1. Neutralization txoj kev
Sib tov cov khoom caustic potassium rau hauv 30 feem pua aqueous tov, qhia meej thiab lim kom tshem tawm cov impurities, ntsuas, thiab ntxiv rau cov tshuaj tiv thaiv corrosion. Maj mam ntxiv qhov tsim nyog ntawm 50 feem pua phosphoric acid tov thaum nplawm, thiab ua cov tshuaj tiv thaiv nruab nrab ntawm 90 ~ 100 degree. Qhov kawg ntawm cov tshuaj tiv thaiv yog tswj ntawm pH 8.5 ~ 9.0 (siv phenolphthalein ua qhov taw qhia kom txog thaum nws tig liab). Thaum tshav kub kub mus rau 120 ~ 124 degree rau concentration, lim thiab tshem tawm cov tshuaj insoluble kom txog thaum cov tshuaj concentration mus txog qhov yuav tsum tau muaj. Qhov pom tseeb meej yog txias kom qis dua 20 degree kom precipitate crystals, ces centrifuged thiab me ntsis cua qhuav kom tau cov khoom tiav ntawm poov tshuaj hydrogen phosphate.
2. Potassium carbonate txoj kev
Hauv kev nplawm tas li, ntxiv cov tshuaj potassium carbonate rau 30 feem pua phosphoric acid tov rau cov tshuaj tiv thaiv, thiab qhov nruab nrab ntawm qhov kawg yog pH 8.5-9.0 (phenolphthalein qhia tsuas yog liab); Ua kom pom tseeb qhov kev daws teeb meem nruab nrab mus rau 120 ~ 124 degree, lim kom tshem tawm cov tshuaj insoluble, thiab tom qab ntawd txias kom qis dua 20 ~ C rau crystallization; Cov khoom yog sib cais thiab qhuav los ntawm centrifugation, thiab niam cawv raug xa mus rau cov txheej txheem neutralization rau rov siv dua.