Investigating Precipitation Behavior of Leached Allanite Rare Earth Ore in Sulfate Solution System - 2022

Uranium (Nuclear Minerals) / Exploration, Mining, Marketing, & Acquisitions

Dailey and 4 co-auithors reported in 2022 on:

• Rare earth elements (REEs) (i.e., scandium, yttrium, lanthanoids) have significant value for energy infrastructure, decarbonization, and defense technologies.
• Recent studies on allanite REE ore:
           Identified and characterized mineralogy and liberation potential.
           Assessed comminution and beneficiation potential.
           Compared REE recovery of direct sulfuric acid leaching to sulfuricacid baking.
•  Purification of the leachate typically follows leaching in most hydrometallurgical process flowsheets.
•  Precipitation is the selective removal of one or more major impurities (i.e., undesirable metal ions) via precipitation [1].
•  Before the final step in the hydrometallurgical process (i.e., metal recovery), targeted removal of unwanted species without significant loss of   valuable metals must occur.
•  The goal of this research is promoting a deeper understanding of the
   precipitation behavior of allanite systems in sulfate solutions.

The authors concluded that:

• The minerology present in different allanite bearing ores may impact precipitation behavior.• Core material appears to have half ferric iron.
• Surface material appears to have predominantly ferrous iron.
• Particle size does not appear to have an impact on precipitation behavior.
• Thus, particle size should be selected to maximize upstream performance.
•  Single stage precipitation of direct leached 500 μm core concentrate at pH 5 could further support large scale, low-cost process [2].

Further research questions need to be addressed include:

• Can peroxide reduction improve TREE and Fe separation?
• How do carbonate precipitants affect precipitation behavior?