A Forward Look into Rare Earth Supply and Demand: A Role for Sedimentary Phosphate Deposits?

Abstract

Rare earth elements, key to many high-technology applications, are regularly making headlines, even in general public newspapers. Will the word run short of rare earth elements and of the many applications that rest on their use? In support to French and European Union policy making, as well as in support to industrial clients, BRGM is monitoring rare earth markets from the supply and the demand sides, as well as for technological shifts that drive them. Not every rare earth element is effectively rare and there are well over 400 ongoing rare earth exploration projects worldwide. Nevertheless, some rare earth elements such as dysprosium, europium and terbium are rare, in high and fast growing demand; as they either are indispensable to the production of Fe-B-Nd (Dy) permanent magnets, the highest performance magnetic material currently being available at industrial scale, or to the production of phosphors essential to the production of fluorescent compact, energy saving, light bulbs and video displays. At the current 10% compound annual growth rate of the demand for these elements, the question arises of their the future availability. Among the many rare-earth bearing minerals apatite is of particular interest as a potential source of rare earth elements, as it is a widespread mineral, forming huge deposits such as the sedimentary and magmatic phosphate deposits. An overview of the potential of sedimentary phosphate deposits as an important source for future rare earth production is presented and discussed.In addition to knowledge about the distribution and concentration of individual rare earth elements in sedimentary phosphate deposits, it is also necessary to understand the partitioning of the individual elements between phosphogypsum and phosphoric acid in the fertilizer production process, as well as available technologies to recover and separate individual rare earth elements from these materials. This could pave the way to the generation of extra added-value for phosphate producers, and to the broadening of the international production base of rare earth elements in high demand by the global economy. The many applications of rare earth elementsAccording the International Union for Pure and Applied Chemistry (IUPAC), rare earth elements (REE) are a group of 17 elements with closely related physical and chemical properties, the 15 lanthanides plus scandium and yttrium. As scandium occurs in different ore deposits than the other REE, only the 16 other elements are further considered and discussed here. Those 16 elements are commonly divided into two groups [1]: the light rare earth elements (LREE) : lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm) and samarium (Sm);

Rare earth elements and select actinoids in the Canadian House Dust Study

“…The REE intercorrelations would also be consistent with dust generated from building materials, as the REE occur together with actinoids U and Th in certain raw materials (such as ion‐absorbing clays, sedimentary phosphates, and phosphogypsum) used for manufacturing building materials such as ceramic tiles, cement, plaster, and plaster‐board . REE mixtures also occur in mineral fertilizers, either unintentionally as phosphate impurities or intentionally to improve crop yields . Finally, significant intercorrelations of REE in house dust could also arise from REE mixtures introduced into consumer products (intentionally or unintentionally), especially as it is very difficult to separate and purify REE due to their similar chemistry…”

Marine Phosphorites as Potential Resources for Heavy Rare Earth Elements and Yttrium

“…Consequently, a search for such deposits with the largest HREY/LREY ratios would help alleviate the supply/oversupply problem. (7) Land-based phosphorite deposits offer a similar potential REY resource as a byproduct or co-product of the focus phosphate mining (e.g., [6,7]). Recovery of these land-based REY would require the addition of costly infrastructure and changes in extractive processing to the existing mining operations.…”

“…For example, it would be beneficial to change the dissolution acid from sulfuric acid, which produces phosphogypsum as a waste product, to hydrochloric acid. This would alleviate processing a second solid for recovery of the REY partitioned into the phosphogypsum phase (e.g., [6,8]). Production of REY as a byproduct or co-product of phosphate mining needs to be considered in the early stages of planning for a new terrestrial or marine mining operation.…”

“…The large land-based carbonatite REY ores contain more than 99% light REY (LREY) and new mines put into operation for recovery of the undersupplied heavy (HREY) as a consequence could create an oversupply of LREY to the market (e.g., [6]). Consequently, a search for deposits with the largest HREY/LREY ratios would help alleviate the supply problem and marine phosphorites might be able to fill that need.…”

An adjustment in regulation policies and its effects on market supply: Game analysis for China’s rare earths

“…Because of their wide use, rare earths are indispensable elements in modern industry; thus, increasing numbers of studies focus on rare earths demand, supply and prices. Golev et al (2014) and Christmann (2014) provided overviews of existing and emerging rare earths supply chains outside of China and concluded that China's rare earths monopoly will be shaken by diversified supply in the near future. However, Massari and Ruberti (2013) indicated that there will be a shortage of rare earths in the future and that prices will rise sharply.…”