Caustic soda(NaOH) ndechimwe chezvakanyanya kukosha makemikari feed stocks, ine yakazara gore negore kugadzirwa kwe106t. NaOH inoshandiswa mune organic chemistry, mukugadzirwa kwealuminium, muindasitiri yemapepa, muindasitiri yekugadzira chikafu, mukugadzira detergents, etc. Caustic soda inobatanidzwa mukugadzirwa kweklorini, 97% iyo inotora. nzvimbo ne electrolysis ye sodium chloride.
Caustic soda ine hutsinye hunokanganisa pazvinhu zvakawanda zvesimbi, kunyanya pakupisa kwakanyanya uye kudzika. Izvo zvave zvichizivikanwa kwenguva yakareba, zvisinei, kuti nickel inoratidzira yakanakisa corrosion kuramba kune caustic soda pane zvese zvakadzika uye tembiricha, sekuratidzwa kweMufananidzo 1. Pamusoro pezvo, kunze kwekunyanya kudzika uye tembiricha, nickel haina kudzivirirwa kune caustic-induced stress-corrosion cracking. Iyo nickel yakajairwa mamakisi alloy 200 (EN 2.4066/UNS N02200) uye alloy 201 (EN 2.4068/UNS N02201) anoshandiswa pamatanho aya ekugadzira soda yekugadzira, iyo inoda yakanyanya kuomarara kuramba. Macathodes ari musero re electrolysis anoshandiswa mu membrane process anogadzirwa ne nickel sheets zvakare. Iwo mayunitsi ekudzika kwedoro anogadzirwa zvakare ne nickel. Ivo vanoshanda zvinoenderana neyakawanda-nhanho evaporation musimboti kazhinji neinodonha firimu evaporator. Muzvikamu izvi nickel inoshandiswa muchimiro chechubhu kana mashiti echubhu kune pre-evaporation heat exchangers, semashizha kana ma plates akavharidzirwa ezvikamu zve pre-evaporation, uye mumapombi ekutakura caustic soda solution. Zvichienderana nehuwandu hwekuyerera, iyo caustic soda crystals (supersaturated solution) inogona kukonzera kukukurwa kwehutu hwehutu hunopisa, izvo zvinoita kuti zvive zvakakosha kuzvitsiva mushure mekushanda kwemakore 2-5. Iyo inodonha-firimu evaporator process inoshandiswa kugadzira yakanyanya kudzika, anhydrous caustic soda. Mukudonha-firimu maitiro akagadzirwa naBertrams, munyu wakanyungudutswa patembiricha ingangoita 400 ° C unoshandiswa senzira yekudziya. Pano machubhu akagadzirwa ne low carbon nickel alloy 201 (EN 2.4068/UNS N02201) anofanirwa kushandiswa nekuti patembiricha yakakwira kupfuura 315 °C (600 °F) iyo yakakwira kabhoni yemhando yenickel giredhi alloy 200 (EN 2.4066/UNS N02200) ) inogona kutungamirira kumvura ye graphite pamiganhu yezviyo.
Nickel ndiyo inosarudzika yekuvaka ye caustic soda evaporator uko austenitic simbi haigone kushandiswa. Pamberi pezvisina kuchena zvakadai semakrorati kana sulfur compounds - kana kana simba rakakwirira richidiwa - chromium-ine zvinhu zvakadai sealloy 600 L (EN 2.4817 / UNS N06600) inoshandiswa mune dzimwe nguva. Zvakare zvinofadza zvikuru kune caustic nharaunda ndiyo yakakwira chromium ine alloy 33 (EN 1.4591/UNS R20033). Kana zvinhu izvi zvichizoshandiswa, zvinofanirwa kuve nechokwadi kuti mamiriro ekushanda haagone kukonzera kushushikana-kuparara kwekuputika.
Alloy 33 (EN 1.4591/UNS R20033) inorakidza kusakara kwekuora mu25 uye 50% NaOH kusvika pakuvira uye mu70% NaOH pa170 °C. Alloy iyi yakaratidzawo kuita kwakanakisa mukuyedza kwemumunda muchirimwa chakafumurwa necaustic soda kubva kudiaphragm process.39 Mufananidzo 21 unoratidza mimwe mibairo maererano nekuiswa kweiyo diaphragm caustic doro, iyo yakasvibiswa nekloridi nemakrorati. Kusvika kuhuwandu hwe45% NaOH, iyo midziyo alloy 33 (EN 1.4591 / UNS R20033) uye nickel alloy 201 (EN 2.4068 / UNS N2201) inoratidza kuenzaniswa kunoshamisa kupikisa. Nekuwedzera tembiricha uye concentration alloy 33 inova yakanyanya kusaga kupfuura nickel. Saka, semugumisiro weiyo yakakwira chromium content alloy 33 inoita seyakanakira kubata caustic mhinduro ine chlorides uye hypochlorite kubva diaphragm kana mercury cell process.
Nguva yekutumira: Zvita-21-2022