Isoda ebabayo(NaOH) ingenye yezitoko zokudla kwamakhemikhali ezibaluleke kakhulu, enomkhiqizo waminyaka yonke ongu-106t. I-NaOH isetshenziswa kumakhemikhali e-organic, ekukhiqizweni kwe-aluminium, embonini yephepha, embonini yokucubungula ukudla, ekukhiqizweni kwezinsipho, njll. I-Caustic soda ingumkhiqizo ohlangene ekukhiqizweni kwe-chlorine, okungu-97% okwenzeka nge-electrolysis ye-sodium chloride.
I-Caustic soda inomthelela omkhulu ezintweni eziningi zensimbi, ikakhulukazi emazingeni okushisa aphezulu kanye nokugxila. Nokho, sekuyisikhathi eside kwaziwa ukuthi i-nickel ibonisa ukumelana okuhle kakhulu nokugqwala ku-caustic soda kuzo zonke izilinganiso kanye nokushisa, njengoba uMfanekiso 1 ubonisa. Ngaphezu kwalokho, ngaphandle kwamazinga aphezulu kakhulu kanye nokushisa, i-nickel ayithinteki ekuqhekekeni okubangelwa ukucindezeleka nokugqwala okubangelwa ukucindezeleka. I-alloy ejwayelekile yama-nickel grades 200 (EN 2.4066/UNS N02200) kanye ne-alloy 201 (EN 2.4068/UNS N02201) ngakho-ke isetshenziswa kulezi zigaba zokukhiqizwa kwe-caustic soda, okudinga ukumelana okuphezulu kakhulu nokugqwala. Ama-cathode esitokisini se-electrolysis asetshenziswa enkambisweni ye-membrane nawo enziwe ngamashidi e-nickel. Amayunithi aphansi okugxila utshwala nawo enziwe nge-nickel. Asebenza ngokwesimiso sokuhwamuka kwezigaba eziningi ikakhulukazi ngama-evaporator efilimu ewayo. Kula mayunithi i-nickel isetshenziswa ngendlela yamapayipi noma amashidi eshubhu ezinto zokushintshanisa ukushisa ngaphambi kokuhwamuka, njengamashidi noma amapuleti amboziwe amayunithi angaphambi kokuhwamuka, kanye nasemapayipini okuthutha isisombululo se-caustic soda. Kuye ngesilinganiso sokugeleza, amakristalu e-caustic soda (isixazululo esigcwalisiwe kakhulu) angabangela ukuguguleka kwamashubhu e-heat exchanger, okwenza kudingeke ukuthi ashintshwe ngemva kwesikhathi sokusebenza seminyaka engu-2-5. Inqubo ye-falling-film evaporator isetshenziselwa ukukhiqiza i-caustic soda egxilile kakhulu, engenamanzi. Enqubweni ye-falling-film eyathuthukiswa yi-Bertrams, usawoti oncibilikisiwe ekushiseni okungaba ngu-400 °C usetshenziswa njengendawo yokushisa. Lapha amashubhu enziwe nge-alloy ye-nickel ephansi yekhabhoni engu-201 (EN 2.4068/UNS N02201) kufanele asetshenziswe ngoba emazingeni okushisa aphezulu kunangu-315 °C (600 °F) okuqukethwe okuphezulu kwekhabhoni kwe-alloy ye-nickel grade ejwayelekile engu-200 (EN 2.4066/UNS N02200) kungaholela ekuweni kwe-graphite emingceleni yokusanhlamvu.
I-Nickel iyinto ekhethwayo yokwakha ama-evaporator e-caustic soda lapho izinsimbi ze-austenitic zingasetshenziswa khona. Lapho kukhona ukungcola okufana nama-chlorate noma ama-sulfur compounds - noma lapho kudingeka amandla aphezulu - kusetshenziswa izinto eziqukethe i-chromium njenge-alloy 600 L (EN 2.4817/UNS N06600) kwezinye izimo. Okunye okuthakazelisa kakhulu ezindaweni ezibangela i-alloy yi-alloy 33 equkethe i-chromium ephezulu (EN 1.4591/UNS R20033). Uma lezi zinto zizosetshenziswa, kumele kuqinisekiswe ukuthi izimo zokusebenza cishe azibangeli ukuqhekeka kokucindezeleka nokugqwala.
I-Alloy 33 (EN 1.4591/UNS R20033) ibonisa ukumelana okuhle kakhulu kokugqwala ku-25 no-50% NaOH kuze kufike lapho ibila khona kanye naku-70% NaOH ku-170 °C. Le alloy iphinde yabonisa ukusebenza okuhle kakhulu ekuhlolweni kwasensimini esitshalweni esivezwe ku-caustic soda evela enqubweni ye-diaphragm.39 Isithombe 21 sibonisa eminye imiphumela mayelana nokuhlushwa kwale diaphragm caustic liquor, eyayingcoliswe ama-chloride nama-chlorate. Kuze kufike ekuhlushweni okungu-45% NaOH, i-alloy yezinto zokwakha 33 (EN 1.4591/UNS R20033) kanye ne-nickel alloy 201 (EN 2.4068/UNS N2201) zibonisa ukumelana okuphawulekayo okufanayo. Ngokushisa okwandayo kanye nokuhlushwa i-alloy 33 iba ukumelana kakhulu kune-nickel. Ngakho-ke, ngenxa yokuqukethwe kwayo okuphezulu kwe-chromium i-alloy 33 ibonakala inenzuzo ukuphatha izixazululo ze-caustic ngama-chloride ne-hypochlorite evela enqubweni ye-diaphragm noma yeseli le-mercury.
Isikhathi sokuthunyelwe: Disemba-21-2022