A. Kev tsim dua tshiab ntawm silica gel tom qab nqus dej
Tom qab silica gel nqus dej noo, nws tuaj yeem tshem tawm los ntawm kev nqus cua sov. Muaj ntau txoj hauv kev cua sov, xws li hluav taws xob cua sov, cua sov pov tseg cua sov, thiab cua sov kom qhuav. Qhov kub kom tshem tawm cov cua sov ntxiv yuav tsum tau tswj ntawm 120-180 ℃. Rau cov xim xiav qhia, ua kom tsis muaj xim silica gel, thiab xiav silica gel, nws tsim nyog los tswj nws ntawm 100-120 ℃. Qhov siab tshaj plaws thaum lub sijhawm rov tsim dua ntawm ntau yam kev lag luam silica gel yuav tsum tsis pub tshaj qhov txwv hauv qab no:
Cov ntxhib-pored silica gel yuav tsum tsis siab tshaj 600 ℃;
Cov nplua-pored silica gel yuav tsum tsis siab tshaj 200 ℃;
Cov kua nplaum qhia tus neeg sawv cev xiav (lossis hloov xim silica gel) yuav tsum tsis txhob siab tshaj 120 ℃;
l Cov kua nplaum Silica-alumina yuav tsum tsis txhob siab tshaj 350 ° C.
Tom qab rov tsim dua silica gel, nws cov ntsiab lus noo noo feem ntau tswj tau qis dua 2% ua ntej nws tuaj yeem siv tau dua.
B. Kev tsim dua tshiab ntawm silica gel tom qab adsorbing organic impurities
1. Txoj kev ci
Rau ntxhib-pored silica gel, nws tuaj yeem muab tso rau hauv qhov cub ci kom maj mam nce qhov kub mus rau 500-600 ℃, thiab nws yuav siv sijhawm li 6-8 teev kom mus txog.
Cov roj hmab hais dawb los yog daj daj. Rau cov nplua-pored silica gel, qhov ntsuas kub tsis tuaj yeem siab tshaj 200 ° C.
2. Yaug txoj kev
Cov silica gel tau nqus tau rau hauv cov dej ua kua kom mus txog qhov khov, ntub, thiab yaug hauv dej kub, thiab tuaj yeem ua ke nrog xab npum kom tshem cov roj pov tseg lossis lwm yam organic tsis huv, thiab tom qab ntawd ntxuav nrog dej huv thiab qhuav thiab qhuav.
3. Huv txoj kev yaug
Raws li hom organic teeb meem adsorbed los ntawm silica gel, cov kuab tshuaj uas tsim nyog tau xaiv los yaj cov organic teeb meem adsorbed hauv silica gel, thiab tom qab ntawd silica gel yog rhaub kom tshem cov kuab tshuaj.
C. Cov teeb meem uas yuav tsum tau them sai sai rau hauv kev tsim dua tshiab ntawm silica gel
1. Thaum ziab thiab rov tsim dua tshiab, xyuam xim txhawm rau ua kom qhov kub nce zuj zus, kom tsis txhob ua kom qhuav qhuav ua rau cov roj hmab tawg thiab ua kom rov zoo li qub.
2. Thaum calcining thiab rov tsim dua silica gel, qhov kub ntau dhau yuav ua rau muaj kev hloov pauv hauv cov qauv pore ntawm silica gel, uas yuav txo qis nws cov txiaj ntsig adsorption thiab cuam tshuam rau nws siv tus nqi. Rau cov xim qhia xim xiav lossis hloov xim silica gel, qhov kub ntawm qhov tsim nyog thiab rov tsim dua yuav tsum tsis pub tshaj 120 ° C, txwv tsis pub cov xim txhim kho xim yuav ploj vim qhov ua rau oxidation maj mam ntawm cov xim tsim tawm.
3. Kev tsim dua tshiab silica gel feem ntau yuav tsum tau sieved kom tshem tau cov khoom me me kom ua rau cov khoom sib xws.