Cov khoom lag luam muaj roj carbon ferriachrome (LCFECR) yog cov khoom tseem ceeb tshaj plaws tsim los ntawm cov txheej txheem metallurgical uas tsom mus rau cov ntsiab lus carbon ntau thaum ua kom tiav chromium purity. Hauv qab no yog cov txheej txheem cej luam ntawm nws cov txheej txheem ntau lawm:
1. Cov Khoom Siv Raw
Chrome Ore: High-qib cov kua txob chromite (fecr₂o₄) lossis feeb rau ntau dua lossis sib npaug rau 40% cr₂o₃.
Txo cov neeg sawv cev: Cke, Anthracite, lossis silicon carbide (SIC) los txo cov chromium oxides.
Fluxes: Txiv qaub (cao), silica (silient), lossis dolomite kom tshem tawm impurities (piv txwv li, sio₂, al₂o₃).
Cov Khoom Siv Carbon: Graphite electrodes hauv hluav taws xob arc rauv (EAF).
2. Cov txheej txheem ntau lawm
A. Fais fab hluav taws xob Rauv (EAF)
Kauj ruam 1: SMELTING:
Chrome ore, txo cov neeg sawv cev, thiab cov flux yog sib xyaw thiab them rau hauv EAF.
Siab tam sim no (3-6 ka) arcs tsim kom muaj qhov kub1,600 degree, Txo cr₂o₃ rau nws yog xim hlau chromium:
CR2 O3 {{{+3 C → 2 {{}} co ↑
Cov ntsiab lus carbon yog tswj tau los ntawm kev hloov kho tus neeg sawv cev kom txo cov neeg sawv cev-rau-ore piv.
Kauj ruam 2: Kho kom zoo:
Cov pa pa ..: Txhaj tshuaj oxygen mus rau hauv cov hlau molten rau oxidize restidual thiab impurities (piv txwv li, p):
C + O2 → CO /00 ↑
Nqus Plawv: Tshem tawm cov roj (piv txwv li, hydrogen, oxygen) los txhim kho kev coj dawb huv.
B. Aluminotması txheej txheem
Siv rau me-teev ntau lawm:
Kev sib xyaw ntawm cov chromium oxide, hmoov txhuas, thiab hlau oxide yog zes.
Txhuas txo cov roj chromium oxide exothermically:
CR2 O3 {{{+2 al → 2cr + Al2 O3 + Tshav Kub
Cov khoom yog tom qab ntawd crushed thiab tshuaj ntsuam rau hauv LCFECR.
C. Ntshav smelting
Advanced qauv siv Plasma Manau:
High-Zog Plasma melts chromite ee thiab txo nws cov pa roj carbon.
Pab kom meej kev tswj cov ntsiab lus carbon (tsawg dua los yog sib npaug rau 0. 1%) thiab minimizes impurities.
3. Cov Txheej Txheem Tseem Ceeb
Qho so: Tswj hwm ntawm1,500-1,600 degreeKom ntseeg tau tias muaj txiaj ntsig zoo.
Tshuaj Tswj Xyuas Kev Tswj Xyuas:
Txwv cov khoom siv cov roj carbon (piv txwv li, siv cov pa roj carbon coke).
Post-sm kev txiav txim siab ntawm cov pa tshuab pa lossis nqus plua plav.
Kev Tswj Xyuas Slag:
Kho cov npoo sib xyaw ua ke (theem pib {{0}}}}} ≈} ≈ 1.5-2.0) kom ntxiab impurities.
4. Cov khoom lag luam thiab cov khib nyiab tswj
Npleem: Muaj siio, al₂o₃, thiab siv tsis tau fluxes; siv hauv Caent ntau lawm.
Hmoov: Captured ntawm lub hnab ntim lossis hluav taws xob thev naus laus zis; Muaj chromium (III) oxide, rov ua dua li feedsock.
Pa ncho: So thiab partmentulations yog txhuam los yog lim kom tau raws li cov qauv ib puag ncig (piv txwv li, EU bef, EPA).
5. Kev Tswj Xyuas Zoo
Tshuaj Lom: Spectrometry (icp-oes) los xyuas cov teeb meem loj dua lossis sib npaug rau 6 0}}}} dua lossis sib npaug nrog 0.1%.
Kev Ntsuas Lub Cev: Txheeb xyuas qhov ntom ntom, melting point, thiab cov khoom sib nqus.
Qauv Ua Haujlwm: ASTM A / ASME A29, EN 1913, lossis GB / T 4009.
