Tare da halaye na musamman na zahiri da sinadarai, kaolin wani muhimmin ma'adinai ne da ba na ƙarfe ba a fannin yumbu, yin takarda, roba, robobi, abubuwan da ba su da ƙarfe, tace mai da sauran fannoni na fasaha na zamani a fannin masana'antu da noma da tsaron ƙasa. Farin kaolin muhimmin alama ne na ƙimar amfani da shi.
Abubuwan da ke shafar farin kaolin
Kaolin wani nau'in dutse ne mai laushi ko kuma dutse mai laushi wanda galibi ya ƙunshi ma'adanai na kaolinite. Tsarin sinadaran kristal ɗinsa shine 2SiO2 · Al2O3 · 2H2O. Ƙananan ma'adanai marasa yumbu sune quartz, feldspar, ma'adanai na ƙarfe, titanium, aluminum hydroxide da oxides, kwayoyin halitta, da sauransu.
Tsarin lu'ulu'u na kaolin
Dangane da yanayin da kuma yanayin ƙazanta a cikin kaolin, ƙazanta da ke haifar da raguwar farin kaolin za a iya raba su zuwa rukuni uku: carbon na halitta; Abubuwan da ke ɗauke da launin fata, kamar Fe, Ti, V, Cr, Cu, Mn, da sauransu; Ma'adanai masu duhu, kamar biotite, chlorite, da sauransu. Gabaɗaya, abubuwan da ke cikin kaolin ƙarami ne, wanda ba shi da tasiri sosai ga farin fata. Haɗin ma'adinai da abubuwan da ke cikin ƙarfe da titanium su ne manyan abubuwan da ke shafar farin kaolin. Rayuwarsu ba wai kawai za ta shafi farin kaolin na halitta ba, har ma za ta shafi farin kaolin da ke cikin calcine. Musamman ma, kasancewar ƙarfe oxide yana da mummunan tasiri ga launin yumbu kuma yana rage haske da juriyar wuta. Kuma ko da adadin oxide, hydroxide da hydrated oxide na ƙarfe oxide ya kai 0.4%, ya isa ya ba da launin ja zuwa launin rawaya. Waɗannan baƙin ƙarfe oxides da hydroxides na iya zama hematite (ja), maghemite (ja-kasa), goethite (rawaya mai launin ruwan kasa), limonite (orange), hydrated iron oxide (ja mai launin ruwan kasa), da sauransu. Za a iya cewa cire ƙazanta na ƙarfe a cikin kaolin yana taka muhimmiyar rawa wajen amfani da kaolin yadda ya kamata.
Yanayin faruwar sinadarin ƙarfe
Yanayin da baƙin ƙarfe ke shiga a cikin kaolin shine babban abin da ke tantance hanyar cire baƙin ƙarfe. Yawancin bincike sun yi imanin cewa baƙin ƙarfe mai siffar crystalline a cikin nau'in ƙananan ƙwayoyin cuta yana haɗuwa a cikin kaolin, yayin da baƙin ƙarfe mai siffar amorphous yana shafa a saman ƙananan ƙwayoyin cuta na kaolin. A halin yanzu, yanayin da baƙin ƙarfe ke shiga a cikin kaolin an raba shi zuwa nau'i biyu a gida da waje: ɗaya yana cikin kaolinite da ma'adanai masu haɗawa (kamar mica, titanium dioxide da ilite), wanda ake kira ƙarfe mai tsari; ɗayan kuma yana cikin nau'in ma'adanai na baƙin ƙarfe masu zaman kansu, wanda ake kira free iron (gami da saman ƙarfe, fine-grained crystalline iron da amorphous iron).
Baƙin ƙarfe da aka cire ta hanyar cire ƙarfe da kuma yin farin ƙarfe na kaolin ƙarfe ne mai 'yanci, galibi ya haɗa da magnetite, hematite, limonite, siderite, pyrite, ilmenite, jarosite da sauran ma'adanai; Yawancin ƙarfe yana wanzuwa a cikin nau'in limonite na colloidal da aka warwatse sosai, kuma ƙaramin adadi ne a cikin nau'in goetite da hematite mai siffar ƙwallo, acicular da rashin daidaituwa.
Hanyar cire ƙarfe da kuma yin farin ƙarfe ta kaolin
Raba ruwa
Ana amfani da wannan hanyar ne musamman don cire ma'adanai masu guba kamar quartz, feldspar da mica, da kuma ƙazanta masu kauri kamar tarkacen duwatsu, da kuma wasu ma'adanai na ƙarfe da titanium. Ba za a iya cire ma'adanai masu ƙazanta masu kama da yawa da narkewa kamar kaolin ba, kuma ingantaccen farin ba a bayyane yake ba, wanda ya dace da fa'ida da farin ma'adinan kaolin mai inganci.
Rabuwar maganadisu
Rashin dattin ma'adinan ƙarfe a cikin kaolin yawanci yana da rauni a maganadisu. A halin yanzu, ana amfani da hanyar rabuwar maganadisu mai ƙarfi mai tsayi, ko kuma a mayar da ma'adinan maganadisu masu rauni zuwa ƙarfe mai ƙarfi bayan an gasa su, sannan a cire su ta hanyar rabuwar maganadisu ta yau da kullun.
Mai raba maganadisu mai tsayin tsayi mai tsayi zobe a tsaye
Babban mai raba maganadisu mai juzu'i don slurry na lantarki
Mai raba maganadisu mai ƙarancin zafin jiki
Hanyar iyo
An yi amfani da hanyar flotation don magance kaolin daga ma'ajiyar farko da ta sakandare. A cikin tsarin flotation, ana raba barbashi na kaolinite da mica, kuma samfuran da aka tsarkake sune kayan da suka dace da masana'antu. Raba flotation na kaolinite da feldspar yawanci ana yin su ne a cikin slurry tare da pH mai sarrafawa.
Hanyar ragewa
Hanyar ragewa ita ce amfani da wani abu mai ragewa don rage dattin ƙarfe (kamar hematite da limonite) a cikin yanayin trivalent na kaolin zuwa ions na ƙarfe bivalent masu narkewa, waɗanda ake cirewa ta hanyar tacewa da wankewa. Cire ƙazanta Fe3+ daga kaolin na masana'antu yawanci ana samunsa ta hanyar haɗa fasahar jiki (raba maganadisu, zaɓin flocculation) da maganin sinadarai a ƙarƙashin yanayi mai acidic ko ragewa.
Sodium hydrosulfite (Na2S2O4), wanda aka fi sani da sodium hydrosulfite, yana da tasiri wajen ragewa da kuma fitar da baƙin ƙarfe daga kaolin, kuma a halin yanzu ana amfani da shi a masana'antar kaolin. Duk da haka, dole ne a aiwatar da wannan hanyar a ƙarƙashin yanayi mai ƙarfi na acidic (pH<3), wanda ke haifar da hauhawar farashin aiki da tasirin muhalli. Bugu da ƙari, halayen sinadarai na sodium hydrosulfite ba su da tabbas, suna buƙatar shirye-shiryen ajiya da jigilar kaya na musamman da tsada.
Thiourea dioxide: (NH2) 2CSO2, TD) wani sinadari ne mai ƙarfi na rage kiba, wanda ke da fa'idodin ƙarfin rage kiba, kyawun muhalli, ƙarancin ruɓewa, aminci da ƙarancin farashin samar da batter. Fe3+wanda ba ya narkewa a cikin kaolin za a iya rage shi zuwa Fe2+mai narkewa ta hanyar TD.
Daga baya, ana iya ƙara farin kaolin bayan tacewa da wankewa. TD yana da ƙarfi sosai a zafin ɗaki da kuma yanayi mai tsaka-tsaki. Ƙarfin rage ƙarfin TD ana iya samunsa ne kawai a ƙarƙashin yanayin alkalinity mai ƙarfi (pH>10) ko dumama (T>70 ° C), wanda ke haifar da tsadar aiki da wahala.
Hanyar iskar shaka
Maganin oxidation ya haɗa da amfani da ozone, hydrogen peroxide, potassium permanganate da sodium hypochlorite don cire layin carbon da aka shafa don inganta farin fata. Kaolin da ke cikin zurfin wuri a ƙarƙashin babban nauyin yana da launin toka, kuma ƙarfen da ke cikin kaolin yana cikin yanayin ragewa. Yi amfani da magungunan oxidizing masu ƙarfi kamar ozone ko sodium hypochlorite don oxidize FeS2 mara narkewa a cikin pyrite zuwa Fe2+ mai narkewa, sannan a wanke don cire Fe2+ daga tsarin.
Hanyar fitar da sinadarin acid
Hanyar cire sinadarin acid ita ce a canza ƙazanta na baƙin ƙarfe mara narkewa a cikin kaolin zuwa abubuwa masu narkewa a cikin ruwan acid (hydrochloric acid, sulfuric acid, oxalic acid, da sauransu), don haka a cimma rabuwar kaolin. Idan aka kwatanta da sauran acid na halitta, ana ɗaukar oxalic acid a matsayin mafi kyau saboda ƙarfinsa na acid, kyakkyawan halayen haɗakarwa da kuma ƙarfin ragewa mai yawa. Tare da oxalic acid, ana iya fitar da baƙin ƙarfe da aka narke daga ruwan leaching a cikin nau'in ferrous oxalate, kuma ana iya ƙara sarrafa shi don samar da hematite mai tsarki ta hanyar calcination. Ana iya samun oxalic acid a araha daga wasu hanyoyin masana'antu, kuma a matakin ƙonawa na kera yumbu, duk wani ragowar oxalate a cikin kayan da aka yi wa magani zai narke zuwa carbon dioxide. Masu bincike da yawa sun yi nazarin sakamakon narke ƙarfe oxide tare da oxalic acid.
Hanyar ƙara yawan zafin jiki
Calcination tsari ne na samar da samfuran kaolin na musamman. Dangane da zafin jiki na magani, ana samar da nau'ikan kaolin daban-daban guda biyu. Calcination a cikin kewayon zafin jiki na 650-700 ℃ yana cire rukunin hydroxyl na tsarin, kuma tururin ruwa mai gudu yana haɓaka laushi da rashin haske na kaolin, wanda shine siffa mai kyau ta amfani da shafi na takarda. Bugu da ƙari, ta hanyar dumama kaolin a 1000-1050 ℃, ba wai kawai zai iya ƙara yawan lalata ba, har ma ya sami 92-95% fari.
Kalin chlorine
An cire ƙarfe da titanium daga ma'adanai na yumbu, musamman kaolin ta hanyar chlorine, kuma an sami sakamako mai kyau. A cikin tsarin chlorine da calcination, a zafin jiki mai girma (700 ℃ - 1000 ℃), kaolinite ya sha wahala wajen samar da metakaolinite, kuma a yanayin zafi mai girma, ana samar da spinel da mullite. Waɗannan canje-canje suna ƙara yawan hydrophobic, tauri da girman barbashi ta hanyar sintering. Ana iya amfani da ma'adanai da aka yi wa magani ta wannan hanyar a masana'antu da yawa, kamar takarda, PVC, roba, robobi, manne, gogewa da man goge baki. Babban hydrophobicity yana sa waɗannan ma'adanai su fi dacewa da tsarin halitta.
Hanyar ƙwayoyin cuta
Fasahar tsarkake ƙwayoyin cuta ta ma'adanai sabuwar hanya ce ta sarrafa ma'adanai, gami da fasahar leaching na ƙwayoyin cuta da fasahar flotation na ƙwayoyin cuta. Fasahar leaching na ƙwayoyin cuta ta ma'adanai wata fasaha ce ta cirewa wadda ke amfani da zurfafa hulɗa tsakanin ƙananan halittu da ma'adanai don lalata layin lu'ulu'u na ma'adanai da kuma narkar da abubuwan da ke da amfani. Ana iya tsarkake pyrite mai oxidized da sauran ma'adanai na sulfide da ke cikin kaolin ta hanyar fasahar cire ƙwayoyin cuta. Ƙananan halittu da ake amfani da su a yau da kullun sun haɗa da Thiobacillus ferrooxidans da ƙwayoyin cuta masu rage Fe. Hanyar ƙananan halittu tana da ƙarancin farashi da ƙarancin gurɓataccen muhalli, wanda ba zai shafi halayen zahiri da sinadarai na kaolin ba. Sabuwar hanya ce ta tsarkakewa da fari tare da yuwuwar haɓaka ma'adanai na kaolin.
Takaitaccen Bayani
Maganin cire ƙarfe da kuma yin farin ƙarfe na kaolin yana buƙatar zaɓar hanya mafi kyau bisa ga dalilai daban-daban na launi da manufofin aikace-aikace daban-daban, inganta cikakken aikin farin ma'adanai na kaolin, da kuma sanya shi ya zama mai amfani mai yawa da ƙimar tattalin arziki. Ya kamata yanayin ci gaba na gaba ya kasance haɗa halayen hanyar sinadarai, hanyar jiki da hanyar ƙwayoyin cuta ta hanyar halitta, don ba da cikakken wasa ga fa'idodin su da kuma rage rashin amfani da gazawarsu, don cimma ingantaccen tasirin farin ƙarfe. A lokaci guda, yana da mahimmanci a ƙara nazarin sabon tsarin hanyoyin cire ƙazanta daban-daban da kuma inganta tsarin don sa cire ƙarfe da farin ƙarfe na kaolin ya haɓaka ta hanyar kore, inganci da ƙarancin carbon.
Lokacin Saƙo: Maris-02-2023