Cov txheej txheem distillation thiab purification ntawm arsenic

Cov txheej txheem distillation thiab purification ntawm arsenic yog ib txoj kev uas siv qhov sib txawv ntawm qhov volatility ntawm arsenic thiab nws cov tshuaj los cais thiab purify, tshwj xeeb tshaj yog tsim rau kev tshem tawm sulfur, selenium, tellurium thiab lwm yam impurities hauv arsenic.Nov yog cov kauj ruam tseem ceeb thiab kev xav txog:

1.Kev kho ua ntej ntawm cov khoom siv raw

• Cov chaw ntawm arsenic nyoosfeem ntau yog cov khoom lag luam ntawm kev smelting ntawm cov zaub mov uas muaj arsenic (piv txwv li arsenite, realgar) lossis cov khib nyiab uas muaj arsenic rov ua dua tshiab.
• Kev ci oxidative(xaiv tau): Yog tias cov khoom siv raw yog arsenic sulfide (piv txwv li As₂S₃), nws yuav tsum tau ci ua ntej kom hloov mus ua cov As₂O₃ uas tsis yaj tau.

As 2S3+9O2 →As2O3+3SO2As2S3+9O2 →As2O3 + 3SO2

2.Chav distillation

• Cov khoom siv: Quartz los yog ceramic still (resistant corrosion, high temperature resistant), nruab nrog condenser tube thiab receiving bottle.
• Kev tiv thaiv inert: Muaj nitrogen los yog carbon dioxide los pab tiv thaiv kom tsis txhob muaj kev phom sij rau arsenic oxidation los yog kev tawg (cov pa arsenic yooj yim hlawv).

3.Cov txheej txheem distillation

• Kev tswj kub:
  • Kev hloov pauv ntawm arsenic: As₂O₃ sublimation ntawm 500-600 °C (arsenic ntshiab sublimation ntawm li 615 °C).
  • Kev sib cais ntawm cov khoom tsis huvCov khoom tsis huv uas tsis kub heev xws li sulfur thiab selenium feem ntau yog volatilized thiab tuaj yeem sib cais los ntawm segmented condensation.
• Kev sau cov dej nooCov pa roj arsenic sib sau ua ke ua cov As₂O₃ uas muaj cov khoom dawb huv lossis cov arsenic hauv thaj chaw sib sau ua ke (100-200°C).).

4.Kev ua tiav tom qab

• Kev txo qis(yog tias xav tau cov tshuaj arsenic): Kev txo qis ntawm As₂O₃ nrog cov pa roj carbon lossis hydrogen

As 2O3 + 3H2 → 2As + 3H2OAs 2 O3 + 3H2 → 2As + 3H2​O

• Kev lim dej hauv lub tshuab nqus tsev: ntxiv kev ntxuav ntawm cov elemental arsenic kom tshem tawm cov khoom tsis huv uas tsis muaj zog.

5.Cov kev ceev faj

• Kev tiv thaiv kev lomTag nrho cov txheej txheem yog kaw kev ua haujlwm, nruab nrog arsenic leakage nrhiav thiab kho cov khoom siv thaum muaj xwm txheej ceev.
• Kev kho roj ntawm tus Tsov tus twTom qab cov dej noo, cov pa roj yuav tsum tau nqus los ntawm cov kua lye (xws li NaOH) lossis cov pa roj carbon activated kom tsis txhob muaj As₂O₃.cov pa phem.
• Kev khaws cia hlau arsenic: khaws cia rau hauv ib qho chaw inert kom tiv thaiv oxidation lossis deliquescent.

6. Kev dawb huvKev txhim kho

• Kev sib xyaw ua ke ntau theem: Kev rov ua kom huv dua tuaj yeem txhim kho qhov huv kom ntau dua 99.99%.
• Thaj chaw yaj (yeem xaiv tau): Kev ua kom huv ntawm cov arsenic hauv cheeb tsam kom txo cov hlau tsis huv ntxiv.

Cov teb ntawm daim ntawv thov

Arsenic uas muaj purity siab siv rau hauv cov ntaub ntawv semiconductor (piv txwv li GaAssiv lead ua), cov khoom siv ntxiv rau cov hlau nplaum, lossis hauv kev tsim cov tsom iav tshwj xeeb. Pcov txheej txheem yuav tsum ua raws li cov cai ib puag ncig nruj kom ntseeg tau tias muaj kev nyab xeeb thiab pov tseg cov khib nyiab raws li txoj cai.