Tungsten valence. Properties thiab daim ntawv thov ntawm tungsten

Ntau cov khoom yuav cia mus ntsib cov lub cev thiab tshuaj thaj chaw ntawm tungsten, saib kom paub meej txog nws nyob rau hauv lub qhov, yog qhov chaw ntawm ntau lawm, cov lus qhib ntawm zaj dab neeg, thiab ntau dua.

Tungsten (W)

Tungsten - yog ib lub caij uas lub Periodic Table of Mendeleev muaj xya caum plaub atomic tooj sau raws nkaus Ii lub Latin cim W. Nyob rau hauv lub li ib txwm tej yam kev mob muaj ib tug grey-nyiaj xim, ci, nyuaj. Ntawm tag nrho cov hlau tungsten yog lub feem ntau refractory. Siab tshaj uas ntawm W, lub melting point xwb tsis yog-hlau - carbon. Nws muaj ib tug high tshuaj kuj. Valence ntawm tungsten - nce mus nce los.

Keeb kwm ntawm foundations

Swedish chemist Carl Wilhelm Scheele nyob rau hauv 1781, nyob rau hauv koom lub processing ntawm scheelite nitric acid, yuav tsim tungsten trioxide - "hnyav pob zeb" daj. Ob xyoos tom qab, twb nyob rau hauv 1783-m, ob tug kwv tij Eluard, chemists Ameslikas los ntawm Spain, cov pej xeem twb paub hais tias lawv yuav tau txais los ntawm wolframite tshiab hlau thiab oxide - tungsten.

Niaj hnub nimno United States, Fabkis thiab teb chaws Aas Kiv siv lub npe ntawm tungsten rau tungsten, uas translates los ntawm Swedish li "hnyav pob zeb". Keeb xeeb, lo lus meant wolframium mineral wolframite. Tom qab ntawd nws kis mus rau cov hlau nws tus kheej.

Tungsten nyob rau hauv cov xwm

Raws li suav Vinogradova, Clarke tooj tungsten ntiaj teb ua kiav txhab yog hais txog 1.3 g / t. Qhov nruab nrab ntsiab lus ntawm cov pob zeb roob ranges, r / t: acidic pob zeb - 1.9, nruab nrab - 1.2, qhov yooj yim - 0.7 ultrabasic - 0.1.

Qhov loj tshaj plaws reserves ntawm no hlau yog feeb meej nyob rau hauv Tuam Tshoj, lub US, Canada thiab Kazakhstan, lub teb chaws xws li Bolivia, Portugal, Uzbekistan, Russia thiab South Kauslim muaj ib tug me me nyob rau hauv kev sib piv nrog rau cov aforementioned States stocks. Nyob rau hauv lub xyoo ua txog 49-50 lab tonnes, ntawm uas 41 los ntawm Tuam Tshoj, Russia feem sau raws nkaus Ii 3.5 tons, Kazakhstan - 0.7, thiab Australia - 0.5 tons.

Nyob rau hauv kev lag luam, lub ntsiab luag hauj lwm yog muab rau wolframite thiab scheelite. Minerals wolframite feem ntau concentrated nyob rau hauv granitic pob zeb thiab lawv nruab nrab concentration sau raws nkaus Ii ib tug los yog ob tug rau ib xees. Feem ntau cov ua teb chaws exporting tungsten. . Tus nqi ntawm no hlau yog es siab thiab tej zaum yuav sib txawv nyob ntawm seb lub hom thiab cov yam nyob rau hauv uas nws yog muag (los ntawm 2172 mus 6250560 xuas.). Lub ntsiab exporters ntawm tungsten xam tau tias yog UK, Tuam Tshoj thiab Australia. Txawv nyob rau hauv loj qhov ntau United States, Lub teb chaws Yelemees, England thiab Nyiv.

Txoj kev rau cov kev npaj

Kev npaj ntawm tungsten - ib tug txheej txheem uas muaj ob peb incremental cov kauj ruam. Thawj raug rho tawm trioxide WO ₃ los ntawm ore concentrates nrog lub rov qab los txheej txheem tom qab mus rau tus hlau hmoov nrog hydrogen nyob rau hauv tej yam kev mob ntawm txog 700 ° C. Vim lub siab heev melting point zoo tshaj plaws txoj kev uas yuav tau txais no hlau yog txhais tau tias ntawm hmoov metallurgy. Nyob rau hauv thawj kauj ruam lub tungsten hmoov yog pressed, ces muab tso rau hauv ib lub hydrogen cua thiab sintered nyob rau hauv tej yam kev mob ntawm txog 1200-1300 ° C. Ntxiv raug hluav taws xob tam sim no thiab cov cua kub kub yog distilled rau peb txhiab degrees, tus txheej txheem no yog nrog los ntawm sintering, thiab cov hlau puv rau hauv ib lub monolith. Tom ntej kev npaj ntawm tungsten thiab nws purification los ntawm lub resulting monolithic ntaub ntawv tshwm sim nyob rau hauv tej yam kev mob ntawm cheeb tsam melting. Txawm li cas los, tungsten hmoov - qhov no yog tsis yog tib daim ntawv ntawm kev npaj uas hlau. Nyob rau hauv qhov kev npaj ntawm W los ntawm pyrolysis ntawm chlorides nws yuav tau twb nyob rau hauv nws yog xim hlau daim ntawv no, tab sis tsis nyob rau hauv ib tug compact thiab hmoov.

Tshuaj zoo cov yam ntxwv

Tungsten yog lub valence ntawm lub nce mus nce los cim, los ntawm ob mus rau. Qhov tseem ruaj khov daim ntawv yuav siv sij hawm rau valency. Di- thiab trivalent ntaub ntawv ntawm lub tebchaw yog tsis ruaj tsis khov thiab tsis muaj tshwj xeeb tseem ceeb, nyob rau hauv kev xyaum tsis siv. Tungsten yog heev resistant rau xeb hlau. Room kub tso cai rau nws kom muaj ib tug tsis tu ncua txoj hauj lwm tsis tau raug xeb; nce mus txog incandescence kub pib rau oxidize, txoj kev ua ib tug tungsten oxide (VI). Yog tus thib ob nyob rau hauv ib tug series ntawm kev nyuaj siab thiab tus nqi qab hydrogen. Xyaum insoluble nyob rau hauv hydrofluoric thiab dilute sulfuric acid. Nitric acid thiab aqua regia ua nto oxidation txheej txheem. Xaus ntawm tau hydrogen peroxide.

Ib tug sib tov ntawm hydrofluoric thiab nitric acid yaj zoo tungsten:

2W + 4HNO ₃ + 10HF à WF ₆ + WOF ₄ + 4NO (gas evolution) + 7H ₂ O.

Nyob rau hauv lub xub ntiag ntawm oxidants yuav reacted nrog ib tug molten alkali:

2W + 4NaOH ₃ + 3O ₂ à 2Na ₂ WO ₄ + 2H ₂ O.

Cov piv txwv saum toj no tshua mus heev maj mam, tab sis nyob rau xeeb cov theem ntawm 400 ° C thiab tungsten self-cua kub ntawm cov tshuaj tiv thaiv yog ceev, ib txhij txoj kev ib tug loj npaum li cas ntawm tshav kub. Tshua uas muaj oxygen thov xeeb lub cim 500 ° C, rau hlau nyob ib leeg pib kom sov.

Dissolve nyob rau hauv ib tug sib tov ntawm hydrofluoric thiab nitric acids ua mus rau tsim geksaftorvolframovoy acid - H ₂ [WF _6]. Ntawm tag nrho cov paub tungsten tebchaw no yog tseem ceeb tshaj plaws anhydride tungsten trioxide los yog tungsten, tungstate, ib tug peroxy compound nrog kuv ₂ WO _X, ib yam khoom uas muab tau los ntawm S, C, thiab halogen pab pawg neeg hais.

Cov khoom ntawm ib tug lub cev xwm

Tungsten yog ib lub teeb grey ci iab hlau. Tungsten kub thaum lub sij hawm melting thiab kub nce mus txog lub siab tshaj plaws elevations Celsius piv nrog rau lwm cov hlau. Muaj yog speculation uas seaborgium muaj txawm ntau dua kev ua tau zoo melting thiab kub cov ntsiab lus, tab sis vim lub fact tias nws "lub neej" yog heev me me, nws yog tsis yooj yim sua hais tseeb, vim nws yog tsis muaj pov thawj los ntawm kev xyaum ua tej. Tungsten pib yaj thaum 3695 K, thaum boiling, xeeb 5828 K. W Net ceev yog nyob ze rau kub - 19,25 grams ib nyhav centimeter. Nws yog yus muaj los ntawm paramagnetic qualities. Nyob rau hauv raws li cov kev ntsuas tsis Brinell hardness yog 488 kg / hli ^2. Thaum nees nkaum degrees Celsius muaj ib tug resistivity ntawm 55 × 10 ^-9 Ohm * m, tab sis nyob rau hauv lub tej yam kev mob ntawm kub ntawm 2700 ° C resistivity index tsub kom mus txog 904 x 10 ^-9 Ohm * m. Lub reflected suab los ntawm tungsten tsiv rau tus ceev ntawm 4290 m / c.

Ib tug ntawm cov co heavy uas muaj hardness thiab melting point loj loj xam tau tias yog tungsten. Cov khoom uas yog xam qhovkev rau hauv nws, txiav txim nws tus nqi rau lub ntiaj teb no kev ua lag luam thiab pab kom dav siv. Cov muaj peev xwm los mus tiv sov dua tso cai loj scale siv tungsten. Hlau, nplooj ntawv thiab ntau yam ntxiv cia koj mus tsim mechanisms uas yuav pab tau ntau, ntau xyoo. Externally zoo xws li cov platinum. Nyob rau hauv cov ntshiab lub xeev thaum rhuab mus 1600 ° C tej zaum yuav zoo yuav forged.

Kev siv cov ntshiab hlau

Cov yooj yim txoj kev ntawm kev siv tungsten - lub hauv paus raws li ib tug refractory khoom nyob rau hauv lub metallurgical kev lag luam.

Yas thiab refractory zog - qhov no yog dab tsi yog hu rau tungsten. Hlau ntawm no hlau yog indispensable nyob rau hauv pab kiag li lawm npaj rau teeb pom kev zoo. Duab hlab thiab lwm yam hlab nrog ib lub tshuab nqus yog tseem lug siv W.

Argon arc vuam ua tsis tau tsis muaj tus electrodes ua nrog tungsten. Lub tshuab nqus tsev kuj cub tawg tseem siv nws raws li ib tug caij cua kub, thiab qhov no hlau hlau yog siv raws li lub rhenium thermocouple.

Lub siab ceev tso cai rau kom siv raws li ib lub hauv paus rau hnyav hom hlau siv raws li ib tug counterweight rau lub armor-tho tub ntxhais sabot thiab projectile sagittal artillery zoo li, cov tub ntxhais rau tej cuab yeej-tho mos txwv thiab txawm gyro stabilizing ya ballistic missile.

Tungsten yuav pab raws li ib qho zoo heev ntawm txoj kev ionizing hom ntawm hluav taws xob. Txawm hais tias nws muaj ib tug ntau dua kev ceev thiab, tshwj xeeb tshaj yog thaum muab piv nrog rau cov pa hmoov txhuas, by luj sib npaug theem muab kev tiv thaiv cov khaub ncaws los yog cov khoom nyob nrog nws siv yooj yim dua. Infusibility zog thiab hardness complicate lub ua, thiab yog li ntawd nyob rau hauv xws li mob feem ntau yog alloys ntawm tungsten thiab npib tsib xee, raws li zoo raws li hlau, tooj liab thiab lwm yam hlau.

Nyob rau hauv qhov kev lag luam los ua ib tug ntau yam ntawm cov khoom cov khoom siv tungsten. Sheet, tungsten hmoov, thiab ib tug pas nrig-electrodes - ib qho ntawm feem ntau cov ntaub ntawv tso zis W.

Siv lub tebchaw

Machining ntawm ntau yam co, raws li zoo raws li cov ntaub ntawv uas ua tau qhov uas tsis yog-metallic xwm ntawm engineering Siv, drilling thiab tsuas kev siv zog alloys thiab puas yam ntaub ntawv raws li nyob rau hauv tungsten carbide, ib tug sib tov ntawm titanium carbide, tantalum carbide thiab tungsten carbide. Nyiaj Muas tungsten ua los ntawm cov ntaub ntawv no raug muab faib ua T30K4, T5K10, VK25, VK8, VC 15 T15K4, BK2, thiab VK6 VK4. Nyiaj Muas TT pab pawg neeg tsuas yog siv rau nyuaj heev machining tej yam kev mob nyob rau hauv ntau zog complexity. Ib tug prime piv txwv yuav pab raws li ib tug poob siab-txheej txheem teb drilling perforator los yog check cov ntaub ntawv uas raug forging hlau nrog kub siab kuj. W yog siv raws li ib tug alloying caij rau steel thiab alloys raws li hlau. "High ceev" steel lettered daim ntawv lo pib nrog P, ntau tshaj 90% ntawm cov qhia comprises tungsten.

Tej zaum txawv tungsten tebchaw yog siv raws li catalysts los yog pigments, high-kub lubricant rau txoj kev hloov ntawm lub tshav kub zog rau hauv hluav taws xob daim ntawv.

Tungsten thiab biology

Tungsten hlau yog tsis suav tias yog tseem ceeb nyob rau hauv biology, tab sis ib txhia cov kab mob thiab archaea raws li ib feem ntawm lawv cov enzymes muaj no tivthaiv, uas yog nyob rau hauv lub active site. Kwv yees li sib sib zog nqus qhov chaw hydrothermal hom archaebacteria nyob-hyperthermophiles, pom tau hais tias nyob rau obligately tungsten. Lub xub ntiag ntawm no hlau nyob rau hauv lub enzyme muaj pes tsawg leeg yog ntshai raws li ib tug tej yam qub qab ntawm thaum ntxov Archean lub sij hawm, nyob rau hauv lwm yam lus, nws yuav them taus los xav hais tias cov thaum ntxov tsos ntawm lub neej nyob rau lub ntiaj teb coj qhov chaw nrog kev koom tes ntawm W.

Raws li cov predominant ib feem ntawm lwm yam hlau, tungsten hmoov av ua voos ntawm cov pa kabmob.

ntaub ntawv isotopes

¹⁸² W (26,41 %), ¹⁸³ W (14,4 %), ¹⁸⁴ W (30,64 %) и ¹⁸⁶ W (28,41 %) . Tungsten ntuj keeb kwm muaj ib tug sib tov ntawm tsib ntau yam ntaub ntawv ntawm isotope, namely ¹⁸⁰ W (0,135 wt.%), ¹⁸² W (26,41%), ¹⁸³ W (14,4%), ¹⁸⁴ W (30,64%) thiab ¹⁸⁶ W (28,41%). Valency tungsten nce mus nce los, thiab yeej ib txwm ua raws li tus xov tooj ntawm 2 mus rau 6, nyob rau hauv tej daim ntawv ntawm cov isotope.

Los ntawm 2016 nws twb paub peb caug-rau txiv neej-ua dag ntaub ntawv ntawm tungsten pom tias radionuclides nrog huab hwm coj tus xov tooj 157 ... 179, 181, 185, 187 ... 197. Qhib tungsten lawm tab radioactivity yog nyob rau hauv 2003, tab sis nws tus nqi yog tsis tshua muaj tsis tshua muaj, uas sib raug rau kwv yees li ob disintegrations ib tug kab ib xyoo, thiab tus mob ntawm no lwj yog hlau α-kev ua si.

Nyob rau hauv xaus

Feem ntau ntawm cov uas twb muaj lawm refractory hlau yog tungsten. Properties xam qhovkev, cia peb mus nrhiav ib qhov chaw nyob rau hauv ib tug ntau ntawm cov muaj tib neeg kev ua ub no, los ntawm engineering thiab xaus nrog kev tiv thaiv los ntawm tawg. Hlau twb qhib roughly ob zaug, ob lub xyoos sib nrug, tab sis tsis Scheele tsis kwv tij Eluard tsis yeej hais tias tsim nyog tso rau hauv Honor ntawm nws foundations. Lub valence ntawm tungsten yog nce mus nce los thiab yuav siv sij hawm ib tug nqi ntawm ob mus rau, tab sis, raws li tau sib tham txog ua ntej lawm, feem ntau ruaj khov daim ntawv muaj rau valence. Nws yog ib heev resistant rau xeb, yuav hnov mob nrog alkali thiab yaj nyob rau hauv ib tug sib tov ntawm hydrofluoric thiab nitric acids.

Nyiaj Muas tungsten muab faib mus rau hauv ib tug lossis loj tus naj npawb ntawm cov hom raws li cov qauv ntawm cov tiav, rau hauv daim ntawv nyob rau hauv uas lub hlau, thiab nws teb ntawm daim ntawv thov. Muaj ntau yam ntaub ntawv ntawm nws isotope, thiab lub caij nyob rau hauv qhov yog tsis zoo cim tej zog thiab qeeb heev disintegrates. Lub hauv paus rau ib tug plurality ntawm qhov chaw thiab spare qhov chaw, ib tug ntau yam ntawm pab kiag li lawm thiab khoom siv los ntawm tus txiv neej, nws yog tungsten. Txawm nqi rau ib kilogram hlau yog heev siab heev, tab sis nws tsis txo qhov kev thov rau nws, vim hais tias ntawm nws zoo sib haum mus rau tus nqi hais tias nws hais rau.