Ama-castable aphansi aphikisayo esimende aqhathaniswa nama-castable avamile aphikisayo esimende e-aluminate. Inani lokwengeza usimende lama-castable avamile aphikisayo esimende e-aluminate ngokuvamile liyi-12-20%, kanti inani lokwengeza amanzi ngokuvamile liyi-9-13%. Ngenxa yenani elikhulu lamanzi engeziwe, umzimba we-cast unezimbobo eziningi, awuqinile, futhi unamandla aphansi; ngenxa yenani elikhulu lesimende engeziwe, yize amandla aphezulu ajwayelekile naphansi okushisa angatholakala, amandla ayancipha ngenxa yokuguqulwa kwekristalu kwe-calcium aluminate emazingeni okushisa aphakathi. Ngokusobala, i-CaO engenisiwe isabela ne-SiO2 kanye ne-Al2O3 ku-castable ukuze ikhiqize ezinye izinto ezinamazinga okuncibilika aphansi, okuholela ekuwohlokeni kwezakhiwo zokushisa okuphezulu kwezinto.
Uma kusetshenziswa ubuchwepheshe bempuphu e-ultrafine, ukuxubana okusebenzayo kakhulu kanye nokuhlelwa kwezinhlayiya zesayensi, okuqukethwe kukasimende kwe-castable kuncishiswa kube ngaphansi kuka-8% kanti okuqukethwe kwamanzi kuncishiswa kube ku-≤7%, futhi i-castable e-refractory series ene-samente ephansi ingalungiswa futhi ilethwe. Okuqukethwe kwe-CaO kungu-≤2.5%, futhi izinkomba zayo zokusebenza ngokuvamile zidlula lezo ze-castables e-refractory cement aluminate. Lolu hlobo lwe-castable e-refractory lune-thixotropy enhle, okungukuthi, izinto ezixubile zinesimo esithile futhi ziqala ukugeleza ngamandla amancane angaphandle. Lapho amandla angaphandle esuswa, agcina isimo esitholiwe. Ngakho-ke, ibizwa nangokuthi i-thixotropic refractory castable. I-castable e-refractory e-self-flowing nayo ibizwa ngokuthi i-thixotropic refractory castable. Ingokwalesi sigaba. Incazelo eqondile ye-castables e-refractory series ene-samente ephansi ayikachazwa kuze kube manje. I-American Society for Testing and Materials (ASTM) ichaza futhi ihlukanisa i-castables e-refractory ngokusekelwe kokuqukethwe kwayo kwe-CaO.
Ukuqina nokuqina okuphezulu yizici ezivelele zama-castable angenasimende ochungechungeni oluphansi. Lokhu kuhle ekuthuthukiseni impilo yesevisi kanye nokusebenza komkhiqizo, kodwa futhi kuletha izinkinga ekubhakeni ngaphambi kokusebenzisa, okungukuthi, ukuthululwa kungenzeka kalula uma ungaqapheli ngesikhathi sokubhaka. Isimo sokuqhuma komzimba singadinga ukuthululwa kabusha okungenani, noma singabeka engcupheni ukuphepha komuntu siqu kwabasebenzi abazungezile ezimweni ezinzima. Ngakho-ke, amazwe ahlukahlukene nawo enze izifundo ezahlukahlukene ngokubhaka ama-castable angenasimende ochungechungeni oluphansi. Izindlela zobuchwepheshe eziyinhloko yilezi: ngokwakha ama-curve e-oven afanele kanye nokwethula ama-agent alwa nokuqhuma amahle kakhulu, njll., lokhu kungenza ama-castable angenasimende Amanzi asuswe kahle ngaphandle kokubangela eminye imiphumela emibi.
Ubuchwepheshe bempuphu ye-Ultrafine buwubuchwepheshe obuyinhloko bezinto eziphothwayo ezincibilikayo zochungechunge lwe-low-cement (njengamanje iningi lempuphu ye-ultrafine esetshenziswa ku-ceramics nasezintweni ezincibilikayo empeleni iphakathi kuka-0.1 no-10m, futhi ikakhulukazi isebenza njengezinto ezisheshisa ukusabalala kanye nezakhiwo ezincibilikisayo. .Eyokuqala yenza izinhlayiya ze-samente zihlakazeke kakhulu ngaphandle kokugoba, kanti eyesibili yenza ama-micropores emzimbeni wokuthulula agcwale ngokugcwele futhi athuthukise amandla.
Izinhlobo ezisetshenziswa kakhulu zempuphu ye-ultrafine njengamanje zifaka phakathi i-SiO2, i-α-Al2O3, i-Cr2O3, njll. Indawo ethile ebusweni bempuphu ye-SiO2 icishe ibe ngu-20m2/g, kanti ubukhulu bayo bempuphu ye-simende bucishe bube yi-1/100 yobukhulu bempuphu ye-simende, ngakho-ke inezakhiwo ezinhle zokugcwalisa. Ngaphezu kwalokho, i-SiO2, i-Al2O3, i-Cr2O3 micropowder, njll. ingakha nezinhlayiya ze-colloidal emanzini. Uma kukhona i-dispersant, kwakheka ungqimba oluphindwe kabili lukagesi phezu kwezinhlayiya ukuze kukhiqizwe ukuxoshwa kwe-electrostatic, okunqoba amandla e-van der Waals phakathi kwezinhlayiya futhi kunciphise amandla okuxhumana. Kuvimbela ukumuncwa kanye nokugobhoza phakathi kwezinhlayiya; ngesikhathi esifanayo, i-dispersant imuncwa nxazonke kwezinhlayiya ukuze yakhe ungqimba lwe-solvent, oluphinde lwandise ukumuncwa kwe-castable. Lokhu futhi kungenye yezindlela zempuphu ye-ultrafine, okungukuthi, ukwengeza impuphu ye-ultrafine kanye ne-dispersants efanele kunganciphisa ukusetshenziswa kwamanzi kwe-castables ezingaphikisi futhi kuthuthukise ukumuncwa.
Ukubekwa kanye nokuqina kwama-castable angenasimende ophansi kuwumphumela wesenzo esihlangene sokubophana ngamanzi kanye nokubophana. Ukumanzisa kanye nokuqina kwesimende se-calcium aluminate ikakhulukazi ukumanzisa kwezigaba ze-hydraulic CA kanye ne-CA2 kanye nenqubo yokukhula kwekristalu yama-hydrate awo, okungukuthi, asabela ngamanzi ukuze akhe i-hexagonal flake noma imikhiqizo ye-CAH10, C2AH8 kanye ne-Hydration efana namakristalu e-cubic C3AH6 kanye nama-gel e-Al2O3аq bese akha isakhiwo senethiwekhi ye-condensation-crystallization esixhumene ngesikhathi sezinqubo zokupholisa nokushisa. Ukuhlangana kanye nokubopha kungenxa yempuphu esebenzayo ye-SiO2 ultrafine eyakha izinhlayiya ze-colloidal lapho ihlangana namanzi, futhi ihlangana nama-ion ahlukana kancane kancane nesithasiselo esengeziwe (okungukuthi i-electrolyte substance). Ngoba izindleko zobuso zalezi zibili ziphambene, okungukuthi, ubuso be-colloid bunama-counter ion afakwe emanzini, okubangela ukuthi amandla ehle futhi ukuminyana kwenzeka lapho ukuminyana kufinyelela "ephuzwini le-isoelectric". Ngamanye amazwi, lapho ukuxoshwa kwe-electrostatic ebusweni bezinhlayiya ze-colloidal kungaphansi kokukhanga kwayo, ukubopha okuhlangene kwenzeka ngosizo lwamandla e-van der Waals. Ngemva kokuba i-refractory castable exutshwe ne-silica powder ifinyeziwe, amaqembu e-Si-OH akhiwe ebusweni be-SiO2 ayomiswa futhi ancishiswe amanzi ukuze ahlangane, akhe isakhiwo senethiwekhi ye-siloxane (Si-O-Si), ngaleyo ndlela aqine. Esakhiweni senethiwekhi ye-siloxane, izibopho phakathi kwe-silicon ne-oxygen azinciphi njengoba izinga lokushisa likhuphuka, ngakho-ke amandla nawo ayaqhubeka nokukhula. Ngesikhathi esifanayo, emazingeni okushisa aphezulu, isakhiwo senethiwekhi ye-SiO2 sizosabela ne-Al2O3 eboshwe kuyo ukuze sakhe i-mullite, engathuthukisa amandla emazingeni okushisa aphakathi naphezulu.
Isikhathi sokuthunyelwe: Feb-28-2024
