Chromium metal inonyanyozivikanwa nokuda kwekushandiswa kwayo mu chromium plating (iyo inowanzonzi 'chrome'), asi iyo inoshandiswa zvikuru inoshandiswa muzvipfeko zvisina utachiona . Zvose zvinoshandiswa zvinobatsirwa nekuoma kwechromium, kushorwa kurora , uye kukwanisa kuputika nokuda kwechimiro chinopenya.
Properties
- Atomic Symbol: Cr
- Atomic Number: 24
- Atomic Misa: 51.996g / mol 1
- Element Category: Transition Metal
- Kuwedzera: 7.19g / cm 3 pa20 ° C
- Melting Point: 3465 ° F (1907 ° C)
- Dhaka rekubikira: 4840 ° F (2671 ° C)
- Kuoma kwaMos: 5.5
Mamiriro
Chromium yakaoma, imomo tsvuku iyo inofanirwa kukosha kwayo kusinganisa kurwisa. Chromium yakachena ine magnetic uye ine brittle, asi kana yakashandiswa inogona kushandiswa uye inoputika kusvika pakupenya, kupera kwemarara.
Chromium inowana zita rayo kubva ku khrōma, shoko rechiGiriki rinoreva ruvara, zvichienderana nekukwanisa kwayo kuburitsa zvakajeka, mavara akasiyana-siyana, zvakadai se chrome oxide.
Nhoroondo
Muna 1797, chiremba wemuFrench Nicolas-Louis Vauguelin akabudisa yakachena yakachena yechromium metal nekubata mambure (chromium-containing mineral) ne potassium carbonate uye achideredza chromic acid inokonzerwa nekasi mu graphite crucible.
Kunyange zvazvo chromium mishonga yakashandiswa mumatare uye pepuru kwezviuru zvemakore, yakanga isina kusvika zvakanaka pashure pokunge Vauguelin awanikwa kuti chromium inoshandisa mumashandisi esimbi yakatanga kukura.
Mukupera kwezana remakore rechi19 nekutanga kwezana remakore rechi20, metallurgists muEurope vakanga vachinyatsoedza nesimbi dzesimbi , vachiedza kubudisa mafiro akasimba uye akachengetedza.
Muna 1912, paaishanda paFirth Brown Laboratories muUnited States, metallurgist Harry Brearley aive nebasa rekuwana imwe yakagadziriswa simbi yemapuranga.
Akawedzera chromium, iyo yaizivikanwa kuva nenzvimbo yakanyunguduka yepamusoro, kumasikironi emasikisi, ichigadzira simbi yekutanga isina chinhu. Zvisinei, panenge panguva imwe chete, vamwe, kusanganisira Elwood Haynes muUnited States nevanjiniya kuKrupp muGermany, vakanga vachirikudzawo chromium ine michina yesimbi. Nekuvandudzika kwevira romugetsi wegetsi, guru-guru rekugadzirwa kwesimbi isina kusina kushandiswa kutevedza nguva pfupi pashure pacho.
Munguva imwecheteyo, kutsvakurudza kwaive kuri kuitwawo pa electro-plating meta, iyo yakabvumira zvigadzirwa zvisingadhuri, zvakadai sesimbi uye nickel , kutora kune kunze kwayo chromium kurwisana nekudzikisa uye kupisa, pamwe chete nemasikirwo ayo anoita. Ikutanga chrome zvinhu zvakaonekwa pamotokari uye maawa ekupedzisira ekupedzisira kuma1920.
Kugadzirwa
Industrial chromium michina inosanganisira chromium metal, ferrochrome, chromium makemikari uye mitsara inotora. Mumakore achangobva kupfuura, pane zvave zvichiitika kune hutano hwakakosha mukugadzirwa kwechromium materials. Izvi zvinoreva kuti mamwe makambani anobatanidzwa mumigodhi ye chromite ore arikugadzirisawo mu chromium metal, ferrochrome uye, pakupedzisira, simbi isina chinhu.
Muna 2010 nyika yose yakakonzerwa nekromite ore (FeCr 2 O 4 ), iyo inoshandiswa mumigodhi yakakonzerwa nekromium yakave mamiriyoni makumi maviri nemashanu.
Ferrochrome yakagadzirwa mamiriyoni manomwe ematani, apo chromium yekushambadzira kwesimbi yaiva mamiriyoni makumi mana. Ferrochromium inobudiswa chete kushandisa magetsi emagetsi, asi chromium metal inogona kugadzirwa kuburikidza ne electrolytic, silico-thermic uye aluminothermic nzira.
Munguva yekugadzirwa kwe ferrochrome, kupisa kwakagadzirwa nemagetsi emagetsi emagetsi, anosvika 5070 ° F (2800 ° C), inokonzera marasha uye coke kuderedza chromium ore kuburikidza nemagetsi anogadzirisa. Pane imwe nguva zvakakwana zvakagadzirwa muvira remoto, simbi yakanyungudutswa yakasvibiswa uye yakasimbiswa mumasvingo makuru asati apwanyika.
Chigadzirwa chechiedza chekukwirira kwechromium metal inokwana 95% yechromium metal yakabudiswa nhasi. Nhanho yekutanga mune izvi inoda kuti chromite ore yakagochwa ne soda uye lime mumhepo pa2000 ° F (1000 ° C), iyo inobatanidza chromate ye sodium ine chinyorwa.
Inogona kubviswa kure nemarara uye inoderedzwa uye inopera se chromic oxide (Cr 2 O 3 ).
Iko chromic oxide inobva yasanganiswa ne- aluminium yakasvibiswa ndokuisa muvhu rakakura. Barium peroxide uye magnesium powder zvino inopararira pamusanganiswa, uye the crucible yakakomberedzwa nejecha (iro rinoshanda sekusungira).
Iko kusanganiswa kunoputirwa, zvichiita kuti oksijeni ichibva kune chromic oxide ichiita nea aluminium kuti ikwanise kubudisa aluminium oxide uye, nokudaro, inosunungura chromium yakaumbwa nesimbi iyo 97-99% yakachena.
Maererano nehuwandu hweUnited States Geological Survey, vaparidzi vakawanda vemakromite ore muna 2009 vaiva South Africa (33%), India (20%), uye Kazakhstan (17%). Makambani makuru ekubudisa ferrochrome anosanganisira Xstrata , Eurasia Natural Resources Corp (Kazakhstan), Samancor (South Africa), uye Hernic Ferrochrome (South Africa).
Applications
Maererano neInternational Development Association yeChromium, yekromite ore yakabudiswa muna 2009, 95.2% yakashandiswa nemabhizimisi ezvematallurgic, 3.2% neyemagetsi ekutsvaga uye mutsara, uye 1,6% nevatengesi vemakemikari. Mishandisirwo yakakosha ye chromium iri mumashizha asingasviki, mashizha akashandiswa, uye zvisizvo zvisingaiti.
Sesivha isina kutaridzika kune mazana emapurisa ane 10% kusvika ku30% chromium (kuburikidza nechiyero) uye izvo hazvigadziri kana dziya nyore nyore sevashandi vanogara. Pakati pemasikironi emasikironi esirivha zana nemakumi mashanu akasiyana-siyana aripo, kunyange zvazvo anenge 10% chete aya ari kushandiswa nguva dzose.
Sources:
Sully, Arthur Henry, naEric A. Brandes. Chromium . London: Butterworths, 1954.
Mugwagwa, Arthur. & Alexander, WO 1944. Metare muBasa reMunhu . 11th Edition (1998).
I International Chromium Development Association (ICDA).
Kunobva: www.icdacr.com
Chromium Superalloy Trade Names
| Zita reMabhizimisi | Chromium Content (% Weight) |
|---|---|
| Hastelloy-X® | 22 |
| WI-52® | 21 |
| Waspaloy® | 20 |
| Nimonic® | 20 |
| IN-718® | 19 |
| Stainless Steels | 17-25 |
| Inconel® | 14-24 |
| Udimet-700® | 15 |