Hafnium, hlau Hf, atomic tooj 72, atomic hnyav 178.49, yog ib tug ci iab nyiaj grey hloov hlau.
Hafnium muaj rau cov isotopes ruaj khov: hafnium 174, 176, 177, 178, 179, thiab 180. Hafnium tsis hnov mob nrog dilute hydrochloric acid, dilute sulfuric acid, thiab muaj zog alkaline daws, tab sis yog soluble hauv hydrofluoric acid thiab aqua regia.Lub npe lub npe los ntawm Latin lub npe ntawm Copenhagen City.
Xyoo 1925, Swedish chemist Hervey thiab Dutch physicist Koster tau ntshiab hafnium ntsev los ntawm fractional crystallization ntawm fluorinated complex ntsev, thiab txo nws nrog hlau sodium kom tau cov ntshiab hlau hafnium.Hafnium muaj 0.00045% ntawm lub ntiaj teb crust thiab feem ntau txuam nrog zirconium nyob rau hauv cov xwm.
Khoom npe: hafnium
Lub ntsiab lus: Hf
Atomic hnyav: 178.49
Element hom: metallic element
Lub cev muaj zog:
Hafniumyog ib tug silver grey hlau nrog ib tug metallic luster;Muaj ob qhov sib txawv ntawm cov hlau hafnium: α Hafnium yog hexagonal zoo sib xws (1750 ℃) nrog qhov kub hloov pauv ntau dua li zirconium.Hlau hafnium muaj allotrope variants ntawm qhov kub thiab txias.Hlau hafnium muaj lub siab neutron absorption cross-section thiab tuaj yeem siv los ua cov khoom siv rau cov reactors.
Muaj ob hom qauv siv lead ua: hexagonal ntom ntim ntawm qhov kub thiab txias hauv qab 1300 ℃ (α- Equation);Ntawm qhov kub siab tshaj 1300 ℃, nws yog lub cev nruab nrab cubic (β- Equation).Ib tug hlau nrog plasticity uas hardens thiab ua brittle nyob rau hauv lub xub ntiag ntawm impurities.Nyob ruaj khov nyob rau hauv cov huab cua, tsuas yog darkens ntawm qhov chaw thaum hlawv.Cov filaments tuaj yeem ignited los ntawm cov nplaim ntawm ib qho kev sib tw.Cov khoom zoo ib yam li zirconium.Nws tsis hnov mob nrog dej, dilute acids, lossis cov hauv paus muaj zog, tab sis yooj yim soluble hauv aqua regia thiab hydrofluoric acid.Feem ntau hauv cov tebchaw nrog a + 4 valence.Hafnium alloy (Ta4HfC5) paub tias muaj qhov siab tshaj plaws melting point (kwv yees li 4215 ℃).
Cov qauv siv lead ua: Cov pob zeb siv lead ua yog hexagonal
CAS Nr .: 7440-58-6
Melting point: 2227 ℃
Kub taw tes: 4602 ℃
Chemical Properties:
Cov khoom siv tshuaj lom neeg ntawm hafnium zoo ib yam li cov zirconium, thiab nws muaj kev tiv thaiv corrosion zoo thiab tsis yooj yim corroded los ntawm cov kua qaub alkali aqueous daws;Yooj yim soluble hauv hydrofluoric acid los tsim fluorinated complexes.Thaum qhov kub thiab txias, hafnium tuaj yeem ncaj qha ua ke nrog cov pa roj xws li oxygen thiab nitrogen los tsim oxides thiab nitrides.
Hafnium feem ntau muaj + 4 valence hauv cov tebchaw.Lub ntsiab compound yoghafnium oxide hmoovHfO2.Muaj peb yam sib txawv ntawm hafnium oxide:hafnium oxide hmoovtau los ntawm kev nruam calcination ntawm hafnium sulfate thiab chloride oxide yog monoclinic variant;Lub hafnium oxide tau los ntawm cua sov lub hydroxide ntawm hafnium nyob ib ncig ntawm 400 ℃ yog tetragonal variant;Yog hais tias calcined saum 1000 ℃, ib tug cubic variant yuav tau.Lwm qhov sib xyaw yogHafnium tetrachloride hmoov, uas yog cov khoom siv raw rau kev npaj hlau hafnium thiab tuaj yeem npaj tau los ntawm kev ua pa roj chlorine ntawm kev sib xyaw ntawm hafnium oxide thiab carbon.Hafnium tetrachloride tuaj rau hauv kev sib cuag nrog dej thiab tam sim ntawd hydrolyzes rau hauv siab ruaj khov HfO (4H2O) 2 + ions.HfO2 + ions muaj nyob rau hauv ntau lub tebchaw ntawm hafnium, thiab tuaj yeem crystallize koob zoo li hydrated hafnium oxychloride HfOCl2 · 8H2O crystals hauv hydrochloric acid acidified hafnium tetrachloride tov.
4-valent hafnium kuj tseem tsim cov complexes nrog fluoride, suav nrog K2HfF6, K3HfF7, (NH4) 2HfF6, thiab (NH4) 3HfF7.Cov complexes tau siv rau kev sib cais ntawm zirconium thiab hafnium.
Common compounds:
Hafnium dioxide: npe Hafnium dioxide;Hafnium dioxide;Cov mis mos molecular: HfO2 [4];Cov Khoom: Dawb hmoov nrog peb cov qauv siv lead ua: monoclinic, tetragonal, thiab cubic.Qhov ceev yog 10.3, 10.1, thiab 10.43g / cm3, feem.Melting point 2780-2920K.Boiling point 5400K.Thermal expansion coefficient 5.8 × 10-6 / ℃.Insoluble hauv dej, hydrochloric acid, thiab nitric acid, tab sis soluble nyob rau hauv concentrated sulfuric acid thiab hydrofluoric acid.Ua los ntawm thermal decomposition lossis hydrolysis ntawm cov tebchaw xws li hafnium sulfate thiab hafnium oxychloride.Cov khoom siv raw rau kev tsim cov hlau hafnium thiab hafnium alloys.Siv los ua cov ntaub ntawv refractory, anti radioactive coatings, thiab catalysts.[5] Atomic zog qib HfO yog ib yam khoom tau txais ib txhij thaum tsim atomic zog qib ZrO.Pib los ntawm theem nrab chlorination, cov txheej txheem ntawm purification, txo, thiab nqus cov distillation yuav luag zoo tib yam rau cov zirconium.
Hafnium tetrachloride: Hafnium (IV) chloride, Hafnium tetrachloride Molecular formula HfCl4 Molecular weight 320.30 Cim: Dawb crystalline block.Sensitive rau noo noo.Soluble nyob rau hauv acetone thiab methanol.Hydrolyze hauv dej los tsim hafnium oxychloride (HfOCl2).Kub rau 250 ℃ thiab evaporate.Irritating rau qhov muag, ua pa, thiab tawv nqaij.
Hafnium hydroxide: Hafnium hydroxide (H4HfO4), feem ntau yog hydrated oxide HfO2 · nH2O, yog insoluble nyob rau hauv dej, yooj yim soluble nyob rau hauv inorganic acids, insoluble nyob rau hauv ammonia, thiab tsis tshua muaj soluble nyob rau hauv sodium hydroxide.Thaum tshav kub kub rau 100 ℃ los ua kom muaj hafnium hydroxide HfO (OH) 2. Dawb hafnium hydroxide precipitate tuaj yeem tau los ntawm reacting hafnium (IV) ntsev nrog dej ammonia.Nws tuaj yeem siv los tsim lwm cov tshuaj hafnium.
Kev tshawb fawb keeb kwm
Keeb kwm Discovery:
Xyoo 1923, Swedish chemist Hervey thiab Dutch physicist D. Koster pom hafnium nyob rau hauv zircon tsim nyob rau hauv Norway thiab Greenland, thiab muab nws lub npe hu ua hafnium, uas yog los ntawm Latin lub npe Hafnia ntawm Copenhagen.Xyoo 1925, Hervey thiab Coster tau sib cais zirconium thiab titanium siv cov txheej txheem ntawm fractional crystallization ntawm fluorinated complex ntsev kom tau cov ntsev hafnium ntshiab;Thiab txo hafnium ntsev nrog nws cov xim hlau sodium kom tau cov hlau ntshiab hafnium.Hervey npaj ib qho piv txwv ntawm ob peb milligrams ntawm ntshiab hafnium.
Kev sim tshuaj ntawm zirconium thiab hafnium:
Hauv kev sim ua los ntawm xibfwb Carl Collins ntawm University of Texas hauv xyoo 1998, nws tau lees tias gamma irradiated hafnium 178m2 (lub isomer hafnium-178m2 [7]) tuaj yeem tso tawm lub zog loj, uas yog tsib qhov kev txiav txim siab ntau dua li tshuaj lom neeg tab sis peb qhov kev txiav txim ntawm qhov loj dua qis dua qhov kev tawm tsam nuclear.[8] Hf178m2 (hafnium 178m2) muaj lub neej ntev tshaj plaws ntawm cov isotopes nyob ntev zoo sib xws: Hf178m2 (hafnium 178m2) muaj ib nrab-lub neej ntawm 31 xyoo, uas ua rau lub ntuj muaj zog ntawm kwv yees li 1.6 trillion Becquerels.Collins tsab ntawv ceeb toom hais tias ib gram ntawm ntshiab Hf178m2 (hafnium 178m2) muaj kwv yees li 1330 megajoules, uas yog sib npaug rau lub zog tso tawm los ntawm kev tawg ntawm 300 kilograms ntawm TNT explosives.Collins daim ntawv tshaj tawm qhia tias txhua lub zog hauv cov tshuaj tiv thaiv no raug tso tawm hauv daim duab X-rays lossis gamma rays, uas tso tawm lub zog ntawm tus nqi nrawm heev, thiab Hf178m2 (hafnium 178m2) tseem tuaj yeem hnov qab ntawm qhov tsis tshua muaj siab.[9] Lub Pentagon tau faib nyiaj rau kev tshawb fawb.Hauv kev sim, qhov sib piv ntawm cov teeb liab-rau-suab nrov tau qis heev (nrog qhov ua yuam kev tseem ceeb), thiab txij li ntawd los, txawm tias muaj ntau qhov kev sim los ntawm cov kws tshawb fawb los ntawm ntau lub koom haum suav nrog United States Department of Defense Advanced Projects Research Agency (DARPA) thiab JASON Defense Advisory. Pab pawg [13], tsis muaj tus kws tshawb fawb tau ua tiav cov tshuaj tiv thaiv no raws li cov xwm txheej tau thov los ntawm Collins, thiab Collins tsis tau muab pov thawj muaj zog los ua pov thawj tias muaj cov tshuaj tiv thaiv no, Collins tau npaj ib txoj hauv kev siv induced gamma ray emission los tso tawm lub zog los ntawm Hf178m2 (hafnium 178m2) [15], tab sis lwm cov kws tshawb fawb tau ua pov thawj tias qhov tshuaj tiv thaiv tsis tuaj yeem ua tiav.[16] Hf178m2 (hafnium 178m2) tau ntseeg dav hauv zej zog kev kawm tsis yog lub hauv paus ntawm lub zog
Daim ntawv thov teb:
Hafnium yog qhov muaj txiaj ntsig zoo vim nws lub peev xwm los tawm cov khoom siv hluav taws xob, xws li siv los ua ib qho filament hauv incandescent teeb.Siv raws li cathode rau X-ray raj, thiab alloys ntawm hafnium thiab tungsten los yog molybdenum yog siv los ua electrodes rau high-voltage paug hlab.Feem ntau siv nyob rau hauv cathode thiab tungsten hlau manufacturing kev lag luam rau X-rays.Ntshiab hafnium yog cov khoom tseem ceeb hauv kev lag luam atomic zog vim nws cov yas, ua haujlwm yooj yim, kub tsis kam, thiab corrosion kuj.Hafnium muaj qhov loj thermal neutron capture cross-section thiab yog ib qho zoo tagnrho neutron absorber, uas tuaj yeem siv los ua tus pas ntsuas kub thiab cov cuab yeej tiv thaiv rau atomic reactors.Hafnium hmoov tuaj yeem siv los ua lub zog rau cov foob pob hluav taws.Lub cathode ntawm X-ray raj tuaj yeem tsim hauv kev lag luam hluav taws xob.Hafnium alloy tuaj yeem ua cov txheej txheem tiv thaiv rau pem hauv ntej rau foob pob hluav taws nozzles thiab glide rov nkag dav hlau, thaum Hf Ta alloy tuaj yeem siv los tsim cov cuab yeej hlau thiab cov ntaub ntawv tiv thaiv.Hafnium yog siv los ua ib qho khoom siv ntxiv hauv cov khoom siv hluav taws xob tiv thaiv tshav kub, xws li tungsten, molybdenum, thiab tantalum.HfC tuaj yeem siv los ua ib qho ntxiv rau cov hlau tawv tawv vim nws qhov siab hardness thiab melting point.Lub melting point ntawm 4TaCHfC yog kwv yees li 4215 ℃, ua nws cov compound nrog lub siab tshaj plaws paub melting point.Hafnium tuaj yeem siv los ua tus getter hauv ntau lub tshuab nyiaj txiag.Hafnium getters tuaj yeem tshem tawm cov pa tsis tsim nyog xws li oxygen thiab nitrogen tam sim no hauv lub cev.Hafnium feem ntau yog siv los ua ib qho ntxiv hauv cov roj hydraulic los tiv thaiv cov roj volatilization ntawm cov roj hydraulic thaum ua haujlwm siab, thiab muaj zog tiv thaiv volatility.Yog li ntawd, nws yog feem ntau siv nyob rau hauv industrial hydraulic roj.Kev kho mob hydraulic roj.
Hafnium caij tseem siv nyob rau hauv qhov tseeb Intel 45 nanoprocessors.Vim lub manufacturability ntawm silicon dioxide (SiO2) thiab nws muaj peev xwm los txo thickness mus txuas ntxiv txhim kho transistor kev ua tau zoo, processor manufacturers siv silicon dioxide raws li cov khoom rau lub rooj vag dielectrics.Thaum Intel tau qhia txog 65 nanometer tsim cov txheej txheem, txawm hais tias nws tau ua txhua yam los txo qhov tuab ntawm silicon dioxide rooj vag dielectric mus rau 1.2 nanometers, sib npaug rau 5 txheej ntawm atoms, qhov nyuaj ntawm kev siv hluav taws xob thiab cua kub dissipation kuj yuav nce ntxiv thaum lub transistor. tau txo qis rau qhov loj ntawm ib qho atom, uas ua rau cov pov tseg tam sim no thiab lub zog hluav taws xob tsis tsim nyog.Yog li ntawd, yog tias cov ntaub ntawv tam sim no txuas ntxiv siv thiab cov tuab ntxiv txo qis, qhov xau ntawm lub qhov rooj dielectric yuav nce ntxiv, nqa cov tshuab transistor mus rau nws qhov txwv.Txhawm rau daws qhov teeb meem tseem ceeb no, Intel tab tom npaj yuav siv cov ntaub ntawv K siab dua (hafnium raws li cov ntaub ntawv) raws li lub rooj vag dielectrics es tsis txhob siv cov silicon dioxide, uas tau ua tiav txo cov pa tawm ntau dua 10 zaug.Piv nrog rau tiam dhau los ntawm 65nm thev naus laus zis, Intel's 45nm txheej txheem nce transistor ceev los ntawm ze li ob zaug, tso cai rau kev nce ntxiv ntawm tag nrho cov transistors lossis txo qis hauv processor ntim.Tsis tas li ntawd, lub zog xav tau rau kev hloov pauv ntawm transistor yog qis dua, txo lub zog siv ze li 30%.Cov kev sib txuas sab hauv yog ua los ntawm tooj liab hlau ua ke nrog qis k dielectric, txhim kho kev ua haujlwm zoo thiab txo qis kev siv hluav taws xob, thiab kev hloov pauv ceev yog li 20% sai dua.
Mineral faib:
Hafnium muaj ntau dua crustal ntau dua li cov hlau siv xws li bismuth, cadmium, thiab mercury, thiab sib npaug hauv cov ntsiab lus rau beryllium, germanium, thiab uranium.Tag nrho cov minerals uas muaj zirconium muaj hafnium.Zircon siv hauv kev lag luam muaj 0.5-2% hafnium.Lub beryllium zircon (Alvite) nyob rau hauv theem nrab zirconium ore tuaj yeem muaj txog li 15% hafnium.Kuj tseem muaj hom metamorphic zircon, cyrtolite, uas muaj ntau dua 5% HfO.Cov reserves ntawm ob lub yav tas los minerals yog me me thiab tseem tsis tau txais yuav nyob rau hauv kev lag luam.Hafnium feem ntau rov qab los thaum lub sij hawm tsim cov zirconium.
Nws muaj nyob rau hauv feem ntau zirconium ore.[18] [19] Vim tias muaj cov ntsiab lus me me hauv lub crust.Nws feem ntau coexists nrog zirconium thiab tsis muaj ore cais.
Txoj kev npaj:
1. Nws tuaj yeem npaj tau los ntawm magnesium txo ntawm hafnium tetrachloride lossis thermal decomposition ntawm hafnium iodide.HfCl4 thiab K2HfF6 kuj tseem siv tau los ua cov khoom siv raw.Cov txheej txheem ntawm electrolytic ntau lawm hauv NaCl KCl HfCl4 los yog K2HfF6 yaj yog zoo ib yam li cov electrolytic zus tau tej cov zirconium.
2. Hafnium coexists nrog zirconium, thiab tsis muaj cov khoom siv raw rau hafnium.Cov khoom siv raw rau kev tsim hafnium yog crude hafnium oxide sib cais thaum lub sijhawm tsim cov zirconium.Extract hafnium oxide siv ion pauv resin, thiab ces siv tib txoj kev raws li zirconium los npaj hlau hafnium los ntawm no hafnium oxide.
3. Nws tuaj yeem npaj tau los ntawm co cua sov hafnium tetrachloride (HfCl4) nrog sodium los ntawm kev txo qis.
Cov txheej txheem ntxov tshaj plaws rau kev sib cais zirconium thiab hafnium yog fractional crystallization ntawm fluorinated complex ntsev thiab fractional nag lossis daus ntawm phosphates.Cov txheej txheem no yog cumbersome rau kev khiav hauj lwm thiab tsuas yog siv rau kev kuaj.Cov thev naus laus zis tshiab rau kev sib cais zirconium thiab hafnium, xws li fractionation distillation, hnyav extraction, ion exchange, thiab fractionation adsorption, tau tshwm sim ib tom qab, nrog cov kuab tshuaj extraction ua tau zoo dua.Ob txoj kev sib cais feem ntau yog thiocyanate cyclohexanone system thiab tributyl phosphate nitric acid system.Cov khoom tau los ntawm cov txheej txheem saum toj no yog tag nrho cov hafnium hydroxide, thiab cov ntshiab hafnium oxide tuaj yeem tau los ntawm calcination.High purity hafnium tuaj yeem tau txais los ntawm ion txauv txoj kev.
Hauv kev lag luam, kev tsim cov hlau hafnium feem ntau cuam tshuam nrog cov txheej txheem Kroll thiab cov txheej txheem Debor Aker.Cov txheej txheem Kroll suav nrog kev txo qis ntawm hafnium tetrachloride siv hlau magnesium:
2Mg+HfCl4- → 2MgCl2+Hf
Txoj kev Debor Aker, tseem hu ua txoj kev iodization, yog siv los ntxuav daim txhuam cev zoo li hafnium thiab tau txais malleable hlau hafnium.
5. Lub smelting ntawm hafnium yog qhov pib zoo ib yam li zirconium:
Thawj kauj ruam yog decomposition ntawm ore, uas muaj peb txoj kev: chlorination ntawm zircon kom tau (Zr, Hf) Cl.Alkali melting ntawm zircon.Zircon yaj nrog NaOH nyob ib ncig ntawm 600, thiab tshaj 90% ntawm (Zr, Hf) O hloov mus rau Na (Zr, Hf) O, nrog SiO hloov mus rau NaSiO, uas yog yaj hauv dej kom tshem tawm.Na (Zr, Hf) O tuaj yeem siv los ua cov tshuaj qub rau kev sib cais zirconium thiab hafnium tom qab yaj hauv HNO.Txawm li cas los xij, lub xub ntiag ntawm SiO colloids ua rau cov kuab tshuaj extraction nyuaj.Sinter nrog KSiF thiab tsau hauv dej kom tau K (Zr, Hf) F tov.Cov tshuaj tuaj yeem cais zirconium thiab hafnium los ntawm fractional crystallization;
Cov kauj ruam thib ob yog kev sib cais ntawm zirconium thiab hafnium, uas tuaj yeem ua tiav los ntawm kev siv cov kuab tshuaj cais tawm siv hydrochloric acid MIBK (methyl isobutyl ketone) system thiab HNO-TBP (tributyl phosphate) system.Kev siv tshuab ntawm ntau theem fractionation siv qhov sib txawv ntawm vapor siab ntawm HfCl thiab ZrCl melts nyob rau hauv siab siab (siab dua 20 atmospheres) tau kawm ntev, uas tuaj yeem txuag cov txheej txheem chlorination thib ob thiab txo cov nqi.Txawm li cas los xij, vim qhov teeb meem corrosion ntawm (Zr, Hf) Cl thiab HCl, nws tsis yooj yim los nrhiav cov khoom siv fractionation kem tsim nyog, thiab nws tseem yuav txo qhov zoo ntawm ZrCl thiab HfCl, nce nqi purification.Nyob rau xyoo 1970, nws tseem nyob rau theem nruab nrab ntawm cov nroj tsuag kuaj;
Qhov thib peb kauj ruam yog qhov thib ob chlorination ntawm HfO kom tau HfCl crude rau txo;
Cov theem plaub yog kev ua kom huv ntawm HfCl thiab magnesium txo.Cov txheej txheem no yog tib yam li kev ua kom huv thiab txo qis ntawm ZrCl, thiab cov khoom ua tiav ib nrab yog coarse sponge hafnium;
Qhov thib tsib kauj ruam yog lub tshuab nqus tsev distill crude sponge hafnium kom tshem tawm MgCl thiab rov qab cov hlau magnesium ntau dhau, uas ua rau cov khoom tiav ntawm daim txhuam cev hlau hafnium.Yog tias tus neeg sawv cev txo qis siv sodium es tsis txhob magnesium, cov kauj ruam thib tsib yuav tsum tau hloov mus rau hauv dej
Txoj kev khaws cia:
Khaws nyob rau hauv ib lub warehouse txias thiab ventilated.Khaws kom deb ntawm qhov hluav taws kub thiab qhov chaw kub.Nws yuav tsum tau muab cais los ntawm oxidants, acids, halogens, thiab lwm yam, thiab tsis txhob sib tov cia.Siv cov khoom tawg-pov thawj teeb pom kev zoo thiab qhov cua qhov chaw.Txwv tsis pub siv cov cuab yeej siv tshuab thiab cov cuab yeej uas ua rau muaj qhov ci ntsa iab.Lub chaw cia khoom yuav tsum tau nruab nrog cov ntaub ntawv tsim nyog kom muaj cov xau.
Post lub sij hawm: Sep-25-2023