Phosphoric acidyog cov khoom siv tshuaj lom neeg yooj yim, dav siv hauv phosphate, chiv, khoom noj khoom haus additive, pub, ntxuav, electronics, nplaim taws thiab lwm yam lag luam. Pure phosphoric acid yog siv lead ua tsis muaj xim, nrog lub melting point ntawm 42.3 degree, high boiling point acid, thiab yooj yim soluble nyob rau hauv dej. Phosphoric acid yog ternary nruab nrab muaj zog acid, uas yog ionized kauj ruam ntawm kauj ruam, tsis yooj yim rau volatilize, decompose, thiab yuav luag tsis muaj oxidation. Nws muaj cov cuab yeej dav dav ntawm cov kua qaub. Hauv kev lag luam, cov concentrated sulfuric acid feem ntau yog siv los ua cov tshuaj calcium phosphate los tsim phosphoric acid. Cov calcium sulfate precipitate uas yog me ntsis soluble hauv dej yog lim tawm, thiab cov filtrate tau txais yog cov tshuaj phosphoric acid.
Phosphoric acid yog ib qho yooj yim chemical raw khoom, dav siv nyob rau hauv phosphate, chiv, zaub mov additive, pub, ntxuav, electronics, nplaim retardant thiab lwm yam lag luam. Pure phosphoric acid yog siv lead ua tsis muaj xim, nrog lub melting point ntawm 42.3 degree, high boiling point acid, thiab yooj yim soluble nyob rau hauv dej. Phosphoric acid yog ternary nruab nrab muaj zog acid, uas yog ionized kauj ruam ntawm kauj ruam, tsis yooj yim rau volatilize, decompose, thiab yuav luag tsis muaj oxidation. Nws muaj cov cuab yeej dav dav ntawm cov kua qaub. Hauv kev lag luam, cov concentrated sulfuric acid feem ntau yog siv los ua cov tshuaj calcium phosphate los tsim phosphoric acid. Cov calcium sulfate precipitate uas yog me ntsis soluble hauv dej yog lim tawm, thiab cov filtrate tau txais yog cov tshuaj phosphoric acid.
Ib txoj hauv kev tsim cov crystalline phosphoric acid los ntawm kev tsom phosphoric acid nrog phosphoric anhydride, cov kauj ruam yog raws li nram no:
Lub purity yog 99.95 feem pua thiab cov ntsiab lus arsenic yog 152 × 10-6 daj phosphorus yog tag nrho melted ntawm 7 0 degree . Raws li qhov piv ntawm 1kg daj phosphorus rau 6. daj phosphorus yog atomized sai heev thiab kub hnyiab heev.
P2O5 generated los ntawm combustion yog nkag mus rau sab saum toj ntawm lub hydration pej thuam, thiab lub pej thuam saum toj yog sprayed nrog deionized dej. Tom qab tau txais dilute acid, dilute acid yog txau. Dilute phosphoric acid yog sprayed tsis tu ncua los ntawm sab saum toj thiab overflows tusyees los ntawm lub puab phab ntsa. P2O5 yog absorbed ncig. Tom qab 1{{10}}0 feem pua H3PO4 tau txais, ib qho dej deionized raug muab ntxiv rau cov pej thuam saum toj kawg nkaus kom txau mus tas li, thiab 100 feem pua H3PO4 raug xa mus rau cov cuab yeej tshem tawm arsenic. HCl roj 0.5 feem pua ntawm tag nrho qhov hnyav ntawm phosphoric acid yog qhia, qhov kub thiab txias yog 130 degree, thiab lub sij hawm yog 120 feeb, txias rau 32 degree, xa mus rau crystallizer, ntxiv 0.4 feem pua phosphoric acid noob los ntawm qhov hnyav ntawm tag nrho cov phosphoric acid, do. , xa mus rau centrifugation rau kev sib cais, thiab tau txais crystalline phosphoric acid khoom. Nws Cheebtsam yog: P2O5 72.42 feem pua, SO42 - 25 × 10-6, Fe 8 × 10-6, As 0.5 × 10-6, Cl{27} } × 10-6,Pb 2 × 10-6.
Ib txheej txheem los tsim phosphoric acid los ntawm kev txo qis ntawm phosphate pob zeb nrog ob txheej txheej pellets yog raws li hauv qab no:
Tshuaj muaj pes tsawg leeg ntawm raw cov ntaub ntawv siv: phosphate pob zeb muaj 525 feem pua P2O5, silica muaj 298 feem pua SiO, thiab coke hmoov muaj 75 feem pua taag carbon. Raws li CaO/SiO2mol piv ntawm 0.4, cov ntsiab lus carbon ntawm peb cov ntaub ntawv raw yog 1.5 npaug ntawm qhov theoretical npaum li cas ntawm P2O5 hauv pob zeb phosphate. Tom qab sib tov thiab sib tsoo rau qhov loj me me ntawm - 200 mesh ＞ 80 feem pua, thiab tom qab ntawd sib tov 2 feem pua sodium humate binder, dej ntxiv los ua cov pellets. Cov dej ntsiab lus ntawm cov pellets yog 12 feem pua, thiab cov pellet loj yog 10 ~ 16 hli. Cov pellets saum toj no yog pelletized rau zaum ob thiab coated nrog ib txheej ntawm coke hmoov nrog - 200 mesh loj dua 80 feem pua. Lub coke hmoov hnyav yog 10 feem pua ntawm qhov hnyav pellet. Cov pellets nrog cov tshuaj lom neeg saum toj no thiab lub cev tshwj xeeb yog qhuav thiab sib sau ua ke ntawm 100 degree, thiab tom qab ntawd xa φ Tsis pub dhau 0.8 × Rau 10m radial ventilated rotary kiln, txo qhov kub ntawm cov pellets hauv lub kiln yog tswj rau 1300 degree, cov ntaub ntawv nyob twj ywm Nyob rau hauv lub kiln rau 1.5 teev, thiab volatilization tus nqi ntawm phosphorus nyob rau hauv pellets yog ntau tshaj 80 feem pua. Cov roj uas tsim tawm uas muaj P2O5 yog hydrated thiab absorbed los tsim phosphoric acid nrog ib tug concentration ntawm 485 feem pua H3PO.
Cov ntaub ntawv raw: Cov khoom siv raw ntawm phosphoric acid yog cov pob zeb phosphate (tsuas yog muaj cov calcium fluorophosphate Ca10F2 (PO4) 6) thiab inorganic acid feem ntau muaj sulfuric acid.
Txoj cai: 3H plus PO4 = H3PO4(Lub hauv paus ntsiab lus: muaj zog acid ua rau qaug zog acid)
Cov txheej txheem ntub dej: Hauv kev lag luam, cov concentrated sulfuric acid reacts nrog calcium phosphate thiab phosphate pob zeb los tsim phosphoric acid, thiab tom qab ntawd lim tawm calcium sulfate nag lossis daus uas me ntsis soluble hauv dej kom tau phosphoric acid tov. Los yog cia dawb phosphorus hnov mob nrog nitric acid kom tau txais cov tshuaj phosphoric acid ntshiab.
3P4 plus 20HNO3 plus 8H2O=12H3PO4 plus 20NO↑
Thermal method: dawb phosphorus hlawv nyob rau hauv cov huab cua los tsim phosphorus pentoxide, uas yog ces ua los ntawm hydration. Nco ntsoov tias dej kub yuav tsum tau siv, vim tias phosphorus pentoxide yuav hnov mob nrog dej txias los tsim cov tshuaj lom metaphosphoric acid.
Kev tsim cov polyphosphoric acid: kev tsim cov polyphosphoric acid feem ntau yog ua los ntawm lub cev qhuav dej ntawm orthophosphoric acid nyob rau hauv qhov tsim nyog.
Recrystallization txoj kev: Dissolve industrial phosphoric acid nyob rau hauv distilled dej, purify cov tshuaj, tshem tawm impurities xws li arsenic thiab hnyav hlau, thiab lim nws kom cov filtrate raws li cov zaub mov uas yuav tsum tau, ces mloog zoo kom npaj tiav edible phosphoric acid.
Siv:
Kev ua liaj ua teb: phosphoric acid yog cov khoom siv raw rau kev tsim cov phosphate chiv tseem ceeb (calcium superphosphate, potassium dihydrogen phosphate, thiab lwm yam), thiab tseem yog cov khoom siv raw rau kev tsim cov khoom noj khoom haus (calcium dihydrogen phosphate).
Kev lag luam: Phosphoric acid yog ib qho tseem ceeb ntawm cov khoom siv raw, thiab nws cov haujlwm tseem ceeb yog raws li hauv qab no:
Cov hlau nto yog kho kom tsim cov phosphate zaj duab xis tsis sib haum ntawm cov hlau nto los tiv thaiv cov hlau los ntawm corrosion.
Nws yog tov nrog nitric acid raws li ib tug tshuaj polishing neeg sawv cev los txhim kho lub smoothness ntawm hlau nto.
Phosphate ester, cov khoom siv raw rau kev tsim cov khoom ntxuav thiab tshuaj tua kab.
Cov khoom siv raw rau kev tsim cov phosphorus uas muaj cov nplaim hluav taws.