Chikhalidwe cha chromium
Chromium, chizindikiro cha chinthu Cr, nambala ya atomiki 24, kulemera kwa atomiki 51.996, ndi gawo la chitsulo chosinthira cha gulu la VIB la tebulo la periodic la zinthu za mankhwala. Chitsulo cha Chromium ndi kristalo wa cubic pakati pa thupi, woyera ngati siliva, kachulukidwe 7.1g/cm³, malo osungunuka 1860℃, malo owira 2680℃, mphamvu yeniyeni ya kutentha pa 25℃ 23.35J/(mol·K), kutentha kwa nthunzi 342.1kJ/mol, kutentha kwa 91.3 W/(m·K) (0-100°C), kukana (20°C) 13.2uΩ·cm, ndi mawonekedwe abwino a makina.
Pali ma valensi asanu a chromium: +2, +3, +4, +5 ndi +6. Pansi pa zochita za endogenous, chromium nthawi zambiri imakhala ndi valensi ya +3. Ma compounds okhala ndi +trivalent chromium ndi okhazikika kwambiri. Ma compounds a +sixvalent chromium, kuphatikiza chromium salts, ali ndi mphamvu zolimbitsa thupi. Ma radii a ionic a Cr3+, AI3+ ndi Fe3+ ndi ofanana, kotero amatha kukhala ndi zofanana zambiri. Kuphatikiza apo, zinthu zomwe zingasinthidwe ndi chromium ndi manganese, magnesium, nickel, cobalt, zinc, ndi zina zotero, kotero chromium imafalikira kwambiri mu magnesium iron silicate minerals ndi accessories minerals.
Kugwiritsa ntchito
Chromium ndi imodzi mwa zitsulo zomwe zimagwiritsidwa ntchito kwambiri m'makampani amakono. Imagwiritsidwa ntchito kwambiri popanga zitsulo zosapanga dzimbiri ndi zitsulo zosiyanasiyana za alloy monga ma ferroalloys (monga ferrochrome). Chromium ili ndi makhalidwe olimba, osawonongeka, osatentha komanso osadzimbidwa. Mchere wa Chrome umagwiritsidwa ntchito kwambiri m'mafakitale a zitsulo, zinthu zosagwirizana ndi kutentha, makampani opanga mankhwala ndi mafakitale opangira zitsulo.
Mu makampani opanga zitsulo, chromium ore imagwiritsidwa ntchito kwambiri kusungunula ferrochrome ndi chromium yachitsulo. Chromium imagwiritsidwa ntchito ngati chowonjezera chachitsulo kuti ipange zitsulo zosiyanasiyana zamphamvu kwambiri, zosagwira dzimbiri, zosatha, kutentha kwambiri, komanso zosagwira okosijeni, monga chitsulo chosapanga dzimbiri, chitsulo chosagwira asidi, chitsulo chosagwira kutentha, chitsulo chokhala ndi mpira, chitsulo cha masika, chitsulo cha zida, ndi zina zotero. Chromium imatha kuwonjezera mphamvu zamakanika komanso kukana kutha kwa chitsulo. Chromium yachitsulo imagwiritsidwa ntchito kwambiri kusungunula zitsulo zapadera zokhala ndi cobalt, nickel, tungsten ndi zinthu zina. Kuyika ndi kuyika kwa chrome kungapangitse chitsulo, mkuwa, aluminiyamu ndi zitsulo zina kupanga malo osagwira dzimbiri, omwe ndi owala komanso okongola.
Mu makampani opanga zinthu zotsutsana ndi chromium, chromium ore ndi chinthu chofunikira kwambiri chomwe chimagwiritsidwa ntchito popanga njerwa za chrome, njerwa za chrome magnesia, zinthu zotsutsana ndi chromium ndi zinthu zina zapadera zotsutsana ndi chromium (konkriti ya chrome). Zinthu zotsutsana ndi chromium zimaphatikizapo njerwa zokhala ndi chrome ore ndi magnesia, sintered magnesia-chrome clinker, njerwa za magnesia-chrome zosungunuka, zosungunuka, zopukutidwa bwino kenako zolumikizidwa ndi magnesia-chrome. Zimagwiritsidwa ntchito kwambiri mu uvuni wotseguka, uvuni wopangira zinthu, ndi zina zotero. Chosinthira zitsulo ndi chozungulira cha ng'anjo yamakampani a simenti, ndi zina zotero.
Mu makampani opanga zinthu zopangira zitsulo, chromium ore sigwirizana ndi zinthu zina zomwe zili mu chitsulo chosungunuka panthawi yothira, imakhala ndi kutentha kochepa, imakana kulowa kwa chitsulo, ndipo imakhala ndi mphamvu yozizira bwino kuposa zircon. Chrome ore ya zinthu zopangira zitsulo ili ndi zofunikira kwambiri pa kapangidwe ka mankhwala ndi kugawa kwa tinthu tating'onoting'ono.
Mu makampani opanga mankhwala, kugwiritsa ntchito mwachindunji kwa chromium ndiko kupanga sodium dichromate (Na2Cr2O7·H2O), kenako kukonza mankhwala ena a chromium kuti agwiritsidwe ntchito m'mafakitale monga utoto, nsalu, electroplating, ndi kupanga zikopa, komanso ma catalysts.
Ufa wa chromium ore wophwanyidwa bwino ndi chinthu chachilengedwe chopaka utoto popanga magalasi, ziwiya zadothi ndi matailosi opakidwa utoto. Pamene sodium dichromate imagwiritsidwa ntchito kuwononga chikopa, mapuloteni (collagen) ndi chakudya chomwe chili m'chikopa choyambirira chimagwirizana ndi mankhwala kuti apange chinthu chokhazikika, chomwe chimakhala maziko a zinthu zachikopa. Mu makampani opanga nsalu, sodium dichromate imagwiritsidwa ntchito ngati chosakaniza mu utoto wa nsalu, chomwe chimatha kulumikiza bwino mamolekyu a utoto ku zinthu zachilengedwe; chingagwiritsidwenso ntchito ngati chowonjezera poizoni popanga utoto ndi zinthu zina.
Mchere wa Chromium
Pali mitundu yoposa 50 ya mchere wokhala ndi chromium yomwe yapezeka m'chilengedwe, koma yambiri mwa iyo ili ndi chromium yochepa komanso kufalikira kofalikira, komwe kumakhala kotsika mtengo kugwiritsidwa ntchito m'mafakitale. Michere yokhala ndi chromium iyi ndi ya ma oxides, ma chromates ndi ma silicates, kuphatikiza ma hydroxides, ma iodate, ma nitrides ndi ma sulfides. Pakati pawo, chromium nitride ndi chromium sulfide zimapezeka mu meteorites zokha.
Monga mtundu wa mchere womwe uli m'gulu la chromium ore subfamily, chromite ndiye mchere wokhawo wofunikira kwambiri wa chromium. Fomula ya mankhwala yongopeka ndi (MgFe)Cr2O4, momwe Cr2O3 ili ndi 68%, ndipo FeO ili ndi 32%. Mu kapangidwe kake ka mankhwala, trivalent cation makamaka ndi Cr3+, ndipo nthawi zambiri pamakhala Al3+, Fe3+ ndi Mg2+, Fe2+ isomorphic substitutions. Mu chromite yeniyeni yopangidwa, gawo la Fe2+ nthawi zambiri limasinthidwa ndi Mg2+, ndipo Cr3+ imasinthidwa ndi Al3+ ndi Fe3+ mpaka madigiri osiyanasiyana. Mlingo wonse wa isomorphic substitution pakati pa zigawo zosiyanasiyana za chromite siwofanana. Ma cations anayi ogwirizana makamaka ndi magnesium ndi iron, ndipo kusintha kwathunthu kwa isomorphic pakati pa magnesium-iron. Malinga ndi njira yogawa zinayi, chromite ikhoza kugawidwa m'magulu anayi: magnesium chromite, iron-magnesium chromite, mafic-iron chromite ndi iron-chromite. Kuphatikiza apo, chromite nthawi zambiri imakhala ndi manganese pang'ono, Chisakanizo chofanana cha titaniyamu, vanadium ndi zinki. Kapangidwe ka chromite ndi ka mtundu wamba wa spinel.
4. Muyezo wabwino wa chromium concentrate
Malinga ndi njira zosiyanasiyana zopangira (mineralization ndi natural ore), chromium ore ya metallurgy imagawidwa m'mitundu iwiri: concentrate (G) ndi lump ore (K). Onani tebulo ili m'munsimu.
Zofunikira pa khalidwe la chromite ore pazitsulo
Ukadaulo wopangira zinthu pogwiritsa ntchito miyala ya Chrome
1) Kusankhidwanso
Pakadali pano, kulekanitsa mphamvu yokoka kuli ndi malo ofunikira pakukongoletsa miyala ya chromium. Njira yolekanitsa mphamvu yokoka, yomwe imagwiritsa ntchito zigawo zomasuka mumadzi amchere ngati njira yoyambira, ikadali njira yayikulu yowonjezerera miyala ya chromium padziko lonse lapansi. Zipangizo zolekanitsa mphamvu yokoka ndi chute yozungulira komanso concentrator ya centrifugal, ndipo kukula kwa tinthu tating'onoting'ono tomwe timakonzedwa ndi kokulirapo. Kawirikawiri, kusiyana kwa kuchuluka kwa chromium ndi miyala ya gangue ndi kwakukulu kuposa 0.8g/cm3, ndipo kulekanitsa mphamvu yokoka kwa tinthu tating'onoting'ono toposa 100um kungakhale kokwanira. Zotsatira zake. Madontho a coarse (100 ~ 0.5mm) ore amasankhidwa kapena kusankhidwa kale ndi heavy-medium beneficiation, yomwe ndi njira yotsika mtengo kwambiri yowonjezerera.
2) Kulekanitsa maginito
Kupatukana kwa maginito ndi njira yopezera phindu yomwe imagawanitsa mchere mu mphamvu ya maginito yosagwirizana kutengera kusiyana kwa maginito kwa mchere womwe uli mu ore. Chromite ili ndi mphamvu zofooka za maginito ndipo imatha kulekanitsidwa ndi olekanitsa maginito okwera kwambiri, olekanitsa maginito a mbale yonyowa ndi zida zina. Ma coefficients enieni a maginito a chromium omwe amapangidwa m'malo osiyanasiyana opanga chromium ore padziko lapansi si osiyana kwambiri, ndipo ndi ofanana ndi ma coefficients enieni a maginito a wolframite ndi wolframite omwe amapangidwa m'madera osiyanasiyana.
Pali zinthu ziwiri zomwe zimagwiritsidwa ntchito pogawa maginito kuti mupeze chromium concentrate yapamwamba: choyamba ndi kuchotsa mchere wamphamvu wa maginito (makamaka magnetite) mu miyala pansi pa mphamvu yofooka ya maginito kuti muwonjezere chiŵerengero cha ferrochrome, ndipo china ndi kugwiritsa ntchito mphamvu yamphamvu ya maginito. Kulekanitsa mchere wa gangue ndi kubwezeretsa chromium ore (mchere wofooka wa maginito).
3) Kusankha magetsi
Kulekanitsa magetsi ndi njira yolekanitsira chromium ore ndi silicate gangue minerals pogwiritsa ntchito mphamvu zamagetsi za mchere, monga kusiyana kwa conductivity ndi dielectric constant.
4) Kuyandama
Pakulekanitsa mphamvu yokoka, miyala ya chromite yopyapyala (-100um) nthawi zambiri imatayidwa ngati mipata, koma chromite ya kukula kumeneku ikadali ndi phindu lalikulu, kotero njira yoyandama ingagwiritsidwe ntchito pa miyala ya chromite yopyapyala yotsika imapezedwanso. Kuyandama kwa chromium ore ndi 20% ~40% Cr2O3 m'mipata ndi mchere wa serpentine, olivine, rutile ndi calcium magnesium carbonate ngati miyala ya gangue. Myalayo imaphwanyidwa bwino mpaka 200μm, galasi lamadzi, phosphate, metaphosphate, fluorosilicate, ndi zina zotero zimagwiritsidwa ntchito kufalitsa ndikuletsa matope, ndipo unsaturated fatty acid imagwiritsidwa ntchito ngati chosonkhanitsa. Kufalikira ndi kuletsa matope a gangue ndikofunikira kwambiri pa njira yoyandama. Ma ayoni achitsulo monga chitsulo ndi lead amatha kuyambitsa chromite. Pamene pH ya matope ili pansi pa 6, chromite sidzayandama kwenikweni. Mwachidule, kugwiritsa ntchito kwa reagent yoyandama ndi kwakukulu, kuchuluka kwa concentrate sikukhazikika, ndipo kuchuluka kwa kuchira ndi kochepa. Ca2+ ndi Mg2+ zosungunuka kuchokera ku mchere wa gangue zimachepetsa kusankha kwa njira yoyandama.
5) Kupindulitsa kwa mankhwala
Njira ya mankhwala ndi yokonza mwachindunji miyala ina ya chromite yomwe singalekanitsidwe pogwiritsa ntchito njira ya thupi kapena mtengo wa njira ya thupi ndi wokwera kwambiri. Chiŵerengero cha Cr/Fe cha concentrate chopangidwa ndi njira ya mankhwala ndi chapamwamba kuposa cha njira yachibadwa ya thupi. Njira za mankhwala zimaphatikizapo: kuyeretsa kosankha, kuchepetsa okosijeni, kulekanitsa kusungunuka, kuyeretsa sulfuric acid ndi chromic acid, kuchepetsa ndi kuyeretsa sulfuric acid, ndi zina zotero. Kuphatikiza njira za thupi ndi mankhwala ndi chithandizo chachindunji cha chromium ore pogwiritsa ntchito njira za mankhwala ndi chimodzi mwa zinthu zazikulu zomwe chromite imapindula nazo masiku ano. Njira za mankhwala zimatha kuchotsa chromium mwachindunji kuchokera mu miyala ndikupanga chromium carbide ndi chromium oxide.
Nthawi yotumizira: Epulo-30-2021