Kev npaj ntawmultrafine tsawg ntiaj teb oxides
Ultrafine rare earth compounds muaj ntau yam kev siv piv rau cov tebchaw uas tsis tshua muaj hauv ntiaj teb nrog qhov loj me me, thiab tam sim no muaj kev tshawb fawb ntxiv rau lawv. Cov txheej txheem kev npaj tau muab faib ua cov txheej txheem txheej txheem, cov txheej txheem ua kua theem, thiab cov txheej txheem roj raws li lub xeev cov khoom sib sau ua ke. Tam sim no, txoj kev ua kua theem yog dav siv nyob rau hauv lub chaw soj nstuam thiab kev lag luam los npaj ultrafine hmoov ntawm tsawg ntiaj teb tebchaw. Nws feem ntau suav nrog txoj kev nag lossis daus, sol gel txoj kev, txoj kev hydrothermal, qauv qauv, txoj kev microemulsion thiab alkyd hydrolysis txoj kev, ntawm cov txheej txheem nag lossis daus yog qhov tsim nyog tshaj plaws rau kev tsim khoom.
Txoj kev nag lossis daus yog ntxiv cov dej nag rau cov hlau ntsev tov rau nag lossis daus, thiab tom qab ntawd lim, ntxuav, qhuav thiab cua sov decompose kom tau cov khoom hmoov. Nws suav nrog txoj kev nag lossis daus ncaj qha, txoj kev nag lossis daus tsis sib xws thiab txoj kev ua dej nag. Hauv cov txheej txheem nag lossis daus, cov av tsis tshua muaj oxides thiab cov av tsis tshua muaj cov ntsev uas muaj cov kua qaub tsis muaj zog tuaj yeem tau txais los ntawm kev hlawv cov nag lossis daus, nrog qhov me me ntawm 3-5 μ m. Qhov chaw tshwj xeeb yog tsawg dua 10 ㎡ / g thiab tsis muaj lub cev tshwj xeeb thiab tshuaj lom neeg. Txoj kev nag lossis daus ammonium carbonate thiab oxalic acid nag lossis daus txoj kev yog tam sim no feem ntau siv txoj hauv kev tsim cov hmoov oxide zoo tib yam, thiab ntev npaum li cov txheej txheem ntawm txoj kev nag lossis daus hloov, lawv tuaj yeem siv los npaj ultrafine tsawg lub ntiaj teb oxide hmoov.
Kev tshawb fawb tau pom tias cov ntsiab lus tseem ceeb cuam tshuam rau qhov loj me thiab morphology ntawm tsawg lub ntiaj teb ultrafine hmoov nyob rau hauv ammonium bicarbonate nag lossis daus txoj kev muaj xws li cov concentration ntawm tsawg ntiaj teb nyob rau hauv cov tshuaj, nag lossis daus kub, nag lossis daus tus neeg sawv cev concentration, thiab lwm yam. kev daws yog tus yuam sij rau kev sib sau ua ke sib cais cov hmoov ultrafine. Piv txwv li, hauv kev sim ntawm Y3 + nag lossis daus los npaj Y2O3, thaum qhov loj ntawm lub ntiaj teb tsis tshua muaj 20 ~ 30g / L (xws li Y2O3), cov txheej txheem nag lossis daus yog du, thiab yttrium oxide ultrafine hmoov tau los ntawm carbonate nag lossis daus los ntawm ziab thiab hlawv yog me me, sib xws, thiab Dispersity zoo.
Hauv cov tshuaj tiv thaiv, qhov kub thiab txias yog qhov txiav txim siab. Hauv cov kev sim saum toj no, thaum qhov kub thiab txias yog 60-70 ℃, nag lossis daus qeeb, kev pom tau nrawm, cov khoom yog xoob thiab tsis sib xws, thiab lawv yog cov kheej kheej kheej kheej; Thaum cov tshuaj tiv thaiv kub qis dua 50 ℃, nag lossis daus cov ntaub ntawv sai dua, nrog ntau cov nplej thiab cov khoom me me. Thaum cov tshuaj tiv thaiv, tus nqi ntawm CO2 thiab NH3 overflows tsawg dua, thiab nag lossis daus yog nyob rau hauv daim ntawv nplaum, uas tsis haum rau kev pom thiab ntxuav. Tom qab raug hlawv rau hauv yttrium oxide, tseem muaj cov blocky tshuaj uas agglomerate tiag thiab muaj qhov loj me me. Qhov concentration ntawm ammonium bicarbonate kuj cuam tshuam qhov loj me me ntawm yttrium oxide. Thaum cov concentration ntawm ammonium bicarbonate tsawg dua 1mol / L, qhov tau txais yttrium oxide particle loj me me thiab sib xws; Thaum cov concentration ntawm ammonium bicarbonate ntau tshaj 1mol / L, nag lossis daus hauv zos yuav tshwm sim, ua rau agglomeration thiab loj dua. Raws li cov xwm txheej tsim nyog, qhov loj me ntawm 0.01-0.5 tuaj yeem tau txais μ M ultrafine yttrium oxide hmoov.
Nyob rau hauv txoj kev oxalate nag lossis daus, oxalic acid tov yog ntxiv dropwise thaum ammonia ntxiv los xyuas kom meej tus nqi pH tas li thaum lub sij hawm cov txheej txheem cov tshuaj tiv thaiv, ua rau ib tug particle loj tsawg dua 1 μ M ntawm yttrium oxide hmoov. Ua ntej, precipitate yttrium nitrate tov nrog ammonia dej kom tau yttrium hydroxide colloid, thiab ces hloov nws nrog oxalic acid tov kom tau ib tug particle loj tsawg tshaj li 1 μ Y2O3 hmoov ntawm m. Ntxiv EDTA rau Y3 + kev daws teeb meem ntawm yttrium nitrate nrog ib qho concentration ntawm 0.25-0.5mol / L, kho pH rau 9 nrog dej ammonia, ntxiv ammonium oxalate, thiab drip ib 3mol / L HNO3 tov ntawm tus nqi ntawm 1-8mL / min ntawm 50 ℃ txog thaum nag lossis daus tiav ntawm pH = 2. Yttrium oxide hmoov nrog qhov loj me ntawm 40-100nm tuaj yeem tau txais.
Thaum lub sij hawm kev npajultrafine tsawg ntiaj teb oxideslos ntawm txoj kev nag lossis daus, qhov sib txawv ntawm cov agglomeration yog nquag tshwm sim. Yog li ntawd, thaum lub sij hawm npaj, yuav tsum nruj me ntsis tswj cov synthesis tej yam kev mob, los ntawm kev kho tus nqi pH, siv sib txawv precipitants, ntxiv dispersants, thiab lwm txoj kev kom tag nrho disperse cov khoom nruab nrab. Tom qab ntawd, txoj kev ziab kom tsim nyog raug xaiv, thiab thaum kawg, zoo dispersed tsawg lub ntiaj teb compound ultrafine hmoov tau los ntawm calcination.
Post lub sij hawm: Apr-21-2023