Soda woopsa(NaOH) ndi imodzi mwa zakudya zofunika kwambiri za mankhwala, zomwe zimapangidwa pachaka ndi 106t. NaOH imagwiritsidwa ntchito mu organic chemistry, popanga aluminiyamu, mumakampani opanga mapepala, mumakampani opanga chakudya, popanga sopo, ndi zina zotero. Caustic soda ndi chinthu chogwirizana popanga chlorine, ndipo 97% ya izi zimachitika chifukwa cha electrolysis ya sodium chloride.
Soda ya Caustic imakhudza kwambiri zinthu zambiri zachitsulo, makamaka kutentha kwambiri. Komabe, kwakhala kudziwika kwa nthawi yayitali kuti nickel imalimbana bwino ndi dzimbiri ku soda ya caustic pa kutentha konse, monga momwe Chithunzi 1 chikusonyezera. Kuphatikiza apo, kupatula kutentha kwambiri, nickel imatetezedwa ku kusweka kwa dzimbiri komwe kumachitika chifukwa cha kupsinjika. Aloyi wodziwika bwino wa nickel 200 (EN 2.4066/UNS N02200) ndi aloyi 201 (EN 2.4068/UNS N02201) amagwiritsidwa ntchito pazigawo izi zopangira soda ya caustic, zomwe zimafuna kukana kwambiri dzimbiri. Ma cathode mu cell ya electrolysis omwe amagwiritsidwa ntchito mu nembanemba amapangidwanso ndi mapepala a nickel. Mayunitsi otsika kuti azitha kusakaniza mowa amapangidwanso ndi nickel. Amagwira ntchito motsatira mfundo ya evaporation ya magawo ambiri makamaka ndi ma evaporators ogwa. Mu mayunitsi awa, nickel imagwiritsidwa ntchito ngati machubu kapena mapepala a chubu a zosinthira kutentha zisanayambe kupsa, ngati mapepala kapena mbale zophimbidwa za mayunitsi asanayambe kupsa, komanso m'mapaipi onyamulira yankho la caustic soda. Kutengera ndi kuchuluka kwa madzi, makristalo a caustic soda (solution ya supersaturated) amatha kuyambitsa kukokoloka kwa machubu osinthira kutentha, zomwe zimapangitsa kuti zikhale zofunikira kuwasintha patatha zaka 2-5 akugwira ntchito. Njira yotulutsira mpweya pogwiritsa ntchito filimu yotsika imagwiritsidwa ntchito popanga soda yosungunuka kwambiri, yopanda madzi. Mu njira yotulutsira mpweya yomwe Bertrams amapanga, mchere wosungunuka pa kutentha kwa pafupifupi 400 °C umagwiritsidwa ntchito ngati chotenthetsera. Apa machubu opangidwa ndi nickel alloy 201 yotsika kaboni (EN 2.4068/UNS N02201) ayenera kugwiritsidwa ntchito chifukwa kutentha kopitilira 315 °C (600 °F) kuchuluka kwa kaboni mu nickel grade alloy 200 (EN 2.4066/UNS N02200) kungayambitse mvula ya graphite pamalire a tirigu.
Nickel ndi chinthu chomwe chimakondedwa kwambiri popanga ma evaporator a caustic soda komwe zitsulo za austenitic sizingagwiritsidwe ntchito. Pakakhala zinthu zosafunika monga ma chlorate kapena ma sulfure - kapena pakafunika mphamvu zambiri - zinthu zokhala ndi chromium monga alloy 600 L (EN 2.4817/UNS N06600) zimagwiritsidwa ntchito nthawi zina. Chinanso chomwe chimapangitsa chidwi kwambiri ndi malo owonongeka ndi alloy 33 yokhala ndi chromium yambiri (EN 1.4591/UNS R20033). Ngati zipangizozi zikugwiritsidwa ntchito, ziyenera kutsimikiziridwa kuti mikhalidwe yogwirira ntchitoyo singayambitse kusweka kwa stress-corrosion.
Aloyi 33 (EN 1.4591/UNS R20033) imawonetsa kukana dzimbiri bwino kwambiri mu 25 ndi 50% NaOH mpaka kutentha kotentha komanso mu 70% NaOH pa 170 °C. Aloyi iyi idawonetsanso magwiridwe antchito abwino kwambiri pamayeso akumunda mu chomera chomwe chidakhudzidwa ndi soda yochokera mu njira ya diaphragm.39 Chithunzi 21 chikuwonetsa zotsatira zina zokhudzana ndi kuchuluka kwa chakumwa choyambitsa diaphragm ichi, chomwe chidaipitsidwa ndi ma chloride ndi ma chlorate. Mpaka kuchuluka kwa 45% NaOH, aloyi 33 (EN 1.4591/UNS R20033) ndi aloyi wa nickel 201 (EN 2.4068/UNS N2201) zikuwonetsa kukana kofananako. Ndi kutentha kowonjezereka komanso kuchuluka kwa aloyi 33 imakhala yolimba kuposa nickel. Chifukwa chake, chifukwa cha kuchuluka kwake kwa chromium, aloyi 33 ikuwoneka kuti ndi yothandiza kuthana ndi mayankho a caustic ndi ma chloride ndi hypochlorite kuchokera mu njira ya diaphragm kapena mercury cell.
Nthawi yotumizira: Disembala-21-2022