Comparing methods for reclaiming ferrofluids used in materials separation

摘要

Ferrofluids can be used for materials separation. During this process losses of the valuable ferrofluids occur when the separated materials are washed. By reclaiming the fluids from the wash liquid, the costs of separation are reduced so that materials with low added value can be separated economically. This paper compares four methods for reclaiming ferrofluids. Small-scale tests were conducted on chemical precipitation, freeze crystallization, nanofiltration and evaporation. The currently feasible methods are nanofiltration and evaporation, so these are also economically compared. What method or combination of methods is economically and technically most attractive, will vary with site specific conditions. In general nanofiltration is found to be the economically most attractive option. These results present strong growth opportunities for separation by ferrofluids.