Halin chromium
Chromium, alamar sinadari Cr, lambar atomic 24, dangin atomic mass 51.996, na cikin ɓangarorin ƙarfe na tsaka-tsaki na rukunin VIB na tebur na lokaci-lokaci na abubuwan sinadarai. Chromium karfe ne jiki-tsakiyar cubic crystal, azurfa-fari, yawa 7.1g / cm³, narkewa batu 1860 ℃, tafasar batu 2680 ℃, takamaiman zafi iya aiki a 25 ℃ 23.35J / (mol · K), zafi na vaporization 342.1kJ / mol, thermal watsin 91.3 W / (m · K) (0-100 ° C), resistivity (20 ° C) 13.2uΩ · cm, tare da kyau inji Properties.
Akwai valences guda biyar na chromium: +2, +3, +4, +5 da +6. A ƙarƙashin yanayin aikin endogenous, chromium gabaɗaya shine +3 valence. Haɗaɗɗen chromium + trivalent sune mafi kwanciyar hankali. + Sixvalent chromium mahadi, gami da chromium salts, suna da kaddarorin oxidizing masu ƙarfi. Radiyoyin ionic na Cr3+, AI3+ da Fe3+ suna kama da juna, don haka suna iya samun kamanceceniya iri-iri. Bugu da ƙari, abubuwan da za a iya maye gurbinsu da chromium sune manganese, magnesium, nickel, cobalt, zinc, da dai sauransu, don haka chromium ya yadu a cikin ma'adinan silicate na baƙin ƙarfe na magnesium da ma'adanai masu mahimmanci.
Aikace-aikace
Chromium yana daya daga cikin karafa da aka fi amfani da su a masana'antar zamani. An fi amfani da shi wajen samar da bakin karfe da nau'ikan karafa daban-daban a cikin nau'in ferroalloys (kamar ferrochrome). Chromium yana da sifofin wuya, juriya, juriya da lalata. Chrome tama ana amfani da ko'ina a karafa, refractory kayan, sinadaran masana'antu da kuma samu masana'antu.
A cikin masana'antar ƙarfe, chromium tama galibi ana amfani dashi don narke ferrochrome da chromium na ƙarfe. Ana amfani da Chromium azaman ƙari na ƙarfe don samar da nau'ikan ƙarfin ƙarfi iri-iri, juriya mai lalata, juriya, zafi mai zafi, da karafa na musamman masu jure iskar shaka, irin su bakin karfe, ƙarfe mai jure acid, ƙarfe mai jure zafi, ball hali karfe, spring karfe, kayan aiki karfe, da dai sauransu Chromium iya bunkasa inji Properties kuma sa juriya na karfe. Karfe chromium ana amfani da shi musamman don narke gami na musamman tare da cobalt, nickel, tungsten da sauran abubuwa. Chrome plating da chromizing zai iya yin karfe, jan karfe, aluminum da sauran karafa su zama wani wuri mai jurewa lalata, wanda yake da haske da kyau.
A cikin masana'antar refractory, chromium tama wani abu ne mai mahimmanci da ake amfani da shi don yin tubalin chrome, tubalin magnesia na chrome, na'urori masu tasowa da sauran kayan haɓaka na musamman (chrome kankare). Abubuwan da ke tushen Chromium galibi sun haɗa da bulo mai chrome ore da magnesia, magnesia-chrome clinker na sintered, bulo na magnesia-chrome na narkar da, narkakkarwa, ƙasa mai kyau sannan kuma tubalin magnesia-chrome. Ana amfani da su ko'ina a cikin buɗaɗɗen murhun murhu, induction tanderu, da dai sauransu. Metallurgical Converter da Rotary makera rufi na siminti masana'antu, da dai sauransu.
A cikin masana'antar kayyade, chromium tama ba zai yi hulɗa tare da wasu abubuwa a cikin narkakkar karfe a lokacin aiwatar da zuba jari, yana da low thermal fadada coefficient, yana da resistant zuwa karfe shigar azzakari cikin farfesa, kuma yana da mafi sanyi aiki fiye da zircon. Chrome tama don ganowa yana da tsauraran buƙatu akan abun da ke tattare da sinadarai da rarraba girman barbashi.
A cikin masana'antar sinadarai, mafi yawan amfani da chromium kai tsaye shine samar da maganin sodium dichromate (Na2Cr2O7·H2O), sannan kuma a shirya wasu mahadi na chromium don amfani da su a masana'antu kamar su pigments, textiles, electroplating, da kera fata, da kuma abubuwan da ke haifar da haɓakawa. .
Ƙaƙƙarfan ƙaƙƙarfan chromium takin foda shine wakili mai launi na halitta a cikin samar da gilashi, yumbu da fale-falen glazed. Lokacin da ake amfani da sodium dichromate don lalata fata, sunadaran (collagen) da carbohydrates a cikin fata na asali suna amsawa tare da sinadarai don samar da hadaddun barga, wanda ya zama tushen kayan fata. A cikin masana'antar masana'anta, ana amfani da sodium dichromate azaman mordant a cikin rini na masana'anta, wanda zai iya haɗa ƙwayoyin rini yadda ya kamata zuwa mahaɗan kwayoyin halitta; Hakanan za'a iya amfani dashi azaman oxidant wajen kera rini da tsaka-tsaki.
Ma'adinan Chromium
Akwai fiye da nau'ikan ma'adanai masu ɗauke da chromium fiye da 50 waɗanda aka gano a cikin yanayi, amma yawancinsu suna da ƙarancin abun ciki na chromium da rarrabawar warwatse, wanda ke da ƙarancin amfanin masana'antu. Waɗannan ma'adanai masu ɗauke da chromium suna cikin oxides, chromates da silicates, ban da ƴan hydroxides, iodates, nitrides da sulfides. Daga cikin su, chromium nitride da chromium sulfide ma'adanai ana samun su ne kawai a cikin meteorites.
A matsayin nau'in ma'adinai a cikin dangin chromium tama, chromite shine kawai muhimmin ma'adinan masana'antu na chromium. Tsarin sinadarai na ka'idar shine (MgFe) Cr2O4, wanda abun ciki na Cr2O3 ya kai 68%, kuma FeO yana da kashi 32%. A cikin abun da ke ciki na sinadarai, trivalent cation galibi Cr3+ ne, kuma galibi akwai Al3+, Fe3+ da Mg2+, Fe2+ isomorphic musanya. A cikin ainihin chromite da aka samar, yawancin Fe2+ ana maye gurbinsu da Mg2+, kuma Cr3+ ana maye gurbinsu da Al3+ da Fe3+ zuwa digiri daban-daban. Cikakken digiri na maye gurbin isomorphic tsakanin sassa daban-daban na chromite bai daidaita ba. Ƙungiyoyin daidaitawa na oda huɗu sun fi magnesium da baƙin ƙarfe, da cikakkiyar maye gurbin isomorphic tsakanin magnesium-iron. Bisa ga hanyar kashi huɗu, ana iya raba chromite zuwa ƙungiyoyi huɗu: magnesium chromite, iron-magnesium chromite, mafic-iron chromite da baƙin ƙarfe-chromite. Bugu da ƙari, chromite sau da yawa yana ƙunshe da ƙaramin adadin manganese, cakuda mai kama da titanium, vanadium da zinc. Tsarin chromite na nau'in spinel na al'ada ne.
4. Kyakkyawan ma'auni na chromium maida hankali
Dangane da hanyoyin sarrafawa daban-daban (ma'adinai da tama na halitta), sinadarin chromium don ƙarfe na ƙarfe ya kasu kashi biyu: mai da hankali (G) da tama (K). Dubi teburin da ke ƙasa.
Bukatun inganci don ma'adinin chromite don ƙarfe
Fasahar fa'ida ta Chrome ore
1) Sake zabe
A halin yanzu, rabuwar nauyi yana ɗaukar matsayi mai mahimmanci a cikin fa'idar chromium tama. Hanyar rabuwa da nauyi, wanda ke amfani da sako-sako da yadudduka a cikin matsakaiciyar ruwa a matsayin dabi'a ta asali, har yanzu ita ce babbar hanyar wadatar ma'adinan chromium a duniya. The nauyi rabuwa kayan aiki ne karkace chute da centrifugal concentrator, da aiki barbashi size kewayon ne in mun gwada da fadi. Gabaɗaya, bambance-bambancen yawa tsakanin ma'adanai na chromium da ma'adinan gangue ya fi 0.8g/cm3, kuma rabuwar nauyi na kowane girman girman 100um na iya zama mai gamsarwa. sakamakon. An jera manyan dunƙule (100 ~ 0.5mm) tama ko an riga an zaɓa ta hanyar fa'ida mai nauyi-matsakaici, wacce hanya ce ta fa'ida ta tattalin arziƙi.
2) Rabuwar Magnetic
Rabuwar Magnetic hanya ce ta fa'ida wacce ke gane rabuwar ma'adanai a cikin filin maganadisu mara daidaituwa dangane da bambancin maganadisu na ma'adinan da ke cikin ma'adinai. Chromite yana da raunin maganadisu mai rauni kuma ana iya raba shi ta hanyar zobe na tsaye high gradient Magnetic separators, rigar farantin maganadisu da sauran kayan aiki. Ƙayyadaddun ƙayyadaddun ƙayyadaddun halayen maganadisu na ma'adinan chromium da aka samar a wurare daban-daban masu samar da ma'adinan chromium a cikin duniya ba su da bambanci sosai, kuma sun yi kama da ƙayyadaddun ƙayyadaddun halayen halayen maganadisu na wolframite da wolframite da aka samar a yankuna daban-daban.
Akwai yanayi guda biyu a cikin yin amfani da rarrabuwar maganadisu don samun babban matakin chromium: ɗayan shine don cire ma'adanai masu ƙarfi na maganadisu (mafi yawan magnetite) a cikin tama a ƙarƙashin filin maganadisu mai rauni don ƙara ƙimar ferrochrome, ɗayan kuma shine don amfani da filin maganadisu mai ƙarfi. Rarraba ma'adanai na gangue da dawo da ma'adinan chromium (ma'adinan Magnetic rauni).
3) Zabin lantarki
Rabuwar wutar lantarki hanya ce ta raba ma'adinan chromium da silicate gangue ta hanyar amfani da kaddarorin lantarki na ma'adanai, kamar bambance-bambance a cikin aiki da kuma dielectric akai-akai.
4) Yin iyo
A cikin aiwatar da rabuwar nauyi, ana watsar da tama mai kyau (-100um) chromite sau da yawa azaman wutsiya, amma chromite na wannan girman har yanzu yana da ƙimar amfani mai yawa, don haka ana iya amfani da hanyar flotation don ƙarancin daraja mai kyau Granular chromite ore. an dawo dasu. Yawo na chromium tama tare da 20% ~ 40% Cr2O3 a cikin wutsiya da serpentine, olivine, rutile da calcium magnesium carbonate ma'adanai kamar gangue ma'adanai. Ana amfani da takin mai kyau zuwa 200μm, gilashin ruwa, phosphate, metaphosphate, fluorosilicate, da dai sauransu ana amfani da su don tarwatsawa da hana sludge, kuma ana amfani da acid fatty acid a matsayin mai tarawa. Watsawa da kuma danne gangue sludge yana da matukar muhimmanci ga tsarin iyo. Ƙarfe irin su baƙin ƙarfe da gubar na iya kunna chromite. Lokacin da ƙimar pH na slurry ta ƙasa da 6, chromite ba zai iya yin iyo ba. A takaice, flotation reagent amfani ne babba, da mayar da hankali sa ne m, da kuma dawo da kudi ne low. Ca2+ da Mg2+ da aka narkar da su daga ma'adanai na gangue suna rage zaɓin tsarin iyo.
5) Amfanin sinadarai
Hanyar sinadarai ita ce a bi da wasu ma'adinan chromite kai tsaye waɗanda ba za a iya raba su ta hanyar zahiri ba ko kuma farashin hanyar jiki ya yi yawa. Matsakaicin Cr/F na maida hankali da aka samar ta hanyar sinadarai ya fi na tsarin jiki na yau da kullun. Hanyoyin sinadarai sun haɗa da: zaɓaɓɓen leaching, rage oxidation, narkewar narkewa, sulfuric acid da chromic acid leaching, raguwa da sulfuric acid leaching, da sauransu. abubuwan da ke faruwa a fa'idar chromite a yau. Hanyoyin sinadarai na iya fitar da chromium kai tsaye daga ma'adanin kuma samar da chromium carbide da chromium oxide.
Lokacin aikawa: Afrilu-30-2021