I-Ceramics
I-alumina ceramic iwuhlobo lwe-ceramic engagugi, ukumelana nokugqwala futhi enamandla amakhulu.Isetshenziswa kabanzi futhi njengamanje iyisigaba esisetshenziswa kakhulu sezitsha zobumba ezisezingeni eliphezulu. Ukuze wenze ukukhiqizwa ngobuningi futhi uhlangabezane nezidingo zokubukeka komkhiqizo ojwayelekile, inani elincane lokugaya kanye nokugaya kalula, kuyadingeka kakhulu ukukhetha indlela yokwenza ukucindezela okomile.Ukucindezela ukucindezela kudinga ukuthi okungenalutho kube yimpushana ene-gradation ethile, enomswakama omncane kanye ne-binder.Ngakho-ke, udaka lwe-batch ngemva kokugaya ibhola kanye nokuchotshozwa okuhle kufanele kumiswe futhi kukhishwe uketshezi lwempuphu kangcono ukuze kutholakale uketshezi lwe-granulated kangcono. I-spray drying granulation isibe indlela eyisisekelo yokukhiqiza i-ceramics yokwakha kanye ne-ceramics entsha.I-powder elungiselelwe yile nqubo ine-fluidity enhle, ingxenye ethile yezinhlayiya ezinkulu nezincane, kanye nobuningi obuhle bobuningi.Ngakho-ke, ukomisa isifutho kuyindlela ephumelela kakhulu yokulungisa i-powder eyomile ecindezelwe.
Ukomiswa ngokufutha kuyinqubo lapho izinto eziwuketshezi (okuhlanganisa nodaka) zishintshwa zibe i-athomu bese ziguqulwa zibe izinto eziyimpushana ezomile endaweni yokomisa eshisayo. Izinto ezisetshenziswayo zenziwa i-athomu zibe amaconsi ayindilinga amahle kakhulu, ngenxa yamaconsi enkungu mahle kakhulu futhi isilinganiso sendawo nevolumu sikhulu kakhulu, umswakama uyahwamuka ngokushesha, futhi izinqubo zokomisa kanye nezinhlayiya ziqedwa ngokuphazima kweso. Usayizi wezinhlayiyana, okuqukethwe umswakama kanye nokuminyana ngobuningi bezinto ezibonakalayo kungalawulwa ngokulungisa imingcele yokusebenza kokumisa. Impushana eyindilinga enekhwalithi efanayo kanye nokuphindaphinda okuhle kungakhiqizwa ngokusebenzisa ubuchwepheshe bokumisa isifutho, ngaleyo ndlela kufinyezwe inqubo yokukhiqiza impushana, kube lula ukukhiqizwa okuzenzakalelayo nokuqhubekayo, futhi kube indlela ephumelelayo yokulungiselela ngezinga elikhulu izinto zokwenziwa ze-alumina ceramic ezomile eziyimpushana.
2.1.1 Ukulungiswa Kodaka
I-alumina yezimboni yesigaba sokuqala enobumsulwa obungu-99% yengezwa cishe ngo-5% wezithasiselo zokulungiselela u-95% we-porcelain material, futhi ukugaya ibhola kwenziwa ngokwesilinganiso sezinto ezibonakalayo: ibhola: amanzi = 1: 2: 1, kanye ne-binder, deflocculant kanye nenani elifanele lamanzi lengezwa ukuze kulungiswe ukumiswa okuqinile okulinganiselwe ukugeleza okuqinile okulinganiselwe ukugeleza okuqinile okulinganiselwe ukugeleza okuqinile kwe-vislurry. okuqukethwe, uhlobo kanye nomthamo we-deflocculant.
2.1.2 Futha inqubo yokomisa
Imingcele yenqubo yokulawula eyinhloko enqubweni yokumisa isifutho yilezi: a). Izinga lokushisa eliphumayo le-dryer.Ngokujwayelekile lilawulwa ku-110℃.b). Idayamitha yangaphakathi yomlomo womlomo.Sebenzisa u-0.16mm noma 0. 8mm orifice plate. c), umehluko wengcindezi yesihlukanisi se-Cyclone, lawula ku-220Pa.
2.1.3 Ukuhlolwa Kokusebenza Kwempushana Ngemva Kokomiswa Ngokufutha
Ukunqunywa komswakama kuzokwenziwa ngokwezindlela ezivamile zokunquma umswakama we-ceramic.I-particlei-morphology kanye nosayizi wezinhlayiyana kubonwe nge-microscope.I-fluidity kanye ne-bulk density ye-powder ihlolwe ngokuvumelana nezindinganiso zokuhlola ze-ASTM ze-fluidity kanye nobuningi be-powder yensimbi. Indlela yilena: ngaphansi kwesimo sokungadlidlizi, impushana engu-50g (enembile iye ku-0. 01g) idlula entanyeni yefaneli yengilazi enobubanzi obungu-6mm nobude obungu-3mm ngenxa yokumanzi kwayo;Ngaphansi kwesimo sokungadlidlizi, impushana idlula kufaneli yengilazi efanayo bese iwela esitsheni esingama-25mm ukuphakama ukusuka kufaneli yengilazi efanayo. Ukuminyana okungadlidlizi ukuminyana kokupakisha okuxekethile.
3.1.1 Ukulungiswa kodaka
Ukusebenzisa inqubo yokumisa i-spray granulation, ukulungiswa kwe-slurry kuyisihluthulelo esibalulekile. Okuqukethwe okuqinile, ukucoleka kanye nokugcwala kodaka kuzothinta ngokuqondile ukuphuma kanye nosayizi wezinhlayiyana zempushana eyomile.
Ngenxa yokuthi impushana yalolu hlobo lwe-alumina porcelain iyinyumba, kuyadingeka ukwengeza inani elifanele le-binder ukuze kuthuthukiswe ukusebenza kwe-blank. Izinto eziphilayo ezivame ukusetshenziswa njenge-dextrin, i-polyvinyl alcohol, i-carboxymethylcellulose, i-polystyrene, njll.I-Polyvinyl alcohol (PVA), i-binder encibilikayo emanzini, yakhethwa kulokhu kuhlolwa kokushisa okuphakathi, okubucayi kakhulu ekushintsheni kwemvelo. kuthinta izakhiwo zempushana eyomile.
I-Polyvinyl alcohol inezinhlobo eziningi ezahlukene, amadigri ahlukene we-hydrolysis kanye nezinga le-polymerization, okuzothinta inqubo yokumisa isifutho. Idigri yayo evamile ye-hydrolysis kanye ne-polymerization degree izothinta inqubo yokumisa isifutho. Umthamo wayo uvame ukuba ngu-014 - 015wt.Ukwengezwa kokuningi kuzokwenza ukuthi i-spray granulation powder yenze izinhlayiya eziqinile ze-powder ukuvimbela izinhlayiya ekukhubazekeni ngesikhathi sokucindezela.Uma izici zezinhlayiyana zingakwazi ukuqedwa ngesikhathi sokucindezela, lezi ziphambeko zizogcinwa emzimbeni oluhlaza futhi azikwazi ukuqedwa ngemva kokudubula, okuzothinta ikhwalithi yomkhiqizo wokugcina. Ukwengeza i-binder amandla amancane kakhulu aluhlaza kuzonyusa ukulahleka kokusebenza. Ukuhlolwa kubonisa ukuthi uma inani elifanele le-binder lengezwa, ingxenye ye-billet eluhlaza ibhekwa ngaphansi kwesibonakhulu. Kungabonakala ukuthi lapho ingcindezi inyuswa isuka ku-3Mpa iye ku-6Mpa, isigaba siyanda ngokushelela, futhi kunenani elincane lezinhlayiya eziyindilinga. Uma ingcindezi ingu-9Mpa, ingxenye ibushelelezi, futhi azikho izinhlayiya eziyindilinga, kodwa ukucindezela okuphezulu kuzoholela ekuhlukaniseni kwe-billet eluhlaza.PVA ivulwa cishe ku-200 ℃.
Qala ukuvutha, futhi ukhiphe cishe ku-360 ℃. Ukuze uhlakaze i-binder yezinto eziphilayo futhi umanzise izinhlayiya ze-billet, yakha i-interlayer ye-liquid phakathi kwezinhlayiya, uthuthukise i-plasticity ye-billet, unciphise ukungqubuzana phakathi kwezinhlayiya kanye nokungqubuzana phakathi kwezinto kanye nesikhunta, ukhuthaze ukwanda kokuminyana kwe-billet ecindezelwe kanye nenani lepulasitiki elicindezelweyo, futhi wengeze inani elifanele lepulasitiki elicindezelweyo kanye nenani elivamile lepulasitiki. esetshenziswayo yi-glycerin, i-ethyl oxalic acid, njll.
Ngenxa yokuthi i-binder iyi-polymer ye-organic macromolecular, indlela yokwengeza i-binder ku-slurry nayo ibaluleke kakhulu.Kungcono kakhulu ukwengeza i-binder elungiselelwe odakeni olufana nokuqukethwe okuqinile okudingekayo.Ngale ndlela, izinto eziphilayo ezingancibilikisiwe nezingahlakazeki zingagwenywa ukuba zilethwe ku-slurry, futhi amaphutha okungenzeka angenzeka, emva kokuba i-binder ikhiqizwa kalula, uma i-binder ikhiqizwa kalula. ukugaya ibhola noma ukugqugquzela. Umoya osongwe econsini usempushaneni eyomile, okwenza izinhlayiya ezomile zibe nomgodi futhi kunciphisa ukuminyana kwevolumu. Ukuze uxazulule le nkinga, ama-defoamers anganezelwa.
Ngenxa yezidingo zezomnotho nezobuchwepheshe, okuqukethwe okuqinile okuphezulu kuyadingeka.Njengoba umthamo wokukhiqiza wesomisi ubhekisela emanzini ahwamukayo ngehora, i-slurry enokuqukethwe okuqinile okuphezulu izokwandisa kakhulu ukuphuma kwempushana eyomile. Lapho okuqukethwe okuqinile kukhuphuka kusuka ku-50% kuya ku-75%, ukukhishwa kwesomisi kuzokhuphuka izikhathi ezimbili.
Okuqukethwe okuqinile okuphansi kuyisizathu esiyinhloko sokwakheka kwezinhlayiya ezingenalutho.Enqubweni yokomisa, amanzi afuduka aye phezu kwamaconsi futhi athwale izinhlayiya eziqinile, okwenza ingxenye engaphakathi yeconsi ibe nembobo; uma ifilimu elinwebekayo eliphansi elikwazi ukungena lakhiwe eduze kwe-droplet, ngenxa yejubane eliphansi lokuhwamuka, izinga lokushisa leconsi liyakhula, futhi amanzi ahwamuke engxenyeni engaphakathi, okwenza i-droplet iqhume. Kuzo zombili izimo, ukwakheka kwezinhlayiya zebhola kuzobhujiswa, futhi kuzokhiqizwa izinhlayiya ezimise okwe-anular noma ze-apula ezimise okwepheya, okuzonciphisa ukuqina koketshezi oluqinile. okuqukethwe kungancipha
Enqubweni yokumisa emfushane, ukuncishiswa kwenqubo yokomisa kunganciphisa inani le-adhesive edluliselwa endaweni eyizinhlayiya kanye namanzi, ukuze kugwenywe ukuthi ukugxila kwe-binder endaweni yezinhlayiyana kukhulu kunesikhungo, ukuze izinhlayiya zibe nendawo eqinile, futhi izinhlayiya zingakhubazeki futhi zichoboze ngesikhathi sokucindezela nokubunjwa, ukuze kuncishiswe isisindo somzimba we-billet. Ngakho-ke, ukuze uthole i-powder eyomile yekhwalithi ephezulu, okuqukethwe okuqinile kwe-slurry kufanele kwandiswe.
I-slurry esetshenziselwa ukomisa isifutho kufanele ibe nomswakama okwanele kanye nomswakama omncane ngangokunokwenzeka.Uma i-viscosity ye-slurry iyancipha ngokungenisa amanzi amaningi, hhayi kuphela ukusetshenziswa kwamandla okomisa kuyanda, kodwa futhi ubuningi bomkhiqizo buyancipha. ingathathwa njenge-colloidal dispersion system.Ithiyori yokuzinza kwe-colloidal ibonisa ukuthi kunamandla amabili asebenza ezinhlayiyeni ezimisiwe: i-van der Waals force (i-Coulomb force) kanye ne-electrostatic repulsion force. Uma amandla ikakhulukazi amandla adonsela phansi, i-agglomeration kanye ne-flocculation izokwenzeka.Ingqikithi yamandla angaba khona (VT) okusebenzelana phakathi kwezinhlayiya zihlobene nebanga lazo, lapho i-VT ngesikhathi esithile iyisamba samandla adonsela phansi i-VA kanye namandla aphikisayo e-VR.Lapho i-VT phakathi kwezinhlayiyana iveza amandla amakhulu anamandla amahle, iwuhlelo lokuncibilika okuthile, i-VA inikezwe amandla. uhlelo yileyo misebenzi elawula i-VR: ukushaja okungaphezulu kwezinhlayiya kanye nokuqina kwezingqimba zikagesi eziphindwe kabili.Ubukhulu bebilayer buhambisana ngokuphambene nempande yesikwele yesibopho se-valence kanye nokugxila kwe-ion ye-equilibrium.Ukucindezelwa kwengqimba ephindwe kabili kunganciphisa umgoqo ongase ube khona we-flocculation, ngakho-ke isibopho se-valence kanye nokugxilwa kwe-valence kanye nokuhlushwa kwe-equilifiers edingekayo ku-equilifiers ezivamile ezisetshenziswayo. HCI, HNO3, NaOH, (CH) 3noh (quaternary amine), GA, njll.
Ngenxa yokuthi i-slurry esekelwe emanzini ye-95 alumina ceramic powder ayithathi hlangothi futhi i-alkalescent, ama-coagulants amaningi anomphumela omuhle wokuhlanjululwa kwezinye i-ceramic slurry alahlekelwa umsebenzi wawo.Ngakho-ke, kunzima kakhulu ukulungisa udaka olunokuqukethwe okuqinile okuphakeme kanye noketshezi oluhle. ukwakheka kwe-micelle kanye nesakhiwo. Inani le-pH le-slurry lizothinta ngokuqondile izinga lokuhlukanisa kanye ne-adsorption, okuholela ekushintsheni kwamandla angu-ζ kanye nokugeleza okuhambisanayo noma ukuhlukaniswa.
I-alumina slurry inenani eliphakeme lokuhle nokubi ζ amandla e-asidi noma i-alkaline medium.Kulesi sikhathi, i-viscosity ye-slurry inenani eliphansi kakhulu le-decoagulation, kuyilapho uma udaka lusesimweni sokungathathi hlangothi, i-viscosity yalo iyakhula, futhi i-flocculation iyenzeka.Kutholakala ukuthi ukugeleza kwe-fluidity kuwukuthuthuka okukhulu kwe-visscorry iyancipha ngokungeza i-demulsifier efanele, ukuze inani layo le-viscosity lisondele kulawo amanzi. I-fluidity yamanzi elinganiswa nge-viscometer elula imizuzwana emi-3 / 100 ml, kanti uketshezi lwe-slurry luyimizuzwana emi-4 / 100 ml. i-viscosity ye-slurry iyancishiswa, ukuze okuqukethwe okuqinile ku-slurry kukhushulwe ku-60%, futhi kungenziwa ukupakisha okuzinzile.Njengoba umthamo wokukhiqiza we-dryer ubhekisela ekuqhumeni kwamanzi ngehora, ngakho-ke ukumiswa.
3.1.2 Ukulawulwa kwamapharamitha abalulekile ohlelweni lokumisa isifutho
Iphethini yokugeleza komoya embhoshongweni wokomisa ithinta isikhathi sokumisa, isikhathi sokugcina, amanzi asele kanye nokunamathela odongeni kwamaconsi.Kulolu cwaningo, inqubo yokuxuba umoya we-droplet iwukugeleza okuxubile, okungukuthi, igesi eshisayo ingena embhoshongweni wokomisa ukusuka phezulu, futhi i-atomizing nozzle ifakwe ngaphansi kombhoshongo wokomisa, ukwakha i-droplet fountain is spray, kanye ne-droplet droplet is spray i-countercurrent, futhi lapho i-droplet ifinyelela phezulu kwe-stroke, iba ukugeleza komfula futhi ifafaze ibe yisimo se-conical.Ngokushesha nje lapho i-droplet ingena embhoshongweni wokomisa, maduzane izofinyelela isivinini esiphezulu sokumisa futhi ingene esigabeni sokumisa isivinini esiqhubekayo. Ubude besigaba sokumisa isivinini esingaguquki buncike kumswakama weconsi, i-viscosity yodaka, izinga lokushisa kanye nomswakama womoya owomile. Iphuzu lomngcele C ukusuka esigabeni sokumisa ngesivinini esingaguquki ukuya esigabeni sokumisa ngokushesha kubizwa ngokuthi iphoyinti elibalulekile. Ngalesi sikhathi, ingaphezulu leconsi alisakwazi ukugcina isimo esigcwele ngokufuduka kwamanzi, Ngokuncipha kwezinga lokuhwamuka, izinga lokushisa lamaconsi liyakhuphuka, futhi ingaphezulu lamaconsi endaweni D ligcwele, kwakheka ungqimba lwegobolondo eliqinile. Ukuhwamuka kuya ngaphakathi, futhi izinga lokomisa liyaqhubeka nokuncipha. Ukuqedwa okuqhubekayo kwamanzi kuhlobene nokungena komswakama wegobolondo eliqinile.Ngakho-ke, kuyadingeka ukulawula imingcele yokusebenza enengqondo.
Umswakamo wempushana eyomile unqunywa izinga lokushisa eliphuma kumshini wokomisa isifutho.Okuqukethwe umswakama kuthinta ukuminyana kwenqwaba kanye nokumanzi kwempushana eyomile, futhi kunquma ikhwalithi yokucindezelwa okungenalutho.I-PVA iyazwela kumswakama. Ngaphansi kwezimo ezihlukene zokuqukethwe komswakama, inani elifanayo le-PVA lingabangela ubulukhuni obuhlukene bongqimba olungaphezulu lwezinhlayiya ze-powder ezomile, okwenza ukuzimisela kwengcindezi kuguquguquke kanye nekhwalithi yokukhiqiza engazinzile ngesikhathi senqubo yokucindezela. Ngakho-ke, izinga lokushisa le-outlet kufanele lilawulwe ngokuqinile ukuze kuqinisekiswe umswakama we-powder owomile. Ngokuvamile, izinga lokushisa lokuphumayo kufanele lilawulwe ku-110 ℃, futhi izinga lokushisa lokungena kufanele lilungiswe ngendlela efanele.Izinga lokushisa lokungena alikho ngaphezu kuka-400 ℃, ngokuvamile lilawulwa cishe ku-380 ℃.Uma izinga lokushisa lokungena liphezulu kakhulu, izinga lokushisa lomoya oshisayo phezulu kombhoshongo lizoshisa kakhulu. Lapho inkungu ikhuphuka ifike endaweni ephakeme kakhulu futhi itholana nomoya oshise ngokweqile, ngenxa yempushana ye-ceramic equkethe i-binder, umphumela we-binder uzoncishiswa, futhi ekugcineni ukusebenza okucindezelayo kwempushana eyomile kuzothinteka.Okwesibili, uma izinga lokushisa lokungena liphezulu kakhulu, impilo yesevisi ye-heater nayo izothinteka, futhi isikhumba se-heater sizowa singene embhoshongweni wokomisa futhi sikhiphe umoya oshisayo ngaphansi kwesimo sezulu esishisayo, sikhiphe impushana epholile. zinqunywa ngokuyisisekelo, izinga lokushisa eliphumayo lingabuye lilungiswe ngokucindezelwa kwephampu yokuphakelayo, umehluko wengcindezi yesihlukanisi sesiphepho, okuqukethwe okuqinile kwe-slurry nezinye izici.
Umehluko wokucindezela we-cyclone separator.Umehluko wengcindezi we-cyclone separator mkhulu, okuzokwandisa izinga lokushisa lokukhipha, ukwandisa ukuqoqwa kwezinhlayiya ezinhle futhi kunciphise isivuno sesomisi.
3.1.3 Izakhiwo zesifutho sempushana eyomisiwe
Ubuningi be-fluidity kanye nokupakisha kwe-alumina ceramic powder elungiselelwe indlela yokumisa isifutho ngokuvamile ingcono kunaleyo elungiselelwe inqubo evamile. Impushana ye-granulation eyenziwa ngesandla ayikwazi ukugeleza kudivayisi ebonayo ngaphandle kokudlidliza, futhi impushana ye-spray granulation ingakwenza lokhu ngokuphelele. Kubhekiselwa kuzinga le-ASTM lokuhlola uketshezi lwempushana yensimbi kanye nokuminyana kwenqwaba, ukuminyana ngobuningi kanye noketshezi lwezinhlayiya ezitholwe ngokomiswa ngokufuthwa ngaphansi kwezimo ezihlukene zokuqukethwe kwamanzi kukalwa. Bheka Ithebula 1.
Ithebula 1 ukuminyana okuxekethile kanye ne-fluidity ye-spray powder omisiwe
Ithebula 1 Ukuminyana kwePowder nezinga lokugeleza
| Okuqukethwe umswakama (%) | 1.0 | 1.6 | 2.0 | 2.2 | 4.0 |
| Ukuminyana kokuqina (g/cm3) | 1.15 | 1.14 | 1.16 | 1.18 | 1.15 |
| I-Liquidity (s) | 5.3 | 4.7 | 4.6 | 4.9 | 4.5 |
Umswakama we-spray powder omisiwe ngokuvamile ulawulwa ku-1 - 3%. Ngalesi sikhathi, i-fluidity ye-powder inhle, engahlangabezana nezidingo zokucindezela ukucindezela.
I-DG1 ukuminyana kwempuphu yembudumbudu eyenziwe ngesandla, futhi i-DG2 ukuminyana kwempushana ye-spray granulation.
I-powder granulated yesandla ilungiswa ngokugaya ibhola, ukomiswa, ukusefa kanye ne-granulation.
Ithebula lesi-2 lokuminyana kwezimpushana ezicindezelwe ezakhiwe yi-granulation eyenziwa ngesandla kanye ne-spray granulation
Ithebula 2 Ukuminyana Komzimba Oluhlaza
| Ingcindezi (MPA) | 4 | 6 | 8 | 10 | 12 | 14 |
| I-DG1 (g/cm3) | 2.32 | 2.32 | 2.32 | 2.33 | 2.36 | 2.4 |
| I-DG2 (g/cm3) | 2.36 | 2.46 | 2.53 | 2.56 | 2.59 | 2.59 |
Ubukhulu bezinhlayiyana kanye ne-morphology yempushana kwabonwa nge-microscope.Kungabonakala ukuthi izinhlayiya ngokuyisisekelo ziyindilinga eqinile, zine-interface ecacile kanye nobuso obushelelezi. Ezinye izinhlayiya zimise okwe-apula, zimise okwepheya noma zifakwe ibhuloho, ezibalelwa ku-3% wengqikithi. Ukusatshalaliswa kosayizi wezinhlayiyana kungokulandelayo: ubukhulu bezinhlayiyana bungama-200 μ m (< 1%), usayizi omncane wezinhlayiyana ngu-20 μ m (ngabanye), izinhlayiya eziningi zilinganiselwa ku-100 μ m (50%), futhi izinhlayiya eziningi zilinganiselwa ku-50 μ m (20%).3.
(1) 95 i-alumina slurry eno-60% wokuqukethwe okuqinile ingatholwa ngokusebenzisa i-PVA njengesibophezelo, ukwengeza i-coagulant efanele kanye nesigcobo.
(2) ukulawula okunengqondo kwemingcele yokusebenza kokumisa okomile kungathola impushana eyomile ekahle.
(3) ngokwamukela inqubo yokumisa isifutho, i-95 alumina powder, elungele inqubo yokucindezela eyomile ngobuningi, ingakhiqizwa. Ukuminyana kwayo okuxekethile kucishe kube ngu-1. 1g/cm3futhi ukuminyana kwe-sintering kungu-3170g/cm3.
