Isoda yeCaustic(NaOH) yenye yezona zinto zibalulekileyo zokutya kweekhemikhali, kunye nemveliso yonyaka epheleleyo ye-106t. I-NaOH isetyenziswe kwi-organic chemistry, ekuveliseni i-aluminium, kumashishini ephepha, kwi-industry processing industry, ekwenzeni i-detergents, njl. indawo nge-electrolysis ye-sodium chloride.
Isoda yeCaustic inefuthe elibukhali kwizinto ezininzi zesinyithi, ngakumbi kumaqondo obushushu aphezulu kunye noxinzelelo. Kuyaziwa ixesha elide, nangona kunjalo, ukuba i-nickel ibonisa ukuxhathisa kwe-corrosion kwi-caustic soda kuzo zonke izigxina kunye namaqondo okushisa, njengoko uMfanekiso 1 ubonisa. Ukongeza, ngaphandle koxinzelelo oluphezulu kakhulu kunye namaqondo obushushu, i-nickel ikhuselekile kwi-caustic-induced stress-corrosion cracking. I-nickel standard grade alloy 200 (EN 2.4066 / UNS N02200) kunye ne-alloy 201 (EN 2.4068 / UNS N02201) ngoko isetyenziswe kula manqanaba okuvelisa i-caustic soda, efuna ukuxhathisa okuphezulu kwe-corrosion. I-cathodes kwiseli ye-electrolysis esetyenziswe kwinkqubo ye-membrane yenziwe ngamashiti e-nickel ngokunjalo. Iiyunithi ezisezantsi zogxininiso lotywala zenziwe nge-nickel. Zisebenza ngokomgaqo wokuphuphuma komphunga wamanqanaba amaninzi ubukhulu becala kunye nezivuzi zefilimu eziwayo. Kwezi yunithi i-nickel isetyenziswa ngendlela yeetyhubhu okanye amaphepha etyhubhu kwi-pre-evaporation exchanger heat exchangers, njengamaphepha okanye iipleyiti ezinamaqabunga kwiiyunithi zangaphambili, kunye nakwimibhobho yokuthutha isisombululo se-caustic soda. Ngokuxhomekeke kwisantya sokuhamba, i-crystals ye-caustic soda (isisombululo se-supersaturated) inokubangela ukukhukuliseka kwimibhobho yokutshintsha ubushushu, okwenza kube yimfuneko ukuyibuyisela emva kwexesha lokusebenza le-2-5 iminyaka. Inkqubo ye-evaporator yefilimu ewayo isetyenziselwa ukuvelisa i-concentrate ephezulu, i-anhydrous caustic soda. Kwinkqubo yokuwa-ifilimu ephuhliswe nguBertrams, ityuwa enyibilikisiweyo kubushushu obumalunga ne-400 °C isetyenziswa njengendawo yokufudumeza. Apha iibhubhu ezenziwe nge-carbon nickel alloy 201 (EN 2.4068 / UNS N02201) kufuneka zisetyenziswe kuba kumaqondo okushisa aphezulu ngaphezu kwe-315 ° C (600 ° F) umxholo ophezulu wekhabhoni womgangatho we-nickel grade alloy 200 (EN 2.4066 / UNS N02200) ) kunokukhokelela kwimvula yegraphite kwimida yeenkozo.
I-nickel yeyona nto ikhethwayo yokwakha i-caustic soda evaporators apho iintsimbi ze-austenitic zingasetyenziswa. Xa kukho ukungcola okufana neklorati okanye i-sulfure compounds - okanye xa kufuneka amandla aphezulu - izinto ezine-chromium ezifana ne-alloy 600 L (EN 2.4817 / UNS N06600) zisetyenziswa kwezinye iimeko. Kwakhona umdla omkhulu weendawo ze-caustic yi-chromium ephezulu equlethe i-alloy 33 (EN 1.4591/UNS R20033). Ukuba ezi zixhobo ziza kusetyenziswa, kufuneka kuqinisekiswe ukuba iimeko zokusebenza azinakwenzeka ukuba zenze i-stress-corrosion cracking.
I-alloy 33 (EN 1.4591 / UNS R20033) ibonisa ukuxhathisa okugqwesileyo kwe-corrosion kwi-25 kunye ne-50% ye-NaOH ukuya kwindawo yokubilisa kunye ne-70% ye-NaOH kwi-170 °C. Le ngxubevange ibonise ukusebenza okugqwesileyo kwiimvavanyo zentsimi kwisityalo esivezwe kwi-caustic soda kwinkqubo ye-diaphragm.39 Umzobo wama-21 ubonisa iziphumo ezithile malunga nokuxinana kobu tywala be-diaphragm caustic, obungcoliswe yikloridi kunye neklorati. Ukufikelela kwi-concentration ye-45% ye-NaOH, i-alloy ye-33 (EN 1.4591 / UNS R20033) kunye ne-nickel alloy 201 (EN 2.4068 / UNS N2201) ibonisa ukuchasana okubalaseleyo. Ngokunyuka kwamaqondo obushushu kunye ne-concentration alloy 33 iba nokuxhathisa ngakumbi kunenickel. Ngaloo ndlela, ngenxa ye-alloy yayo ephezulu ye-chromium i-33 ibonakala inenzuzo yokusingatha izisombululo ze-caustic kunye ne-chlorides kunye ne-hypochlorite ukusuka kwi-diaphragm okanye inkqubo ye-mercury cell.
Ixesha lokuposa: Dec-21-2022