Yanayin chromium
Chromium, alamar abu Cr, lambar atomic 24, nauyin atomic na dangi 51.996, yana cikin sinadarin ƙarfe mai canzawa na rukunin VIB na teburin lokaci-lokaci na abubuwan sinadarai. Karfe Chromium lu'ulu'u ne mai siffar cubic a tsakiya na jiki, fari-fari, yawa 7.1g/cm³, wurin narkewa 1860℃, wurin tafasa 2680℃, takamaiman ƙarfin zafi a 25℃ 23.35J/(mol·K), zafin tururi 342.1kJ/mol, yanayin zafi 91.3 W/(m·K) (0-100°C), juriya (20°C) 13.2uΩ·cm, tare da kyawawan halayen injiniya.
Akwai valence guda biyar na chromium: +2, +3, +4, +5 da +6. A ƙarƙashin yanayin aikin endogenous, chromium gabaɗaya yana da valence +3. Compounds tare da +trivalent chromium sune mafi karko. +Sixvalent chromium compounds, gami da gishirin chromium, suna da ƙarfin oxidizing properties. Ionic radius na Cr3+, AI3+ da Fe3+ suna kama da juna, don haka suna iya samun nau'ikan kamanceceniya iri-iri. Bugu da ƙari, abubuwan da za a iya maye gurbinsu da chromium sune manganese, magnesium, nickel, cobalt, zinc, da sauransu, don haka chromium yana yaɗuwa sosai a cikin ma'adanai na magnesium iron silicate da ma'adanai masu dacewa.
Aikace-aikace
Chromium yana ɗaya daga cikin ƙarfe da aka fi amfani da shi a masana'antar zamani. Ana amfani da shi galibi wajen samar da bakin ƙarfe da ƙarfe daban-daban na ƙarfe a cikin nau'in ferroalloys (kamar ferrochrome). Chromium yana da halaye na tauri, juriya ga lalacewa, juriya ga zafi da juriya ga tsatsa. Ana amfani da ma'adinan Chrome sosai a fannin ƙarfe, kayan da ba sa jurewa, masana'antar sinadarai da masana'antar ƙarfe.
A masana'antar ƙarfe, ana amfani da ma'adinan chromium galibi don narkar da ferrochrome da ƙarfe chromium. Ana amfani da Chromium azaman ƙarin ƙarfe don samar da nau'ikan ƙarfe na musamman masu ƙarfi, masu jure tsatsa, masu jure lalacewa, masu jure zafi, da masu jure oxidation, kamar bakin ƙarfe, ƙarfe mai jure acid, ƙarfe mai jure zafi, ƙarfe mai ɗaukar ƙwallo, ƙarfe mai jure bazara, ƙarfe na kayan aiki, da sauransu. Chromium na iya haɓaka halayen injiniya da juriyar lalacewa na ƙarfe. Ana amfani da chromium na ƙarfe galibi don narkar da ƙarfe na musamman tare da cobalt, nickel, tungsten da sauran abubuwa. Rufin Chrome da chromizing na iya sa ƙarfe, jan ƙarfe, aluminum da sauran ƙarfe su zama saman da ke jure tsatsa, wanda yake da haske da kyau.
A cikin masana'antar da ke hana ruwa gudu, ma'adinin chromium muhimmin abu ne da ake amfani da shi wajen yin tubalin chrome, tubalin chrome magnesia, kayan da ke hana ruwa gudu da sauran kayan da ke hana ruwa gudu na musamman (simintin chrome). Masu hana ruwa gudu na tushen chrome galibi sun haɗa da tubalin da ke da ma'adinin chrome da magnesia, sintered magnesia-chrome clinker, narkakken tubalin magnesia-chrome, narkakken, niƙakken niƙa sannan a haɗa tubalin magnesia-chrome. Ana amfani da su sosai a cikin tanda mai buɗewa, tanda mai shigarwa, da sauransu. Mai canza ƙarfe da rufin tanda mai juyawa na masana'antar siminti, da sauransu.
A masana'antar hakar ma'adinai, ma'adinin chromium ba zai yi mu'amala da sauran abubuwa a cikin ƙarfe mai narkewa ba yayin aikin zuba, yana da ƙarancin ƙimar faɗaɗa zafi, yana da juriya ga shigar ƙarfe, kuma yana da aikin sanyi mafi kyau fiye da zircon. Ma'adinin chrome don hakar ma'adinai yana da ƙa'idodi masu tsauri kan abubuwan da ke cikin sinadarai da rarraba girman barbashi.
A masana'antar sinadarai, amfani da chromium kai tsaye shine samar da sinadarin sodium dichromate (Na2Cr2O7·H2O), sannan a shirya wasu mahaɗan chromium don amfani a masana'antu kamar su pigments, yadi, electroplating, da ƙera fata, da kuma abubuwan da ke ƙara kuzari.
Garin ma'adinan chromium da aka niƙa da kyau wani abu ne da ake amfani da shi wajen yin fenti na halitta a fannin samar da gilashi, yumbu da tayal ɗin gilashi. Lokacin da ake amfani da sodium dichromate don lalata fata, furotin (collagen) da carbohydrates a cikin fata na asali suna amsawa da sinadarai don samar da wani tsari mai ƙarfi, wanda ya zama tushen kayayyakin fata. A masana'antar yadi, ana amfani da sodium dichromate a matsayin wani abu mai ƙarfi a cikin rini na yadi, wanda zai iya haɗa ƙwayoyin rini da mahaɗan halitta yadda ya kamata; haka nan ana iya amfani da shi azaman mai hana iskar shaka a cikin kera rini da tsaka-tsaki.
Ma'adinan Chromium
Akwai nau'ikan ma'adanai sama da 50 da aka gano a yanayi, amma yawancinsu suna da ƙarancin sinadarin chromium da kuma rarrabawar da ba a amfani da ita a masana'antu, wanda ke da ƙarancin amfani da shi a masana'antu. Waɗannan ma'adanai masu ɗauke da sinadarin chromium suna cikin oxides, chromates da silicates, ban da wasu ƴan hydroxides, iodates, nitrides da sulfides. Daga cikinsu, ma'adanai masu ɗauke da sinadarin chromium nitride da chromium sulfide ana samun su ne kawai a cikin meteorites.
A matsayin nau'in ma'adinai a cikin ƙaramin dangin ma'adinan chromium, chromite shine kawai ma'adinan masana'antu mai mahimmanci a cikin chromium. Tsarin sinadaran ka'idar shine (MgFe)Cr2O4, wanda abun ciki na Cr2O3 ya kai kashi 68%, kuma FeO ya kai kashi 32%. A cikin abun da ke cikin sinadarai, cation na trivalent shine Cr3+, kuma sau da yawa akwai maye gurbin isomorphic Al3+, Fe3+ da Mg2+, Fe2+. A cikin ainihin chromite da aka samar, galibi ana maye gurbin wani ɓangare na Fe2+ da Mg2+, kuma Cr3+ ana maye gurbinsa da Al3+ da Fe3+ zuwa matakai daban-daban. Cikakken matakin maye gurbin isomorphic tsakanin sassa daban-daban na chromite ba daidai ba ne. Cations masu tsari huɗu galibi magnesium da ƙarfe ne, da kuma maye gurbin isomorphic tsakanin magnesium-iron gaba ɗaya. Dangane da hanyar rarrabuwa huɗu, ana iya raba chromite zuwa ƙananan ƙungiyoyi huɗu: magnesium chromite, iron-magnesium chromite, mafic-iron chromite da iron-chromite. Bugu da ƙari, chromite sau da yawa yana ɗauke da ƙaramin adadin manganese, Cakuda iri ɗaya na titanium, vanadium da zinc. Tsarin chromite yana da nau'in spinel na yau da kullun.
4. Ingancin ma'aunin sinadarin chromium
Dangane da hanyoyin sarrafawa daban-daban (ma'adinai da ma'adinan halitta), an raba ma'adinan chromium don aikin ƙarfe zuwa nau'i biyu: mai da hankali (G) da ma'adinan dunƙule (K). Duba teburin da ke ƙasa.
Bukatun inganci don ma'adinan chromite don aikin ƙarfe
Fasahar inganta ma'adanai ta Chrome
1) Sake zaɓe
A halin yanzu, rabuwar nauyi tana da muhimmiyar rawa wajen samar da ma'adinin chromium. Hanyar rabuwar nauyi, wadda ke amfani da layi mai laushi a cikin ruwa a matsayin babban aiki, har yanzu ita ce babbar hanyar wadatar da ma'adinin chromium a duk duniya. Kayan aikin rabuwar nauyi suna da ma'adinin karkace da kuma mai tara centrifugal, kuma girman barbashi da ake sarrafawa yana da faɗi sosai. Gabaɗaya, bambancin yawa tsakanin ma'adanai na chromium da ma'adanai na gangue ya fi 0.8g/cm3, kuma rabuwar nauyi na kowane girman barbashi sama da 100um na iya zama mai gamsarwa. Sakamakon. Ana tsara ko kuma a zaɓi ma'adinin da ya yi kauri (100 ~ 0.5mm) ta hanyar amfani da ma'adinin matsakaici mai nauyi, wanda hanya ce mai matuƙar araha.
2) Rabuwar maganadisu
Rabawar maganadisu wata hanya ce ta samar da mafita wadda ke gano rabuwar ma'adanai a cikin filin maganadisu mara tsari bisa ga bambancin maganadisu na ma'adanai a cikin ma'adinan. Chromite yana da rauni a cikin halayen maganadisu kuma ana iya raba shi ta hanyar masu raba maganadisu masu tsayi, masu raba maganadisu da sauran kayan aiki. Takamaiman ma'aunin amsawar maganadisu na ma'adanai na chromium da aka samar a wurare daban-daban na samar da ma'adinan chromium a duniya ba su da bambanci sosai, kuma suna kama da takamaiman ma'aunin amsawar maganadisu na wolframite da wolframite da aka samar a yankuna daban-daban.
Akwai yanayi biyu wajen amfani da rabuwar maganadisu don samun tarin chromium mai inganci: na farko shine a cire ma'adanai masu ƙarfi na maganadisu (galibi magnetite) a cikin ma'adinan ƙarƙashin raunin filin maganadisu don ƙara rabon ferrochrome, ɗayan kuma shine a yi amfani da ƙarfin filin maganadisu. Raba ma'adanai na gangue da dawo da ma'adinan chromium (ma'adanai masu rauni na maganadisu).
3) Zaɓin lantarki
Raba wutar lantarki hanya ce ta raba ma'adanai na chromium da silicate gangue ta hanyar amfani da halayen lantarki na ma'adanai, kamar bambance-bambancen da ke cikin watsa wutar lantarki da kuma dielectric constant.
4) Tafiye-tafiye
A tsarin raba nauyi, ana zubar da ma'adinan chromite mai laushi (-100um) a matsayin wutsiya, amma chromite na wannan girman har yanzu yana da ƙimar amfani mai yawa, don haka ana iya amfani da hanyar flotation don ƙarancin ma'adinan chromite mai laushi. Ana dawo da flotation na ma'adinan chromite mai 20% ~40% Cr2O3 a cikin wutsiya da ma'adinan serpentine, olivine, rutile da calcium magnesium carbonate a matsayin ma'adanai na gangue. Ana niƙa ma'adinan sosai zuwa 200μm, ana amfani da gilashin ruwa, phosphate, metaphosphate, fluorosilicate, da sauransu don warwatsewa da hana sludge, kuma ana amfani da fatty acid mara cikawa azaman mai tarawa. Yaɗuwa da danne sludge na gangue yana da matukar muhimmanci ga tsarin flotation. ions na ƙarfe kamar ƙarfe da gubar na iya kunna chromite. Lokacin da ƙimar pH na slurry ta ƙasa da 6, chromite ba zai yi iyo ba. A takaice, yawan amfani da reagent na flotation yana da girma, matakin tattarawa ba shi da tabbas, kuma ƙimar dawowa ƙasa ce. Ca2+ da Mg2+ da aka narkar daga ma'adanai masu kama da gangue suna rage zaɓin tsarin flotation.
5) Amfani da sinadarai
Hanyar sinadarai ita ce a yi maganin wasu ma'adanai na chromite kai tsaye waɗanda ba za a iya raba su ta hanyar jiki ba ko kuma farashin hanyar jiki yana da yawa. Rabon Cr/Fe na mai da hankali da aka samar ta hanyar sinadarai ya fi na hanyar jiki ta yau da kullun. Hanyoyin sinadarai sun haɗa da: cirewar zaɓi, rage iskar shaka, rabuwar narkewa, cirewar acid na sulfuric da chromic acid, ragewa da cirewar acid na sulfuric, da sauransu. Haɗin hanyoyin jiki da sinadarai da kuma magance ma'adinan chromium kai tsaye ta hanyar hanyoyin sinadarai suna ɗaya daga cikin manyan abubuwan da ke faruwa a cikin samar da chromite a yau. Hanyoyin sinadarai na iya cire chromium kai tsaye daga ma'adinan kuma samar da chromium carbide da chromium oxide.
Lokacin Saƙo: Afrilu-30-2021