Specialization of Rare Earth Deposits According to the Elemental Composition of Their Ores

In the 21st century, the scale of the use of rare earth elements (REEs) by industry has been increasing at a high rate. However, the demand for individual REEs is growing unevenly: for some elements, the growth in demand is very large, while for others it is less significant or absent. Due to disproportions between the capabilities of the currently exploited resource base and the consumption of individual REEs, prices for scarce praseodymium, neodymium, and heavy lanthanides are from one to two orders of magnitude higher than for other REEs. The importance of these elements for both traditional and innovative sectors of modern industry makes them not just scarce, but critical. Therefore, exploration companies around the world consider the discovery of deposits with an increased proportion of these deficient REEs as a big bonus. At the same time, exploration work of the initial stage is often carried out without a preliminary strategy, since the scientific and methodological literature does not contain empirically substantiated data on possible variations in the fluctuations in the ratios between scarce and nondeficient REEs in deposits of different types. Data on the distribution of REEs in ores from 127 REE deposits from all over the world were collected and compared for the first time. The deposits represent nine metallogenic types that have attracted interest from exploration or mining companies in recent decades. Possible ranges of values were established for the relative proportions of deficient REE groups. For some types of deposits, mineralogical or geological features have been established that affect the increase in the proportion of deficient REEs in ores. The data obtained quantitatively mark the boundaries of specialization of different types of REE deposits in terms of the most requested groups of REEs. Such information enables specialists to more targetedly carry out regional forecasting and early stage exploration to identify deposits with the desired ratio of different REE groups.