Lub platinum pab pawg neeg hlau: ib tug saib xyuas ntawm daim ntawv teev, cov khoom thiab cov kev siv

Platinum pab pawg neeg hlau - yog rau noble precious tshuaj ntsiab uas yog juxtaposed nyob rau hauv lub periodic rooj. Tag nrho cov kev hloov co ntawm cov pab pawg 5-6, 8-10 hom sij hawm.

Platinum Group Co: Sau

Cov pab pawg neeg muaj cov nram qab no rau tshuaj ntsiab teem nyob rau hauv kev txiav txim ntawm ua atomic yuag:

• Ru - ruthenium.
• V - Rhodium.
• Pls - palladium.
• Os - Os.
• Ir - iridium.
• Pt - platinum.

Platinum pab pawg neeg hlau muaj ib tug silvery-dawb Hawj txawm, nrog rau cov kev zam ntawm osmium, uas yog xim xiavlus-dawb. Lawv tshuaj paradoxical tus cwj pwm nyob rau hauv hais tias lawv yog heev resistant rau feem ntau reagents, tab sis yog siv raws li catalysts los yog accelerating nkag tswj tus nqi ntawm oxidation, yuav txo tau thiab hydrogenation tshua.

Ruthenium thiab osmium yog crystallized nyob rau hauv hexagonal close-packed system, thaum lwm tus neeg muaj ib lub ntsej muag-rau nruab nrab nyhav qauv. Qhov no yog thaws rov los nyob rau hauv ntau dua hardness ntawm ruthenium thiab osmium.

Keeb kwm ntawm foundations

Txawm hais tias platinum-kub artifacts sau hnub tim rau 700 BC. e., ntawm lub xub ntiag ntawm hlau nws yog es lo tshaj regularity. Lub Jesuits nyob rau hauv lub XVI xyoo pua, hais tuab gray pebbles txuam nrog alluvial kub deposits. Cov pob zeb yuav tsis tau melted, tab sis lawv tsim ib qho hlau nrog kub, lub bullion yuav nkig, thiab nws yog tsis yooj yim sua rau ntxuav. Lub pob zeb pib hu Platina del Pinto - pellets ntawm nyiaj cov ntaub ntawv uas los ntawm lub Pinto dej, ib tug tributary ntawm tus dej San Juan nyob rau hauv Colombia.

Malleable platinum, uas muaj peev xwm muab tau tsuas yog tom qab ib tug ua tiav hlau tu, twb singled tawm los ntawm qhov Fabkis physicist Shaba nyob rau hauv 1789. Los ntawm nws tau ua ib khob, nyob rau Pope Pius VI. Nyob rau hauv lub qhib ntawm palladium nyob rau hauv 1802, hais tias cov lus Askiv chemist William Wollaston, uas lub npe hu ua tshuaj. platinum-pab pawg neeg hlau caij tom qab lub asteroid. Wollaston tom qab tshaj tawm hais tias lub foundations ntawm lwm yam khoom uas tam sim no nyob rau hauv platinum ore. Nws nws hu ua rhodium vim lub liab xim ntawm cov hlau salts. Qhib iridium (hu ua tom qab tus vajtswv poj niam ntawm tus zaj sawv Iris vim hais tias ntawm lub variegated nws ntsev) thiab osmium (los ntawm Greek lo lus "tsw" vim hais tias ntawm cov tshuaj tsis hnov tsw ntawm nws volatile oxide) tau ua los ntawm cov British chemist Smithson Tennant nyob rau hauv 1803. Fabkis zaum Hippolyte Victor Collet-Deskoti, Antoine-Fransua Furkrua, thiab Nicolas-Lui Voklen pom tias ob co txhij. Ruthenium, cais thiab qhia los ntawm lub xeem caij tau txais nws lub npe los ntawm lub Latin lub npe ntawm Lavxias teb sab Lavxias teb sab chemist Karl Karlovich Klaus nyob rau hauv 1844.

Tsis zoo li tej yooj yim cais nyob rau hauv ib tug kuj ntshiab lub xeev los ntawm tej yam yooj yim hluav taws refining cov neeg ua hauj xws li kub, nyiaj thiab co ntawm cov platinum pab pawg neeg yuav tsum tau complex aqueous tshuaj kho mob. Cov kev tsis muaj kom txog thaum lub caij puv 19 xyoo pua, li ntawd, lub cim thiab kev rho tawm ntawm platinum pab pawg neeg lagged qab cov nyiaj thiab kub rau txhiab xyoo. Nyob rau hauv tas li ntawd, lub siab melting point ntawm cov hlau tau tas lawv cov kev siv kom txog thaum kev soj ntsuam ntawm nyob rau hauv teb chaws Aas Kiv, Fabkis, Lub teb chaws Yelemees thiab Russia tsis tau tsim cov hau kev rau platinum hloov dua siab tshiab rau hauv ib daim ntawv haum rau ua. Raws li cov zoo zoo nkauj tshooj ntawm lub platinum pab pawg neeg pib yuav tsum tau siv nyob rau hauv hniav nyiaj hniav kub txij thaum 1900. Txawm tias qhov no siv yog tseem tseem ceeb niaj hnub no, ntau npaum li cas ntawm nws muaj surpassed. Palladium tau los ua ib tug heev nrov khoom rau cov neeg nyob rau hauv xov tooj relay systems thiab lwm yam wireless kev sib txuas lus, kom ntseeg tau ib tug ntev kev pab cuam lub neej thiab siab cia siab rau, thiab platinum, vim hais tias ntawm nws cov hauj txim yaig, thaum lub sij hawm ob ntiaj teb rog pib yuav tsum tau siv nyob rau hauv muaj qub kev sib ntaus los aircraft.

Tom qab tsov rog lub molecular extension hloov dua siab tshiab txoj kev nyob rau hauv cov roj av refining tau tsim ib tug enormous kev thov rau catalytic zog muaj los ntawm cov hlau los ntawm lub platinum pab pawg neeg. Los ntawm lub xyoo 1970, noj tau ntau zog ntau heev tshaj dua thaum lub tsheb emissions qauv nyob rau hauv lub US thiab lwm lub teb chaws tau coj mus rau qhov kev siv ntawm cov tshuaj nyob rau hauv lub catalytic hloov dua siab tshiab ntawm rav cua tsheb roj cua.

ore

Tsuas yog rau me me alluvial deposits ntawm platinum, palladium thiab osmiridium (ib tug hlau ntawm iridium thiab osmium), zoo tsis muaj ore, uas tau ib tug loj feem tshuaj caij - ib tug platinum pab pawg neeg hlau. Minerals no feem ntau yog muaj nyob rau hauv sulfide ores, tshwj xeeb yog pentlandite (Ni, Fe) ₉ S _8. Cov feem ntau laurite Rus _2, irarsite, (Ir, Ru, v, Pt) lub nroog Yeiuxalees, osmiridium (Ir, Os), cooperite, (pts) thiab Bragg (Pt, Pls) S.

Lub ntiaj teb no lub loj tshaj plaws tso nyiaj ntawm platinum pab pawg neeg hlau - Bushveld complex nyob rau hauv South Africa. Loj stocks ntawm raw cov ntaub ntawv yog feeb meej nyob rau hauv tso ntawm Sudbury nyob rau hauv Canada thiab Norilsk-Talnakh nyob rau hauv Siberia. Nyob rau hauv Teb Chaws Asmeskas, qhov loj tshaj plaws deposits ntawm platinum pab pawg neeg minerals muaj nyob rau hauv Stillwater, Montana, tiam sis ntawm no lawv yog me npaum li cas tshaj nyob rau hauv South Africa thiab Russia. Lub ntiaj teb no lub loj tshaj plaws platinum producers yog South Africa, Zog ntawm Guj kuj, Zimbabwe thiab Canada.

Mining thiab refining

Major South African thiab Canadian kuv ua los ntawm tsuas txoj kev. Zoo tag nrho cov platinum pab pawg neeg hlau yog muab rho tawm los ntawm tooj liab los yog npib tsib xee sulfide minerals siv flotation sib cais. Melting concentrate ua ib tug sib tov uas yog ntxuav tawm ntawm tooj liab thiab npib tsib xee sulphides nyob rau hauv ib tug autoclave. Leaching cov khoom residue muaj los ntawm 15 mus rau 20% platinum pab pawg neeg hlau.

Tej thaum mus txog rau flotation siv lub ntiajteb txawj nqus sib cais. Cov no ib tug concentrate muaj 50% ntawm platinum hlau, uas eliminates lub tseem ceeb ntawm smelting.

txhua yam khoom

Lub platinum pab pawg neeg hlau no ho sib txawv txhua yam khoom. Platinum thiab palladium yog heev mos mos thiab heev malleable. Nrog rau cov co thiab lawv alloys yuav tsum khiav ob kub thiab txias. Rhodium yog thawj kho nrog ib tug kub, thiab ces tseem yuav kho tau nrog txias haum heev annealing. Iridium thiab ruthenium yuav tsum tau rhuab, txias ua hauj lwm, lawv tsis muab nyob rau hauv.

Osmium - cov khoom thiab cov pab pawg neeg muaj lub siab tshaj plaws melting kub, tab sis nws ib txwm mus oxidation imposes nws tus kheej cov kev txwv. Iridium yog feem ntau corrosion-resistant ntawm lub platinum co, rhodium thiab ris txiaj ntsim rau lub preservation ntawm lawv lub zog thaum muaj kev kub kub.

yam ntxwv daim ntawv sau npe

Raws li huv si annealed platinum yog heev mos mos, nws yog susceptible rau khawb thiab kev puas tsuaj. Yuav kom nce nws hardness yog fused nrog ib tug plurality ntawm lwm yam hais. Platinum hniav nyiaj hniav kub yog nrov heev nyob rau Nyiajpoom Teb, nyob qhov twg nws yog hu ua "Hackin" thiab "dawb kub". Alloys rau hniav nyiaj hniav kub uas muaj 90% Pt thiab 10% Pls, uas yog ib qho yooj yim los mus daws thiab soldering. Tsis tas li ntawd ntawm ruthenium pab txoj kev hardness ntawm lub alloy, thaum tswj cov oxidation kuj. Lub alloys ntawm platinum, palladium thiab tooj liab yog siv nyob rau hauv lub forged khoom, txij thaum lawv yog nyuaj platinum-palladium thiab tsawg kim.

Crucibles siv rau cov tib muaju nyob rau hauv lub semiconductor kev lag luam, yuav tsum tau xeb kuj thiab stability sov siab. Rau daim ntawv thov no, nws yog ib qhov zoo tshaj plaws suited platinum, platinum-rhodium, thiab iridium. Platinum-rhodium hlau siv nyob rau hauv qhuav ntawm thermocouples uas yog siv rau cov ntsuas kub muaj peevxwm mus txog 1800 ° C. Palladium yog siv yog nyob rau hauv cov ntshiab los yog nyob rau hauv mixed daim ntawv nyob rau hauv hluav taws xob pab kiag li lawm (50% noj), nyob rau hauv kev kho hniav alloys (30%). Rhodium, ruthenium thiab osmium yog tsis tshua muaj siv nyob rau hauv nws cov ntshiab daim ntawv - lawv pab raws li dopant mus rau lwm yam platinum pab pawg neeg hlau.

catalysts

Hais txog 42% ntawm lub platinum ua nyob rau hauv lub sab hnub poob, yog siv raws li catalyst. Ntawm no, 90% yog siv nyob rau hauv lub tsheb tso systems, nyob rau lub refractory pellets los yog honeycombs coated nrog platinum (thiab palladium, thiab rhodium) txhawb hloov dua siab tshiab ntawm unburned hydrocarbons, carbon monoxide thiab nitrogen oxides rau hauv dej, carbon dioxide thiab nitrogen.

Ib hlau ntawm platinum thiab 10% rhodium nyob rau hauv daim ntawv ntawm ib tug liab-kub hlau daim phiaj ua hauj lwm pab raws li ib lub hauv paus nyob rau hauv cov tshuaj tiv thaiv ntawm ammonia thiab cua mus tsim nitrogen oxides thiab nitric acid. Thaum pub ntawm ammonia nrog methane sib tov yuav tsum npaj kom txhij hydrocyanic acid. Thaum refining platinum rau ntawm qhov chaw ntawm lub alumina granules nyob rau hauv lub reactor yog ib lub hauv paus rau lub hloov dua siab tshiab ntawm txoj saw branched molecules ntawm cov roj nyob rau hauv isoparaffins uas xav nyob rau hauv ib tug sib tov ntawm high-octane roj av.

Electroplating

Tag nrho platinum pab pawg neeg hlau yuav tsum muaj ntaub ntawv galvanically. Vim hais tias ntawm cov hardness thiab gloss ntawm lub txheej yog feem ntau thov rhodium. Txawm tias nws muaj nqis nyob rau piv thicknesses siab tshaj platinum qis ceev tso cai rau kev siv ntawm tsawg luj ntawm cov ntaub ntawv uas.

Palladium - platinum pab pawg neeg hlau, uas yog yooj yim los mus siv rau cov txheej. Vim lub dag lub zog ntawm cov khoom qab considerably. Ruthenium tau pom daim ntawv thov nyob rau hauv cov twj paj nruag npaj rau cov kev kho mob ntawm tsis sib haum xeeb thaum uas tsis muaj siab.

tshuaj tebchaw

Organic ceg ntawm platinum pab pawg neeg hlau xws li alkilplatiny ceg siv raws li catalysts nyob rau hauv lub polymerization ntawm olefins, zus tau tej cov polypropylene thiab polyethylene, raws li zoo raws li lub oxidation ntawm ethylene rau acetaldehyde.

platinum ntsev yog nce siv nyob rau hauv cancer kws khomob. Piv txwv li, lawv yog ib feem ntawm cov tshuaj xws li "Carboplatin" thiab "cisplatin". Ruthenium oxide coated electrodes siv nyob rau hauv qhuav ntawm tshuaj thiab sodium chlorate. Rhodium sulfate thiab rhodium phosphate siv nyob rau hauv electroplating da.