Barium Extraction txheej txheem

(1) Kev npaj ntawm barium oxide 

Qhov zoo tshaj plaws barite ore yuav tsum xub xaiv tes thiab ntab, thiab tom qab ntawd hlau thiab silicon raug tshem tawm kom tau txais cov ntsiab lus uas muaj ntau tshaj 96% barium sulfate. Cov hmoov ore uas muaj qhov me me ntawm tsawg dua 20 mesh yog tov nrog cov thee lossis roj av coke hmoov hauv qhov hnyav piv ntawm 4: 1, thiab ci ntawm 1100 ℃ hauv qhov cub reverberatory. Cov barium sulfate raug txo kom barium sulfide (feem ntau hu ua "dub tshauv"), thiab cov tshuaj barium sulfide tau leached nrog dej kub. Txhawm rau hloov barium sulfide rau hauv barium carbonate nag lossis daus, sodium carbonate lossis carbon dioxide yuav tsum tau ntxiv rau barium sulfide aqueous tov. Barium oxide tuaj yeem tau los ntawm kev sib xyaw barium carbonate nrog cov hmoov carbon thiab calcining nws saum toj 800 ℃. Nws yuav tsum raug sau tseg tias barium oxide yog oxidized los ua barium peroxide ntawm 500-700 ℃, thiab barium peroxide tuaj yeem decomposed los ua barium oxide ntawm 700-800 ℃. Yog li ntawd, txhawm rau zam kev tsim cov barium peroxide, cov khoom calcined yuav tsum tau txias los yog quenched nyob rau hauv kev tiv thaiv ntawm inert gas. 

(2) Aluminothermic txo txoj kev los tsim cov hlau barium 

Vim muaj cov khoom xyaw sib txawv, muaj ob qhov kev cuam tshuam ntawm txhuas txo barium oxide:

6BaO+2Al →3BaO•Al2O3+3Ba↑

Or: 4BaO+2Al →BaO•Al2O3+3Ba↑

Ntawm 1000-1200 ℃, ob qhov kev cuam tshuam no tsim cov barium tsawg heev, yog li xav tau lub tshuab nqus tsev twj tso kua mis kom txuas ntxiv cov pa barium los ntawm thaj chaw tshuaj tiv thaiv mus rau thaj tsam condensation kom cov tshuaj tiv thaiv tuaj yeem txuas mus rau sab xis. Cov seem tom qab cov tshuaj tiv thaiv yog tshuaj lom thiab yuav tsum tau kho ua ntej yuav muab pov tseg.

Kev npaj cov khoom sib xyaw barium 

(1) Txoj kev npaj ntawm barium carbonate 

① Carbonization txoj kev

Cov txheej txheem carbonization feem ntau suav nrog kev sib xyaw barite thiab thee hauv ib qho kev faib ua feem, crushing lawv mus rau hauv lub qhov cub rotary thiab calcining thiab txo lawv ntawm 1100-1200 ℃ kom tau barium sulfide yaj. Cov pa roj carbon dioxide tau nkag mus rau hauv cov tshuaj barium sulfide rau carbonization, thiab cov tshuaj tiv thaiv yog raws li nram no:

BaS + CO2 + H2O = BaCO3 + H2S

Cov tau txais barium carbonate slurry yog desulfurized, ntxuav thiab nqus lim, thiab ces qhuav thiab crushed ntawm 300 ℃ kom tau ib tug tiav barium carbonate khoom. Txoj kev no yog qhov yooj yim hauv cov txheej txheem thiab tus nqi qis, yog li nws tau txais los ntawm cov tuam ntxhab feem ntau.

② Ob chav decomposition txoj kev

Barium sulfide thiab ammonium carbonate tau dhau los ua cov tshuaj tiv thaiv ob npaug, thiab cov tshuaj tiv thaiv yog raws li nram no:

BaS+(NH4)2CO3=BaCO3+(NH4)2S

Los yog barium chloride reacts nrog potassium carbonate, thiab cov tshuaj tiv thaiv yog raws li nram no:

BaCl2+K2CO3=BaCO3+2KCl

Cov khoom tau txais los ntawm cov tshuaj tiv thaiv yog ces ntxuav, lim, qhuav, thiab lwm yam kom tau ib tug tiav lawm barium carbonate khoom.

③ Barium carbonate txoj kev

Barium carbonate hmoov yog reacted nrog ammonium ntsev los tsim cov ntsev barium soluble, thiab ammonium carbonate yog recycled. Soluble barium ntsev yog ntxiv rau ammonium carbonate rau precipitate refined barium carbonate, uas yog lim thiab qhuav kom cov khoom tiav. Tsis tas li ntawd, cov cawv niam uas tau txais tuaj yeem rov ua dua. Cov tshuaj tiv thaiv yog raws li nram no:

BaCO3 + 2HCl = BaCl2 + H2O + CO2

BaCl2+2NH4OH=Ba(OH)2+2NH4Cl

Ba(OH)2+CO2=BaCO3+H2O 

(2) Txoj kev npaj ntawm barium titanate 

① Txheej txheej txheej txheej

Barium titanate tuaj yeem tau txais los ntawm calcining barium carbonate thiab titanium dioxide, thiab lwm yam ntaub ntawv tuaj yeem doped rau hauv nws. Cov tshuaj tiv thaiv yog raws li nram no:

TiO2 + BaCO3 = BaTiO3 + CO2↑

② Coprecipitation method

Barium chloride thiab titanium tetrachloride yog tov thiab yaj nyob rau hauv sib npaug zos npaum li cas, rhuab mus rau 70 ° C, thiab ces oxalic acid yog ntxiv dropwise kom tau hydrated barium titanyl oxalate [BaTiO (C2O4) 2•4H2O] precipitate, uas yog ntxuav, qhuav, thiab ces tanium barium oxide. Cov tshuaj tiv thaiv yog raws li nram no:

BaCl2 + TiCl4 + 2H2C2O4 + 5H2O = BaTiO(C2O4)2•4H2O↓ + 6HCl

BaTiO(C2O4)2•4H2O = BaTiO3 + 2CO2↑ + 2CO↑ + 4H2O

Tom qab ntaus cov metatitanic acid, barium chloride tov yog ntxiv, thiab ces ammonium carbonate yog ntxiv nyob rau hauv stirring los tsim ib coprecipitate ntawm barium carbonate thiab metatitanic acid, uas yog calcined kom tau cov khoom. Cov tshuaj tiv thaiv yog raws li nram no:

BaCl2 + (NH4) 2CO3 = BaCO3 + 2NH4Cl

H2TiO3 + BaCO3 = BaTiO3 + CO2↑ + H2O 

(3) Kev npaj ntawm barium chloride 

Cov txheej txheem ntau lawm ntawm barium chloride feem ntau suav nrog hydrochloric acid txoj kev, barium carbonate txoj kev, calcium chloride txoj kev thiab magnesium chloride txoj kev raws li txoj kev sib txawv lossis cov khoom siv raw.

① Hydrochloric acid txoj kev. Thaum barium sulfide kho nrog hydrochloric acid, cov tshuaj tiv thaiv tseem ceeb yog:

BaS+2HCI=BaCl2+H2S↑+Q