I-Caustic soda(I-NaOH) ingesinye sezitokwe zokudla zamakhemikhali ezibaluleke kakhulu, ezinomkhiqizo ophelele wonyaka we-106t.I-NaOH isetshenziswa ku-organic chemistry, ekukhiqizeni i-aluminium, embonini yamaphepha, embonini yokucubungula ukudla, ekwenzeni izinto zokuhlanza, njll. I-Caustic soda ingumkhiqizo ohlangene ekukhiqizeni i-chlorine, i-97% yayo ethatha. indawo nge-electrolysis ye-sodium chloride.
I-Caustic soda inomthelela onamandla ezintweni eziningi zensimbi, ikakhulukazi emazingeni okushisa aphezulu kanye nokugxila.Nokho, isikhathi eside kwaziwa ukuthi i-nickel ikhombisa ukumelana nokugqwala okuhle kakhulu kwe-caustic soda kukho konke ukugxila namazinga okushisa, njengoba uMdwebo 1 ubonisa.Ukwengeza, ngaphandle kokugxila okuphezulu kakhulu namazinga okushisa, i-nickel ivikelekile ekuqhekekeni kokucindezeleka okubangelwa yi-caustic-corrosion.I-nickel standard grade alloy 200 (EN 2.4066/UNS N02200) kanye nealloy 201 (EN 2.4068/UNS N02201) asetshenziswa kulezi zigaba zokukhiqizwa kwe-caustic soda, okudinga ukumelana nokugqwala okuphezulu kakhulu.Ama-cathode esitokisini se-electrolysis asetshenziswa kwinqubo ye-membrane enziwe ngamashidi we-nickel futhi.Amayunithi angaphansi komfula okugxilwa kuwo otshwaleni nawo enziwe nge-nickel.Asebenza ngokuhambisana nesimiso sokuhwamuka kwezigaba eziningi ikakhulukazi ngezihwamuko zefilimu eziwayo.Kula mayunithi i-nickel isetshenziswa ngendlela yamashubhu noma amashidi amashubhu okushintshanisa ukushisa kwangaphambi kokuhwamuka, njengamashidi noma amapuleti agqoke amayunithi angaphambi kokuhwamuka, nasemapayipini okuthutha isixazululo se-caustic soda.Ngokuya ngesilinganiso sokugeleza, amakristalu e-caustic soda (isixazululo se-supersaturated) angabangela ukuguguleka kwamashubhu okushintshanisa ukushisa, okwenza kube nesidingo sokuwashintsha ngemva kwesikhathi sokusebenza seminyaka engu-2-5.Inqubo ye-evaporator yefilimu ewayo isetshenziselwa ukukhiqiza i-soda e-anhydrous caustic egxile kakhulu.Enqubweni yefilimu ewayo eyakhiwe ngabakwa-Bertrams, usawoti oncibilikisiwe ezingeni lokushisa elingu-400 °C usetshenziswa njengendawo yokushisisa.Lapha amashubhu enziwe nge-low carbon nickel alloy 201 (EN 2.4068/UNS N02201) kufanele asetshenziswe ngoba emazingeni okushisa angaphezu kuka-315 °C (600 °F) okuqukethwe kwekhabhoni ephezulu ye-standard nickel grade alloy 200 (EN 2.4066/UNS N02200) ) kungaholela emvuleni ye-graphite emingceleni yokusanhlamvu.
I-Nickel iyinto ekhethwayo yokwakha izifudumezi zesoda ye-caustic lapho izinsimbi ze-austenitic zingakwazi ukusetshenziswa.Lapho kukhona ukungcola okufana nama-chlorate noma ama-sulfur compounds - noma lapho amandla aphezulu edingeka - izinto eziqukethe i-chromium njenge-alloy 600 L (EN 2.4817/UNS N06600) zisetshenziswa kwezinye izimo.Okunye okuthakaselayo kakhulu ezindaweni ze-caustic i-chromium ephezulu equkethe i-alloy 33 (EN 1.4591/UNS R20033).Uma lezi zinto zizosetshenziswa, kufanele kuqinisekiswe ukuthi izimo zokusebenza azikwazi ukubangela ukuqhekeka kwe-stress-corrosion.
I-alloy 33 (EN 1.4591/UNS R20033) ibonisa ukumelana nokugqwala okuhle kakhulu ku-25 kanye no-50% we-NaOH kuze kufike endaweni yokubilisa futhi ngo-70% NaOH ku-170 °C.Le alloy iphinde yabonisa ukusebenza okuhle kakhulu ekuhlolweni kwensimu esitshalweni esichayeke ku-caustic soda kusukela kunqubo ye-diaphragm.39 Umfanekiso 21 ubonisa imiphumela ethile mayelana nokugxiliswa kwalolu tshwala lwe-diaphragm caustic, olwalungcoliswe i-chloride ne-chlorate.Kufika ekuhlanganiseni okungu-45% we-NaOH, ingxubevange yezinto 33 (EN 1.4591/UNS R20033) ne-nickel alloy 201 (EN 2.4068/UNS N2201) ibonisa ukumelana okuvelele okuqhathanisekayo.Ngokukhuphuka kwezinga lokushisa kanye nengxube ye-concentration 33 iba ukumelana nangokwengeziwe kune-nickel.Ngakho-ke, ngenxa ye-alloy yayo ephezulu ye-chromium 33 ibonakala inenzuzo ukuphatha izixazululo ze-caustic nge-chlorides ne-hypochlorite kusuka ku-diaphragm noma inqubo yeseli ye-mercury.
Isikhathi sokuthumela: Dec-21-2022