Abstract
A future perspective of the supply of mineral resources is discussed on the basis of the example of rare earth elements (REE). Rare earth elements have been produced from monazite, bastnäsite, and ionic clay ores mostly in China during the last two decades. However, Chinese resource nationalism over the production and export has made the supply of REE unstable in terms of price and quantity. A possible alternative REE source is phosphate ores, which contain a few amount of REE as impurities with some toxic and radioactive elements. Despite low in REE concentration in phosphate ores, more than 300,000 tons of REE (as oxides), which correspond to more than two times of present-day REE demand in the world, are included in the ores annually produced from the mines for fertilizer production. The recovery of REE with other impurities from phosphate ores is beneficial not only to produce REE but also to avoid pollution in farming lands. While our society shifts from the plundering one to the sustainable one, in which mineral resources would be completely recycled, it is desired to recover all the by-product elements from the major ores in order to decrease the impacts on the environment and trigger innovations in the manufacturing industry.
