Kev ua kom huv ntawm high-purity selenium (≥99.999%) muaj kev sib xyaw ua ke ntawm lub cev thiab tshuaj siv los tshem tawm cov impurities xws li Te, Pb, Fe, thiab As. Cov hauv qab no yog cov txheej txheem tseem ceeb thiab cov kev txwv:
1. Nqus Distillation
Txheej Txheem Flow:
1. Muab cov selenium crude (≥99.9%) rau hauv lub quartz crucible nyob rau hauv lub tshuab nqus tsev distillation cub.
2. Kub rau 300-500 ° C hauv qab lub tshuab nqus tsev (1-100 Pa) rau 60-180 feeb.
3. Selenium vapor condenses nyob rau hauv ob-theem condenser (theem qis nrog Pb/Cu hais, sab sauv rau selenium sau).
4. Sau selenium los ntawm lub condenser sab saud; 碲 (Te) thiab lwm yam siab-boiling impurities nyob rau hauv qis theem.
Parameters:
- Kub: 300-500 ° C
- Siab: 1-100 Pa
- Cov khoom siv condenser: Quartz lossis stainless hlau.
2. Tshuaj Purification + Nqus Distillation
Txheej Txheem Flow:
1. Oxidation Combustion: React crude selenium (99.9%) nrog O₂ ntawm 500 ° C los ua SeO₂ thiab TeO₂ gases.
2. Solvent Extraction: Dissolve SeO₂ hauv cov tshuaj ethanol-dej, lim tawm TeO₂ precipitate.
3. Kev txo qis: Siv hydrazine (N₂H₄) kom txo SeO₂ rau elemental selenium.
4. Sib sib zog nqus De-Te: Oxidize selenium dua rau SeO₄²⁻, ces rho Te siv cov kuab tshuaj extraction.
5. Thaum kawg Nqus Distillation: Purify selenium ntawm 300-500 ° C thiab 1-100 Pa kom ua tiav 6N (99.9999%) purity.
Parameters:
- Oxidation kub: 500 ° C
- Hydrazine ntau npaum: Ntau dhau los ua kom tiav kev txo qis.
3. Electrolytic Purification
Txheej Txheem Flow:
1. Siv cov khoom siv hluav taws xob (xws li selenous acid) nrog qhov ceev ntawm 5-10 A / dm².
2. Selenium deposits ntawm cathode, thaum selenium oxides volatilize ntawm lub anode.
Parameters:
Tam sim no ceev: 5-10 A / dm²
- Electrolyte: Selenous acid lossis selenate tov.
4. Cov kuab tshuaj Extraction
Txheej Txheem Flow:
1. Extract Se⁴⁺ los ntawm cov tshuaj siv TBP (tributyl phosphate) los yog TOA (trioctylamine) nyob rau hauv hydrochloric los yog sulfuric acid media.
2. Sawb thiab precipitate selenium, ces recrystallize.
Parameters:
- Extractant: TBP (HCl nruab nrab) lossis TOA (H₂SO₄ nruab nrab)
- Ntau theem: 2-3.
5. Zone Melting
Txheej Txheem Flow:
1. Rov ua dua ib cheeb tsam-melt selenium ingots kom tshem tawm cov kab impurities.
2. Haum rau kev ua tiav> 5N purity los ntawm high-purity pib cov ntaub ntawv.
Nco tseg: Yuav tsum muaj cov cuab yeej tshwj xeeb thiab muaj zog siv zog.
Daim duab qhia
Rau kev siv pom, xa mus rau cov duab hauv qab no los ntawm cov ntaub ntawv:
- Nqus Distillation Teeb: Schematic ntawm ob-theem condenser system.
- Se-Te Phase Diagram: Qhia txog kev sib tw sib cais vim yog cov ntsiab lus kub kub.
Cov ntaub ntawv
- Nqus distillation thiab tshuaj txoj kev:
- Electrolytic thiab hnyav extraction:
- Cov txheej txheem Advanced thiab cov nyom:
Lub sij hawm xa tuaj: Mar-21-2025