Selenium, raws li ib qho tseem ceeb ntawm cov khoom siv semiconductor thiab cov khoom siv raw, muaj nws cov kev ua tau zoo cuam tshuam los ntawm nws cov purity. Thaum lub tshuab nqus tsev distillation purification txheej txheem, oxygen impurities yog ib qho tseem ceeb ntawm selenium purity. Kab lus no muab cov ncauj lus kom ntxaws txog ntau txoj hauv kev thiab cov tswv yim los txo cov ntsiab lus oxygen thaum lub sij hawm ntxuav selenium ntawm lub tshuab nqus tsev distillation.

I. Txo cov ntsiab lus Oxygen hauv Raw Material Pretreatment Theem

1. Kev lim dej ua ntej ntawm cov khoom siv raw

Raw selenium feem ntau muaj ntau yam impurities, suav nrog oxides. Ua ntej nkag mus rau hauv lub tshuab nqus tsev distillation, tshuaj ntxuav cov txheej txheem yuav tsum tau ua haujlwm kom tshem tawm cov oxides saum npoo. Feem ntau siv cov tshuaj ntxuav tu muaj xws li:

• Dilute hydrochloric acid tov (5-10% concentration): Zoo yaj oxides xws li SeO₂
• Ethanol lossis acetone: Siv los tshem tawm cov kab mob organic
• Deionized dej: Ntau cov yaug kom tshem tawm cov kua qaub seem

Tom qab ntxuav, ziab yuav tsum tau ua nyob rau hauv ib qho inert gas (piv txwv li, Ar los yog N₂) cua kom tiv thaiv re-oxidation.

2. Kev kho ua ntej txo cov khoom siv raw

Kev kho txo ​​qis ntawm cov khoom siv raw ua ntej lub tshuab nqus tsev distillation tuaj yeem txo cov ntsiab lus oxygen:

• Kev txo qis hydrogen: Qhia cov purity siab hydrogen (purity ≥99.999%) ntawm 200-300 ° C kom txo SeO₂ rau elemental selenium
• Carbothermal txo: Sib tov selenium raw khoom nrog high-purity carbon hmoov thiab tshav kub mus rau 400-500 ° C nyob rau hauv lub tshuab nqus tsev los yog inert cua, inducing cov tshuaj tiv thaiv C + SeO₂ → Se + CO₂
• Kev txo cov sulfide: Gases xws li H₂S tuaj yeem txo selenium oxides ntawm qhov kub thiab txias.

II. Tsim thiab ua haujlwm zoo ntawm lub tshuab nqus tsev Distillation

1. Kev xaiv thiab teeb tsa ntawm lub tshuab nqus tsev

Lub tshuab nqus tsev siab yog qhov tseem ceeb rau kev txo cov ntsiab lus oxygen:

• Siv lub twj tso kua mis diffusion + txhua yam twj tso kua mis ua ke, nrog lub tshuab nqus tsev qhov kawg mus txog tsawg kawg 10⁻⁴ Pa
• Lub kaw lus yuav tsum tau nruab nrog lub ntsuas txias kom tiv thaiv rov qab-diffusion ntawm roj vapor
• Tag nrho cov kev sib txuas yuav tsum siv cov hlau nplaum kom tsis txhob muaj cov roj hmab ntsaws ruaj ruaj
• Lub kaw lus yuav tsum tau ua kom txaus ci-tawm degassing (200-250 ° C, 12-24 teev)

2. Precise Control ntawm Distillation Kub thiab Siab

Optimal txheej txheem parameter ua ke:

• Distillation kub: Tswj nyob rau hauv thaj tsam ntawm 220-280 ° C (hauv qab selenium lub boiling point ntawm 685 ° C)
• Lub kaw lus siab: Khaws ntawm 1-10 Pa
• Cua sov tus nqi: 5-10 ° C / min kom tsis txhob ua phem evaporation thiab entrainment
• Condensation tsam kub: Khaws ntawm 50-80 ° C kom ua tiav selenium condensation

3. Multi-Stage Distillation Technology

Multi-theem distillation tuaj yeem txo qis cov ntsiab lus oxygen:

• Thawj theem: Rough distillation tshem tawm feem ntau volatile impurities
• Qhov thib ob theem: tswj qhov kub thiab txias kom sau cov feem tseem ceeb
• Qhov thib peb theem: Tsawg-kub, qeeb distillation kom tau txais high-purity khoom
  Qhov sib txawv condensation kub tuaj yeem siv nruab nrab ntawm theem rau fractional condensation

III. Kev Pabcuam Txheej Txheem

1. Inert Gas Protection Technology

Txawm hais tias kev khiav hauj lwm hauv lub tshuab nqus tsev, qhov kev qhia tsim nyog ntawm high-purity inert gas pab txo cov ntsiab lus oxygen:

• Tom qab tshem tawm cov txheej txheem, sau nrog high-purity argon (purity ≥99.9995%) rau 1000 Pa
• Siv cov roj dynamic tiv thaiv, tsis tu ncua qhia me me ntawm argon (10-20 sccm)
• Txhim kho cov pa roj purifiers ntawm cov roj inlets kom tshem tawm cov pa seem thiab cov dej noo

2. Ntxiv cov Oxygen Scaveners

Ntxiv cov pa oxygen tsim nyog rau cov khoom siv raw tuaj yeem txo cov ntsiab lus oxygen:

• Magnesium hlau: Muaj zog affinity rau oxygen, tsim MgO
• Aluminium hmoov: tuaj yeem tshem tawm oxygen thiab sulfur ib txhij
• Cov hlau tsis tshua muaj hauv ntiaj teb: Xws li Y, La, thiab lwm yam, nrog rau kev tshem tawm cov pa oxygen zoo heev
  Tus nqi ntawm oxygen scavenger feem ntau yog 0.1-0.5 wt% ntawm cov khoom siv raw; Cov nyiaj ntau dhau tuaj yeem cuam tshuam rau selenium purity

3. Molten Filtration Technology

Lim molten selenium ua ntej distillation:

• Siv quartz lossis ceramic lim nrog qhov pore loj ntawm 1-5 μm
• Tswj qhov ntsuas kub ntawm 220-250 ° C
• Muaj peev xwm tshem tawm cov khoom oxide khoom
• Cov lim yuav tsum tau pre-degassed nyob rau hauv lub tshuab nqus tsev siab

IV. Tom qab kho thiab khaws cia

1. Cov khoom ntim thiab tuav

• Lub condenser collector yuav tsum tau tsim raws li ib tug detachable qauv rau yooj yim cov ntaub ntawv retrieval nyob rau hauv ib tug inert ib puag ncig
• Sau selenium ingots yuav tsum tau ntim rau hauv ib lub hnab looj tes argon
• Nto etching yuav ua tau yog tias tsim nyog los tshem tawm cov txheej txheem oxide

2. Kev tswj xyuas qhov chaw cia

• Cia ib puag ncig yuav tsum kom qhuav (dej point ≤-60 ° C)
• Siv ob-txheej txheej ntim ntim ntim nrog cov roj purity siab inert
• Pom zoo cia kub hauv qab 20 ° C
• Tsis txhob cuam tshuam lub teeb kom tiv thaiv photocatalytic oxidation cov tshuaj tiv thaiv

V. Kev Tswj Xyuas Zoo thiab Kev Xeem

1. Kev soj ntsuam hauv online

• Nruab cov roj seem seem (RGA) los saib xyuas cov pa oxygen ib feem ntawm lub sijhawm
• Siv cov pa oxygen sensors los tswj cov pa oxygen hauv cov pa tiv thaiv
• Ua haujlwm infrared spectroscopy los txheeb xyuas cov yam ntxwv ntawm qhov nqus ntawm Se-O daim ntawv cog lus

2. Kev soj ntsuam cov khoom tiav

• Siv inert gas fusion-infrared absorption txoj kev los txiav txim cov ntsiab lus oxygen
• Secondary ion mass spectrometry (SIMS) los soj ntsuam cov pa oxygen
• X-ray photoelectron spectroscopy (XPS) txhawm rau txheeb xyuas cov tshuaj lom neeg

Los ntawm cov kev ntsuas dav dav tau piav qhia saum toj no, cov ntsiab lus oxygen tuaj yeem tswj tau qis dua 1 ppm thaum lub tshuab nqus tsev distillation purification ntawm selenium, ua tau raws li qhov yuav tsum tau ua rau kev siv cov selenium siab. Hauv kev tsim khoom tiag tiag, cov txheej txheem yuav tsum tau ua kom zoo raws li cov khoom siv thiab cov khoom yuav tsum tau ua, thiab yuav tsum tsim kom muaj kev tswj xyuas nruj.