Calcium carbide

Vim los ntawm kev sib cuam tshuam ntawm cov pa roj carbon ntawm kub siab, carbides tau txais. Piv txwv, calcium carbide: Ca + 2C → CaC2. Ntawm tag nrho cov carbides, nws muaj lub tswv yim zoo tshaj plaws. Ntshiab CaC2 yog ib qho khoom zoo heev, xim tsis muaj kob yog tsim los ntawm Ca2 + thiab C2-ions. Lwm cov npe yog calcium acetylenide los yog calcium carbonate. Cov qog no yog 64.1 g / mol. Nws tsis tuaj yeem ua rau tsis taus thiab tsis yog nyob hauv ib qho ntawm cov paub cov kuab tshuaj, tab sis decomposes nyob rau hauv qhov kev txiav txim ntawm cov dej. Nws ceev yog 2.22 g / cm³. Qhov nruab nrab yog 2160 ° C, thiab lub npau npau yog 2300 ° C. Los ntawm cov xwm txheej ntawm lub cev yog hais txog cov khoom tsis tshua muaj kev phom sij (1st hoob ntawm kev nyab xeeb).

Thawj thawj zaug, calcium acetylenide tau txais nyob rau hauv 1862 los ntawm tus kws hu ua German Friedrich Weller thaum uas muaj cov pa roj carbon dioxide los ntawm kev ua los ntawm zinc thiab calcium. Nws kuj tau piav cov tshuaj tiv thaiv ntawm cov calcium uas carbonated H2O. Txawm nrog nws cov khoom siv (piv txwv li, nrog atmospheric noo noo), calcium carbide reacts heev, nrog tso tawm ib tug loj npaum li cas ntawm tshav kub. Tab sis thaum muaj dej tsis tau, cov acetylene uas ua tau tuaj yeem ua rau nws tus kheej. Calcium carbide reacts violently nrog dilute inorganic acids thiab aqueous ntsiab ntawm alkalis. Nyob rau tib lub sijhawm, acetylene kuj tau tso tawm. Ua kom muaj zog txo tus neeg sawv cev, CaC2 yuav rov qab tau tag nrho cov hlau oxides rau carbides los yog ntshiab hlau.

Zus tau cov calcium carbide tsis yooj yim dua los ntawm calcium nws tus kheej, tab sis ntawm nws cov oxide. Thaum kub siab (2000 txog 2300 ° C), nws raug rov qab los. Nyob rau hauv cov ntaub ntawv no, cov hlau thiab cov pa roj carbon monoxide yog: CaO + 3C → CO ↑ + CaC2. Cov txheej txheem yuav siv sij hawm qhov chaw nyob rau hauv ib tug hluav taws xob arc rauv taws nyob rau ib incandescent sib tov ntawm ceev txiv qaub thiab coke los yog Anthracite. Lub crude cov khoom no yog dawb, muaj ib tug grayish xim, vim hais tias nws muaj impurities nyob rau hauv daim ntawv ntawm cov dawb carbon, oxide, thiab sulfide, calcium phosphide thiab lwm yam tshuaj tebchaw. Qhov loj feem ntawm CaC2 nyob rau hauv nws yog 80-85%.

Nyob rau hauv kev cuam tshuam ntawm carbides nrog dej, txawm hlau los yog acetylene tso tawm. Hauv ob hom, calcium carbide reacts nrog dej. Acetylene, tau los ntawm cov tshuaj tiv thaiv, uas muaj cov khoom muaj nuj nqi: 2H2O + CaC2 → C2H2 + Ca (OH) 2, yog kev ua thiab muaj ntxhiab tsw, raws li nws muaj ntau hom impurities (NH3, H2S, PH3 thiab lwm tus). Txawm hais tias nyob rau hauv nws cov ntshiab daim ntawv nws yog ib tug tsis muaj roj tsis muaj xim nrog ib tug yam ntxwv me ntsis, thiab nws dissolves haum zoo nyob rau hauv dej. Nws yog ib qho tseem ceeb kom tau calcium cyanamide (a raw khoom nyob rau hauv zus tau tej cov cyanide tebchaw los yog thov raws li ib tug fertilizer) carbide los ntawm reacting nws nrog nitrogen ntawm cov tshuaj tiv thaiv kab zauv: N2 + → CaCN2 CaC2 + C.

Hauv yav dhau los, CaC2 tau siv ntau hauv cov roj teeb, uas nws tau txais kev pabcuam li ntawm cov nplaim acetylene. Tam sim no, txoj kev siv lub teeb pom kev zoo no tsuas yog siv rau kev tshawb txuj ci xwb, nws tseem siv tau ntab thiab lighthouses. Lwm cov kev siv tseem ceeb ntawm CaC2 yog cov yees technologies, qhov twg nws yog ib qho khoom siv raw. Piv txwv li, nyob rau hauv qhuav ntawm tshuaj, mas lawv nws yog ib hluavtaws roj hmab. Kuj ntawm carbonaceous calcium uas tau txais acetylene dub, yas chloride, acetic acid, acrylonitrile, ethylene, acetone, artificial resins, styrene. Hauv metallurgy nws ua hauj lwm rau deoxidize co thiab desulfurize (txo cov pa thiab cov dej qab ntsev, feem). Calcium carbide yog siv los ua cog kev loj hlob, hmoov carbide reagent (acetylene welding).

Tau txais txhua ton ntawm CaC2 yuav tsum tau kwv yees li 3 txhiab kW / h ntawm hluav taws xob. Yog li ntawd, nws yog ib qho ncaj ncees nyob rau hauv muaj ntawm luv nqi rau nws. Txawm li cas los xij, feem ntau, lub ntiaj teb cov kua carbon dioxide loj hlob tuaj. Yog tias nyob hauv 70 lub xyoo dhau los, txog li 5 lab tons tau tsim txhua xyoo, tom qab ntawd xyoo no nws tau loj hlob li ob zaug. Li no, nyob rau hauv Suav teb, cov kua roj acetylene raws li calcium carbide yog qhov tseem ceeb ntawm cov khoom siv raw cov chemicals, tshwj xeeb tshaj yog rau cov PVC. Zus tau tej cov acetylene los ntawm nws cov raw khoom ntau yig tshaj siv mas roj. Yog li ntawd, nws cov khoom nyob rau hauv Suav teb yog nce. Nyob rau hauv 2005, nws mus txog 8.94 lab tons, thiab muaj tiag tiag lub sij hawm los tsim 17 lab tons.

Nyob rau hauv sib piv rau Suav teb, nyob rau hauv Teb Chaws Asmeskas, Tebchaws Europe thiab Nyij Pooj, kev noj cov calcium uas yog feem ntau txo. Cov theem ntawm nws cov khoom nyob rau hauv lub tebchaws United States nyob rau hauv lub 90's tsuas yog 236 txhiab tons ib xyoo. Nyob rau hauv peb lub teb chaws, cov calcium uas carbide ua raws li cov specifications teem tawm nyob rau hauv ISO 1460-81. Cov neeg tau txais kev pab yog Ukraine, Uzbekistan, Romania thiab Slovakia. Vim lub high school lub hwj chim tau ntawm cov khoom nyob rau hauv kev twb kev txuas nrog cov kev nce rau hauv tus nqi ntawm hluav taws xob noj ntawm calcium acetylide nyob rau hauv Russia thiab exporting lub teb chaws poob los ntawm ib nrab.