Strontium (Sr) yog ib qho tshuaj lom neeg, ib qho alkaline ntiaj teb hlau ntawm pawg thib 2 ntawm lub sijhawm. Siv nyob rau hauv lub teeb liab teeb liab thiab phosphors, ua rau muaj kev phom sij loj rau kev noj qab haus huv hauv xov tooj cua.
Discovery keeb kwm
Mineral los ntawm ib lub mine nyob ze lub zos Strontian hauv Scotland. Nws yog thawj zaug lees paub tias muaj ntau yam ntawm barium carbonate, tab sis Adair Crawford thiab William Cruikshank tau tawm tswv yim hauv xyoo 1789 tias nws yog cov khoom sib txawv. Tus kws kho mob Thomas Charles Hope tau hu ua cov pob zeb hauv av tshiab strontite tom qab lub zos, thiab cov strontium oxide SrO, strontium. Cov hlau raug cais tawm hauv xyoo 1808 los ntawm Sir Humphry Davy, uas electrolyzed ib qho sib xyaw ntawm cov hydroxide ntub dej lossis cov tshuaj chloride nrog mercury oxide siv cov mercury cathode thiab tom qab ntawd evaporated cov mercury los ntawm qhov tshwm sim amalgam. Nws muab lub npe tshiab siv lub hauv paus ntawm lo lus "strontium".
Nyob hauv ntuj
Tus txheeb ze ntau ntawm strontium, peb caug-yim lub caij nyoog ntawm lub sijhawm lub sijhawm, hauv qhov chaw kwv yees yog 18.9 atoms rau txhua 10 6 silicon atoms. Nws yog hais txog0.04% ntawm qhov loj ntawm lub ntiaj teb crust. Qhov nruab nrab concentration ntawm cov khoom nyob rau hauv dej hiav txwv yog 8 mg / L.
Cov tshuaj lom neeg strontium yog dav pom nyob rau hauv cov xwm txheej thiab kwv yees tias yog 15th feem ntau cov khoom nyob rau hauv lub ntiaj teb, mus txog qhov ntau ntawm 360 feem ntawm ib lab. Muab nws cov reactivity heev, nws tsuas muaj nyob rau hauv daim ntawv ntawm cov tebchaw. Nws cov minerals tseem ceeb yog celestine (sulfate SrSO 4) thiab strontianite (carbonate SrCO3). Ntawm cov no, celestite tshwm sim nyob rau hauv kom muaj nuj nqis txaus rau cov txiaj ntsig mining, ntau tshaj 2/3 ntawm lub ntiaj teb cov khoom uas los ntawm Tuam Tshoj, thiab Spain thiab Mexico muab feem ntau ntawm cov so. Txawm li cas los xij, nws muaj txiaj ntsig ntau dua rau kuv cov strontianite, vim tias strontium feem ntau siv rau hauv daim ntawv carbonate, tab sis muaj qee qhov kev paub txog kev tso nyiaj.
Properties
Strontium yog cov hlau mos, zoo ib yam li txhuas, uas ci zoo li nyiaj thaum txiav. Nyob rau hauv cov huab cua, nws sai sai reacts nrog oxygen thiab noo noo nyob rau hauv cov huab cua, tau ib tug yellowish tint. Yog li ntawd, nws yuav tsum tau muab cia rau hauv kev sib cais los ntawm huab cua huab cua. Feem ntau nws yog khaws cia rau hauv kerosene. Nws tsis tshwm sim hauv lub xeev dawb hauv qhov xwm txheej. Nrog calcium, strontium muaj nyob rau hauv tsuas yog 2 lub ntsiab ores: celestite (SrSO 4) thiab strontianite (SrCO 3).
Nyob rau hauv cov tshuaj tshuaj magnesium-calcium-strontium (alkaline ntiaj teb hlau) Sr yog nyob rau hauv pawg 2 (yav tas los 2A) ntawm lub sij hawm ntawm lub sij hawm ntawm Ca thiab Ba. Tsis tas li ntawd, nws nyob hauv lub sijhawm thib 5 ntawm rubidium thiab yttrium. Txij li thaum lub atomic radius ntawm strontiumzoo ib yam li lub vojvoog ntawm calcium, nws yooj yim hloov tom kawg hauv cov zaub mov. Tab sis nws yog softer thiab ntau reactive nyob rau hauv dej. Tsim hydroxide thiab hydrogen gas ntawm kev sib cuag. 3 allotropes ntawm strontium paub nrog kev hloov pauv ntawm 235 ° C thiab 540 ° C.
Alkaline ntiaj teb hlau feem ntau tsis hnov mob nrog nitrogen hauv qab 380 ° C thiab tsim tsuas yog oxide nyob rau hauv chav tsev kub. Txawm li cas los xij, hauv daim ntawv hmoov, strontium spontaneously ignites tsim oxide thiab nitride.
Tshuaj thiab lub cev muaj zog
Tus yam ntxwv ntawm cov tshuaj strontium raws li txoj kev npaj:
- Npe, cim, tus lej atomic: strontium, Sr, 38.
- Pab, lub sijhawm, thaiv: 2, 5, s.
- Atomic mass: 87.62 g/mol.
- E-config: [Kr]5s2.
- Kev faib cov hluav taws xob hauv cov plhaub: 2, 8, 18, 8, 2.
- Gensity: 2.64g/cm3.
- Melting thiab boiling ntsiab lus: 777 ° C, 1382 ° C.
- Oxidation xeev: 2.
Isotopes
Natural strontium yog sib xyaw ntawm 4 cov isotopes ruaj khov: 88 Sr (82.6%), 86 Sr (9, 9%), 87Sr (7.0%) thiab 84Sr (0.56%). Ntawm cov no, tsuas yog 87 Sr yog radiogenic - nws yog tsim los ntawm kev lwj ntawm lub xov tooj cua isotope ntawm rubidium 87 Rb nrog ib nrab-lub neej ntawm 4.88 × 10 10 xyoo. Nws ntseeg tau tias 87 Sr tau tsim thaum lub sijhawm "primordial nucleosynthesis" (ib theem pib ntawm Big Bang) nrog rau isotopes 84 Sr,86Sr and 88Sr. Nyob ntawm qhovqhov chaw, qhov piv ntawm 87Sr thiab 86Sr yuav txawv ntau dua 5 npaug. Qhov no yog siv nyob rau hauv kev sib tham geological qauv thiab txiav txim lub hauv paus chiv keeb ntawm skeletons thiab av nplaum artifacts.
Raws li qhov tshwm sim ntawm kev tawm tsam nuclear, kwv yees li 16 cov khoom siv hluav taws xob hluav taws xob hluav taws xob ntawm strontium tau txais, ntawm qhov uas qhov ruaj khov tshaj plaws yog 90 Sr (ib nrab-lub neej 28.9 xyoo). Qhov no isotope, tsim nyob rau hauv ib tug nuclear tawg, yog suav hais tias yog qhov txaus ntshai decay khoom. Vim nws cov tshuaj zoo sib xws rau calcium, nws nkag mus rau hauv cov pob txha thiab cov hniav, qhov uas nws txuas ntxiv mus tshem tawm electrons, ua rau hluav taws xob puas, pob txha pob txha puas, cuam tshuam kev tsim cov qe ntshav tshiab, thiab ua rau mob qog noj ntshav.
Txawm li cas los xij, raws li kev tswj hwm kev kho mob, strontium yog siv los kho qee yam mob qog noj ntshav thiab mob qog nqaij hlav pob txha. Nws kuj yog siv nyob rau hauv daim ntawv ntawm strontium fluoride nyob rau hauv cov tshuaj tam sim no qhov chaw thiab nyob rau hauv radioisotope thermoelectric generators, uas hloov lub tshav kub ntawm nws radioactive decay rau hauv hluav taws xob, ua hauj lwm raws li ntev-nyob, lub teeb yuag zog qhov chaw nyob rau hauv navigation buoys, tej thaj chaw deb huab cua chaw nres tsheb thiab spacecraft.
89Sr yog siv los kho mob qog noj ntshav vim tias nws tawm tsam cov pob txha, tsim cov hluav taws xob beta, thiab lwj tom qab ob peb lub hlis (ib nrab-lub neej 51 hnub).
Cov tshuaj lom neeg strontium tsis yog qhov tseem ceeb rau kev ua neej zoo dua, nws cov ntsev feem ntau tsis muaj tshuaj lom. Dab tsi ua90Sr txaus ntshai, siv los ua kom pob txha ceev thiab loj hlob.
Kev sib txuas
Cov khoom ntawm cov tshuaj strontium zoo ib yam li cov calcium. Hauv cov tebchaw, Sr muaj qhov tshwj xeeb oxidation xeev +2 raws li Sr2+ ion. Cov hlau yog cov neeg ua haujlwm txo qis thiab yooj yim reacts nrog halogens, oxygen thiab sulfur los tsim halides, oxide thiab sulfide.
Strontium tebchaw muaj cov nqi lag luam tsawg, vim tias cov calcium thiab barium sib txuas feem ntau ua tib yam tab sis pheej yig dua. Txawm li cas los xij, qee qhov ntawm lawv tau pom daim ntawv thov hauv kev lag luam. Nws tseem tsis tau paub txog cov tshuaj dab tsi kom ua tiav cov xim crimson hauv foob pob hluav taws thiab teeb liab teeb. Tam sim no tsuas yog strontium ntsev xws li Sr(NO3)2 thiab Sr(ClO) chlorate yog siv los ua tiav cov xim no.3)2 . Kwv yees li 5-10% ntawm tag nrho cov khoom ntawm cov tshuaj no yog siv los ntawm pyrotechnics. Strontium hydroxide Sr(OH)2 yog qee zaum siv los rho cov suab thaj los ntawm molasses vim nws tsim cov saccharide soluble uas cov piam thaj tuaj yeem yooj yim rov tsim dua los ntawm kev ua ntawm carbon dioxide. SrS monosulfide yog siv los ua tus neeg sawv cev depilatory thiab cov khoom muaj nyob rau hauv phosphors ntawm electroluminescent li thiab luminous xim.
Strontium ferrites tsim ib tsev neeg ntawm cov tebchaw nrog cov qauv dav dav SrFexOy, tau txais los ntawm qhov kub thiab txias (1000-1300 °C) cov tshuaj tiv thaiv SrCO3 thiabFe2O3. Lawv yog siv los ua cov hlau nplaum ceramic, uas yog siv dav hauv cov neeg hais lus, lub tsheb cua wiper motors thiab cov menyuam yaus cov khoom ua si.
Production
Ntau cov mineralized celestite SrSO4 yog hloov mus rau carbonate nyob rau hauv ob txoj kev: ncaj qha leached nrog sodium carbonate tov los yog rhuab nrog thee los ua sulfide. Nyob rau theem ob, cov khoom muaj xim tsaus yog tau, muaj cov strontium sulfide. Qhov no "dub tshauv" yaj hauv dej thiab lim. Strontium carbonate precipitates los ntawm sulfide tov los ntawm kev qhia carbon dioxide. Sulfate raug txo kom sulfide los ntawm carbothermal txo SrSO4 + 2C → SrS + 2CO2. Lub xovtooj ntawm tes tuaj yeem tsim los ntawm cathodic electrochemical kev sib cuag, nyob rau hauv uas ib tug txias hlau pas nrig, ua raws li ib tug cathode, kov lub nto ntawm ib tug sib tov ntawm poov tshuaj thiab strontium chlorides, thiab nce thaum lub strontium solidifies ntawm nws. Cov tshuaj tiv thaiv ntawm cov electrodes tuaj yeem sawv cev raws li hauv qab no: Sr2+ + 2e- → Sr (cathode); 2Cl- → Cl2 + 2e- (anode).
Metallic Sr kuj tuaj yeem rov qab los ntawm nws cov oxide nrog txhuas. Nws yog malleable thiab ductile, ib tug zoo conductor ntawm hluav taws xob, tab sis yog siv kuj me ntsis. Ib qho ntawm nws siv yog ua tus neeg sawv cev alloying rau txhuas los yog magnesium nyob rau hauv casting ntawm lub tog raj kheej blocks. Strontium txhim kho machinability thiab creep kujhlau. Lwm txoj hauv kev kom tau txais strontium yog txo nws cov oxide nrog txhuas hauv lub tshuab nqus tsev ntawm qhov ntsuas kub distillation.
siv lag luam
Cov tshuaj lom neeg strontium yog dav siv hauv cov iav ntawm cov xim TV cathode ray raj los tiv thaiv X-ray nkag mus. Nws kuj tseem siv tau rau hauv cov xim pleev xim. Qhov no zoo li yog ib qho ntawm feem ntau qhov chaw ntawm pej xeem raug rau strontium. Tsis tas li ntawd, cov khoom siv los tsim cov hlau nplaum ferrite thiab ua kom zoo zinc.
Strontium ntsev yog siv hauv pyrotechnics vim lawv xim cov nplaim liab thaum hlawv. Thiab ib qho alloy ntawm strontium ntsev nrog magnesium yog siv los ua ib feem ntawm incendiary thiab teeb liab mixs.
Titanate muaj qhov ntsuas siab tsis txaus ntseeg thiab qhov muag pom, ua rau nws muaj txiaj ntsig hauv optics. Nws tuaj yeem siv los hloov cov pob zeb diamond, tab sis tsis tshua siv rau lub hom phiaj no vim nws qhov softness thiab qhov tsis zoo rau khawb.
Strontium aluminate yog lub ci phosphor nrog phosphorescence ruaj khov ntev ntev. Cov oxide qee zaum siv los txhim kho qhov zoo ntawm cov iav glazes. Lub isotope 90 Sr yog ib qho zoo tshaj plaws nyob rau lub sijhawm muaj zog beta emitters. Nws yog siv los ua lub zog hluav taws xob rau cov hluav taws xob hluav taws xob hluav taws xob hluav taws xob hluav taws xob (RTGs), uas hloov cov cua sov tawm thaum lub sij hawm lwj ntawm cov khoom siv hluav taws xob rau hauv hluav taws xob. Cov khoom siv no yog siv hauvspacecraft, tej thaj chaw deb huab cua chaw nres tsheb, navigation buoys, thiab lwm yam. - qhov twg yuav tsum tau ib lub teeb thiab nyob ntev nuclear-hluav taws xob qhov chaw.
Kev kho mob ntawm strontium: tus yam ntxwv ntawm cov khoom, kev kho mob nrog tshuaj
Isotope 89Sr yog cov khoom muaj nyob hauv cov tshuaj xov tooj cua Metastron, siv los kho pob txha mob los ntawm kev mob qog nqaij hlav hauv prostate. Cov tshuaj strontium ua haujlwm zoo li calcium, feem ntau suav nrog hauv cov pob txha hauv qhov chaw uas muaj osteogenesis. Qhov no localization tsom rau cov hluav taws xob cuam tshuam rau cov qog nqaij hlav cancer.
Radioisotope 90Sr kuj siv rau kev kho mob qog noj ntshav. Nws cov hluav taws xob beta thiab lub neej ntev ib nrab yog qhov zoo tagnrho rau kev kho hluav taws xob saum npoo av.
Ib qho tshuaj sim ua los ntawm kev sib xyaw strontium nrog ranelic acid txhawb cov pob txha loj hlob, ua kom cov pob txha ceev thiab txo cov pob txha. Stronium ranelate tau sau npe hauv Tebchaws Europe raws li kev kho mob osteoporosis.
Strontium chloride qee zaum siv rau hauv cov tshuaj txhuam hniav rau cov hniav rhiab. Nws cov ntsiab lus nce mus txog 10%.
Kev Tiv Thaiv
Ntshiab strontium muaj cov tshuaj lom neeg ua haujlwm siab, thiab nyob rau hauv lub xeev crushed, cov hlau spontaneously ignites. Yog li ntawd, cov tshuaj no suav hais tias yog hluav taws kub.
Nyob rau tib neeg lub cev
Tib neeg lub cev nqus strontium tib yam li calcium. Ob tug noCov ntsiab lus yog cov tshuaj zoo sib xws uas cov ntaub ntawv ruaj khov ntawm Sr tsis ua rau muaj kev pheej hmoo loj rau kev noj qab haus huv. Nyob rau hauv sib piv, cov xov tooj cua isotope 90 Sr tuaj yeem ua rau ntau yam pob txha thiab kab mob, nrog rau cov pob txha mob cancer. Chav tsev strontium yog siv los ntsuas qhov hluav taws xob ntawm absorbed 90 Sr.
