Graphite: ntom, khoom, daim ntawv thov nta thiab hom

2024 Tus sau: Howard Calhoun | [email protected]. Kawg hloov kho: 2023-12-17 10:28

Graphite yog ib yam khoom uas tshwm sim ib txwm muaj. Qhov no yog ib qho kev hloov kho ntawm cov pa roj carbon monoxide, uas yog tus cwj pwm los ntawm qee yam siv lead ua lattice. Qhov no txiav txim siab cov khoom uas graphite muaj. Carbon tshwm sim nyob rau hauv cov xwm nyob rau hauv ob lub ntsiab. Cov no yog graphite thiab pob zeb diamond. Lawv cov qauv tshuaj zoo ib yam, tab sis lawv lub cev muaj zog sib txawv.

Nws yog cov qauv siv lead ua lattice uas cuam tshuam rau cov yam ntxwv no. Nws muaj cov electrons dawb uas txiav txim siab lub cev ntawm cov teeb meem. Graphite, uas nws qhov ntom ntom, hom thiab qhov dav yog qhov nthuav dav rau ntau qhov kev lag luam, tsim nyog xav txog ntau yam.

Basic nta

Graphite yog cov khoom grey nrog cov xim hlau. Nws muaj thermal conductivity (3.55 W / deg. / cm). Vim li no, graphite nquag siv nyob rau hauv ntau yam lag luam. Daim duab no yog siab dua li ntawm ib lub cib, uas tau piav qhia los ntawm lub xub ntiag ntawm mobile electrons nyob rau hauv lub siv lead ua lattice. Lawv kuj pab txhawb kom zoo hluav taws xob conductivity. Nyob rau hauv tag nrho cov xeev ntawm kev sib sau ua ke, cov khoom no yog tus cwj pwm los ntawm qhov tsis muaj zog tam sim no (los ntawm 0.4 txog 0.6 ohms).

Graphite yog ib yam khoom tsis muaj zog uas tsis yaj los ntawm cov khoom siv tshuaj lom neeg. Qhov no yog ua tau tsuas yog thaum nws nkag mus rau hauv nruab nrab ntawm molten hlau nrog ib tug kub boiling point. Graphite nyob rau hauv cov xwm txheej zoo li no melts tag, tsim carbides.

Tsawg coefficient ntawm kev sib txhuam thiab siab melting point ua rau cov khoom sealing zoo. Qhov ceev ntawm graphite (kg / m3) yog 2.23. Tab sis tib lub sijhawm, cov khoom siv khoov thiab txiav zoo.

qauv

Xav txog qhov ceev ntawm graphite, nrog rau cov khoom thiab hom, nws yuav tsum tau them sai sai rau nws cov qauv. Qhov no yog ib txheej txheej. Nws carbon atoms kab nyob rau hauv ib tug honeycomb zoo li siv lead ua lattice. Hexagons nyob rau hauv ib txheej haum snugly ua ke. Txawm li cas los xij, kev sib raug zoo ntawm txhua qib tsis muaj zog. Nws yog qhov tshwj xeeb no uas ua rau nws yooj yim tawg graphite.

Ntawm Mohs nplai, qhov nyuaj ntawm cov khoom yog ib qho. Rau kev sib piv, qhov ntsuas no yog 10 rau pob zeb diamond, thiab 5 rau porcelain stoneware. Ntawm qhov kub ntawm 1500 ° C, raws li cov kws tshawb fawb, cov siv lead ua lattice ntawm graphite tuaj yeem hloov mus ua pob zeb diamond.

Thaum kev ua lag luam, cov qauv ntawm cov teeb meem hloov pauv. Nyob rau tib lub sijhawm, cov qib sib txawv ntawm graphite muaj cov khoom sib txawv. Yog tias cov khoom rho tawm tsis tau ua tiav, nws yog ib yam khoom ntuj tsim.

Natural Graphite

Graphite, qhov ntom thiab cov khoom ntawm qhov sib txawv loj nyob ntawm lub hom ntawm cov chaw tsim khoom, pom nyob rau hauv tej yam ntuj tso nyob rau hauv 2 lub ntsiab variants. Thawj homhu ua hexagonal. Nws muaj ib tug siv lead ua lattice nyob rau hauv uas ib nrab ntawm cov atoms nyob rau hauv txhua txheej yog saum toj no thiab hauv qab no qhov chaw ntawm lub hexagon.

Qhov kev hloov kho thib ob yog rhombohedral. Txhua txheej plaub rov ua dua thawj zaug. Qhov kev hloov kho no tshwm sim hauv qhov tsuas yog hauv daim ntawv ntawm impurities. Yog hais tias cov khoom no yog rhuab ntawm ib tug kub ntawm 2500-3300 K, ces nws siv lead ua lattice yuav tig mus rau hauv ib tug hexagonal. Nyob rau hauv tej yam ntuj tso, cov khoom yog feem ntau pom nyob rau hauv daim ntawv no.

Composition

Hauv qhov xwm txheej, graphite yeej tsis pom nyob hauv nws daim ntawv ntshiab. Nws muaj cov hmoov tshauv loj heev (qee zaum txog 20%). Nws muaj ntau yam sib txawv (FeO, MgO, CuO, CaO, thiab lwm yam). Txog li 2% ntawm qhov loj hauv ntuj graphite tuaj yeem nyob hauv cov pa roj. Bitumen thiab dej kuj tseem tuaj yeem tshwm sim.

Qhov ntom ntawm graphite hmoov sib txawv nyob ntawm qhov tawg, muaj qhov pores. Tus nqi saum toj no tuaj yeem raug txo kom 2.09kg/m3. Graphite yog greasy rau kov. Yog tias koj coj nws nrog koj txhais tes, lub cim cim yuav nyob twj ywm ntawm koj cov ntiv tes. Yog li ntawd, rods rau ib tug cwj mem yooj yim yog tsim los ntawm cov khoom zoo li no. Nws tso cov cim meej rau ntawm daim ntawv.

Artificial graphite

Rau ntau lawm, nws yog ib qho tseem ceeb heev uas yuav tau xav txog dab tsi yog qhov ceev ntawm graphite. Physics qhia meej tias qhov ntau dua qhov ntom ntawm cov khoom no, nws qhov thermal conductivity ntau dua. Artificial graphite yog tus yam ntxwv los ntawm siab purity (txog 99%). Nws kuj ua rau kom qhov ntom ntawm cov khoom zoo heev.

Kev tsim cov graphite refined yog ua los ntawm thermochemical thiab thermomechanical influences. Rau txhua ceg ntawm kev tsim khoom, ib yam khoom uas muaj qee yam zoo yog tsim. Qhov no ua rau nws muaj peev xwm ua tau raws li qhov xav tau ntawm kev lag luam hauv graphite nrog cov yam ntxwv ntawm lub cev.

Kev sau cov khoom cuav suav nrog kev rhuav tshem cov khoom siv los ntawm qhov chaw. Muaj foundry, electrocarbon, roj teeb, elemental, lubricating thiab mem hluav graphite. Kuj tseem muaj cov qib tshwj xeeb siv hauv cov tshuab hluav taws xob nuclear.

Scope of application

Thaum lub sijhawm tsim khoom, qee yam khoom ntawm graphite tau teeb tsa. Kev siv cov tshuaj no yog tag nrho rau lawv. Graphite yog siv hauv metallurgy hauv kev tsim cov pwm refractory lossis ladles, ntim. Nyob rau hauv cov txheej txheem casting, cov hmoov los ntawm cov khoom nthuav tawm yog siv los ua lubricant. Ib qho ntawm cov khoom ntawm refractory cib kuj yog graphite. Nws yog ntxiv rau qhov sib tov hauv kev tsim cov yas.

Cov khoom siv no kuj yog siv los tsim cov khoom siv hluav taws xob tiv tauj. Qhov no yog txhawb los ntawm cov khoom siv hluav taws xob hluav taws xob ntawm cov khoom siv.

Graphite mem hluav paub, tej zaum, rau txhua tus neeg. Cov khoom siv no kuj tseem siv los tsim qee hom xim. Hauv qhov no, nws yog xim dub (thiab tsis yog grey) graphite uas siv. Cov xim no muaj cov khoom tiv thaiv corrosion.

Pob zeb diamonds yog tau los ntawm cov pob zeb hauv av nthuav tawm. Lawv siv thaum twgkev tsim cov cuab yeej hnyav txiav. Hauv kev tsim kho tshuab, graphite hmoov ua cov khoom siv rau cov kabmob, nrog rau cov piston thiab cov nplhaib sib khi. Raws li cov roj nplua nyeem, nws tsim nyog rau kev ua cov tsheb kauj vab chains, tsheb springs, qhov rooj hinges.

Txawm tias muaj ntau yam tshuaj muaj graphite.

Daim Ntawv Thov Khoom Noj

Cov khoom nthuav tawm kuj tau siv dav hauv kev lag luam khoom noj. Txhawm rau ua qhov no, thaum lub sijhawm tsim khoom, nws dhau los ua qee yam. Qhov ntom ntawm hlau, ethyl cawv, graphite thiab qab zib, yog vim li cas pom tseeb, txawv. Tab sis cov ntaub ntawv nthuav tawm tuaj yeem muaj thiab ua ib feem ntawm qee yam khoom. Nws muaj nyob rau hauv paraffins, esters, cawv thiab txawm qab zib.

Qhov no tuaj yeem txheeb xyuas tau los ntawm kev sim yooj yim. Ua ntej koj yuav tsum noj ib daim qab zib. Nws muab tso rau ntawm lub hau tawv thiab npog nrog lub hau (koj tuaj yeem siv lub thimble). Tom qab ntawd cov hlau uas cov piam thaj yog npog yog rhuab heev. Nyob rau tib lub sijhawm, cov pa luam yeeb yuav tawm los ntawm hauv qab lub thimble. Yog tias koj nqa ib qho kev sib tw rau nws, roj yuav hlawv.

Thaum cov pa taws tso tseg, koj tuaj yeem tshem lub thimble. Muaj ib qho xim dub ntawm lub hau. Qhov no yog thee. Nws yog cov carbon uas graphite yog ua los ntawm.

Nyob hauv ntuj

Graphite, uas nws qhov ceev yog nyob ntawm nws cov purity, pom nyob rau hauv cov xwm txheej loj loj. Kwv yees li ntawm 600 txhiab tons ntawm cov khoom no yog mined txhua xyoo thoob plaws ntiaj teb. Qhov loj tshajnws cov reserves yog concentrated nyob rau hauv Mexico, lub Czech koom pheej, Tuam Tshoj, Ukraine, Brazil, Russia, Canada thiab South Kauslim.

Txij thaum ancient sij hawm, graphite deposits aroused lub paj ntawm noob neej. Niaj hnub no, cov khoom siv ntuj tsim no tau tsim los txhawm rau muab kev lag luam nrog cov khoom siv nrog cov khoom zoo. Graphite muaj nyob rau hauv granites, calcareous pob zeb, mica los yog gneiss nyob rau hauv daim ntawv ntawm fibrous los yog crystalline inclusions. Mining yog ua los ntawm kev qhib qhov av thiab hauv av.

Graphite nqi

Graphite, qhov ntom thiab purity uas cuam tshuam rau nws tus nqi, tam sim no muag ntawm tus nqi tsim nyog. Qhov no yog cuam tshuam los ntawm qhov loj ntawm nws cov muaju, nrog rau cov ntsiab lus carbon. Qhov siab dua, qhov kim dua graphite yog. Nrog rau cov pa roj carbon ntau txaus, cov khoom siv lub cev ntawm cov khoom nce. Qhov no muaj txiaj ntsig rau kev lag luam hauv ntau yam kev lag luam.

Hnub no tus nqi nruab nrab ntawm graphite yog li 45 rubles / kg. Yog hais tias nws tau ua tiav artificially, tus nqi nce ntau. Tsis tas li ntawd, tus nqi ntawm cov ntxhia ntuj nyob ntawm qhov chaw tso nyiaj.

Kev paub txog cov khoom tseem ceeb thiab cov yam ntxwv ntawm graphite, peb tuaj yeem xaus tias ob qho tib si tus nqi thiab cov khoom zoo ntawm cov khoom nyob ntawm nws qhov ntom. Yog li ntawd, cov ntxhia mined nyob rau hauv cov xwm yog raug rau tom qab ua. Qhov no txhim kho nws qhov zoo.