Molybdenum Concentrate Smelting: Roasting, Leaching thiab Hydrogen Reduction

Daim ntawv pub khoom noj thiab khoom siv

Thawj pub yog molybdenite, MoS2, uas muaj 59.94% molybdenum thiab 40.06% sulfur los ntawm stoichiometry. Lub smelter hloov qhov no mus rau ib qho ntawm peb cov khoom lag luam: kev molybdenum oxide rau steelmaking, ferromolybdenum rau tib lub lag luam uas tus tswv alloy nyiam, los yog ntshiab molybdenum trioxide thiab ammonium molybdate rau tshuaj thiab hlau hmoov siv. Ferromolybdenum yog pauv raws li ASTM A132 thiab, hauv kev lag luam thoob ntiaj teb, raws li ISO 5451, nrog cov qib kev lag luam nqa kwv yees li 60% txog 70% Mo.

Oxidative Roasting

Nyob rau hauv cov pa txoj kev molybdenite yog roasted nyob rau hauv huab cua rau molybdenum roasted xuab zeb, los ntawm uas molybdenum trioxide yog zoo tu qab tso los ntawm sublimation los yog los ntawm ib tug ntub txoj kev. Roasting cov concentrates hloov cov sulfide rau oxide thiab tsis lees txais cov sulfur li SO2 nyob rau hauv off- roj, uas yuav tsum tau ntes thiab kho. Nyob ntawm cov khoom siv thiab cov khoom siv ntxiv, cov txheej txheem yog ua raws li cov khoom siv hluav taws xob roasting, cov khoom siv hluav taws xob hluav taws xob roasting, ntau -chamber furnace roasting, fluidised txaj roasting lossis flash furnace roasting.

Kev xaiv roaster yog kev ua haujlwm ntawm qib siab thiab kev tuav roj. Cov hom hluav taws xob qub yog qhov yooj yim tab sis tsim kom muaj cov plua plav thiab fume ntau, muab cov molybdenum rov qab qis dua, thiab tso cai rau feem ntau ntawm cov rhenium hauv cov concentrate los qhia rau cov plua plav flue ntau dua li cov khoom sib sau. Rau qis -qib thiab complex concentrates cov kev no tsis tshua haum tshaj li fluidised txaj los yog flash roasting, qhov twg roj ntim ib tonne ntawm pub yog qis dua thiab rhenium rov qab los ntawm lub tshuab ntxhua khaub ncaws yog qhov ua tau.

Leaching, Purification thiab Reduction

Roasted calcine yog leached nrog ammonia, uas dissolves molybdenum li ammonium molybdate thiab tawm insoluble residue qab. Cov tshuaj yog purified, ces concentrated thiab crystallized los tsim ammonium molybdate crystals, los yog acidified rau precipitate ib molybdate uas cais los ntawm soluble impurities. Ob yam khoom yog calcined rau ntshiab molybdenum trioxide.

Molybdenum hlau yog ces tsim los ntawm hydrogen txo cov trioxide. Kev txo qis yog ua nyob rau hauv ob theem hauv kev coj ua, thawj zaug rau molybdenum dioxide thiab tom qab ntawd mus rau cov hmoov hlau, vim tias ib qho - theem txo yog qhov nyuaj rau kev tswj thiab ua rau cov hmoov ntxhib, tsis zoo sinterable hmoov. Txo qhov kub thiab txias taw tes ntawm hydrogen teeb cov hmoov particle loj, uas nyob rau hauv lem txiav txim siab sintering tus cwj pwm ntawm lub tom ntej compact. Cov khoom zeb ua los ntawm cov hmoov no raug txiav txim raws li ASTM B386 rau phaj, ntawv, sawb thiab ntawv ci thiab ASTM B387 rau bar, pas nrig thiab hlau.

Hydrometallurgical Alternatives

Nyob rau hauv txoj kev nitric acid lub autoclave converts MoS2 rau soluble molybdate siv cua los yog oxygen raws li oxidant. Cov txheej txheem siv cov oxidant pheej yig tab sis xav tau qhov kub thiab txias, cov khoom siv tshuaj tiv thaiv zoo thiab kev tswj nruj ntawm cov leaching tej yam kev mob, thiab nws muaj kev nyab xeeb kev nyab xeeb uas txwv tsis pub siv. Sodium hypochlorite leaching yog siv rau qib qis - cov khoom siv tailings; nws dissolves molybdenum yooj yim tab sis cov hypochlorite decomposes nrog oxygen evolution thiab kuj oxidises lwm cov hlau sulfides, uas nws hydroxides tuaj yeem co-precipitate molybdate thiab rov qab molybdenum rau qhov seem. Electro-oxidation leaching yog ib qho kev txhim kho ntawm txoj kev ntawd, nyob rau hauv uas slurried concentrate yog pub rau ib tug electrolytic cell uas muaj sodium chloride tov thiab anodically generated hypochlorite ua oxidation, muab siab leaching tus nqi, me me tej yam kev mob thiab yooj yim rau kev tswj ntawm cov tshuaj tiv thaiv kev taw qhia thiab tus nqi.

Emerging Routes thiab Recovery Economics

Ob txoj hauv kev ntxiv yog siv. Molybdenite concentrate tuaj yeem ua tiav yam tsis muaj oxidising ci los ntawm cov pa oxygen siab leaching ncaj qha rau cov ntshiab molybdenum trioxide. Tsawg-qib oxidised ore tuaj yeem leached nrog sulfuric acid, nrog molybdenum rov qab los ntawm kev daws los ntawm kev sib pauv ion lossis hnyav rho tawm. Nyob rau hauv ob qho tib si kev lag luam nyob ntawm seb los ntawm - cov khoom lag luam rov qab, tshwj xeeb tshaj yog rhenium, thiab seb lub xaib puas tuaj yeem tswj cov reagent thiab effluent loads uas txoj kev xaiv.

Cov lus nug nquag

Q:Dab tsi yog molybdenum cov ntsiab lus ntawm molybdenite?
A: MoS2 muaj 59.94% molybdenum thiab 40.06% sulfur los ntawm stoichiometry.

Q:Vim li cas molybdenum txo qis hauv ob theem?
A: Txo trioxide rau dioxide thiab tom qab ntawd rau hlau muab kev tswj zoo dua ntawm cov hmoov me me thiab sinterability dua li ib kauj ruam txo.

Q:Txoj kev roasting twg tsawg kawg yog tsim nyog rau qis -qib concentrate?
A: Cov laus ntau-chamber thiab cov hluav taws xob hluav taws xob txoj hauv kev, vim lawv cov plua plav thiab cov pa taws siab, txo qis rov qab thiab tsis zoo rhenium capture.

Q:Yuav ua li cas molybdenum rov qab los ntawm ammonia leach cawv?
A: Cov dej cawv yog purified thiab ces crystallized li ammonium molybdate los yog acidified rau precipitate molybdate, thiab cov khoom yog calcined rau molybdenum trioxide.

Q:Dab tsi specifications npog cov khoom tiav zeb?
A: ASTM B386 rau phaj, ntawv, sawb thiab ntawv ci; ASTM B387 rau bar, pas nrig thiab hlau; ferromolybdenum raws li ASTM A132.