Engineering and Mining Journal - Whether the market is copper, gold, nickel, iron ore, lead/zinc, PGM, diamonds or other commodities, E&MJ takes the lead in projecting trends, following development and reporting on the most efficient operating pr
Issue link: https://emj.epubxp.com/i/887604
RECLAIMING RARE EARTHS OCTOBER 2017 • E&MJ; 65 www.e-mj.com The day may come when a coal miner pro- cesses waste and overburden to commer- cially produce rare earth elements (REEs) for domestic and foreign markets. If the government, a handful of academics, and some dedicated companies have anything to do with it, that day may arrive with- in a half-decade. Meanwhile, high in the Mohave desert, an idled open-pit mine stands testament to a different future. A researcher of the Molycorp Mountain Pass REEs mine bankruptcy says that govern- ment involvement in REEs extraction from coal amounts to little more than a political stunt, some well-meaning the- ater to benefit beleaguered energy sector players that once contributed to political campaigns. Both camps, however, ac- knowledge that if REEs can be econom- ically produced from coal, then the black rock will suddenly be doing more than lighting the night. It might save America from a massive power grab by the totali - tarian Chinese. REEs are not particularly rare. With the right technology and systems in place, they could be a byproduct of a number of mines, to include those producing iron, uranium and phosphate. REEs are so known because while they may not be uncommon, they are often found in trac- es and, yearly, are produced in compar- atively limited quantities globally. They are used in most modern computerized electronics. REE-based polymers make up the circuitry and electrical compo- nents of an in-cab computer, for example. And no matter where on Earth they are mined, those components are the product of a value chain owned almost exclusively by China. Specifically, two cities, Bautou and Ganzho, are referred to as "rare earth cities," where oxides are transformed into magnets, lasers, and alloys for circuits and chips. For easy access to those parts, Amer- ican companies set up or contract fac- tories in China. Chinese companies then have easy access to American intellec- tual property to craft cheap knock-offs. Some within the U.S. government are increasingly concerned about a U.S. military entirely dependent on a value chain owned and located in China. Of equal concern should be America's ad- diction to technology. A scan of the daily headlines reveals a country headed toward automated ev- erything, to include some aspects of government. If all things remain equal, that automated future will be brought to Americans by China. China has deep- seated totalitarian tendencies, to in- clude automated blanket surveillance and censorship, and an emergent citizen digital rating system, where the govern- ment rates each citizen based on both public (and, soon, private) information. That rating can be referenced by employ- ers, creditors, insurers, hospitals, edu- cators and permitting bodies. When the Pentagon contracts for cruise missiles or fighter jets, it imports a bit of that. And when someone equips their mine for In- dustry 4.0, they do too. REEs in Coal Coal is now proposed as one of the first stepping stones on the path to self- sufficiency regarding raw REEs supply. Indeed, bound in coal, alongside other elements, are some heavy REEs that have military and strategic applications. Various university studies reveal that, while concentrations vary, both heavy and light REEs are found in coal mines around the country. A white paper released this year by a team from Southern Illinois Univer- sity titled Chemical Extraction of Rare Earth Elements From Coal Ash reported "14 coal samples of different coal ranks, from lignite to anthracite, originating from all over the country indicated a maximum coal ash REE content of more than 700 parts per million (ppm) for the highest rank coal sample." Most of the REEs were light. "A maximum of 27% of (heavy) REEs was found in a low volatile bituminous coal sample." Higher rank coals contain more of the heavy REEs, which see higher demand than the light elements. Acid leaching and solvent ex- traction tests revealed possible processes for recovery. A paper by a team from the Univer- sity of Kentucky released this year and titled Process Evaluation and Flowsheet Development for the Recovery of Rare Earth Elements From Coal and Associ- ated Byproducts reported that samples from three operating coal processing plants revealed REE concentrations "from around 300 ppm to as high as 1,308 ppm on an ash basis. The values ranged from $121 to $315 per ton of feedstock[.]" An ultrafine particle con- centrator raised that to 17,500 ppm, a ratio of 53:1. "The REEs contained in mixed-phased particles, also known as middlings, from the three coal seams were found to be effectively recovered by leaching using nitric acid at pH zero under atmospheric pressure and a solu- tion temperature of 75°C," the group reported. A recovery rate of 80% was reported "for middlings from the Fire Clay coal seam." The group arrived at a flowsheet for a processing facility to produce a REE oxide concentrate "from the waste streams of an existing coal preparation plant." A related group produced a paper this year titled Concentration of Rare Earth Minerals From Coal by Froth Flo- Government Bankrolls Initial Efforts to Extract Rare Earths From Coal Waste The Department of Energy is funding coal research that could help yield metals of critical military and strategic importance by 2020, but to do so must meet strict regulations and face entrenched Chinese competition By Jesse Morton, Technical Writer