Soda CausticʻO (NaOH) kekahi o nā waihona hānai kemika koʻikoʻi loa, me ka huina o ka hana makahiki he 106t. Hoʻohana ʻia ʻo NaOH i ke kemika organik, i ka hana ʻana o ka alumini, i ka ʻoihana pepa, i ka ʻoihana hana meaʻai, i ka hana ʻana i nā detergents, a pēlā aku. ʻO ka soda caustic kahi huahana like i ka hana ʻana o ka chlorine, 97% o ia mea e hana ʻia e ka electrolysis o ka sodium chloride.
He hopena koʻikoʻi ko ka soda caustic ma ka hapa nui o nā mea metala, ʻoi aku hoʻi i nā mahana kiʻekiʻe a me nā ʻano like ʻole. Eia naʻe, ua ʻike ʻia no ka manawa lōʻihi, he kūpaʻa maikaʻi loa ka nickel i ka soda caustic ma nā ʻano like ʻole a me nā mahana, e like me ka hōʻike ʻana o ke Kiʻi 1. Eia kekahi, koe wale nō nā ʻano like ʻole a me nā mahana kiʻekiʻe loa, ʻaʻole pale ka nickel i ka haki ʻana o ka stress-corrosion i hoʻoulu ʻia e ka caustic. No laila, hoʻohana ʻia ka nickel standard classes alloy 200 (EN 2.4066/UNS N02200) a me ka alloy 201 (EN 2.4068/UNS N02201) ma kēia mau pae o ka hana soda caustic, kahi e koi ai i ke kūpaʻa kiʻekiʻe loa. Hana ʻia nā cathodes i loko o ke kelepona electrolysis i hoʻohana ʻia i ke kaʻina hana membrane me nā pepa nickel. Hana ʻia nā ʻāpana downstream no ka hoʻopaʻa ʻana i ka waiʻona me ka nickel. Hana lākou e like me ke kumumanaʻo evaporation multi-stage me nā evaporators kiʻiʻoniʻoni hāʻule. Ma kēia mau ʻāpana, hoʻohana ʻia ka nickel ma ke ʻano o nā paipu a i ʻole nā pepa paipu no nā mea hoʻololi wela pre-evaporation, ma ke ʻano he mau pepa a i ʻole nā papa i uhi ʻia no nā ʻāpana pre-evaporation, a ma nā paipu no ka lawe ʻana i ka hopena soda caustic. Ma muli o ka nui o ke kahe ʻana, hiki i nā kristal soda caustic (ka hopena supersaturated) ke hana i ka ʻino ʻana ma nā paipu mea hoʻololi wela, kahi e pono ai ke hoʻololi iā lākou ma hope o kahi manawa hana o 2-5 mau makahiki. Hoʻohana ʻia ke kaʻina hana evaporator hāʻule-kiʻi e hana i ka soda caustic anhydrous i hoʻopaʻa nui ʻia. Ma ke kaʻina hana hāʻule-kiʻi i hoʻomohala ʻia e Bertrams, hoʻohana ʻia ka paʻakai heheʻe ma kahi mahana o 400 °C ma ke ʻano he mea hoʻomehana. Maanei, pono e hoʻohana ʻia nā paipu i hana ʻia me ka nickel alloy haʻahaʻa kalapona 201 (EN 2.4068/UNS N02201) no ka mea i nā mahana i ʻoi aku ma mua o 315 °C (600 °F) ʻo ke kiʻekiʻe o ka nui o ke kalapona o ka nickel grade alloy maʻamau 200 (EN 2.4066/UNS N02200) hiki ke alakaʻi i ka ua ʻana o ka graphite ma nā palena o ka palaoa.
ʻO ka nikala ka mea i makemake nui ʻia no ke kūkulu ʻana no nā evaporators soda caustic kahi hiki ʻole ke hoʻohana ʻia nā kila austenitic. I ke alo o nā mea haumia e like me nā chlorates a i ʻole nā hui sulfur - a i ʻole ke koi ʻia nā ikaika kiʻekiʻe - hoʻohana ʻia nā mea i loaʻa ka chromium e like me ka alloy 600 L (EN 2.4817/UNS N06600) i kekahi mau hihia. He mea hoihoi nui hoʻi no nā wahi caustic ʻo ia ka alloy chromium kiʻekiʻe 33 (EN 1.4591/UNS R20033). Inā e hoʻohana ʻia kēia mau mea, pono e hōʻoia ʻia ʻaʻole paha e hoʻoulu nā kūlana hana i ka haki ʻana o ka stress-corrosion.
Hōʻike ka Alloy 33 (EN 1.4591/UNS R20033) i ke kūpaʻa maikaʻi loa i ka palaho ma 25 a me 50% NaOH a hiki i ka paila a ma 70% NaOH ma 170 °C. Ua hōʻike pū kēia alloy i ka hana maikaʻi loa i nā hoʻokolohua kahua ma kahi mea kanu i hōʻike ʻia i ka soda caustic mai ke kaʻina hana diaphragm.39 Hōʻike ka Kiʻi 21 i kekahi mau hopena e pili ana i ka nui o kēia wai ʻona caustic diaphragm, i haumia ʻia me nā chlorides a me nā chlorates. A hiki i ka nui o 45% NaOH, hōʻike nā mea alloy 33 (EN 1.4591/UNS R20033) a me ka nickel alloy 201 (EN 2.4068/UNS N2201) i kahi kūpaʻa like. Me ka hoʻonui ʻana o ka mahana a me ka nui o ka alloy 33 e lilo i mea kūpaʻa ma mua o ka nickel. No laila, ma muli o kona ʻano chromium kiʻekiʻe, ʻike ʻia he mea maikaʻi ka alloy 33 e lawelawe i nā hopena caustic me nā chlorides a me ka hypochlorite mai ke kaʻina hana diaphragm a i ʻole ka mercury cell.
Ka manawa hoʻouna: Dec-21-2022