Izinsimbi ze-refractory zikasimende eziphansi ziqhathaniswa nezinsimbi zendabuko ze-aluminate ze-refractory. Isamba sokwengezwa kukasimende sezinsimbi zendabuko ze-aluminate eziphikisayo ngokuvamile ziba ngu-12-20%, kanti inani lokwengezwa kwamanzi ngokuvamile liyi-9-13%. Ngenxa yenani eliphezulu lamanzi angeziwe, umzimba we-cast unezimbotshana eziningi, awuminyene, futhi unamandla aphansi; ngenxa yesamba esikhulu sikasimende esingeziwe, nakuba amandla aphezulu okushisa avamile futhi aphansi angatholakala, amandla ayancipha ngenxa yokuguqulwa kwe-crystalline ye-calcium aluminate emazingeni okushisa aphakathi. Ngokusobala, i-CaO eyethulwe ihlangana ne-SiO2 kanye ne-Al2O3 ku-castable ukuze kukhiqizwe izinto ezithile ezincibilika kancane, okuholela ekulimaleni kwezakhiwo zezinga lokushisa eliphezulu.
Lapho kusetshenziswa ubuchwepheshe be-ultrafine powder, izixube ezisebenza kahle kakhulu kanye nokuhlukaniswa kwezinhlayiyana zesayensi, okuqukethwe kukasimende kwe-castable kuncishiswa kube ngaphansi kuka-8% futhi okuqukethwe kwamanzi kuncishiswa ku-≤7%, futhi uchungechunge lwe-low-cement refractory castable okulungisiwe futhi kwalethwa Kokuqukethwe kwe-CaO kungu-≤2.5%, futhi izinkomba zayo zokusebenza ngokuvamile zidlula lezo ze-aluminum refractory castables usimende. Lolu hlobo lwe-refractory castable lune-thixotropy enhle, okungukuthi, into ehlanganisiwe inomumo othile futhi iqala ukugeleza ngamandla amancane angaphandle. Lapho amandla angaphandle esuswa, agcina isimo esitholiwe. Ngakho-ke, kubizwa nangokuthi i-thixotropic refractory castable. I-self-flowing refractory castable ibizwa nangokuthi i-thixotropic refractory castable. Ngokwalesi sigaba. Incazelo enembayo yochungechunge oluphansi lukasimende olusakazwayo lwe-refractory ayikachazwa kuze kube manje. I-American Society for Testing and Materials (ASTM) ichaza futhi ihlukanise ama-castable aphikisayo ngokusekelwe kokuqukethwe kwawo kwe-CaO.
Aminyene namandla aphezulu yizici ezivelele zochungechunge lwe-refractory castables lukasimende oluphansi. Lokhu kuhle ekuthuthukiseni impilo yesevisi nokusebenza komkhiqizo, kodwa futhi kuletha izinkinga ekubhakeni ngaphambi kokusetshenziswa, okungukuthi, ukuthulula kungenzeka kalula uma ungaqaphile ngesikhathi sokubhaka. Isimo sokuqhuma komzimba singadinga ukuthelwa kabusha okungenani, noma singabeka engcupheni ukuphepha komuntu siqu kwabasebenzi abazungezile ezimeni ezinzima. Ngakho-ke, amazwe ahlukahlukene nawo aqhube izifundo ezehlukene ekubhakeni ama-castables e-refractory anosimende aphansi. Izinyathelo zobuchwepheshe eziyinhloko yilezi: ngokwenza ama-curve e-ovini anengqondo futhi wethule ama-anti-explosion agents amahle kakhulu, njll., lokhu kungenza ama-castables aphikisayo Amanzi aqedwe kahle ngaphandle kokubangela eminye imiphumela emibi.
Ubuchwepheshe bempushana be-Ultrafine buwubuchwepheshe obuyisihluthulelo bochungechunge lwezinsimbi eziphikisayo ezinosimende ophansi (okwamanje iningi lezimpushana ze-ultrafine ezisetshenziswa kuma-ceramics nezinto eziphikisayo empeleni ziphakathi kuka-0.1 no-10m, futhi zisebenza ikakhulukazi njengezisheshisi zokuhlakaza kanye nezixhumi zesakhiwo. izinhlayiya zikasimende zihlakazeke kakhulu ngaphandle kwe-flocculation, kuyilapho lokhu kugcina kwenza ama-micropores emzimbeni othululwayo agcwale ngokugcwele futhi athuthukise amandla.
Izinhlobo ezisetshenziswa kakhulu njengamanje ze-ultrafine powders zifaka i-SiO2, i-α-Al2O3, i-Cr2O3, njll. Indawo ethize ye-SiO2 micropowder icishe ibe ngu-20m2/g, futhi usayizi wayo wezinhlayiyana cishe u-1/100 wosayizi wezinhlayiyana zikasimende, ngakho-ke inhle. izakhiwo zokugcwalisa. Ngaphezu kwalokho, i-SiO2, i-Al2O3, i-Cr2O3 micropowder, njll. ingase futhi yakhe izinhlayiya ze-colloidal emanzini. Uma i-dispersant ikhona, kwakheka ungqimba oluphindwe kabili lukagesi olugqagqene phezu kwezinhlayiya ukuze kukhiqizwe i-electrostatic repulsion, enqoba amandla e-van der Waals phakathi kwezinhlayiya futhi inciphise amandla esixhumi esibonakalayo. Ivimbela i-adsorption kanye ne-flocculation phakathi kwezinhlayiya; ngesikhathi esifanayo, i-dispersant i-adsorbed ezungeze izinhlayiya ukuze zenze isendlalelo se-solvent, okwandisa no-fluidity we-castable. Lokhu futhi kungenye yezindlela ze-ultrafine powder, okungukuthi, ukwengeza i-ultrafine powder kanye nama-dispersants afanelekile kunganciphisa ukusetshenziswa kwamanzi ama-castables aphikisayo futhi kuthuthukise uketshezi.
Ukusetha nokuqina kwama-castables aphansi we-cement refractory kuwumphumela wesenzo esihlanganisiwe se-hydration bonding kanye ne-cohesion bonding. I-hydration kanye nokuqina kukasimende we-calcium aluminate ngokuyinhloko ukugeleza kwezigaba ze-hydraulic CA ne-CA2 kanye nenqubo yokukhula kwekristalu yama-hydrates awo, okungukuthi, asabela ngamanzi ukuze enze i-hexagonal flake noma i-CAH10, i-C2AH8 kanye nemikhiqizo ye-Hydration efana nenaliti enjalo. njengamakristalu e-cubic C3AH6 kanye namajeli e-Al2O3аq abe esebumba uhlaka lwenethiwekhi exhumene ye-condensation-crystallization ngesikhathi sezinqubo zokuphulukisa nezokushisa. I-agglomeration ne-bonding kungenxa ye-SiO2 ultrafine powder esebenzayo eyenza izinhlayiya ze-colloidal lapho ihlangana namanzi, futhi ihlangana nama-ion ahlukaniswe kancane kancane nesithasiselo esingeziwe (okungukuthi into ye-electrolyte). Ngoba amashaji angaphezulu kwakho kokubili aphambene, okungukuthi, i-colloid surface ine-adsorbed counter ions, okubangela i-£2 Amandla ehle futhi ukufingqa kwenzeka lapho i-adsorption ifinyelela "iphoyinti le-isoelectric". Ngamanye amazwi, lapho i-electrostatic repulsion ebusweni bezinhlayiya ze-colloidal ingaphansi kokukhanga kwayo, ukuhlangana okuhlangene kwenzeka ngosizo lwe-van der Waals force. Ngemuva kokuthi i-refractory castable exutshwe ne-silica powder ifinyeziwe, amaqembu e-Si-OH akhiwe ebusweni be-SiO2 ayomiswa futhi aphelelwe amanzi ukuze abe ibhuloho, enze isakhiwo senethiwekhi ye-siloxane (Si-O-Si), ngaleyo ndlela aqina. Esakhiweni senethiwekhi ye-siloxane, izibopho phakathi kwe-silicon nomoya-mpilo azinciphi njengoba izinga lokushisa likhuphuka, ngakho amandla nawo ayaqhubeka nokukhula. Ngesikhathi esifanayo, emazingeni okushisa aphezulu, isakhiwo senethiwekhi ye-SiO2 sizosabela nge-Al2O3 ehlanganiswe kuyo ukuze yenze i-mullite, engathuthukisa amandla emazingeni okushisa aphakathi nendawo naphezulu.
Isikhathi sokuthumela: Feb-28-2024
