Nrog rau cov khoom tshwj xeeb thiab tshuaj lom neeg, kaolin yog cov khoom siv tsis yog hlau uas tsis tseem ceeb hauv cov khoom siv ceramics, kev ua ntawv, roj hmab, yas, refractories, roj av refining thiab lwm yam kev lag luam thiab kev ua liaj ua teb thiab kev tiv thaiv lub teb chaws. Qhov dawb ntawm kaolin yog qhov qhia tseem ceeb ntawm nws cov txiaj ntsig daim ntawv thov.
Cov yam tseem ceeb uas cuam tshuam rau qhov dawb ntawm kaolin
Kaolin yog ib hom av nplaum zoo lossis pob zeb av nplaum uas muaj cov zaub mov kaolinite. Nws cov mis tshuaj siv lead ua yog 2SiO2 · Al2O3 · 2H2O. Muaj me ntsis cov zaub mov uas tsis yog av nplaum xws li quartz, feldspar, hlau, titanium, txhuas hydroxide thiab oxides, organic matter, thiab lwm yam.
Cov qauv crystalline ntawm kaolin
Raws li lub xeev thiab qhov xwm txheej ntawm cov khoom tsis huv hauv kaolin, cov khoom tsis huv uas ua rau cov dawb ntawm kaolin txo qis tuaj yeem muab faib ua peb pawg: cov pa roj carbon organic; Cov ntsiab lus xim, xws li Fe, Ti, V, Cr, Cu, Mn, thiab lwm yam; Cov zaub mov tsaus nti, xws li biotite, chlorite, thiab lwm yam. Feem ntau, cov ntsiab lus ntawm V, Cr, Cu, Mn thiab lwm yam ntsiab lus hauv kaolin yog me me, uas muaj me ntsis cuam tshuam rau qhov dawb. Cov khoom xyaw thiab cov ntsiab lus ntawm hlau thiab titanium yog cov yam tseem ceeb uas cuam tshuam rau qhov dawb ntawm kaolin. Lawv qhov muaj nyob yuav tsis tsuas yog cuam tshuam rau qhov dawb ntawm kaolin xwb, tab sis kuj cuam tshuam rau nws qhov dawb calcined. Tshwj xeeb, qhov muaj hlau oxide muaj qhov cuam tshuam tsis zoo rau xim ntawm av nplaum thiab txo nws qhov ci thiab hluav taws tsis kam. Thiab txawm tias qhov ntau ntawm oxide, hydroxide thiab hydrated oxide ntawm hlau oxide yog 0.4%, nws txaus los muab cov av nplaum liab rau xim daj. Cov hlau oxides thiab hydroxides no tuaj yeem yog hematite (liab), maghemite (liab-xim av), goethite (xim av daj), limonite (txiv kab ntxwv), hydrated hlau oxide (xim av liab), thiab lwm yam. Nws tuaj yeem hais tias kev tshem tawm cov hlau tsis huv hauv kaolin ua lub luag haujlwm tseem ceeb heev hauv kev siv kaolin zoo dua.
Lub xeev tshwm sim ntawm cov hlau
Qhov xwm txheej ntawm cov hlau hauv kaolin yog qhov tseem ceeb tshaj plaws los txiav txim siab txoj kev tshem tawm hlau. Muaj ntau txoj kev tshawb fawb ntseeg tias cov hlau crystalline hauv daim ntawv ntawm cov khoom me me yog sib xyaw hauv kaolin, thaum cov hlau amorphous yog coated rau ntawm qhov chaw ntawm cov khoom me me ntawm kaolin. Tam sim no, qhov xwm txheej ntawm cov hlau hauv kaolin tau muab faib ua ob hom hauv tsev thiab txawv teb chaws: ib qho yog nyob rau hauv kaolinite thiab cov khoom siv ntxiv (xws li mica, titanium dioxide thiab illite), uas yog hu ua cov hlau qauv; qhov tod yog nyob rau hauv daim ntawv ntawm cov hlau ywj pheej, hu ua hlau dawb (suav nrog cov hlau saum npoo, cov hlau crystalline zoo thiab cov hlau amorphous).
Cov hlau uas raug tshem tawm los ntawm kev tshem tawm hlau thiab ua kom dawb ntawm kaolin yog hlau dawb, feem ntau suav nrog magnetite, hematite, limonite, siderite, pyrite, ilmenite, jarosite thiab lwm yam minerals; Feem ntau cov hlau muaj nyob rau hauv daim ntawv ntawm cov colloidal limonite uas tau tawg ua ntau heev, thiab me me hauv daim ntawv ntawm spherical, acicular thiab irregular goethite thiab hematite.
Kev tshem tawm hlau thiab kev ua kom dawb ntawm kaolin
Kev sib cais dej
Txoj kev no feem ntau yog siv los tshem tawm cov khoom tsis zoo xws li quartz, feldspar thiab mica, thiab cov khoom tsis huv xws li cov pob zeb tawg, nrog rau qee cov hlau thiab titanium minerals. Cov khoom tsis huv uas muaj qhov ceev thiab solubility zoo ib yam li kaolin tsis tuaj yeem tshem tawm, thiab qhov kev txhim kho dawb tsis pom tseeb, uas yog qhov tsim nyog rau kev ua kom zoo thiab ua kom dawb ntawm cov kaolin ore zoo.
Kev sib cais sib nqus
Cov hlau tsis huv hauv kaolin feem ntau yog cov hlau nplaum tsis muaj zog. Tam sim no, feem ntau yog siv txoj kev sib cais sib nqus muaj zog siab, lossis cov hlau nplaum tsis muaj zog raug hloov mus ua hlau oxide muaj zog tom qab ci, thiab tom qab ntawd tshem tawm los ntawm txoj kev sib cais sib nqus ib txwm muaj.
Ntsug nplhaib siab gradient sib nqus separator
Cov sib nqus sib cais siab rau cov khoom siv electromagnetic slurry
Cov sib nqus sib cais kub tsawg
Txoj kev ua kom ntab
Txoj kev flotation tau siv los kho kaolin los ntawm cov khoom tso thawj zaug thiab theem ob. Hauv cov txheej txheem flotation, cov kaolinite thiab mica me me raug sib cais, thiab cov khoom ntshiab yog ntau yam khoom siv raw khoom lag luam tsim nyog. Kev sib cais xaiv flotation ntawm kaolinite thiab feldspar feem ntau yog ua tiav hauv cov slurry nrog pH tswj.
Txoj kev txo qis
Txoj kev txo qis yog siv tus neeg sawv cev txo qis los txo cov hlau tsis huv (xws li hematite thiab limonite) hauv lub xeev trivalent ntawm kaolin rau cov hlau ions bivalent uas yaj tau, uas raug tshem tawm los ntawm kev lim thiab ntxuav. Kev tshem tawm Fe3 + impurities los ntawm kaolin kev lag luam feem ntau yog ua tiav los ntawm kev sib txuas cov thev naus laus zis (kev sib cais sib nqus, kev xaiv flocculation) thiab kev kho tshuaj hauv qab acidic lossis txo cov xwm txheej.
Sodium hydrosulfite (Na2S2O4), tseem hu ua sodium hydrosulfite, muaj txiaj ntsig zoo rau kev txo thiab tshem tawm hlau ntawm kaolin, thiab tam sim no siv rau hauv kev lag luam kaolin. Txawm li cas los xij, txoj kev no yuav tsum tau ua nyob rau hauv cov xwm txheej acidic muaj zog (pH <3), ua rau cov nqi khiav lag luam siab thiab cuam tshuam rau ib puag ncig. Tsis tas li ntawd, cov khoom siv tshuaj lom neeg ntawm sodium hydrosulfite tsis ruaj khov, xav tau kev khaws cia thiab kev thauj mus los tshwj xeeb thiab kim.
Thiourea dioxide: (NH2) 2CSO2, TD) yog ib qho tshuaj uas muaj zog heev, uas muaj qhov zoo ntawm kev muaj peev xwm txo qis, kev phooj ywg ib puag ncig, kev lwj qis, kev nyab xeeb thiab tus nqi qis ntawm kev tsim khoom ntau. Cov tshuaj Fe3 + uas tsis yaj hauv kaolin tuaj yeem txo kom yaj tau Fe2 + los ntawm TD.
Tom qab ntawd, qhov dawb ntawm kaolin tuaj yeem nce ntxiv tom qab lim thiab ntxuav. TD ruaj khov heev ntawm chav tsev kub thiab qhov tsis muaj zog. Lub peev xwm txo qis ntawm TD tsuas yog tuaj yeem tau txais nyob rau hauv cov xwm txheej ntawm alkalinity muaj zog (pH> 10) lossis cua sov (T> 70 ° C), ua rau tus nqi ua haujlwm siab thiab nyuaj.
Txoj kev oxidation
Kev kho oxidation suav nrog kev siv ozone, hydrogen peroxide, potassium permanganate thiab sodium hypochlorite los tshem tawm cov txheej carbon adsorbed kom txhim kho qhov dawb. Cov kaolin nyob rau hauv qhov tob dua hauv qab cov overburden tuab dua yog grey, thiab cov hlau hauv kaolin nyob rau hauv lub xeev txo qis. Siv cov neeg sawv cev oxidizing muaj zog xws li ozone lossis sodium hypochlorite los oxidize insoluble FeS2 hauv pyrite rau soluble Fe2+, thiab tom qab ntawd ntxuav kom tshem tawm Fe2+ ntawm lub cev.
Txoj kev siv kua qaub los ntxuav
Txoj kev leaching acid yog hloov cov hlau tsis muaj zog hauv kaolin mus rau hauv cov tshuaj soluble hauv cov kua qaub (hydrochloric acid, sulfuric acid, oxalic acid, thiab lwm yam), yog li ua tiav kev sib cais ntawm kaolin. Piv nrog rau lwm cov organic acids, oxalic acid yog suav tias yog qhov muaj kev cia siab tshaj plaws vim nws lub zog acid, cov khoom zoo complexing thiab muaj peev xwm txo qis siab. Nrog oxalic acid, cov hlau yaj tuaj yeem precipitated los ntawm cov kua leaching hauv daim ntawv ntawm ferrous oxalate, thiab tuaj yeem ua tiav ntxiv los ua cov hematite ntshiab los ntawm calcination. Oxalic acid tuaj yeem tau txais pheej yig los ntawm lwm cov txheej txheem kev lag luam, thiab nyob rau theem tua hluav taws ntawm kev tsim khoom siv ceramic, txhua qhov seem oxalate hauv cov khoom kho yuav raug decomposed rau hauv carbon dioxide. Ntau tus kws tshawb fawb tau kawm txog cov txiaj ntsig ntawm kev yaj hlau oxide nrog oxalic acid.
Txoj kev calcination kub siab
Kev calcination yog cov txheej txheem ntawm kev tsim cov khoom kaolin qib tshwj xeeb. Raws li qhov kub kho, ob qib sib txawv ntawm calcined kaolin raug tsim tawm. Calcination hauv qhov kub ntawm 650-700 ℃ tshem tawm cov hydroxyl pawg, thiab cov dej pa tawm ua rau kom muaj zog thiab opacity ntawm kaolin, uas yog ib qho zoo tagnrho ntawm daim ntawv thov txheej. Tsis tas li ntawd, los ntawm kev ua kom sov kaolin ntawm 1000-1050 ℃, nws tsis tsuas yog ua rau abradability, tab sis kuj tau txais 92-95% dawb.
Kev siv tshuaj chlorine los ua kom calcination
Hlau thiab titanium raug tshem tawm ntawm cov av nplaum, tshwj xeeb tshaj yog kaolin los ntawm chlorination, thiab tau txais cov txiaj ntsig zoo. Hauv cov txheej txheem ntawm chlorination thiab calcination, ntawm qhov kub siab (700 ℃ - 1000 ℃), kaolinite tau dhau los ua dehydroxylation los tsim metakaolinite, thiab ntawm qhov kub siab dua, spinel thiab mullite theem tau tsim. Cov kev hloov pauv no ua rau hydrophobicity, hardness thiab qhov loj ntawm cov khoom me me los ntawm sintering. Cov zaub mov kho hauv txoj kev no tuaj yeem siv rau hauv ntau yam lag luam, xws li ntawv, PVC, roj hmab, yas, nplaum, polishing thiab tshuaj txhuam hniav. Qhov hydrophobicity siab dua ua rau cov zaub mov no sib xws nrog cov kab ke organic.
Txoj kev tshawb nrhiav txog kab mob me me
Kev siv tshuab microbial purification ntawm cov zaub mov yog ib qho tshiab ntawm kev ua cov zaub mov, suav nrog kev siv tshuab microbial leaching thiab kev siv tshuab microbial flotation. Kev siv tshuab microbial leaching ntawm cov zaub mov yog ib qho thev naus laus zis rho tawm uas siv kev sib cuam tshuam tob ntawm cov kab mob me me thiab cov zaub mov kom rhuav tshem cov pob zeb siv lead ua ke thiab yaj cov khoom siv tau. Oxidized pyrite thiab lwm yam sulfide ores uas muaj nyob hauv kaolin tuaj yeem raug purified los ntawm kev siv tshuab microbial extraction. Cov kab mob me me uas siv feem ntau suav nrog Thiobacillus ferrooxidans thiab Fe-reducing bacteria. Txoj kev microbiological muaj tus nqi qis thiab tsis muaj kuab paug rau ib puag ncig, uas yuav tsis cuam tshuam rau cov khoom siv lub cev thiab tshuaj ntawm kaolin. Nws yog ib txoj kev ntxuav thiab ua kom dawb tshiab nrog kev cia siab rau kev txhim kho rau cov zaub mov kaolin.
Kev Txheeb Xyuas
Kev tshem tawm hlau thiab kev kho kom dawb ntawm kaolin yuav tsum xaiv txoj kev zoo tshaj plaws raws li ntau yam xim ua rau thiab ntau yam kev siv, txhim kho kev ua kom dawb ntawm cov zaub mov kaolin, thiab ua rau nws muaj txiaj ntsig zoo thiab muaj txiaj ntsig zoo. Lub neej yav tom ntej kev loj hlob yuav tsum yog kev sib xyaw cov yam ntxwv ntawm txoj kev tshuaj lom neeg, txoj kev lub cev thiab txoj kev microbiological organically, kom muab kev ua si tag nrho rau lawv cov txiaj ntsig thiab tswj lawv cov qhov tsis zoo thiab qhov tsis zoo, kom ua tiav cov txiaj ntsig zoo dua. Tib lub sijhawm, nws tseem tsim nyog los kawm ntxiv txog cov txheej txheem tshiab ntawm ntau txoj kev tshem tawm cov khoom tsis huv thiab txhim kho cov txheej txheem kom tshem tawm hlau thiab dawb ntawm kaolin tsim nyob rau hauv kev coj ntawm ntsuab, ua haujlwm tau zoo thiab qis carbon.
Lub sijhawm tshaj tawm: Lub Peb Hlis-02-2023