(Session 5)Process mineralogical studies in the beneficiation of rare earth element ores

摘要

Rare earth elements (REE) have gained prominence over the last few years, overconcerns of sustainable supply to meet growing global demand. With increasedefforts at finding alternatives to Chinese supply for this critical commodity, attentionhas shifted to the potential exploitation of REE deposits all over the world. In order tocompete in a fluctuating market for REE, the feasibility of mining and extraction mustbe proved. Deposits of REE occur in a variety of geological settings, resulting invariability in the mineralogy of the REE and gangue minerals from one deposit toanother. Consideration of the type, size and liberation characteristics of the REEminerals, as well as the gangue minerals present and their textural association withREE minerals, is therefore of utmost importance when designing the metallurgicalflow sheet for a particular style of mineralisation. A carbonatite-derived ore is considered, to illustrate how mineralogy affectsprocessing options for REE extraction during scoping testwork. Differentcombinations of hydrometallurgical testwork were used in flowsheet developmentwork, with resultant products mineralogically characterised to assess ore andintermediate product response in each instance. The results confirm that alteration styles of carbonatite derived ores impact on,particularly, gangue mineralogy, such that different approaches must be taken forREE extraction.