1. Sodium dihydrogen phosphate txoj kev:
Neutralize cov dej qab zib tshauv nrog phosphoric acid ntawm 80-100 degree rau 2h, lub resulting sodium dihydrogen phosphate tov yog evaporated, concentrated, txias thiab crystallized kom tau sodium dihydrogen phosphate dihydrate, rhuab mus rau 110-230 degree kom tshem tawm 2 crystals Dej, txuas ntxiv kom sov kom tshem tawm cov qauv dej, thiab ntxiv cua sov mus rau 620 degree C kom lub cev qhuav dej, qhov ua rau sodium metaphosphate yaj, thiab polymerize rau hauv sodium hexametaphosphate. Tom qab ntawd tshem tawm, quenched ntawm 650 degree mus rau 60-80 degree, ntsiav tshuaj, thiab pulverized kom tau cov khoom tiav ntawm sodium hexametaphosphate.
2. Phosphorus pentoxide txoj kev:
Cov phosphorus pentoxide tau los ntawm kev kub hnyiab, oxidizing thiab txias daj phosphorus nyob rau hauv cov huab cua qhuav yog tov nrog dej qab zib tshauv nyob rau hauv ib qho kev faib ua feem (Na2O: P2O5=1-1.1). Cov hmoov sib xyaw yog ua kom sov tsis ncaj rau hauv graphite crucible kom lub cev qhuav dej thiab fuse, thiab qhov tshwm sim ntawm sodium hexametaphosphate yaj yog quenched, ntsiav tshuaj thiab pulverized kom tau txais cov khoom lag luam sodium hexametaphosphate.
3. Thaum tshav kub kub ntawm reagent sodium dihydrogen phosphate mus rau 700-900 degree kom yaj, thaum lub yaj yog tag nrho pob tshab thiab cov npuas sab hauv ploj, ces quench mus rau 60-80 degree kom tau ib tug flake iav khoom, uas yog sodium hexametaphosphate .
4. Lub reagent sodium dihydrogen phosphate yog rhuab mus rau 250 degree thiab quenched kom tau lub dimer ntawm sodium metaphosphate; rhuab mus rau 650 degree thiab quenched kom tau txais sodium hexametaphosphate.
5. Phosphoric anhydride txoj kev Tom qab cua sov thiab melting daj phosphorus, nws raug xa mus rau lub oxidative combustion rauv, thiab oxidative combustion cov tshuaj tiv thaiv yog nqa tawm nrog oxygen nyob rau hauv cov huab cua qhuav los tsim ib tug intermediate khoom, phosphoric anhydride. Tom qab sib tov phosphoric anhydride thiab dej qab zib tshauv, tom qab kub kub polymerization cov tshuaj tiv thaiv, quenching ntsiav tshuaj kom tau daim ntawv sodium hexametaphosphate; Tom qab crushing, hmoov sodium hexametaphosphate tuaj yeem tau.
6. Neutralization polymerization txoj kev:
Cov txheej txheem thev naus laus zis yog raws li hauv qab no: phosphoric acid thiab kua sodium hydroxide yog feem ntau dhau los ntawm lawv cov batch controllers (tswj cov tswv yim ntawm cov kua alkali thiab acid nyob rau hauv txhua batch, tsis siv neeg batching, thiab kev pub ceev ceev tuaj yeem hloov kho arbitrarily nyob rau hauv qhov ntau. 0 ~ 20L / min), raws li qhov xav tau Cov nyiaj ntxiv yog txuas ntxiv thiab raug ntxiv rau lub tank nruab nrab rau cov tshuaj tiv thaiv tsis zoo. Tom qab cov tshuaj tiv thaiv tiav lawm, tus nqi pH nce mus txog 4 txog 4.4, thiab disodium hydrogen phosphate tsim tawm, uas raug xa mus rau lub tank qib siab los ntawm lub twj tso kua mis neutralization.
Ib qho nyiaj ntawm disodium hydrogen phosphate yog tsis tu ncua thiab sib npaug xa mus rau lub tshuab ziab khaub ncaws kom ziab kom tau cov flake disodium hydrogen phosphate nrog cov ntsiab lus noo noo, thiab tom qab ntawd txuas ntxiv xa mus rau qhov kub siab ( 750-850 degree ) hauv qhov cub polymerization, yaj thiab polymerize disodium hydrogen phosphate; cov khoom molten ntws tawm tsis tu ncua los ntawm lub tshuab hluav taws xob polymerization, thiab quenched thiab nias rau hauv cov ntsiav tshuaj kom tau txais flaky sodium hexametaphosphate, uas yog crushed thiab soj ntsuam kom tau cov khoom.
