Gabatarwa
Graphite muhimmin ma'adinan ma'adinai ne mai mahimmanci wanda ba{0}}arafa ba tare da keɓaɓɓen kaddarorin ƙarfe biyu da kuma waɗanda ba na ƙarfe ba. An san shi da "hanyoyi masu mahimmanci da ke tallafawa ci gaban fasaha mai zurfi a cikin karni na 21" kuma an dade ana kiransa da "black zinariya". Babban graphite mai tsafta yana nufin graphite tare da abun cikin carbon fiye da 99.99%. Yana fasalta ingantacciyar mai- kai, babban ƙarfi, kyakyawan halayen lantarki, acid/alkali/lalata/juriya mai zafi, ƙarancin faɗaɗawa, ingantaccen kwanciyar hankali na sinadarai, babban aikin rufewa, da ɗaki da ƙaƙƙarfan tsari. Ana amfani da shi sosai a aikin injiniyan lantarki, ƙarfe, tsaro na ƙasa, sararin samaniya, makamashi, masana'antar sinadarai da sauran sassa. Musamman ma, tana taka muhimmiyar rawa a masana'antu masu tasowa kamar shirye-shiryen na'urorin semiconductor na ƙarni na uku, masana'antar nukiliya, da masana'antar photovoltaic, suna yin tasiri mai nisa kan tattalin arzikin Sin.
1. Kayayyakin Graphite Ore
Graphite wani ma'adinai ne wanda ya ƙunshi abubuwan carbon, baƙar fata mai haske mai launi tare da luster na ƙarfe da anisotropy. Its yawa ne 2.09-2.23 g / cm³, narkewa batu 3850 digiri, tafasar batu 4250 digiri, zafi sha iya aiki 6.9036 × 10⁷ J / kg, nuna kyau kwarai thermal kwanciyar hankali.
2. Babban -Mafi Girma
2.1Maɗaukakin Halitta -Tsarin Zane
Dangane da albarkatun albarkatun ƙasa da hanyoyin shirye-shirye, za a iya raba babban zana mai tsafta - za a iya raba graphite mai tsafta zuwa babban ginshiƙi na halitta{1}} tsaftataccen graphite mai tsafta da babban zanen roba{2}} tsaftataccen zane.
Ana amfani da graphite mai tsafta ko'ina a fagage daban-daban saboda kyawawan halayensa na lantarki da yanayin zafi, kamar su kayan da ke jujjuyawa, kayan kariya na tsatsa, electrodes na carbon, janareta, man shafawa, da kayan kariya a masana'antar nukiliya. Haɗaɗɗen graphite mai girma{3}, tare da nau'ikan nau'ikan halitta iri ɗaya da rarraba girman barbashi, ana amfani da su a cikin anodes da aka riga aka gasa, graphite na musamman, masana'antar nukiliya da sauran filayen. Hanyoyi na shirye-shiryen babban graphite mai tsafta - sun bambanta da albarkatun ƙasa daban-daban.
Babu graphite mai tsabta a cikin yanayi. Graphite ore sau da yawa ya ƙunshi ƙazanta irin su SiO₂, Al₂O₃, FeO, CaO, P₂O₅, CuO, wanda yawanci ya zama kamar ma'adanai kamar ma'adini, pyrite, carbonate, kazalika da gaseous abubuwan ciki har da ruwa, kwalta, CO₂, H₂, CH₄, da N₂. Sabili da haka, nazarin graphite yana buƙatar ƙaddara ba kawai ƙayyadadden abun ciki na carbon ba amma har ma al'amura masu canzawa da abun cikin ash. Ayyukan tsarkakewa na zane suna nufin cire waɗannan ƙazanta yadda ya kamata. Mafi girman tsarkin graphite (watau mafi girman abun cikin carbon), mafi girman ƙimarsa kuma mafi girman iyakar aikace-aikacensa.
Shirye-shiryen babban graphite mai girma daga graphite na halitta yawanci ya haɗa da tsarkakewa na farko na graphite tama ta flotation, ƙarin tsarkakewa na flotation maida hankali ta hanyar alkali -hanyar acid ko hanyar hydrofluoric acid, kuma a ƙarshe samun samfuran graphite mai girma ta hanyar high{3}}hanyar zafin jiki ko yanayin zafi{4}
2.2 Mafi Girman Rubutu -Tsarin Zane
Zane-zane na roba gabaɗaya yana nufin kayan graphite waɗanda aka samar ta hanyar amfani da manyan coke na man petur da kuma farar coke a matsayin aggregates, ƙara farar kwal a matsayin ɗaure da sauran na'urorin haɗi, tare da jerin manyan jiyya na zazzagewar zafin jiki-. Gabaɗaya, ana yin magani da farko sannan a sanya su a cikin ma'aunin zafi na musamman{3} don graphitization da tsarkakewa. Babban nau'ikan tanderun sun haɗa da tanderun graphitization na Acheson, tanderun graphitization na ciki, da ci gaba da graphitization tanderun lantarki. Matsanancin zafin jiki- a cikin tanderun yana graphitizes coke petroleum coke da pitch coke, kuma ana gabatar da iskar halogen don magance ƙazanta, wanda daga nan sai a narkar da iskar gas kuma a canza shi don samun graphite mai girma-.
Ko da yake ana iya cire wani ɓangare na ƙazanta a cikin coke na man petur da kuma farar coke a lokacin haɓakar zafi mai ƙarfi a cikin samar da graphite mai girma{1}, akwai ƙayyadaddun buƙatu don abubuwan da ke cikin sulfur da toka a cikin albarkatun ɗanyen coke mai. Tare da karuwar amfani da babban danyen mai - sulfur mai girma - sulfur man coke shima yana girma. Don saduwa da ƙaramin - sulfur da ake buƙata na coke na man petur don samar da ginshiƙi mai tsafta{7}, masana da yawa sun gudanar da bincike mai zurfi kan-aiki mai inganci da ingantacciyar hanyoyin lalata coke man fetur.
Tsaftar hoto yana ƙayyade aikin sabis da cikakkun kaddarorin masu zurfin graphite{0} Mafi girman tsarki, mafi girman ƙimar aikace-aikacen. Misali:
Graphite azaman abu na anode don batirin lithium{0}ion yana buƙatar tsabta sama da 99.98%;
Grafite na halitta don lu'u-lu'u na roba na roba yana buƙatar tsabta sama da 99.999%, tare da abun ciki na boron a ƙasa 0.01 × 10⁻;
graphite na musamman don sararin samaniya, tsaron ƙasa, da masana'antar nukiliya yana buƙatar tsabtar 99% ~ 99.99% ko ma mafi girma;
Graphite foda don haɗawa na uku{0}}aramin semiconductor SiC wafers yana buƙatar tsafta gwargwadon 99.9995% ko sama.
Tsabtace graphite shine tushe don shirya duk kayan graphite da kuma batun gama gari a cikin haɓaka kayan graphite. Hanyoyin tsarkakewa na graphite tare da ƙarancin amfani da makamashi, ƙarfin ƙarfi, da ƙarancin gurɓataccen gurɓataccen abu sune fifikon R&D na yanzu.
3. Fasaha Tsarkake Hotuna
3.1 Hanyar Ruwa
Yin amfani da kyawawan iya yin iyo na graphite na halitta, tafiyar matakai na flotation tare da ɗimbin ɗigon ruwa an tsara su don raba graphite flake ko graphite microcrystalline daga ma'adanai masu alaƙa kamar kaolin, quartz, da mica a cikin tama mai hoto na halitta. Wannan fasaha na iya haɓaka tama mai graphite sosai tare da ƙimar ƙasa da kashi 20% cikin ƙimar graphite tare da tsaftar 95%, wanda galibi ana amfani da shi azaman ɗanyen abu don samar da ginshiƙi mai tsafta na halitta-.
3.2 Alkali -Hanyar Acid
Tsarin tsarkakewa ya haɗa da haɗin alkali da acidolysis. A cikin haɗin alkali, ƙazanta a cikin graphite kamar Al₂O₃, Fe₂O₃, SiO₂, MgO, CaO suna amsawa tare da NaOH a babban zafin jiki don samar da ruwa{1}} hydroxides marasa narkewa; wasu ƙazanta (misali, SiO₂) suna samar da ruwa{4}}kayayyaki masu narkewa, waɗanda ake cirewa ta hanyar leƙen ruwa da wankewa. A cikin acidolysis, graphite da hydroxides bayan fusion na alkali ana haɗe su da hydrochloric acid na wani ma'auni don zafi mai zafi, yana mai da su zuwa chlorides mai narkewa wanda sai a wanke da ruwa. Za a iya samun babban graphite mai tsafta sama da 99% bayan acidolysis.
A halin yanzu, hanyar alkali - ana amfani da acid a ko'ina a masana'antu, tare da fa'idodi kamar ƙaramar saka hannun jari na lokaci, babban daraja, da daidaita tsarin aiki mai ƙarfi. Duk da haka, yana da kurakurai da suka haɗa da buƙatar ƙididdige yawan zafin jiki{3}, yawan amfani da makamashi, dogon lokacin amsawa, lalata kayan aiki mai tsanani, babban hasarar graphite, da tsananin gurɓataccen ruwan sha.
3.3 Hanyar Gasasshen Chlorination
A kusan digiri 1000, ana shigar da iskar chlorine cikin graphite. Yin amfani da ƙaƙƙarfan kadarar chlorine, ƙazantar oxide na ƙarfe a cikin graphite ana yin oxidized cikin chlorides tare da ƙananan yanayin zafi. A ƙarƙashin wannan zafin jiki, chlorides na ƙarfe na iya zama da sauri gas ɗin gas kuma a fitar da su da yawa, ana fahimtar tsarkakewar graphite.
Gasasshen chlorination gabaɗaya ana amfani da shi azaman ƙarin tsari don tsarkakewa graphite, daidaitawa da sauran matakai, kuma yana da fa'idodi na zahiri musamman wajen cire ƙazantattun ƙarfe. Duk da haka, yawan guba, lalata da gurɓataccen muhalli na chlorine yana hana yaduwar wannan tsari zuwa wani ɗan lokaci. Bugu da kari, yana da wahala a samar da zane mai tsafta{2}high-, kuma tsarin mara tsayayye shima yana shafar aikace-aikacen sa.
3.4 Hanyar Hydrofluoric Acid
Najasa a cikin ɗanyen tama yana amsawa tare da acid hydrofluoric don samar da ruwa{0}}mai narkewar fluorides da fluorosilicates, waɗanda ake cirewa ta hanyar wanke ruwa don samun graphite mai girma{1}.
Babban fa'idodin hanyar hydrofluoric acid shine haɓakar ƙazanta mai ƙazanta, ƙimar samfur mai girma, ƙaramin tasiri akan aikin graphite, da ƙarancin kuzari. Rashin hasara shi ne cewa hydrofluoric acid yana da guba sosai kuma yana lalata, yana buƙatar tsauraran matakan kariya a cikin samarwa, kuma babban jarin kare muhalli yana rage girman gasa na tattalin arziki.
3.5 Babban -Tsarin Tsabtace Zazzabi
Dangane da ƙa'idar cewa graphite yana da babban wurin tafasa yayin da sauran ƙazanta ke da ƙarancin tafasasshen ruwa, graphite na halitta tare da abun ciki na carbon kusan 80% ana sanya shi a cikin tanderun tsarkakewa a digiri 1500 don gas da cire ƙarancin ƙazanta{2}. Sa'an nan ya shiga tanderu a 25002800 digiri don cire ƙarin ƙazanta, kuma a ƙarshe tanderu a 28003200 digiri tare da dacewa HF da HCl gas. Waɗannan iskar gas ɗin suna amsawa tare da ƙazantattun ƙarfe masu tafasa a cikin zafin jiki mai zafi don samar da ƙarancin fluorides da chlorides, waɗanda aka fitar da gas kuma ana fitarwa. Ta wannan hanyar, ana tsarkake graphite na halitta zuwa 99.99% ~ 99.9998% abun ciki na carbon.
Babban abubuwan da ke shafar tsarkin graphite sun haɗa da ingancin albarkatun ƙasa, tsabtataccen graphite crucible, hanyar dumama graphitization, da girman barbashi na graphite. Wannan tsari yana da manyan buƙatu don tsabtataccen kayan albarkatun ƙasa, ƙarancin kayan abu da fasahar kayan aiki, tare da yawan amfani da makamashi da babban saka hannun jari. Don haka, aikace-aikacen sa na yanzu yana iyakance, galibi a fannoni na musamman kamar sararin samaniya, tsaro na ƙasa da masana'antar nukiliya tare da manyan buƙatun ingancin hoto.
3.6 Hanyar Tsabtace Gas Halogen
Babban{0}} aikace-aikacen masana'antu na ƙarshe (misali, masana'antar semiconductor) na buƙatar tsaftar graphite sama da 99.999%, wanda ba za a iya samu ta hanyar tsaftar yanayi mai girma ba kawai. Masana'antu gabaɗaya suna ɗaukar hanyar tsarkakewar iskar halogen (wanda ake kira tsarkakewar jiki). Tare da karuwar zafin tanderu da digiri na injin, wasu ƙazanta a cikin samfuran graphite suna canzawa ta atomatik. Ga sauran ƙazanta da ke buƙatar yanayin zafi mai girma, iskar halogen (mafi yawan chlorine da halogenated hydrocarbons) suna canza su zuwa halides tare da ƙananan narkewa da wuraren tafasa. A ƙarƙashin aikin haɗin gwiwar, ana cire ƙazanta don cimma tsarkakewar graphite.
4. Aikace-aikace na Babban -Tsarin Graphite
4.1 Abubuwan Lubricating
A matsayin ɗaya daga cikin ƙaƙƙarfan man shafawa na gama gari, tsarin zanen graphite yana ba shi kayan shafa mai kai{0}. Ƙarƙashin matsananciyar matsananciyar ƙarfi da ƙarfi yayin bushewar gogayya tare da karafa, yadudduka na graphite suna zamewa, suna samar da fim ɗin canja wurin bakin ciki na graphite akan farfajiyar gogayya ta ƙarfe a microscopically. Don haka, ƙayyadaddun juzu'i mai bushewa tsakanin graphite da ƙarfe ya yi ƙasa da na tsakanin ƙarfe, yana mai da shi abin sa mai kamar kansa-.
Ƙarfe-ƙarfe a cikin ƙarfe{0}} graphite friction nau'i-nau'i yawanci sun haɗa da 45 # karfe, 40Cr karfe, bakin karfe, simintin ƙarfe, gami da jan ƙarfe, da sauransu. Ƙarfe da sawa na graphite{4}}ƙarfe nau'i-nau'i yana da alaƙa da nau'in da kaddarorin kayan ƙarfe. Rage juzu'i da lalacewa tsakanin nau'ikan juzu'i na inji shine babbar hanyar inganta inganci da rayuwar sabis na sassan injina. Nazarin tasirin lodi, zafin jiki, saurin zamewa, yanayin yanayin yanayi da rubutu yana taimakawa tsawaita rayuwar graphite{7}}ƙarfe juzu'i.
4.2 Abubuwan Rufewa
Fadada graphite za a iya sarrafa shi zuwa sassauƙan graphite bayan jiyya -, tare da ƙarancin faɗaɗawar zafi (1×10⁻⁶~30×10⁻⁶ K⁻¹). Ba ya raguwa ko fashe a ƙananan zafin jiki, kuma baya yin laushi ko rarrafe a yanayin zafi mai girma.
Idan aka kwatanta da kayan hatimi na gargajiya (asbestos, roba, cellulose da abubuwan haɗin su), graphite mai sassauƙa yana da kewayon zazzabi na sabis (200 ~ 450 digiri a cikin iska). Saboda haka, faɗaɗa graphite ne yadu amfani da sealing abu a cikin inji, karafa, mota, shipbuilding, petrochemical da sauran filayen.
4.3 Harshe -Kayan baya
Za a iya haɗa graphite mai faɗaɗa tare da polymers, resins, da sauransu don samar da kayan hana wuta. Idan akwai wuta, graphite mai faɗaɗawa yana faɗaɗa cikin sauri don samar da shimfidar rufin rufin zafi mai faɗaɗa akan saman kayan, yana ba da kyakkyawan yanayin zafi da kuma toshe sakin iskar gas mai guba.
4.4 Abubuwan Haɗaɗɗen Electrode
Expandable graphite da ake amfani da shirya daban-daban baturi lantarki kayan saboda da high aiki surface, high sinadaran kwanciyar hankali, mai kyau thermal da lantarki watsin, da kuma sauki shiri. Tsayayyen tsarinsa yadda ya kamata yana iyakance girman haɓaka kayan lantarki (misali, a cikin batirin Li/S ko Li/Si) yayin hawan keke, inganta rayuwar zagayowar.
Haka kuma, mafi girman tazarar graphite mai faɗaɗawa yana ba da ƙarin sarari don tsaka-tsakin Li⁺, Na⁺, Mg²⁺, Zn²⁺ a cikin batura na biyu na ƙarfe{0}ion (lithium{1}}ion, sodium{2}}ion, magnesium{3}ion, zinc{4}} ion ƙarfin ajiya), ƙara kuzari da ƙarfin ƙarfin kuzari), ƙara ƙarfin ƙarfin kuzari. Hakanan za'a iya amfani da graphite mai faɗaɗawa azaman kayan lantarki don masu ƙarfin ƙarfi.
Bugu da ƙari, ƙaƙƙarfan abubuwan graphite tare da matrix polymer ba su da nauyi, mara nauyi{0}} kuma mai sauƙin ƙirƙira. Ana iya daidaita kaddarorin lantarki da yawa ta hanyar canza adadin faɗuwar graphite.
4.5 Na Gargajiya da Ƙarshen - Ƙarshen Masana'antu
Ƙarfe na lantarki da masana'antar gano masana'antu manyan filayen amfani da al'ada ne na graphite, galibi ana amfani da su don narkewar lantarki da shafi don yin simintin ƙarfe na ƙarfe, jan karfe, aluminum da sauran ƙarfe marasa ƙarfe. Buƙatar graphite a cikin masana'antar fensir ya kasance ɗan kwanciyar hankali.
Kayayyakin zane suna da tsari mai sauƙi, kiyayewa{0} kyauta, juriya mai ƙarfi, babban nauyi{1}}ƙarfin ɗauka da juriya mai ƙarfi, kuma ana amfani da su sosai a cikin manyan ma'auni na kayan aikin makamashin nukiliya, wutar lantarki, sararin samaniya da filayen soja.
4.6 Kayayyakin Wutar Nukiliya
Graphite don makamashin nukiliya ana amfani da shi ko'ina a cikin babban iskar gas mai zafi{1}, kamar raƙuman ruwa, abubuwan mai da abubuwan tallafi. Bearings da jagorar bearings a ci-gaba da makaman nukiliya manyan famfo a Rasha yawanci amfani da siliconized graphite. Graphite yana da kyakkyawan aikin nukiliya kuma galibi ana amfani dashi azaman mai daidaitawa da mai nuni a cikin reactors.
4.7 Semiconductor Materials
A cikin masana'antar semiconductor, samfuran graphite ana amfani da su sosai a cikin manyan kayan aikin maganin zafin zafi kamar murhun haɓakar crystal, tanderun carbonization da tanderu graphitization.
Manyan samfuran graphite{{0}tsaftacewa na ƙarni na uku- silicon carbide (SiC) sun haɗa da faifan faifai, dumama da foda don haɓakar kristal, waɗanda tsarkin su ke ƙayyadad da ingancin lu'ulu'u na SiC. Tsarkake irin wannan babban zane mai girma{3} yana ɗaukar hanyoyin sinadarai na zahiri{4}}, yana buƙatar tsarki Sama da ko daidai da 99.9995%, tare da ƙayyadaddun iyaka akan ƙazanta ɗaya (misali, B ƙasa da ko daidai da 0.05×10⁻⁶, Al Kasa ko daidai da 0.0⁻⁻⁻⁻)
4.8 Kayayyakin lu'u-lu'u na roba
A halin yanzu, lu'u-lu'u ɗaya{0}crystal ana haɗa shi ne ta hanyar High-Hanyar Matsawa{2}}Hanyar Zazzabi (HPHT) da Hanyar Tushen Tushen Sinadari (CVD). CVD yana amfani da hydrogen-mai ɗauke da iskar gas (methane, hydrogen, da sauransu), yana haifar da ƙazanta hydrogen da damuwa a cikin lu'ulu'u na lu'u-lu'u. Lu'u lu'u lu'u-lu'u na HPHT tare da gami na gargajiya azaman masu haɓakawa sun ƙunshi wasu ƙazanta na ƙarfe, suna yin haɗin lu'u-lu'u na "ultra{7} tsantsa" mai wahala da ƙalubale.
Recent breakthroughs in static ultra-high pressure technology have enabled direct synthesis of diamond from graphite under extreme P-T conditions (>15 GPA, digiri 2000). A karkashin irin wannan yanayi, graphite yana canzawa zuwa lu'u-lu'u cikin sauri, yana samar da centimeters{3}} aggregates polycrystalline mai girma da tsafta.
Kammalawa
Babban nau'ikan graphite da ake amfani da su a cikin Sin sun haɗa da babban hoto mai tsafta{0}, graphite istatic, graphite mai faɗaɗawa, graphite mai haske, graphite colloidal da graphene. Haɓaka tsaftar graphite buƙatu ne gama gari tsakanin duk samfuran graphite{2}}mahimmin mahimmanci amma mai wahala.
Yayin da ake buƙatar manyan graphite mai girma{0}a cikin manyan filayen fasaha{1} ke ci gaba da haɓaka kuma buƙatun tsabta suna ƙara ƙarfi, fasahohin da ke da alaƙa suna cikin muhimmin mataki suna jiran ci gaba.
