Kaolin, calcined kaolin, ntxuav kaolin, metakaolin.

Cov kev siv ntawm kaolin muaj xws li:
Ua cov khoom siv raw khoom tsim nyog rau ntau lub lag luam, xws li kev ua ntawv, ceramics, roj hmab, kev lag luam tshuaj lom neeg, txheej, tshuaj thiab kev tiv thaiv lub teb chaws, kaolin muaj qee yam plasticity, uas ua rau lub cev av nkos ceramic zoo rau kev tig, grouting thiab tsim.

Lub luag haujlwm ntawm kaolin hauv cov khoom siv ceramics yog los qhia Al2O3, uas yog qhov zoo rau kev tsim cov mullite thiab txhim kho nws cov tshuaj lom neeg ruaj khov thiab lub zog sintering.

Thaum lub sijhawm sintering, kaolin decomposes rau hauv mullite, tsim lub hauv paus tseem ceeb ntawm lub zog ntsuab, uas tuaj yeem tiv thaiv kev hloov pauv ntawm cov khoom, nthuav qhov kub tua hluav taws, thiab ua rau lub cev ntsuab muaj qee qhov dawb.

Metakaolin (MK luv luv) yog ib qho anhydrous txhuas silicate (Al2O3 · 2SiO2, AS2 luv luv) tsim los ntawm kev qhuav kaolin (Al2O3 · 2SiO2 · 2H2O, AS2H2 luv luv) ntawm qhov kub tsim nyog (600 ~ 900 ℃). Kaolin yog ib qho ntawm cov qauv silicate, thiab cov txheej raug khi los ntawm van der Waals bond, uas OH ions raug khi ruaj khov. Thaum kaolin raug cua sov hauv huab cua, nws cov qauv yuav hloov pauv ntau zaus. Thaum nws raug cua sov txog li 600 ℃, cov qauv txheej ntawm kaolin yuav raug rhuav tshem vim yog kev qhuav dej, tsim cov theem hloov pauv metakaolin nrog crystallinity tsis zoo. Vim tias cov qauv molecular ntawm metakaolin tsis xwm yeem, nws nthuav tawm lub xeev thermodynamic metastable thiab muaj gellability nyob rau hauv kev txhawb nqa kom zoo.

Metakaolin yog ib hom tshuaj sib xyaw ua ke uas muaj zog heev. Nws yog ib qho amorphous aluminium silicate uas tsim los ntawm ultra-fine kaolin calcined ntawm qhov kub qis. Nws muaj cov dej num pozzolanic siab, feem ntau yog siv ua cov tshuaj sib xyaw ua ke, thiab kuj tseem siv tau los ua cov polymers geological ua tau zoo.