Habka oksaydhaynta hawada waa habka oksaydhaynta oo ka faa'iidaysata ogsijiinta hawada ku jirta si ay u oksijisoceriumtetravalent iyadoo ay jiraan xaalado gaar ah. Habkani wuxuu caadi ahaan ku lug leeyahay duban fluorocarbon cerium ore, oxalates naadir ah, iyo carbonates hawada ku jira (oo loo yaqaan oxidation dubay) ama dubitaanka naadirka dhulka hydroxides (oxidation hawo qalalan) ama soo bandhigida hawo galay naadirka dhulka hydroxides slurry (oxidation hawo qoyan) ee oksaydhka.
1. Oxidation dubay
Dubidda cerium-ka fluorocarbon waxay ku urursan tahay hawada 500 ℃ ama dubitaanka Bayunebo naadirka dhulka waxa ay ku urursan tahay sodium carbonate hawada 600-700 ℃. Inta lagu jiro burburka macdanta dhifka ah ee dhulka, cerium ee macdanta ayaa oksaydhaysan ilaa tetravalent. Hababka loo kala saaroceriumWaxyaabaha la kariyey waxaa ka mid ah habka milixda ee labka ah ee sulfate, habka soo saarista dareeraha, iwm.
Marka lagu daro dubay oksaydhka eedhul dhif ahXooga saara, milixyada sida dhulku naadirka ah oxalate iyo karbohaydraytyada dhulka dhifka ah waxay maraan burbur ku dhex jira jawiga hawada, iyo cerium waxa la ogaysiiyaa CeO2. Si loo hubiyo u milmayn wanaagsan ee isku dhafka ah ee oksaydhka dhulka naadirka ah ee lagu helo duban, heerkulka dubantu waa inaanu noqon mid aad u sarreeya, badanaa inta u dhaxaysa 700 iyo 800 ℃. Oksaydhisku waxa lagu milmi karaa 1-1.5mol/L xal sulfuric acid ama 4-5mol/L nitric acid. Marka lagu daadiyo macdanta la dubay leh sulfuric acid iyo nitric acid, cerium inta badan waxay u gashaa xalka qaab tetravalent ah. Midda hore waxay ku lug leedahay helitaanka xal sulfate ah oo naadir ah oo ka kooban 50g/L REO qiyaastii 45 ℃, ka dibna soo saarida cerium dioxide iyadoo la adeegsanayo habka soo saarista P204; Tan dambe waxay ku lug leedahay diyaarinta xal naadir ah oo dhulka ah oo ka kooban REO oo ah 150-200g/L heerkul ah 80-85 ℃, ka dibna la isticmaalo soo saarista TBP si loo kala saaro cerium.
Marka oksaydhyada dhulka dhifka ah lagu milmo sulfuric acid ama nitric acid, CeO2 waa mid aan la milmi karin. Sidaa darteed, qadar yar oo hydrofluoric acid ah ayaa loo baahan yahay in lagu daro xalka sida kicinta marxaladda dambe ee kala dirida si loo hagaajiyo milanka CeO2.
2. oksidation hawada qalalan
Geli hydroxide-ka naadirka ah ee foornada qallajisa oo oksijiye ku geli xaaladaha hawo leh 100-120 ℃ 16-24 saacadood. Falcelinta oksaydhisku waa sida soo socota:
4Ce(OH)3+O2+2H2O=4Ce(OH)4
Heerka oksaydhka ee cerium wuxuu gaari karaa 97%. Haddii heerkulka oksaydhisku uu sii kordhayo ilaa 140 ℃, wakhtiga oksaydhka waa la soo gaabin karaa 4-6 saacadood, heerka oksaydhka ee cerium sidoo kale wuxuu gaari karaa 97% ~ 98%. Habka oksaydhka hawada qalalan ayaa soo saara xaddi badan oo boodh ah iyo xaalado shaqo oo liita, kuwaas oo inta badan hadda lagu isticmaalo shaybaarka.
3. oksidation hawada qoyan atmospheric
Isku qas hydroxide naadirka ah ee biyaha si aad u sameysid slurry, kontor fiirsashada REO ilaa 50-70g/L, ku dar NaOH si aad u kordhiso alkalinity slurry ilaa 0.15-0.30mol/L, iyo marka lagu kululeeyo 85 ℃, si toos ah u geli hawada oxidize dhammaan cerium trivalent ee slurry ilaa tetravalent cerium. Inta lagu jiro habka oksaydheynta, uumiga biyuhu waa mid aad u weyn, sidaas darteed xaddi cayiman oo biyo ah waa in lagu kabaa wakhti kasta si loo ilaaliyo feejignaanta xasilloon ee dhul naadir ah. Marka 40L of slurry waa oksaydhized qayb kasta, wakhtiga oksaydhisku waa 4-5 saacadood, iyo heerka oksaydhka ee cerium wuxuu gaari karaa 98%. Marka 8m3 ee slurry earth hydroxide naadir ah waa oksaydhized mar kasta, heerka socodka hawadu waa 8-12m3 / min, iyo wakhtiga oksaydhka ayaa la kordhiyay ilaa 15h, heerka oksaydhka ee cerium wuxuu gaari karaa 97% ~ 98%.
Tilmaamaha habka oksaydhka hawada qoyan ee atmospheric waa: heerka oksaydhka sare ee cerium, wax soo saarka weyn, xaaladaha shaqada wanaagsan, hawlgalka fudud, iyo habkan waxaa inta badan loo isticmaalaa in warshadaha si ay u soo saaraan cerium dioxide cayriin.
4. oksaydhaynta hawada qoyan oo la cadaadiyo
Cadaadiska caadiga ah, oksaydheynta hawadu waxay qaadataa wakhti dheer, dadkuna waxay soo gaabinayaan wakhtiga oksaydhka iyagoo isticmaalaya cadaadis. Kordhinta cadaadiska hawada, taas oo ah, korodhka cadaadiska qayb ka mid ah oksijiinta ee nidaamka, waxay ku habboon tahay kala dirida oksijiinta ee xalka iyo faafinta oksijiinta si ay u faafiso dusha sare ee qaybaha hydroxide dhulka dhifka ah, sidaas awgeed dardargelinta habka oksaydhka.
Isku qas hydroxide naadirka ah oo biyo ah ilaa 60g/L, ku hagaaji pH ilaa 13 oo leh sodium hydroxide, kor u qaad heerkulka ilaa 80 ℃, geli hawada ogsaydhka, xakamayn cadaadiska 0.4MPa, oo oxidize 1 saac. Heerka oksaydhka ee cerium wuxuu gaari karaa in ka badan 95%. Wax soo saarka dhabta ah, oxidation-ka alaabta ceeriin ee dhifka ah ee dhulka hydroxide waxaa lagu helaa beddelaad alkali iyada oo loo marayo roobabka milixda kakan ee sodium sulfate. Si loo gaabiyo geeddi-socodka, roobabka milixda adag ee sodium sulfate ee dhulka dhifka ah iyo xalalka alkaline ayaa lagu dari karaa haanta oksaydhka ee la cadaadiyo, iyadoo la ilaalinayo cadaadis iyo heerkul gaar ah. Hawo ama ogsijiin qani ah ayaa la soo gelin karaa si loogu beddelo dhulka dhifka ah ee milixda adag u beddela hydroxides naadirka ah ee dhulka, isla mar ahaantaana, Ce (OH) 3 ee ku jirta waxa loo rogi karaa Ce (OH) 4.
Xaaladaha la cadaadiyo, heerka beddelka alkali ee cusbada adag, heerka oksaydhka ee cerium, iyo heerka oksaydhka ee cerium ayaa dhamaantood la hagaajiyay. Ka dib 45 daqiiqo oo falcelin ah, heerka beddelka ee alkali cusbo labanlaab ah iyo heerka oksaydhka cerium ayaa gaadhay in ka badan 96%.
Waqtiga boostada: Meey-09-2023