SOLVENT EXTRACTION
Solvent extraction (SX), sometimes called liquid ion exchange, is used to selectively concentrate and purify a desired element after it has been dissolved in an aqueous solution, frequently an acid leach liquor. The liquor is contacted with an organic solvent, chosen for its selectivity towards the element or elements of interest. This technology was first used by mining companies for purification of uranium and vanadium during the uranium boom after World War II, and then for copper in the early 1960s. Hazen played a major role in the development of and pilot plant work in the first commercial copper SX—electrowinning plant located at the Bluebird Mine in Arizona.
For more than 40 years, Hazen has played a significant role in the development of this technology and its transfer from laboratory experiments to commercial operation and continues to assist clients as the technology has spread to other metal recovery systems. We have the experienced staff and facilities to serve clients in all aspects of SX technology, from preliminary shakeout tests to integrated pilot plant operation that provide design and operating criteria. In addition to copper recovery, Hazen has developed SX processes to recover:
- nickel and cobalt
- uranium and vanadium
- phosphoric acid
- molybdenum
- boron and lithium
- platinum group metals
- rare earth elements
Our work has resulted in over 20 patents for SX technologies, and many operating commercial plants now utilize SX systems developed at Hazen.