper from ion exchange resins” by Byleveld, Edward, Patent US4371506, Hemsley Engineering Ltd.