Calcined kaolin, kuma aka sani da calcined lãka, wani nau'i ne na kaolin wanda ya sami takamaiman canje-canjen physicochemical ta hanyar calcination. Wannan tsari ya ƙunshi sintering kaolin a cikin tanderun ƙirƙira a wani zafin jiki na wani ƙayyadadden lokaci, canza kaddarorinsa don biyan takamaiman buƙatu.
Kaolin, wani gauraye maras ƙarfe ba na inorganic, yana fuskantar rikitattun canje-canje yayin ƙirƙira. Da farko, ana cire kwayoyin ruwa, gami da ruwa mai ɗorewa da tsarin, a yanayin zafi daga 100 ° C zuwa 550 ° C. Bayan 550 ° C, tsarin bushewa yana raguwa har zuwa 800 ° C, lokacin da aka cire sauran ruwa gaba daya. A yanayin zafi sama da 925 ° C, kaolin da ba shi da ruwa yana canzawa zuwa sabbin matakai kamar aluminum spinel da mullite, wanda ke ƙara gyara tsarinsa da kaddarorinsa.
Calcined kaolin yana alfahari da babban fari, ƙarfin rufewa mai ƙarfi, kyakkyawan aikin watsa haske, ƙarancin mai, dakatarwa mai kyau, mannewa mai ƙarfi, da ɗankowar tarwatsewa. Waɗannan halayen sun sa an yi amfani da shi sosai a cikin fenti, sutura, yin takarda, yumbu, robobi, roba, da igiyoyin lantarki. Zai iya haɓaka aikin samfur kuma yana rage farashin samarwa sosai. Misali, a cikin masana'antar takarda, kaolin calcined na iya jujjuya shi ko cikakken maye gurbin titanium dioxide azaman filler, rage farashin yayin kiyaye kyakkyawan aiki.
A taƙaice, calcined kaolin, tare da kyawawan kaddarorin sa da aikace-aikace iri-iri, yana taka muhimmiyar rawa a masana'antu daban-daban. Its halaye na musamman da fadi da kewayon amfani da shi ya zama abin da ba makawa a cikin masana'antu na zamani.
