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tee MININGNot so rare after allJack Lifton says there are plenty of rare earthsfor our clea n technologies and gadgets , it justdepends how desperately we want themR EFINERY ca talysts , hyhrid carbatteries, mohile phones, weaponssystems and wind turbines all relyon 17 so-called rare earth elem ents (REEs),97% of which are prod uced hy China.

The remainder are sourced from Russia,hidia and Malaysia, meaning that som e ofthe world's dom inant u sers and developers ofhigh-end technology such as Japan and theUS are wholly depende nt on imports.

This vulnerability has caught the attentionof the industrial commun ity, governmen ts,an d the public at large after China threatene dto block exports to Japan during toughdiplomatic negotiations in October. It alsowarned the world that itwas consideringreducing its exports ofREEs in a bid tosecure its own future supplies and lessen theharsh environmental impacts of mining andprocessing the metals.

This has led many to ask the soberingquestion: are there enough REEs to sustainand allow for the spread of a technologicalconsum er society? The answer is yes.

REEs did not get their moniker becausethey are only found in China but becausethey are distributed in exceedingly lowvolumes throughout the earth's crust. Thereis enough to go around to avoid them beingmonopo lised if we are desperate enough notto want it that way.a history of increasingseparationREEs are found mbted tog ether in varyingproportions. Atfirst, he 17 REEs (see Figure1) were thought to be just one or two untilthe late 19''' and early 20th centuries wh en

4 4 during the 1990s,the price of separatedREEs from Chinabegan to fall and theirpurity to rise just aswestern researchers

Figure V. Elements and their estimateof crustal abundances, atomic numberand selected uses [Estimates of crustalabundances taken from Lide (1997)]

HEAVYGadolinium / 6.2 ppm (64)

rare-earth permanent magnets.nuclear reactor components

Terbium /1 .2 ppm (65)phosphors, lasers, fuel cells

Dysprosium / 5.2 ppm (66) rare-earth permanentmagnets, nuclear reactors components

Holmium /1.3ppm (67) lasers,nuclear reactor components

Erbium / 3.5 ppm (68) lasers,nuclear reactor components /g 1 )

T h u l i u m / 0 . 5 2 p p m (69 ) lasers, componmedical imaging tracii

Ytterbium / 3.2 ppm (70) Yttrium /medical imaging, steel doping im

Lutetium / 0.8 ppm (71 ) cataiyindustrial catalysis supen

LIGHTLanthanum / 39 ppm / (57)

NiMH batteries, industrial catalysis,speciaiist giass

Cerium / 66.5 ppm / (58) automotive catalysis,mischmetal lighter flints

Praseodymium / 9.2 ppm (59) aerospacecomponents, rare-earth permanent magnets

Neodymium / 41.5 ppm (60)rare-earth permanent magnets, lasers, glass

Promethium / (less than 1 kg total)(61) nuclearbatteries

Samarium / 7.05 ppm (62) industrial catalysis,rare-earth permanent magnets

Europium / 2 ppm (63)phosphors, lasers

(21): aerospacecomponents, refinery

tracing agentsYttrium / 33 ppm / (39):

industrialcataiysis, lasers,superconductors

the development of optical spectroscopyallowed them to be distinguished from oneanothe r well before they could be chemicallyseparated.Itwasn't possible to separate them vdthout

a cost far in excess of their end-u se va lueuntil the late 20''' century , for most of themanyway. Thus REEs, until recently, w erelargely use d as unseparated metals, misch(German for "mixed") metals for cigarettelighter fiints and military tracer ammunition.

Individual REEs are separated using thetiny differences in their solubility. Solventexchange separado n is t ime consuming,labour intensive, and costly. MolycorpMinerals built the world's first comm ercial-scale REE separation plant at Mountain Pass,California, to isolate europium . Europiumwas the element of choice for producing ared colour generating cathodoluminescentphosphor - and so colour television wascommercialised.

The 1980s witnessed an increase in

The batteries tended to use mixed REEs orat best, in the case of the magnets, a mixtureof praseody mium and neodymium.

However, research showed that REEswould have to be completely isolated totake full advantage of their electrical andelectronic properties; the problem of highlabour costs and time intensive separationsremained.

Interest arose in China, vdth its lowlabour costs and significant and accessibledomestic deposits of REEs. Furthermore , itbecame obvious that with less importanceplaced on environmental or worker safety,China could and would employ som e low-cost mining methods that other countrieswould not. Since manual labour was muchcheaper than elsewhere, Chinese co mpaniesrelied on a huge labour force rather tha nexpensive capital investments in thelatest mining and processing machinery,and employed a make do attitude to theequipment it did have to buy.

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tce MININGundergoing intense development. Thusinfrastructure was already in place for therare earth miners, significantly reducing if notremoving entirely infrastructure overheads .

During the 1990s, the price of sep arate d REEfrom China began to fall and their purity torise just as western resea rchers were realisingthe benefits of separated REEs.

The result was that more and m oreproduction and assembly of REPMs andNiMH batteries was outsourced to Chinaalong with their manufacturing technology totake double ad vantage of low labour and rawmaterial costs. Western mines, including theone at M ountain Pass, found it impossible tocom pete, so were shut down.

From th e poin t of view of we stern freemarket capitalists, outsourcing to China wasglobalisation w orking efficiently to bringdown costs and challenge conventionaltechnology - in this case ferrite m agnets andlead acid batteries.

No one seem ed to consider that Chinawould rapidly develop the skills or theinternal m arket to use REEs - at the very leastnot for generations to com e.raising the heatCar makers then bec ame interested in REPMs,as they allowed m otors to be m iniaturised,which saved weight and increased fuelefficiency. E ncoura ged by the po tentia l ofhigh volume application, magnet researchersin the US, lapan, and even China startedadapting REPMs to maintain their m aximumfiux at the kinds of temp eratures typicallyencou ntered in a car's engine bay.

An alloy of the REE dysprosium andneodymium achieved this, but the theorybehind the proc ess was not well understoodand the practical know-how was fiercelyguarded by the lapanese manufacturers, whileat the same time C hina held a monopoly

on the relatively unc om mo n heavy REE,dysprosium. There were fears that therewould not be enough dysprosium tosupport the automotive industry's needs.

It was well known that uran ium ores oftencontained elevated levels of heavy REEs buttheir con centration was still so low as tomake the metallurgy daunting, and no onewas willing to spen d mon ey to solve sucha problem, which involved the h andlingof enorm ous volum es of solvents beingmethodically mixed with each other a ndthen separated and treated to extract a tinyfraction over and over again, if it involvedradioactive species.

China's geology once again cam e to therescue. In some of its southern provinces,including Sichuan, there are weatheredclay deposits where the radioactive specieshave already been wa shed away leaving theheavy REEs. This natural "separation" ofheavy REEs is uniqu e in the world and hasgreatly simplified safety.

However, if these ionic clayswere in theWest it is unlikely they would have beendeveloped as their low grades and the lackof supporting infrastructure w ould havebeen obstacles too big to overcome.

It didn't stop Chinese entre prene urs who,using che ap unskilled labour, fiood hilltopswith chemical reagents and channel theminto catch basins ma de from plastic-linedearthen pond s. The extraction liquor isconcen trated by letting it partially e vaporateand is then proc essed with crude tanks andmakeshift solvent exchange. Only a smallfraction of the heavy REEs are recovered thisway, most rem ain in the process residue.

which is essential for non-incandescentlighting an d displays, a nd 8000 t/y ofyttrium, essential for high tem peratureaircraft and rocket engines.

In 2009, China an nou nce d it mightcease exporting heavy REEs to conserve itsremaining reserves for domestic demand,which is growing at an unprecedented rate.

On 14 November 2010, China announ cedit was cutting exports of all basic formsof REEs to conserve them for future useand restore the damaged environmentat the mining sites. Such environmentalremed iation will require a slow down orperhaps even a temporary shutdown ofthe mines , so that either conservationor stockpiling, or both, might be nownecessary to preserve China's domesticsecurity of supply, the Chinese governm entsaid.

China w ill not allow foreign firms tocome in and improve productionefficiencies over fears they might benefitfrom the information a bout its naturalresources. Meanw hile, Chinese explorationhas not found a replacem ent for ionic claysthat could support global dem and forheavy REE.in search of a plan BUnsurprisingly, the hunt is now on foreconomically viable sources outside C hina.

Japan's Toyota is pushing thedevelopment of a mining com plex inVietnam which would fulfil all of itsconceivable needs for light REE for batteriesand magnets.

Simultaneously other Japanese andKorean com panies are looking at deposits

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MINING tee

re-opened at Mountain Pass, California. Therest of the former mines are either too smallor too old to be of further ec onom ic value ifthey con tain only light REEs.

Glohal exploration h as found at least halfa dozen deposits with significantly highproportions of heavy REEs with promisingfinds in Australia, Canada, Namibia,Madagascar, Sou th Africa, and the US.

The race to develop anoth er sou rce ofheavy REEs is on, an d is expec ted to eclipsethe competition to develop the moreplentiful light REEs.

China and Japan produce more than80% of REPMs used for motors and sensorsin today's cleanest vehicles (these devicescontain as much as 12% hyweight ofdysprosium and dem and is projected togrow year-on-year) there is cause to suggestthat Chinese and Japanese companies,and REPM manufacturers in particular, theend user community, should take a lead indetermining and financing the developmentof such deposits.

However, such developmen ts areunlikely to be profitable if the o utpu t is onlyrare earth concentrates or even initiallyseparated rare earth compounds such asoxides or oxalates. Therefore such miningoperations must be vertically integrated intosupply chains so that enough value is addedto the concentrates and simple separationsto make them profitable.

This could m ean REPM end-us ers suchas the makers of motor vehicles, windturbines, and weaponry backwards-integrating their supply chain right into therare earths mines, or nations that have aneconomic interest in some or all such types

one or more heavy mines and hold them asinvestments for end-users, high value supplychain component makers, or governments.long view requiredNo matter which finance or holding solutionis chos en, the financial backer m ust carefullystudy all the enabling technologies, ie thechemical extraction, separation, and refiningto high purity metals of each unique depositso as to quantify the costs and estimate thechance of success for each proposed venture.A study published in November by the

US Geological Survey, in res pons e to a USdefence bill, reported that "unfortunately, thetimes required for developm ent of new minesis on the order of at least a decade ':

It app ears tha t the future supp ly of heavyREEs, upon which the largest portion ofthe revenues and strategic value of therare earths depends, is itself reliant on theforesight of governments and large industrialenterprises.

Quick action must be taken to developa more diverse range of mines and supplychains if the world wants to con tinue to userare earths in their gadgets and clean powertechnologies.

Process and chemical engineers have anintegral role to play in develop ing new andimproved extraction processes that allowfor chea per m ore efficient recovery of thesecrucial elemen ts. Further along the supplychain, researchers continue to look forsuitable replacem ents for REE and developproces ses an d pra ctices to recover REEs atthe end of a produ ct's life - thoug h this isalso a commercial challenge due to the traceamounts they contain, t e e

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