Intshayelelo yeMveliso enokuKhanya eSisamente esiphantsi

Ii-castables ezinganyangekiyo zesamente zithelekiswa nee-castables zesamente ze-aluminate zendabuko. Ubungakanani bokongeza isamente kwii-castables zesamente zendabuko ze-aluminate zesamente zemveli zihlala ziyi-12-20%, kwaye ubuninzi bokongeza amanzi buhlala buyi-9-13%. Ngenxa yobuninzi bamanzi ongezelelweyo, umzimba we-cast unemingxuma emininzi, awuxinene, kwaye unamandla aphantsi; ngenxa yobuninzi besamente ongezelelweyo, nangona amandla aphezulu aqhelekileyo kunye nobushushu obuphantsi anokufunyanwa, amandla ayancipha ngenxa yokuguqulwa kwe-calcium aluminate kwi-crystalline kumaqondo obushushu aphakathi. Ngokucacileyo, i-CaO engenisiweyo isabela kwi-SiO2 kunye ne-Al2O3 kwi-castable ukuvelisa ezinye izinto ezinamaqondo aphantsi okunyibilika, okubangela ukuwohloka kweempawu zobushushu obuphezulu bezinto.

Xa kusetyenziswa itekhnoloji yepowder ecolekileyo kakhulu, ukuxubana okusebenzayo kakhulu kunye nokuhlelwa kweesuntswana zesayensi, umxholo wesamente we-castable uncitshiswa ube ngaphantsi kwe-8% kwaye umxholo wamanzi uncitshiswa ube yi-≤7%, kwaye uthotho lwesamente oluncinci olunokuchasana nolwesamente lungalungiswa kwaye lungeniswe. Umxholo we-CaO yi-≤2.5%, kwaye izalathisi zayo zokusebenza ngokubanzi zidlula ezo ze-aluminate cement refractory castables. Olu hlobo lwe-refractory castable lune-thixotropy elungileyo, oko kukuthi, izinto ezixutyiweyo zinesimo esithile kwaye ziqala ukuhamba ngamandla amancinci angaphandle. Xa amandla angaphandle esusiwe, agcina isimo esifunyenweyo. Ke ngoko, ikwabizwa ngokuba yi-thixotropic refractory castable. I-self-flowing refractory castable ikwabizwa ngokuba yi-thixotropic refractory castable. Ikweli candelo. Intsingiselo echanekileyo ye-low cement refractory castables ayikachazwa okwangoku. I-American Society for Testing and Materials (ASTM) ichaza kwaye ihlela ii-refractory castables ngokusekelwe kumxholo wazo we-CaO.

Ukuqina kunye namandla aphezulu zezona mpawu zibalaseleyo zee-castables ezinganyangekiyo zesamente ephantsi. Oku kulungile ekuphuculeni ubomi benkonzo kunye nokusebenza kwemveliso, kodwa kuzisa iingxaki ekubhakeni ngaphambi kokusetyenziswa, oko kukuthi, ukugalela kunokwenzeka ngokulula ukuba awulumkanga ngexesha lokubhaka. Imeko yokuqhuma komzimba ingafuna ukugalelwa kwakhona ubuncinane, okanye inokubeka emngciphekweni ukhuseleko lomntu lwabasebenzi abakungqongileyo kwiimeko ezinzima. Ke ngoko, amazwe ahlukeneyo enze nezifundo ezahlukeneyo malunga nokubhaka ii-castables ezinganyangekiyo zesamente ephantsi. Amanyathelo obuchwephesha aphambili ngala: ngokwenza ii-oven curves ezifanelekileyo kunye nokungenisa ii-arhente ezibalaseleyo zokulwa nokuqhuma, njl.njl., oku kunokwenza ii-castables ezinganyangekiyo. Amanzi asuswa kakuhle ngaphandle kokubangela ezinye iziphumo ebezingalindelekanga.

Itekhnoloji ye-ultrafine powder yeyona teknoloji iphambili kwii-castables ezinqabileyo zesamente ephantsi (okwangoku uninzi lwee-powders ezicocekileyo ezisetyenziswa kwi-ceramics nakwizinto ezinqabileyo ziphakathi kwe-0.1 kunye ne-10m, kwaye zisebenza kakhulu njenge-dispersion accelerators kunye ne-structural densifiers. .Eyokuqala yenza amasuntswana esamente asasazeke kakhulu ngaphandle kokutyibilika, ngelixa eyesibini yenza ii-micropores emzimbeni othululwayo zizaliswe ngokupheleleyo kwaye ziphucula amandla.

Iintlobo zepowders ezisetyenziswa rhoqo ngoku ziquka iSiO2, α-Al2O3, Cr2O3, njl. Indawo ethile yomphezulu we-SiO2 micropowder imalunga ne-20m2/g, kwaye ubukhulu bayo besuntswana bumalunga ne-1/100 yobukhulu besuntswana yesamente, ngoko ke ineempawu ezilungileyo zokuzalisa. Ukongeza, i-SiO2, Al2O3, Cr2O3 micropowder, njl. nazo zinokwenza amasuntswana e-colloidal emanzini. Xa kukho i-dispersant, umaleko ombane ophindwe kabini uhlanganiswa phezu kwamasuntswana ukuze kuveliswe i-electrostatic repulsion, eyoyisa amandla e-van der Waals phakathi kwamasuntswana kwaye inciphise amandla ojongano. Ithintela ukufunxwa kunye nokuxinana phakathi kwamasuntswana; kwangaxeshanye, i-dispersant ifunxwa ijikeleze amasuntswana ukuze yenze umaleko we-solvent, okwandisa ukufunxwa kwe-castable. Le yenye yeendlela ze-ultrafine powder, oko kukuthi, ukongeza i-ultrafine powder kunye ne-dispersants ezifanelekileyo kunokunciphisa ukusetyenziswa kwamanzi kwe-castables ezinganyangekiyo kwaye kuphuculwe ukufunxwa.

Ukubekwa kunye nokuqina kwee-castables ezinganyangekiyo zesamente ephantsi sisiphumo sesenzo esidibeneyo sokudibanisa amanzi kunye nokudibanisa ukuhlangana. Ukudibanisa amanzi kunye nokuqina kwesamente ye-calcium aluminate ikakhulu kukuxinana kwe-hydraulic phases CA kunye ne-CA2 kunye nenkqubo yokukhula kwekristale yee-hydrates zazo, oko kukuthi, zisabela ngamanzi ukuze zenze i-hexagonal flake okanye iimveliso ze-CAH10, C2AH8 kunye ne-Hydration ezifana neekristale ze-cubic C3AH6 kunye neejeli ze-Al2O3аq emva koko zenze isakhiwo senethiwekhi ye-condensation-crystallization edibeneyo ngexesha leenkqubo zokupholisa kunye nokufudumeza. Ukuhlanganiswa kunye nokudibanisa kungenxa ye-active SiO2 ultrafine powder eyenza amaqhekeza e-colloidal xa idibana namanzi, kwaye idibana nee-ions eziqhekeka kancinci kwi-additive eyongeziweyo (oko kukuthi, i-electrolyte substance). Ngenxa yokuba iindleko zomphezulu zezi zimbini zichasene, oko kukuthi, umphezulu we-colloid une-adsorption counter ions, nto leyo ebangela ukuba i-£2 iyancipha kwaye i-condensation iyenzeka xa i-adsorption ifikelela "kwindawo ye-isoelectric". Ngamanye amazwi, xa ukugxothwa kwe-electrostatic kumphezulu wee-colloidal particles kungaphantsi kokutsala kwayo, ukubopha okudibeneyo kwenzeka ngoncedo lwe-van der Waals force. Emva kokuba i-refractory castable exutywe ne-silica powder ixinyiwe, amaqela e-Si-OH akhiwe kumphezulu we-SiO2 ayomiswa aze adibane ukuze adibanise, enze isakhiwo senethiwekhi ye-siloxane (Si-O-Si), ngaloo ndlela aqine. Kwisakhiwo senethiwekhi ye-siloxane, iibhondi phakathi kwe-silicon kunye ne-oxygen azinciphi njengoko ubushushu busanda, ngoko ke amandla nawo ayaqhubeka nokwanda. Kwangaxeshanye, kumaqondo obushushu aphezulu, isakhiwo senethiwekhi ye-SiO2 siya kusabela ne-Al2O3 egqunywe kuyo ukuze senze i-mullite, enokuphucula amandla kumaqondo obushushu aphakathi naphezulu.