Nrog rau lub cev tshwj xeeb thiab tshuaj lom neeg, kaolin yog ib qho khoom siv tsis muaj hlau tsis zoo hauv ceramics, ntawv ua, roj hmab, yas, refractories, roj av refining thiab lwm yam kev lag luam thiab kev ua liaj ua teb thiab kev tiv thaiv kev lag luam hauv teb chaws. Lub whiteness ntawm kaolin yog ib qho tseem ceeb qhia ntawm nws daim ntawv thov nqi.
Cov yam ntxwv cuam tshuam rau qhov dawb ntawm kaolin
Kaolin yog ib hom av nplaum zoo los yog av nplaum pob zeb feem ntau tsim los ntawm cov zaub mov kaolinite. Nws cov qauv siv lead ua tshuaj yog 2SiO2 · Al2O3 · 2H2O. Ib qho me me ntawm cov zaub mov uas tsis yog av nplaum yog quartz, feldspar, hlau minerals, titanium, aluminium hydroxide thiab oxides, organic teeb meem, thiab lwm yam.
Crystalline qauv ntawm kaolin
Raws li lub xeev thiab xwm ntawm impurities nyob rau hauv kaolin, cov impurities uas ua rau kom txo cov whiteness ntawm kaolin yuav muab faib ua peb pawg: organic carbon; Cov xim xim, xws li Fe, Ti, V, Cr, Cu, Mn, thiab lwm yam; Cov ntxhia tsaus nti, xws li biotite, chlorite, thiab lwm yam. Feem ntau, cov ntsiab lus ntawm V, Cr, Cu, Mn thiab lwm yam hauv kaolin yog me me, uas tsis tshua muaj kev cuam tshuam rau cov xim dawb. Cov ntxhia muaj pes tsawg leeg thiab cov ntsiab lus ntawm cov hlau thiab titanium yog lub ntsiab tseem ceeb cuam tshuam rau cov xim dawb ntawm kaolin. Lawv lub neej yuav tsis tsuas cuam tshuam rau lub ntuj whiteness ntawm kaolin, tab sis kuj cuam tshuam rau nws calcined whiteness. Tshwj xeeb, muaj cov hlau oxide muaj kev cuam tshuam tsis zoo rau cov xim av nplaum thiab txo nws qhov ci ntsa iab thiab hluav taws kub. Thiab txawm hais tias tus nqi ntawm oxide, hydroxide thiab hydrated oxide ntawm hlau oxide yog 0.4%, nws yog txaus los muab cov av nplaum sediment liab mus rau xim daj. Cov hlau oxides thiab hydroxides no tuaj yeem yog hematite (liab), maghemite (liab-xim av), goethite (xim daj daj), limonite (txiv kab ntxwv), hydrated hlau oxide (xim av liab), thiab lwm yam. Nws tuaj yeem hais tias tshem tawm cov hlau impurities. hauv kaolin plays lub luag haujlwm tseem ceeb hauv kev siv kaolin zoo dua.
Qhov tshwm sim ntawm lub xeev ntawm cov hlau
Qhov tshwm sim ntawm cov hlau hauv kaolin yog qhov tseem ceeb ntawm kev txiav txim siab ntawm kev tshem tawm cov hlau. Ib tug loj tus naj npawb ntawm cov kev tshawb fawb ntseeg hais tias crystalline hlau nyob rau hauv daim ntawv ntawm cov zoo hais yog tov nyob rau hauv kaolin, thaum amorphous hlau yog coated rau ntawm qhov chaw ntawm zoo hais ntawm kaolin. Tam sim no, lub xeev tshwm sim ntawm cov hlau nyob rau hauv kaolin yog muab faib ua ob hom nyob rau hauv tsev thiab txawv teb chaws: ib tug yog nyob rau hauv kaolinite thiab accessory minerals (xws li mica, titanium dioxide thiab illite), uas yog hu ua structural hlau; Lwm qhov yog nyob rau hauv daim ntawv ntawm cov hlau tsis muaj zog, hu ua dawb hlau (xws li hlau nto, nplua-grained crystalline hlau thiab amorphous hlau).
Cov hlau tshem tawm los ntawm kev tshem tawm hlau thiab ntxuav cov kaolin yog dawb hlau, 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 heev dispersed colloidal limonite, thiab ib tug me me nyob rau hauv daim ntawv ntawm spherical, acicular thiab irregular goethite thiab hematite.
Hlau tshem tawm thiab ua kom dawb txoj kev ntawm kaolin
Kev sib cais dej
Txoj kev no feem ntau yog siv los tshem tawm cov zaub mov detrital xws li quartz, feldspar thiab mica, thiab coarser impurities xws li pob zeb khib nyiab, nrog rau qee cov hlau thiab titanium minerals. Impurity cov zaub mov uas zoo sib xws thiab solubility rau kaolin tsis tuaj yeem raug tshem tawm, thiab kev txhim kho whiteness kuj tsis pom tseeb, uas yog tsim rau cov txiaj ntsig zoo thiab ua kom dawb ntawm cov khoom zoo tshaj plaws kaolin ore.
Sib nqus sib cais
Hlau ntxhia impurities hauv kaolin feem ntau tsis muaj zog hlau nplaum. Tam sim no, lub siab gradient muaj zog sib nqus sib cais txoj kev feem ntau yog siv, lossis cov hlau nplaum tsis muaj zog tau hloov mus rau hauv cov hlau nplaum hlau oxide muaj zog tom qab ci, thiab tom qab ntawd tshem tawm los ntawm txoj kev sib nqus sib nqus zoo tib yam.
Ntiv nplhaib siab gradient sib nqus separator
High gradient magnetic separator rau electromagnetic slurry
Tsawg kub superconducting magnetic separator
Flotation txoj kev
Txoj kev flotation tau siv los kho kaolin los ntawm thawj thiab theem nrab deposits. Nyob rau hauv cov txheej txheem flotation, kaolinite thiab mica hais yog sib cais, thiab cov khoom purified yog ob peb yam tsim nyog qib raw khoom. Kev xaiv flotation sib cais ntawm kaolinite thiab feldspar feem ntau yog ua nyob rau hauv slurry nrog tswj pH.
Txoj kev txo qis
Txoj kev txo qis yog siv tus neeg saib xyuas kom txo tau cov hlau impurities (xws li hematite thiab limonite) nyob rau hauv lub xeev trivalent ntawm kaolin rau soluble bivalent hlau ions, uas yog tshem tawm los ntawm kev pom thiab ntxuav. Kev tshem tawm ntawm Fe3 + impurities los ntawm kev lag luam kaolin feem ntau yog ua tiav los ntawm kev sib txuas cov cuab yeej siv lub cev (sib nqus sib cais, xaiv flocculation) thiab tshuaj kho mob hauv acidic lossis txo cov mob.
Sodium hydrosulfite (Na2S2O4), tseem hu ua sodium hydrosulfite, yog siv los txo thiab leaching hlau los ntawm kaolin, thiab tam sim no siv hauv kaolin kev lag luam. Txawm li cas los xij, txoj kev no yuav tsum tau ua raws li qhov muaj zog acidic (pH <3), uas ua rau cov nqi khiav lag luam siab thiab kev cuam tshuam ib puag ncig. Tsis tas li ntawd, cov khoom siv tshuaj lom neeg ntawm sodium hydrosulfite tsis ruaj khov, yuav tsum tau tshwj xeeb thiab kim cia thiab kev thauj mus los.
Thiourea dioxide: (NH2) 2CSO2, TD) yog ib qho muaj zog txo tus neeg sawv cev, uas muaj qhov zoo ntawm kev muaj peev xwm txo qis, kev phooj ywg ib puag ncig, qis decomposition tus nqi, kev nyab xeeb thiab tus nqi qis ntawm batch ntau lawm. Insoluble Fe3 + hauv kaolin tuaj yeem txo kom soluble Fe2 + los ntawm TD.
Tom qab ntawd, qhov dawb ntawm kaolin tuaj yeem nce ntxiv tom qab pom thiab ntxuav. TD yog ruaj khov heev ntawm chav tsev kub thiab nruab nrab tej yam kev mob. Lub peev xwm txo qis ntawm TD tsuas yog tuaj yeem tau txais nyob rau hauv cov xwm txheej muaj zog alkalinity (pH> 10) lossis cua sov (T> 70 ° C), uas ua rau cov nqi ua haujlwm siab thiab nyuaj.
Txoj kev oxidation
Kev kho oxidation suav nrog kev siv ozone, hydrogen peroxide, potassium permanganate thiab sodium hypochlorite kom tshem tawm cov pa roj carbon monoxide los txhim kho cov xim dawb. Lub kaolin nyob rau hauv qhov ntxaum nyob rau hauv lub thicker overburden yog grey, thiab cov hlau nyob rau hauv lub kaolin yog nyob rau hauv lub xeev txo. Siv cov tshuaj 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.
Acid leaching txoj kev
Cov kua qaub leaching txoj kev yog los hloov cov insoluble hlau impurities nyob rau hauv kaolin rau hauv soluble tshuaj nyob rau hauv acidic tov (hydrochloric acid, sulfuric acid, oxalic acid, thiab lwm yam), yog li paub qhov sib cais ntawm kaolin. Piv nrog rau lwm cov organic acids, oxalic acid yog suav tias yog qhov zoo tshaj plaws vim nws cov kua qaub zog, zoo complexing cuab yeej thiab siab txo peev xwm. Nrog oxalic acid, cov hlau yaj tuaj yeem ua los ntawm cov tshuaj leaching hauv daim ntawv ntawm ferrous oxalate, thiab tuaj yeem ua tiav ntxiv los tsim 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 hauv lub sijhawm tua hluav taws ntawm cov khoom siv ceramic, cov khoom seem oxalate nyob rau hauv cov khoom kho yuav decomposed rau hauv carbon dioxide. Ntau tus kws tshawb fawb tau kawm cov txiaj ntsig ntawm kev ua kom cov hlau oxide yaj nrog oxalic acid.
Kub calcination txoj kev
Calcination yog cov txheej txheem ntawm kev tsim cov khoom siv kaolin tshwj xeeb. Raws li kev kho kub, ob qib sib txawv ntawm calcined kaolin yog tsim. Calcination nyob rau hauv qhov kub thiab txias ntawm 650-700 ℃ tshem tawm cov txheej txheem hydroxyl pawg, thiab evaporation dej vapor txhim khu elasticity thiab opacity ntawm kaolin, uas yog ib tug zoo tagnrho attribute ntawm daim ntawv txheej daim ntawv thov. Tsis tas li ntawd, los ntawm cua sov kaolin ntawm 1000-1050 ℃, nws tuaj yeem tsis tsuas yog nce abradability, tab sis kuj tau txais 92-95% whiteness.
Chlorination calcination
Hlau thiab titanium raug tshem tawm los ntawm cov av nplaum, tshwj xeeb tshaj yog kaolin los ntawm chlorination, thiab tau txais txiaj ntsig zoo. Nyob rau hauv tus txheej txheem ntawm chlorination thiab calcination, nyob rau hauv kub (700 ℃ - 1000 ℃), kaolinite tau undergone dehydroxylation los ua metakaolinite, thiab nyob rau hauv kub siab, spinel thiab mullite theem yog tsim. Cov kev hloov pauv no nce hydrophobicity, hardness thiab loj ntawm cov khoom los ntawm sintering. Cov minerals kho nyob rau hauv txoj kev no yuav siv tau nyob rau hauv ntau industries, xws li ntawv, PVC, roj hmab, yas, adhesives, polishing thiab tshuaj txhuam hniav. Qhov siab dua hydrophobicity ua rau cov zaub mov no sib haum nrog cov kab ke organic.
Txoj kev microbiological
Microbial purification thev naus laus zis ntawm cov zaub mov yog ib yam tshiab ntawm kev ua cov ntxhia, suav nrog microbial leaching technology thiab microbial flotation technology. Microbial leaching technology ntawm cov zaub mov yog ib qho kev siv tshuab extraction uas siv cov kev sib sib zog nqus ntawm cov kab mob thiab cov zaub mov los rhuav tshem cov siv lead ua lattice ntawm cov zaub mov thiab yaj cov khoom muaj txiaj ntsig. Oxidized pyrite thiab lwm yam sulfide ores muaj nyob rau hauv kaolin tuaj yeem ua kom huv los ntawm microbial extraction technology. Feem ntau siv cov kab mob xws li Thiobacillus ferrooxidans thiab Fe-txo cov kab mob. Cov txheej txheem microbiological muaj tus nqi qis thiab ib puag ncig tsis zoo, uas yuav tsis cuam tshuam rau lub cev thiab tshuaj lom neeg ntawm kaolin. Nws yog ib txoj kev ua kom huv thiab ntxuav hniav dawb nrog txoj kev loj hlob rau kaolin minerals.
Cov ntsiab lus
Kev tshem tawm cov hlau thiab kev kho kom dawb ntawm kaolin yuav tsum xaiv txoj kev zoo tshaj plaws raws li cov xim sib txawv thiab cov hom phiaj ntawm daim ntawv thov sib txawv, txhim kho kev ua kom zoo nkauj ntawm kaolin minerals, thiab ua kom nws muaj txiaj ntsig zoo thiab kev siv nyiaj txiag. Txoj kev loj hlob yav tom ntej yuav tsum tau muab cov yam ntxwv ntawm cov txheej txheem tshuaj, lub cev txoj kev thiab microbiological txoj kev organically, thiaj li muab tag nrho cov kev ua si rau lawv qhov zoo thiab txwv tsis pub lawv qhov tsis zoo thiab qhov tsis zoo, thiaj li ua tiav cov nyhuv whitening zoo dua. Nyob rau tib lub sijhawm, nws tseem yuav tsum tau kawm ntxiv txog cov txheej txheem tshiab ntawm ntau yam kev tshem tawm impurity thiab txhim kho cov txheej txheem kom cov hlau tshem tawm thiab ntxuav ntawm kaolin txhim kho nyob rau hauv cov kev taw qhia ntawm ntsuab, muaj txiaj ntsig thiab cov pa roj carbon tsawg.
Post lub sij hawm: Mar-02-2023