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Wannan binciken ya binciki tasirin ƙazanta na NH4+ da rabon iri akan tsarin girma da aikin nickel sulfate hexahydrate a ƙarƙashin crystallization mai sanyi mara tsayawa, kuma ya binciki tasirin ƙazanta na NH4+ akan tsarin girma, halayen zafi, da ƙungiyoyin aiki na nickel sulfate hexahydrate. A ƙarancin yawan ƙazanta, ions na Ni2+ da NH4+ suna fafatawa da SO42− don ɗaurewa, wanda ke haifar da raguwar yawan lu'ulu'u da ƙimar girma da ƙaruwar kuzarin kunna lu'ulu'u. A yawan yawan ƙazanta, an haɗa ions na NH4+ cikin tsarin lu'ulu'u don samar da gishiri mai rikitarwa (NH4)2Ni(SO4)2 6H2O. Samuwar gishiri mai rikitarwa yana haifar da ƙaruwar yawan lu'ulu'u da ƙimar girma da raguwar kuzarin kunna lu'ulu'u. Kasancewar yawan ions na NH4+ mai girma da ƙasa yana haifar da karkacewar lattice, kuma lu'ulu'u suna da kwanciyar hankali a yanayin zafi har zuwa 80 °C. Bugu da ƙari, tasirin ƙazanta na NH4+ akan tsarin girma na lu'ulu'u ya fi na rabon iri. Idan yawan dattin ya yi ƙasa, dattin yana da sauƙin haɗawa da lu'ulu'u; idan yawan dattin ya yi yawa, dattin yana da sauƙin haɗawa cikin lu'ulu'u. Rabon iri na iya ƙara yawan lu'ulu'u sosai kuma ya ɗan inganta tsarkin lu'ulu'u.
Yanzu haka sinadarin nickel sulfate hexahydrate (NiSO4 6H2O) muhimmin abu ne da ake amfani da shi a masana'antu daban-daban, ciki har da kera batura, samar da wutar lantarki, abubuwan kara kuzari, har ma da samar da abinci, mai, da turare. 1,2,3 Muhimmancinsa yana karuwa tare da saurin bunkasa motocin lantarki, wadanda suka dogara sosai kan batirin lithium-ion (LiB) na nickel. Ana sa ran amfani da sinadarin nickel mai yawan gaske kamar NCM 811 zai mamaye nan da shekarar 2030, wanda hakan zai kara yawan bukatar sinadarin nickel sulfate hexahydrate. Duk da haka, saboda karancin albarkatu, samarwa ba zai iya biyan bukatar da ke karuwa ba, wanda hakan ke haifar da gibi tsakanin wadata da bukata. Wannan karancin ya haifar da damuwa game da samuwar albarkatu da daidaiton farashi, wanda hakan ke nuna bukatar samar da ingantaccen sinadarin nickel sulfate mai tsafta, mai karko a cikin batiri. 1,4
Ana samun samar da sinadarin nickel sulfate hexahydrate gabaɗaya ta hanyar amfani da sinadarin crystallization. Daga cikin hanyoyi daban-daban, hanyar sanyaya hanya ce da ake amfani da ita sosai, wadda ke da fa'idodin ƙarancin amfani da makamashi da kuma ikon samar da kayan da ke da tsafta. 5,6 Bincike kan yadda ake amfani da sinadarin nickel sulfate hexahydrate ta amfani da sinadarin crystallization mai sanyaya jiki wanda ba ya tsayawa ya sami ci gaba sosai. A halin yanzu, yawancin bincike sun mayar da hankali kan inganta tsarin crystallization ta hanyar inganta sigogi kamar zafin jiki, saurin sanyaya jiki, girman iri da kuma pH. 7,8,9 Manufar ita ce ƙara yawan sinadarin crystallization da tsarkin lu'ulu'u da aka samu. Duk da haka, duk da cikakken nazarin waɗannan sigogi, har yanzu akwai babban gibi a cikin kulawar da aka bayar ga tasirin ƙazanta, musamman ammonium (NH4+), akan sakamakon crystallization.
Ana iya samun ƙazanta na Ammonium a cikin ruwan nickel da ake amfani da shi don yin crystallization na nickel saboda kasancewar ƙazanta na ammonium yayin aikin haƙowa. Ana amfani da Ammonium a matsayin wakili mai saponifying, wanda ke barin ƙaramin adadin NH4+ a cikin ruwan nickel. 10,11,12 Duk da yawan ƙazanta na ammonium, tasirinsu akan halayen lu'ulu'u kamar tsarin lu'ulu'u, tsarin girma, halayen zafi, tsarki, da sauransu har yanzu ba a fahimce su sosai ba. Iyakantaccen bincike kan tasirinsu yana da mahimmanci saboda ƙazanta na iya hana ko canza girman lu'ulu'u kuma, a wasu lokuta, suna aiki azaman masu hanawa, wanda ke shafar sauyawa tsakanin siffofin lu'ulu'u masu narkewa da tsayayye. 13,14 Fahimtar waɗannan tasirin yana da mahimmanci daga mahangar masana'antu saboda ƙazanta na iya yin illa ga ingancin samfur.
Dangane da wata tambaya ta musamman, wannan binciken ya yi nufin bincika tasirin dattin ammonium akan halayen lu'ulu'u na nickel. Ta hanyar fahimtar tasirin datti, ana iya haɓaka sabbin hanyoyi don sarrafawa da rage tasirinsu mara kyau. Wannan binciken ya kuma bincika alaƙar da ke tsakanin yawan datti da canje-canje a cikin rabon iri. Tunda ana amfani da iri sosai a cikin tsarin samarwa, an yi amfani da sigogin iri a cikin wannan binciken, kuma yana da mahimmanci a fahimci alaƙar da ke tsakanin waɗannan abubuwan biyu. 15 An yi amfani da tasirin waɗannan sigogi biyu don nazarin yawan lu'ulu'u, tsarin girma na lu'ulu'u, tsarin lu'ulu'u, yanayin jiki, da tsarki. Bugu da ƙari, an ƙara bincika halayen motsi, halayen zafi, da ƙungiyoyin aiki na lu'ulu'u a ƙarƙashin tasirin ƙazanta na NH4+ kawai.
Kayan da aka yi amfani da su a cikin wannan binciken sune nickel sulfate hexahydrate (NiSO 6H2O, ≥ 99.8%) da GEM ta samar; ammonium sulfate ((NH)SO2, ≥ 99%) da aka saya daga Tianjin Huasheng Co., Ltd.; ruwan da aka tace. Gilashin iri da aka yi amfani da shi shine NiSO2 6H2O, an niƙa shi an kuma tace shi don samun girman barbashi iri ɗaya na 0.154 mm. An nuna halayen NiSO2 6H2O a cikin Tebur 1 da Hoto na 1.
An binciki tasirin ƙazanta na NH4+ da rabon iri akan crystallization na nickel sulfate hexahydrate ta amfani da sanyaya lokaci-lokaci. An gudanar da duk gwaje-gwajen a zafin farko na 25 °C. An zaɓi 25 °C a matsayin zafin crystallization idan aka yi la'akari da iyakokin sarrafa zafin jiki yayin tacewa. Crystallization na iya faruwa ta hanyar canjin zafin jiki kwatsam yayin tace mafita masu zafi ta amfani da mazubin Buchner mai ƙarancin zafin jiki. Wannan tsari na iya yin tasiri sosai ga motsi, ɗaukar ƙazanta, da kuma wasu kaddarorin crystal.
An fara shirya maganin nickel ta hanyar narke 224 g NiSO4 6H2O a cikin ruwan da aka tace na 200 ml. Yawan da aka zaɓa ya yi daidai da supersaturation (S) = 1.109. An tantance supersaturation ta hanyar kwatanta narkewar lu'ulu'u na nickel sulfate da aka narkar da su da hexahydrate na nickel sulfate a 25 °C. An zaɓi ƙaramin supersaturation don hana crystallization kwatsam lokacin da aka rage zafin zuwa na farko.
An binciki tasirin yawan ion na NH4+ akan tsarin crystallization ta hanyar ƙara (NH4)2SO4 a cikin maganin nickel. Yawan ion na NH4+ da aka yi amfani da shi a cikin wannan binciken sune 0, 1.25, 2.5, 3.75, da 5 g/L. An dumama maganin a 60 °C na tsawon minti 30 yayin da ake juyawa a 300 rpm don tabbatar da haɗakar iri ɗaya. Daga nan aka sanyaya maganin zuwa zafin amsawar da ake so. Lokacin da zafin ya kai 25 °C, an ƙara nau'ikan lu'ulu'u daban-daban na iri (rabobin iri na 0.5%, 1%, 1.5%, da 2%) zuwa maganin. An ƙayyade rabon iri ta hanyar kwatanta nauyin iri da nauyin NiSO4 6H2O a cikin maganin.
Bayan an ƙara nau'ikan iri a cikin maganin, tsarin lu'ulu'u ya faru ta hanyar halitta. Tsarin lu'ulu'u ya ɗauki mintuna 30. An tace maganin ta amfani da matse mai tacewa don ƙara raba lu'ulu'u da aka tara daga maganin. A lokacin aikin tacewa, ana wanke lu'ulu'u akai-akai da ethanol don rage yiwuwar sake sake haɗawa da kuma rage mannewar ƙazanta a cikin maganin zuwa saman lu'ulu'u. An zaɓi Ethanol don wanke lu'ulu'u saboda lu'ulu'u ba sa narkewa a cikin ethanol. An sanya lu'ulu'u da aka tace a cikin incubator na dakin gwaje-gwaje a zafin digiri 50 Celsius. Cikakkun sigogin gwaji da aka yi amfani da su a wannan binciken an nuna su a cikin Jadawali na 2.
An tantance tsarin lu'ulu'u ta amfani da kayan aikin XRD (SmartLab SE—HyPix-400) kuma an gano kasancewar mahaɗan NH4+. An yi gwajin SEM (Apreo 2 HiVac) don nazarin yanayin lu'ulu'u. An tantance halayen zafi na lu'ulu'u ta amfani da kayan aikin TGA (TG-209-F1 Libra). An yi nazarin ƙungiyoyin aiki ta hanyar FTIR (JASCO-FT/IR-4X). An tantance tsarkin samfurin ta amfani da kayan aikin ICP-MS (Prodigy DC Arc). An shirya samfurin ta hanyar narkar da 0.5 g na lu'ulu'u a cikin 100 mL na ruwan da aka tace. An ƙididdige yawan lu'ulu'u (x) ta hanyar raba nauyin lu'ulu'u da aka fitar ta hanyar nauyin lu'ulu'u da aka shigar bisa ga dabarar (1).
inda x shine yawan lu'ulu'u, wanda ya bambanta daga 0 zuwa 1, mout shine nauyin lu'ulu'u masu fitarwa (g), min shine nauyin lu'ulu'u masu shigarwa (g), msol shine nauyin lu'ulu'u a cikin maganin, kuma mseed shine nauyin lu'ulu'u iri.
An ƙara bincika yawan lu'ulu'u don tantance motsin girma na lu'ulu'u da kuma kimanta ƙimar kuzarin kunnawa. An gudanar da wannan binciken da rabon shuka na 2% da kuma irin wannan hanyar gwaji kamar yadda aka saba. An ƙayyade sigogin lu'ulu'u na isothermal ta hanyar kimanta yawan lu'ulu'u a lokutan lu'ulu'u daban-daban (minti 10, 20, 30, da 40) da kuma yanayin zafi na farko (minti 25, 30, 35, da 40 °C). Yawan da aka zaɓa a zafin farko ya yi daidai da ƙimar supersaturation (S) na 1.109, 1.052, 1, da 0.953, bi da bi. An ƙayyade ƙimar supersaturation ta hanyar kwatanta narkewar lu'ulu'u na nickel sulfate da aka narkar da su tare da narkewar nickel sulfate hexahydrate a zafin farko. A cikin wannan binciken, narkewar NiSO4 6H2O a cikin 200 mL na ruwa a yanayin zafi daban-daban ba tare da ƙazanta ba an nuna shi a Hoto na 2.
Ana amfani da ka'idar Johnson-Mail-Avrami (ka'idar JMA) don nazarin halayen isothermal crystallization. Ana zaɓar ka'idar JMA saboda tsarin crystallization ba ya faruwa har sai an ƙara nau'ikan iri a cikin maganin. An bayyana ka'idar JMA kamar haka:
Inda x(t) ke wakiltar canjin a lokacin t, k yana wakiltar ma'aunin canjin lokaci, t yana wakiltar lokacin sauyawa, kuma n yana wakiltar ma'aunin Avrami. An samo ma'aunin 3 daga dabara (2). Ana ƙayyade kuzarin kunnawa na crystallization ta amfani da lissafin Arrhenius:
Inda kg shine madaidaicin saurin amsawa, k0 shine madaidaici, Misali shine kuzarin kunnawa na girma na lu'ulu'u, R shine madaidaicin iskar gas (R=8.314 J/mol K), kuma T shine zafin isothermal crystallization (K).
Siffa ta 3a ta nuna cewa rabon shuka da yawan sinadarin da ke cikin maganin suna da tasiri kan yawan sinadarin nickel. Lokacin da yawan sinadarin da ke cikin maganin ya karu zuwa 2.5 g/L, yawan sinadarin da ke cikin maganin ya ragu daga 7.77% zuwa 6.48% (rabon iri na 0.5%) da kuma daga 10.89% zuwa 10.32% (rabon iri na 2%). Ƙarin ƙaruwa a yawan sinadarin da ke cikin maganin ya haifar da ƙaruwa daidai a yawan sinadarin da ke cikin maganin. Mafi girman yawan amfanin da ake samu ya kai 17.98% lokacin da rabon shuka ya kai 2% kuma yawan sinadarin da ke cikin maganin ya kai 5 g/L. Canje-canje a cikin tsarin yawan sinadarin da ke cikin maganin tare da ƙaruwar yawan sinadarin da ke cikin maganin na iya danganta da canje-canje a cikin tsarin girman sinadarin da ke cikin maganin. Lokacin da yawan sinadarin da ke cikin maganin ya yi ƙasa, ions na Ni2+ da NH4+ suna fafatawa don ɗaurewa da SO42−, wanda ke haifar da ƙaruwar narkewar nickel a cikin maganin da kuma raguwar yawan sinadarin da ke cikin maganin. 14 Idan yawan datti ya yi yawa, tsarin gasa yana ci gaba da faruwa, amma wasu ions na NH4+ suna daidaitawa da ions na nickel da sulfate don samar da gishirin ninki biyu na ammonium sulfate na nickel. 16 Samuwar gishiri biyu yana haifar da raguwar narkewar sinadarin, ta haka ne ke ƙara yawan amfani da kristal. Ƙara yawan amfani da shi na iya ci gaba da inganta yawan amfani da kristal. Iri na iya fara aiwatar da nucleation da haɓakar kristal ta hanyar samar da yankin farko na saman don ions na narkewa don tsarawa da samar da lu'ulu'u. Yayin da rabon iri ke ƙaruwa, yankin farko na saman don ions don tsarawa yana ƙaruwa, don haka ana iya samar da ƙarin lu'ulu'u. Saboda haka, ƙara yawan amfani da shi yana da tasiri kai tsaye akan ƙimar girma na kristal da yawan amfani da kristal. 17
Sigogi na NiSO4 6H2O: (a) yawan lu'ulu'u da (b) pH na maganin nickel kafin da kuma bayan allurar.
Siffa ta 3b ta nuna cewa rabon iri da yawan sinadarin da ke cikinsa yana shafar pH na maganin nickel kafin da kuma bayan ƙara iri. Manufar sa ido kan pH na maganin ita ce fahimtar canje-canje a cikin daidaiton sinadarai a cikin maganin. Kafin ƙara nau'ikan nau'ikan, pH na maganin yana raguwa saboda kasancewar ions na NH4+ waɗanda ke fitar da protons na H+. Ƙara yawan sinadarin da ke cikinsa yana haifar da ƙarin protons na H+ da ake fitarwa, ta haka ne ake rage pH na maganin. Bayan ƙara nau'ikan nau'ikan, pH na dukkan maganin yana ƙaruwa. Yanayin pH yana da alaƙa mai kyau da yanayin yawan sinadarin da ke cikinsa. An sami mafi ƙarancin ƙimar pH a yawan sinadarin da ke cikinsa na 2.5 g/L da rabon iri na 0.5%. Yayin da yawan sinadarin da ke cikinsa ya ƙaru zuwa 5 g/L, pH na maganin yana ƙaruwa. Wannan lamari abu ne da za a iya fahimta, tunda samuwar ions na NH4+ a cikin maganin yana raguwa ko dai saboda sha, ko saboda haɗawa, ko saboda sha da haɗa ions na NH4+ ta hanyar lu'ulu'u.
An ƙara gudanar da gwaje-gwaje da bincike kan yawan amfanin kristal don tantance yanayin haɓakar kristal da kuma ƙididdige kuzarin kunnawa na haɓakar kristal. An bayyana sigogin motsin kristal na isothermal a cikin sashin Hanyoyi. Hoto na 4 yana nuna taswirar Johnson-Mehl-Avrami (JMA) wanda ke nuna halayen motsin haɓakar kristal na nickel sulfate. An samar da taswirar ta hanyar zana ƙimar ln[− ln(1− x(t))] akan ƙimar ln t (Equation 3). Ƙimar gradient da aka samu daga taswirar sun yi daidai da ƙimar JMA index (n) wanda ke nuna girman lu'ulu'u mai girma da tsarin girma. Yayin da ƙimar yankewa ke nuna ƙimar girma wanda ke wakiltar ta hanyar ln k mai ɗorewa. Ƙimar JMA index (n) tana tsakanin 0.35 zuwa 0.75. Wannan ƙimar n yana nuna cewa lu'ulu'u suna da girma mai girma ɗaya kuma suna bin tsarin girma mai sarrafawa da watsawa; 0 < n < 1 yana nuna girma mai girma ɗaya, yayin da n < 1 yana nuna tsarin girma mai sarrafawa da watsawa. 18 Yawan girma na k mai ɗorewa yana raguwa tare da ƙaruwar zafin jiki, wanda ke nuna cewa tsarin lu'ulu'u yana faruwa da sauri a ƙananan zafin jiki. Wannan yana da alaƙa da ƙaruwar supersaturation na maganin a ƙananan zafin jiki.
Shirye-shiryen Johnson-Mehl-Avrami (JMA) na nickel sulfate hexahydrate a yanayin zafi daban-daban na crystallization: (a) 25 °C, (b) 30 °C, (c) 35 °C da (d) 40 °C.
Ƙarin ƙwayoyin cuta ya nuna irin wannan yanayin girma a duk yanayin zafi. Lokacin da yawan ƙwayoyin cuta ya kai 2.5 g/L, ƙimar girman ƙwayoyin cuta ta ragu, kuma lokacin da yawan ƙwayoyin cuta ya fi 2.5 g/L, ƙimar girman ƙwayoyin cuta ta ƙaru. Kamar yadda aka ambata a baya, canjin yanayin girman ƙwayoyin cuta ya faru ne saboda canjin tsarin hulɗa tsakanin ions a cikin maganin. Lokacin da yawan ƙwayoyin cuta ya yi ƙasa, tsarin gasa tsakanin ions a cikin maganin yana ƙara yawan narkewar sinadarin, wanda hakan ke rage yawan haɓakar ƙwayoyin cuta. 14 Bugu da ƙari, ƙarin yawan ƙwayoyin cuta yana sa tsarin girma ya canza sosai. Lokacin da yawan ƙwayoyin cuta ya wuce 3.75 g/L, ana samun ƙarin sabbin ƙwayoyin cuta, wanda ke haifar da raguwar narkewar sinadarin, don haka yana ƙara yawan haɓakar ƙwayoyin cuta. Ana iya nuna samuwar sabbin ƙwayoyin cuta ta hanyar samuwar gishiri biyu (NH4)2Ni(SO4)2 6H2O). 16 Lokacin da ake tattaunawa kan tsarin girma na lu'ulu'u, sakamakon diffraction na X-ray yana tabbatar da samuwar gishiri biyu.
An ƙara kimanta aikin taswirar JMA don tantance kuzarin kunnawa na crystallization. An ƙididdige kuzarin kunnawa ta amfani da lissafin Arrhenius (wanda aka nuna a cikin Lissafi (4)). Hoto na 5a yana nuna alaƙar da ke tsakanin ƙimar ln(kg) da ƙimar 1/T. Sannan, an ƙididdige kuzarin kunnawa ta amfani da ƙimar gradient da aka samu daga makircin. Hoto na 5b yana nuna ƙimar kuzarin kunnawa na crystallization a ƙarƙashin yawan ƙazanta daban-daban. Sakamakon ya nuna cewa canje-canje a cikin yawan ƙazanta yana shafar kuzarin kunnawa. Ƙarfin kunnawa na crystallization na crystallization na nickel sulfate ba tare da ƙazanta ba shine 215.79 kJ/mol. Lokacin da yawan ƙazanta ya kai 2.5 g/L, ƙarfin kunnawa yana ƙaruwa da 3.99% zuwa 224.42 kJ/mol. Ƙaruwar kuzarin kunnawa yana nuna cewa shingen makamashi na tsarin crystallization yana ƙaruwa, wanda zai haifar da raguwar ƙimar girma na crystal da yawan samar da crystal. Lokacin da yawan ƙazanta ya fi 2.5 g/L, ƙarfin kunnawa na crystallization yana raguwa sosai. A lokacin da aka samu yawan kazanta na 5 g/l, makamashin kunnawa shine 205.85 kJ/mol, wanda ya yi ƙasa da kashi 8.27% fiye da makamashin kunnawa a lokacin da aka samu yawan kazanta na 2.5 g/l. Raguwar kuzarin kunnawa yana nuna cewa tsarin lu'ulu'u ya sauƙaƙa, wanda hakan ke haifar da ƙaruwar yawan girma da yawan lu'ulu'u.
(a) Daidaita taswirar ln(kg) idan aka kwatanta da 1/T da kuma (b) kuzarin kunnawa Misali na lu'ulu'u a yawan najasa daban-daban.
An binciki tsarin girmar kristal ta hanyar amfani da XRD da FTIR spectroscopy, kuma an yi nazarin motsin girmar kristal da kuzarin kunnawa. Hoto na 6 yana nuna sakamakon XRD. Bayanan sun yi daidai da PDF #08–0470, wanda ke nuna cewa α-NiSO4 6H2O ne (ja silica). Crystal ɗin yana cikin tsarin tetragonal, rukunin sararin samaniya shine P41212, sigogin tantanin halitta sune a = b = 6.782 Å, c = 18.28 Å, α = β = γ = 90°, kuma girman shine 840.8 Å3. Waɗannan sakamakon sun yi daidai da sakamakon da Manomenova et al suka buga a baya. 19 Gabatar da ions na NH4+ kuma yana haifar da samuwar (NH4)2Ni(SO4)2 6H2O. Bayanan suna cikin PDF No. 31–0062. Gilashin yana cikin tsarin monoclinic, rukunin sararin samaniya P21/a, sigogin tantanin halitta sune a = 9.186 Å, b = 12.468 Å, c = 6.242 Å, α = γ = 90°, β = 106.93°, kuma girman shine 684 Å3. Waɗannan sakamakon sun yi daidai da binciken da aka yi a baya wanda Su et al.20 suka ruwaito.
Tsarin rarraba hasken X-ray na lu'ulu'u na nickel sulfate: (a-b) 0.5%, (c-d) 1%, (e-f) 1.5%, da kuma (g-h) rabon iri na 2%. Hoton da ke dama yana nuna girman hoton hagu.
Kamar yadda aka nuna a cikin Hotuna na 6b, d, f da h, 2.5 g/L shine mafi girman iyakar yawan ammonium a cikin maganin ba tare da samar da ƙarin gishiri ba. Lokacin da yawan rashin danshi ya kai 3.75 da 5 g/L, ana haɗa ions na NH4+ cikin tsarin lu'ulu'u don samar da gishirin hadaddun (NH4)2Ni(SO4)2 6H2O. A cewar bayanai, ƙarfin kololuwar gishirin hadaddun yana ƙaruwa yayin da yawan rashin danshi ke ƙaruwa daga 3.75 zuwa 5 g/L, musamman a 2θ 16.47° da 17.44°. Ƙaruwar kololuwar gishirin hadaddun ya faru ne kawai saboda ƙa'idar daidaiton sinadarai. Duk da haka, ana lura da wasu kololuwar da ba su dace ba a 2θ 16.47°, wanda za a iya dangantawa da nakasar roba ta lu'ulu'u. 21 Sakamakon halayen kuma ya nuna cewa babban rabon iri yana haifar da raguwar ƙarfin kololuwar gishirin hadaddun. Babban rabon iri yana hanzarta tsarin lu'ulu'u, wanda ke haifar da raguwar sinadarin da ke narkewa. A wannan yanayin, tsarin girma na lu'ulu'u yana mai da hankali kan iri, kuma samuwar sabbin matakai yana kawo cikas ga raguwar yawan ruwan da ke narkewa. Sabanin haka, lokacin da rabon iri ya yi ƙasa, tsarin lu'ulu'u yana jinkiri, kuma yawan ruwan da ke narkewa ya kasance a matakin da ya fi girma. Wannan yanayin yana ƙara yiwuwar nucleation na gishirin ninki biyu da ba shi da narkewa sosai (NH4)2Ni(SO4)2 6H2O). An bayar da bayanan ƙarfin kololuwar gishirin ninki biyu a cikin Jadawali na 3.
An yi gwajin FTIR don bincika duk wani matsala ko canje-canje a cikin tsarin layin mai masaukin baki saboda kasancewar ions na NH4+. An gano samfuran da ke da rabon shuka na 2% akai-akai. Hoto na 7 yana nuna sakamakon halayen FTIR. Manyan kololuwar da aka lura a 3444, 3257 da 1647 cm−1 sun faru ne saboda yanayin mikewa na kwayoyin halitta na O-H. Kololuwar a 2370 da 2078 cm−1 suna wakiltar haɗin hydrogen tsakanin kwayoyin ruwa. An danganta wannan rukunin a 412 cm−1 da girgizar Ni-O. Bugu da ƙari, ions na SO4− kyauta suna nuna manyan hanyoyin girgiza guda huɗu a 450 (υ2), 630 (υ4), 986 (υ1) da 1143 da 1100 cm−1 (υ3). Alamomin υ1-υ4 suna wakiltar halayen yanayin girgiza, inda υ1 ke wakiltar yanayin da ba ya lalacewa (miƙawa mai siffa ɗaya), υ2 yana wakiltar yanayin da ba ya lalacewa sau biyu (lanƙwasa mai siffa ɗaya), kuma υ3 da υ4 suna wakiltar yanayin da ba ya lalacewa sau uku (miƙawa mara daidaituwa da lanƙwasa mara daidaituwa, bi da bi). 22,23,24 Sakamakon halayen ya nuna cewa kasancewar ƙazanta na ammonium yana ba da ƙarin kololuwa a lambar raƙuman ruwa ta 1143 cm-1 (wanda aka yiwa alama da da'ira ja a cikin hoton). Ƙarin kololuwar a 1143 cm-1 yana nuna cewa kasancewar ions na NH4+, ba tare da la'akari da yawansu ba, yana haifar da karkacewar tsarin lattice, wanda ke haifar da canji a cikin mitar girgiza na ƙwayoyin ion sulfate a cikin lu'ulu'u.
Dangane da sakamakon XRD da FTIR da suka shafi halayen motsi na girma da kuzarin kunnawa, Hoto na 8 ya nuna tsarin tsarin crystallization na nickel sulfate hexahydrate tare da ƙara ƙazanta na NH4+. Idan babu ƙazanta, ions na Ni2+ za su yi aiki tare da H2O don samar da nickel hydrate [Ni(6H2O)]2−. Sannan, nickel hydrate ya haɗu da ions na SO42− don samar da ƙwayoyin Ni(SO4)2−6H2O kuma ya girma ya zama lu'ulu'u na nickel sulfate hexahydrate. Lokacin da aka ƙara ƙaramin yawan ƙazanta na ammonium (2.5 g/L ko ƙasa da haka) zuwa maganin, [Ni(6H2O)]2− yana da wuya a haɗa gaba ɗaya da ions na SO42− saboda ions [Ni(6H2O)]2− da NH4+ suna fafatawa don haɗuwa da ions na SO42−, kodayake har yanzu akwai isassun ions na sulfate don amsawa tare da ions biyu. Wannan yanayin yana haifar da ƙaruwa a cikin kuzarin kunnawa na crystallization da raguwar ci gaban crystal. 14,25 Bayan an samar da ƙwayoyin hexahydrate na nickel sulfate kuma aka girma su zama lu'ulu'u, ana haɗa ions na NH4+ da (NH4)2SO4 da yawa a saman lu'ulu'u. Wannan ya bayyana dalilin da yasa ƙungiyar aiki ta SO4− ion (lambar raƙuman ruwa 1143 cm−1) a cikin samfuran NSH-8 da NSH-12 ta kasance tana samuwa ba tare da tsarin doping ba. Lokacin da yawan ƙazanta ya yi yawa, ana fara haɗa ions na NH4+ cikin tsarin lu'ulu'u, yana samar da gishiri biyu. 16 Wannan lamari yana faruwa ne saboda rashin ions na SO42− a cikin maganin, kuma ions na SO42− suna ɗaurewa da hydrates na nickel da sauri fiye da ions na ammonium. Wannan tsari yana haɓaka nucleation da haɓakar gishiri biyu. A lokacin aikin haɗa, ana samar da ƙwayoyin Ni(SO4)2− 6H2O da (NH4)2Ni(SO4)2− 6H2O a lokaci guda, wanda ke haifar da ƙaruwa a adadin ƙwayoyin da aka samu. Ƙara yawan ƙwayoyin yana haɓaka haɓakar lu'ulu'u da raguwar kuzarin kunnawa.
Ana iya bayyana yadda sinadarin sinadarin nickel sulfate hexahydrate ke narkar da shi a cikin ruwa, ƙara ƙaramin adadin ammonium sulfate mai yawa, sannan a aiwatar da tsarin crystallization kamar haka:
An nuna sakamakon siffantawar SEM a cikin Hoto na 9. Sakamakon siffantawar ya nuna cewa adadin gishirin ammonium da aka ƙara da rabon shuka ba su da tasiri sosai kan siffar lu'ulu'u. Girman lu'ulu'u da aka samar ya kasance iri ɗaya, kodayake manyan lu'ulu'u suna bayyana a wasu wurare. Duk da haka, har yanzu ana buƙatar ƙarin siffantawa don tantance tasirin yawan gishirin ammonium da rabon shuka akan matsakaicin girman lu'ulu'u da aka samar.
Tsarin lu'ulu'u na NiSO4 6H2O: (a–e) 0.5%, (f–j) 1%, (h–o) 1.5% da (p–u) rabon iri 2% wanda ke nuna canjin yawan NH4+ daga sama zuwa ƙasa, wanda shine 0, 1.25, 2.5, 3.75 da 5 g/L, bi da bi.
Siffa ta 10a tana nuna lanƙwasa TGA na lu'ulu'u masu yawan ƙazanta daban-daban. An yi nazarin TGA akan samfuran tare da rabon shuka na 2%. An kuma yi nazarin XRD akan samfurin NSH-20 don tantance mahaɗan da aka samar. Sakamakon XRD da aka nuna a Siffa ta 10b ya tabbatar da canje-canje a cikin tsarin lu'ulu'u. Ma'aunin thermogravimetric ya nuna cewa duk lu'ulu'u da aka haɗa suna nuna kwanciyar hankali na zafi har zuwa 80°C. Daga baya, nauyin lu'ulu'u ya ragu da 35% lokacin da zafin jiki ya karu zuwa 200°C. Rage nauyin lu'ulu'u ya faru ne saboda tsarin ruɓewa, wanda ya haɗa da asarar ƙwayoyin ruwa guda 5 don samar da NiSO4 H2O. Lokacin da zafin jiki ya karu zuwa 300–400°C, nauyin lu'ulu'u ya sake raguwa. Rage nauyin lu'ulu'u ya kai kusan 6.5%, yayin da asarar nauyin samfurin lu'ulu'u na NSH-20 ya ɗan fi girma, daidai 6.65%. Rarrabuwar ions na NH4+ zuwa iskar NH3 a cikin samfurin NSH-20 ya haifar da ɗan raguwa kaɗan. Yayin da zafin jiki ya ƙaru daga 300 zuwa 400°C, nauyin lu'ulu'u ya ragu, wanda ya haifar da dukkan lu'ulu'u suna da tsarin NiSO4. Ƙara zafin jiki daga 700°C zuwa 800°C ya sa tsarin lu'ulu'u ya canza zuwa NiO2, wanda ya haifar da sakin iskar SO2 da O2.25,26
An tantance tsarkin lu'ulu'u na nickel sulfate hexahydrate ta hanyar tantance yawan NH4+ ta amfani da kayan aikin DC-Arc ICP-MS. An tantance tsarkin lu'ulu'u na nickel sulfate ta amfani da dabara (5).
Inda Ma shine nauyin ƙazanta a cikin lu'ulu'u (mg), Mo shine nauyin lu'ulu'u (mg), Ca shine yawan ƙazanta a cikin maganin (mg/l), V shine girman maganin (l).
Siffa ta 11 ta nuna tsarkin lu'ulu'u na nickel sulfate hexahydrate. Darajar tsarki ita ce matsakaicin ƙimar halaye 3. Sakamakon ya nuna cewa rabon shuka da yawan ƙazanta suna shafar tsarkin lu'ulu'u na nickel sulfate da aka samar kai tsaye. Mafi girman yawan ƙazanta, haka nan yawan shaƙar ƙazanta, wanda ke haifar da ƙarancin tsarkin lu'ulu'u da aka samar. Duk da haka, tsarin shaƙar ƙazanta na iya canzawa dangane da yawan ƙazanta, kuma jadawalin sakamakon ya nuna cewa shaƙar ƙazanta gabaɗaya ta lu'ulu'u ba ya canzawa sosai. Bugu da ƙari, waɗannan sakamakon kuma suna nuna cewa babban rabon shuka na iya inganta tsarkin lu'ulu'u. Wannan lamari yana yiwuwa ne saboda lokacin da yawancin ƙwayoyin lu'ulu'u da aka samar suka taru akan ƙwayoyin nickel, yuwuwar taruwar ions na nickel akan nickel ya fi girma. 27
Binciken ya nuna cewa ions na ammonium (NH4+) suna da tasiri sosai kan tsarin crystallization da kuma halayen crystalline na crystallines na nickel sulfate hexahydrate, kuma sun bayyana tasirin rabon iri akan tsarin crystallization.
Idan yawan ammonium ya wuce 2.5 g/l, yawan yawan ammonium da girman kristal suna raguwa. Idan yawan ammonium ya wuce 2.5 g/l, yawan yawan ammonium da girman kristal suna ƙaruwa.
Ƙara ƙazanta a cikin ruwan nickel yana ƙara gasa tsakanin NH4+ da [Ni(6H2O)]2− ions don SO42−, wanda ke haifar da ƙaruwa a cikin kuzarin kunnawa. Ragewar kuzarin kunnawa bayan ƙara yawan ƙazanta ya faru ne saboda shigar da ions na NH4+ cikin tsarin lu'ulu'u, don haka samar da gishiri biyu (NH4)2Ni(SO4)2− 6H2O).
Amfani da mafi girman rabon iri zai iya inganta yawan amfanin lu'ulu'u, yawan girma na lu'ulu'u da kuma tsarkin lu'ulu'u na nickel sulfate hexahydrate.
Demirel, HS, da sauransu. Maganin hana narkewar sinadarai na nickel sulfate hydrate mai nauyin batir yayin sarrafa laterite. Satumba. Fasahar Tsarkakewa, 286, 120473. https://doi.org/10.1016/J.SEPPUR.2022.120473 (2022).
Saguntala, P. da Yasota, P. Amfani da lu'ulu'u na nickel sulfate a yanayin zafi mai yawa: Nazarin halaye tare da ƙarin amino acid a matsayin masu ɗaukar nauyi. Mater. Today Proc. 9, 669–673. https://doi.org/10.1016/J.MATPR.2018.10.391 (2019).
Babaahmadi, V., da sauransu. Lalacewar yanayin nickel a saman yadi tare da bugu mai amfani da polyol akan rage graphene oxide. Mujallar Injiniyan Jiki da Sinadarai na saman Colloidal 703, 135203. https://doi.org/10.1016/J.COLSURFA.2024.135203 (2024).
Fraser, J., Anderson, J., Lazuen, J., da sauransu. “Buƙatar nan gaba da tsaron samar da nickel ga batirin motocin lantarki.” Ofishin Littattafai na Tarayyar Turai; (2021). https://doi.org/10.2760/212807
Hahn, B., Böckman, O., Wilson, BP, Lundström, M. da Louhi-Kultanen, M. Tsarkakewa na nickel sulfate ta hanyar lu'ulu'u mai tsari tare da sanyaya. Fasahar Injiniyan Sinadarai 42(7), 1475–1480. https://doi.org/10.1002/CEAT.201800695 (2019).
Ma, Y. da sauransu. Amfani da hanyoyin hazo da lu'ulu'u wajen samar da gishirin ƙarfe don kayan batirin lithium-ion: bita. Karfe. 10(12), 1-16. https://doi.org/10.3390/MET10121609 (2020).
Masalov, VM, da sauransu. Girman lu'ulu'u guda ɗaya na nickel sulfate hexahydrate (α-NiSO4.6H2O) a ƙarƙashin yanayin yanayin zafi mai ƙarfi. Gilashin kristal. 60(6), 963–969. https://doi.org/10.1134/S1063774515060206 (2015).
Choudhury, RR et al. α-Nickel sulfate hexahydrate lu'ulu'u: Alaƙa tsakanin yanayin girma, tsarin lu'ulu'u, da kaddarorinsa. JApCr. 52, 1371–1377. https://doi.org/10.1107/S1600576719013797FILE (2019).
Hahn, B., Böckman, O., Wilson, BP, Lundström, M. da Louhi-Kultanen, M. Tsarkakewa na nickel sulfate ta hanyar lu'ulu'u mai sanyaya jiki. Fasahar Injiniyan Sinadarai 42(7), 1475–1480. https://doi.org/10.1002/ceat.201800695 (2019).