ʻO ke ʻano o ka chromium
ʻO Chromium, hōʻailona element Cr, helu atomika 24, nuipaʻa atomika pili 51.996, no ka element metala hoʻololi o ka hui VIB o ka papa periodic o nā element kemika. ʻO ka metala Chromium he kristal cubic i waenakonu o ke kino, keʻokeʻo kālā, density 7.1g/cm³, heheʻe 1860℃, he paila 2680℃, ka hiki ke wela kikoʻī ma 25℃ 23.35J/(mol·K), wela o ka vaporization 342.1kJ/mol, conductivity thermal 91.3 W/(m·K) (0-100°C), resistivity (20°C) 13.2uΩ·cm, me nā waiwai mechanical maikaʻi.
ʻElima mau valences o ka chromium: +2, +3, +4, +5 a me +6. Ma lalo o nā kūlana o ka hana endogenous, ʻo ka chromium ma ke ʻano maʻamau he +3 valence. ʻO nā hui me ka chromium +trivalent ka mea paʻa loa. ʻO nā hui chromium +sixvalent, me nā paʻakai chromium, he mau waiwai oxidizing ikaika. Ua like nā radii ionic o Cr3+, AI3+ a me Fe3+, no laila hiki iā lākou ke loaʻa nā ʻano like like. Eia kekahi, ʻo nā mea hiki ke pani ʻia me ka chromium he manganese, magnesium, nickel, cobalt, zinc, a pēlā aku, no laila ua hoʻolaha nui ʻia ka chromium i nā mineral magnesium iron silicate a me nā mineral accessory.
Noi
ʻO Chromium kekahi o nā metala i hoʻohana nui ʻia i ka ʻoihana hou. Hoʻohana nui ʻia ia i ka hana ʻana i ke kila kila a me nā kila alloy like ʻole ma ke ʻano o nā ferroalloys (e like me ka ferrochrome). Loaʻa iā Chromium nā ʻano o ka paʻakikī, ke kūpaʻa i ke kapa, ke kūpaʻa i ka wela a me ke kūpaʻa i ka corrosion. Hoʻohana nui ʻia ka Chrome ore i ka metallurgy, nā mea refractory, ka ʻoihana kemika a me nā ʻoihana foundry.
I ka ʻoihana metallurgical, hoʻohana nui ʻia ka chromium ore e hoʻoheheʻe i ka ferrochrome a me ka chromium metallic. Hoʻohana ʻia ka Chromium ma ke ʻano he mea hoʻohui kila e hana i nā ʻano kila kūikawā ikaika kiʻekiʻe, kūpaʻa i ka corrosion, kūpaʻa i ke kapa, kūpaʻa i ka mahana kiʻekiʻe, a me ka oxidation-resistant, e like me ke kila kila kila, ke kila kūpaʻa waikawa, ke kila kūpaʻa wela, ke kila pōpō, ke kila puna, ke kila mea hana, a pēlā aku. Hiki i ka Chromium ke hoʻonui i nā waiwai mechanical a me ke kūpaʻa i ke kapa o ke kila. Hoʻohana nui ʻia ka chromium metal e hoʻoheheʻe i nā mea hui kūikawā me ka cobalt, nickel, tungsten a me nā mea ʻē aʻe. Hiki i ka Chrome plating a me ka chromizing ke hana i ke kila, ke keleawe, ka alumini a me nā metala ʻē aʻe e hana i kahi ʻili kūpaʻa i ka corrosion, he ʻālohilohi a nani hoʻi.
I loko o ka ʻoihana pale ahi, he mea pale ahi koʻikoʻi ka chromium ore i hoʻohana ʻia no ka hana ʻana i nā piliki chrome, nā piliki chrome magnesia, nā pale ahi holomua a me nā mea pale ahi kūikawā ʻē aʻe (chrome concrete). ʻO nā pale ahi e pili ana i ka chromium e komo pū me nā piliki me ka chrome ore a me ka magnesia, ka sintered magnesia-chrome clinker, nā piliki magnesia-chrome i hoʻoheheʻe ʻia, nā piliki magnesia-chrome i hoʻoheheʻe ʻia, i wili maikaʻi ʻia a laila i hoʻopaʻa ʻia. Hoʻohana nui ʻia lākou i nā umu kapuahi hāmama, nā umu induction, a pēlā aku. Hoʻololi metallurgical a me ka uhi umu rotary o ka ʻoihana sima, a pēlā aku.
I loko o ka ʻoihana hale hana hao, ʻaʻole e launa pū ka chromium ore me nā mea ʻē aʻe i loko o ke kila i hoʻoheheʻe ʻia i ka wā o ke kaʻina ninini ʻana, he haʻahaʻa kona coefficient hoʻonui wela, kū i ke komo ʻana o ka metala, a ʻoi aku ka maikaʻi o ka hana hoʻoluʻu ma mua o ka zircon. He mau koi koʻikoʻi ko ka chrome ore no ka hale hana hao e pili ana i ka hoʻohuihui kemika a me ka hoʻolaha ʻana o ka nui o nā ʻāpana.
I ka ʻoihana kemika, ʻo ka hoʻohana pololei loa ʻana o ka chromium ka hana ʻana i ka hopena sodium dichromate (Na2Cr2O7·H2O), a laila e hoʻomākaukau i nā hui chromium ʻē aʻe no ka hoʻohana ʻana i nā ʻoihana e like me nā pigments, textiles, electroplating, a me ka hana ʻili, a me nā catalysts.
ʻO ka pauka chromium ore i wili maikaʻi ʻia he mea hoʻoluʻu kūlohelohe ia i ka hana ʻana i ke aniani, nā keramika a me nā tile glazed. Ke hoʻohana ʻia ka sodium dichromate e hōʻino i ka ʻili, hana ka protein (collagen) a me nā carbohydrates i loko o ka ʻili kumu me nā mea kemika e hana i kahi paʻakikī paʻa, kahi e lilo ai i kumu o nā huahana ʻili. I loko o ka ʻoihana lole, hoʻohana ʻia ka sodium dichromate ma ke ʻano he mordant i ka hoʻoluʻu lole, hiki ke hoʻopili pono i nā molekala dye i nā hui organik; hiki ke hoʻohana ʻia ma ke ʻano he oxidant i ka hana ʻana i nā dyes a me nā intermediates.
Minerala chromium
Aia ma mua o 50 mau ʻano minelala i loaʻa ka chromium i ʻike ʻia ma ke ʻano, akā ʻo ka hapa nui o lākou he haʻahaʻa ka nui o ka chromium a me ka hoʻolaha hoʻopuehu ʻia, kahi waiwai hoʻohana haʻahaʻa o ka ʻoihana. No nā oxides, chromates a me silicates kēia mau minelala i loaʻa ka chromium, me kekahi mau hydroxides, iodates, nitrides a me sulfides. I waena o lākou, loaʻa wale nā minelala chromium nitride a me chromium sulfide i nā meteorites.
Ma ke ʻano he ʻano mineral i loko o ka ʻohana chromium ore, ʻo chromite wale nō ka mineral ʻoihana koʻikoʻi o chromium. ʻO ke ʻano kemika theoretical ʻo (MgFe)Cr2O4, kahi e helu ai ka nui o Cr2O3 no 68%, a ʻo FeO no 32%. I loko o kona ʻano kemika, ʻo ka cation trivalent ka mea nui ʻo Cr3+, a he pinepine nā Al3+, Fe3+ a me Mg2+, Fe2+ isomorphic substitutions. I loko o ka chromite i hana maoli ʻia, ua pani pinepine ʻia kahi hapa o Fe2+ e Mg2+, a ua pani ʻia ʻo Cr3+ e Al3+ a me Fe3+ i nā kekelē like ʻole. ʻAʻole kūlike ke kekelē piha o ka hoʻololi isomorphic ma waena o nā ʻāpana like ʻole o chromite. ʻO nā cations hoʻohui ʻehā-kauoha he magnesium a me ka hao nui, a ʻo ka hoʻololi isomorphic piha ma waena o ka magnesium-hao. Wahi a ke ʻano mahele ʻehā, hiki ke hoʻokaʻawale ʻia ka chromite i ʻehā mau hui liʻiliʻi: magnesium chromite, iron-magnesium chromite, mafic-iron chromite a me iron-chromite. Eia kekahi, loaʻa pinepine i ka chromite kahi liʻiliʻi o ka manganese, kahi hui like o ka titanium, vanadium a me ka zinc. ʻO ke ʻano o ka chromite he ʻano spinel maʻamau.
4. Kūlana maikaʻi o ka chromium concentrate
Wahi a nā ʻano hana like ʻole (mineralization a me ka ore kūlohelohe), ua māhele ʻia ka chromium ore no ka metallurgy i ʻelua ʻano: concentrate (G) a me ka puʻupuʻu ore (K). E nānā i ka papa ma lalo.
Nā koi maikaʻi no ka chromite ore no ka metallurgy
ʻenehana hoʻomaikaʻi ʻana i ka ʻaihao Chrome
1) Koho hou ʻana
I kēia manawa, ke noho nei ka hoʻokaʻawale ʻana o ke koʻikoʻi i kahi kūlana koʻikoʻi i ka hoʻomaikaʻi ʻana i ka chromium ore. ʻO ke ʻano hoʻokaʻawale koʻikoʻi, kahi e hoʻohana ai i ka papa wehe i loko o ka wai wai ma ke ʻano he ʻano kumu, ʻo ia nō ke ʻano nui no ka hoʻonui ʻana i ka chromium ore ma ka honua holoʻokoʻa. ʻO ka lako hoʻokaʻawale koʻikoʻi he chute spiral a me kahi centrifugal concentrator, a he ākea ka laulā o ka nui o nā ʻāpana hana. Ma keʻano laulā, ʻoi aku ka ʻokoʻa o ka density ma waena o nā minelala chromium a me nā minelala gangue ma mua o 0.8g/cm3, a hiki ke ʻoluʻolu ka hoʻokaʻawale koʻikoʻi o kekahi nui o nā ʻāpana ma mua o 100um. ka hopena o. Hoʻokaʻawale ʻia nā puʻupuʻu coarse (100 ~ 0.5mm) ore a i ʻole koho mua ʻia e ka beneficiation kaumaha-waena, he ʻano hoʻomaikaʻi waiwai loa ia.
2) Ka hoʻokaʻawale magnetic
ʻO ka hoʻokaʻawale magnetic kahi ʻano hana hoʻomaikaʻi e hoʻomaopopo ana i ka hoʻokaʻawale ʻana o nā minelala i loko o kahi kahua magnetic like ʻole e pili ana i ka ʻokoʻa magnetic o nā minelala i loko o ka ore. He nāwaliwali nā waiwai magnetic o Chromite a hiki ke hoʻokaʻawale ʻia e nā mea hoʻokaʻawale magnetic gradient kiʻekiʻe o ke apo vertical, nā mea hoʻokaʻawale magnetic wet plate a me nā lako ʻē aʻe. ʻAʻole ʻokoʻa loa nā coefficient susceptibility magnetic kikoʻī o nā minelala chromium i hana ʻia ma nā wahi hana chromium ore like ʻole ma ka honua, a ua like ia me nā coefficient susceptibility magnetic kikoʻī o wolframite a me wolframite i hana ʻia ma nā wahi like ʻole.
ʻElua mau kūlana i ka hoʻohana ʻana i ka hoʻokaʻawale magnetic e loaʻa ai ka chromium concentrate kiʻekiʻe: ʻo kekahi e wehe i nā minelala magnetic ikaika (ʻo ia hoʻi ka magnetite) i loko o ka ore ma lalo o kahi kahua magnetic nāwaliwali e hoʻonui i ka lakio o ka ferrochrome, a ʻo kekahi e hoʻohana i kahi kahua magnetic ikaika. Ka hoʻokaʻawale ʻana o nā minelala gangue a me ka hoʻōla ʻana o ka chromium ore (nā minelala magnetic nāwaliwali).
3) Koho uila
ʻO ka hoʻokaʻawale uila kahi ʻano hana e hoʻokaʻawale ai i ka chromium ore a me nā minelala gangue silicate ma ka hoʻohana ʻana i nā waiwai uila o nā minelala, e like me nā ʻokoʻa o ka conductivity a me ka dielectric constant.
4) Lana ʻana
I ke kaʻina hana o ka hoʻokaʻawale ʻana i ke kaumaha, hoʻolei pinepine ʻia ka ʻaila chromite maikaʻi (-100um) e like me nā tailings, akā ʻo ka chromite o kēia nui he waiwai hoʻohana kiʻekiʻe nō ia, no laila hiki ke hoʻohana ʻia ke ʻano flotation no ka ʻaila chromite Granular maikaʻi haʻahaʻa. ʻO ka flotation o ka ʻaila chromium me 20% ~40% Cr2O3 i loko o nā tailings a me nā minelala serpentine, olivine, rutile a me ka calcium magnesium carbonate e like me nā minelala gangue. Kuʻi maikaʻi ʻia ka ʻaila i 200μm, hoʻohana ʻia ke aniani wai, phosphate, metaphosphate, fluorosilicate, a pēlā aku e hoʻopuehu a kāohi i ka sludge, a hoʻohana ʻia ka waikawa momona unsaturated ma ke ʻano he mea hōʻiliʻili. He mea nui loa ka hoʻopuehu a me ka hoʻopau ʻana i ka sludge gangue i ke kaʻina hana flotation. Hiki i nā ion metala e like me ka hao a me ke kēpau ke hoʻāla i ka chromite. Ke emi ka waiwai pH o ka slurry ma lalo o 6, ʻaʻole e lana ka chromite. I ka pōkole, nui ka hoʻohana ʻana o ka reagent flotation, paʻa ʻole ka papa concentrate, a haʻahaʻa ka helu hoʻōla. ʻO Ca2+ a me Mg2+ i hoʻoheheʻe ʻia mai nā minelala gangue e hōʻemi i ke koho ʻana o ke kaʻina hana flotation.
5) Hoʻomaikaʻi kemika
ʻO ke ʻano kemika, ʻo ia ka mālama pololei ʻana i kekahi mau ʻāpana chromite i hiki ʻole ke hoʻokaʻawale ʻia e ke ʻano kino a i ʻole ke kiʻekiʻe o ke kumukūʻai o ke ʻano kino. ʻOi aku ka kiʻekiʻe o ka lakio Cr/Fe o ka concentrate i hana ʻia e ke ʻano kemika ma mua o ke ʻano kino maʻamau. ʻO nā ʻano kemika: ka leaching koho, ka hoʻemi ʻana o ka oxidation, ka hoʻokaʻawale ʻana i ka hoʻoheheʻe ʻana, ka leaching sulfuric acid a me ka chromic acid, ka hoʻemi ʻana a me ka leaching sulfuric acid, a pēlā aku. ʻO ka hui pū ʻana o nā ʻano kino-kemika a me ka mālama pololei ʻana i ka chromium ore e nā ʻano kemika kekahi o nā ʻano nui i ka hoʻomaikaʻi ʻana i ka chromite i kēia lā. Hiki i nā ʻano kemika ke unuhi pololei i ka chromium mai ka ʻāpana a hana i ka chromium carbide a me ka chromium oxide.
Ka manawa hoʻouna: ʻApelila-30-2021