Tasirin ethers cellulose akan juyin halittar abubuwan ruwa da samfuran hydration na manna siminti sulphoaluminate

Abubuwan da ake buƙata na ruwa da juyin halitta microstructure a cikin cellulose ether modified sulphoaluminate ciminti (CSA) slurry an yi nazari ta ƙananan ƙarfin maganadisu na makamashin nukiliya da mai nazarin thermal. Sakamakon ya nuna cewa bayan haɓakar ether na cellulose, ya ƙaddamar da ruwa tsakanin tsarin flocculation, wanda aka kwatanta shi a matsayin kololuwar shakatawa na uku a cikin lokacin shakatawa mai jujjuyawa (T2), kuma adadin ruwan da aka shayar da shi yana da alaƙa da daidaituwa tare da sashi. Bugu da ƙari, ether cellulose ya taimaka wajen yin musayar ruwa tsakanin ciki da kuma tsaka-tsakin floc na CSA. Kodayake ƙari na ether cellulose ba shi da tasiri a kan nau'ikan samfuran hydration na ciminti sulphoaluminate, zai shafi adadin samfuran hydration na takamaiman shekaru.

Mabuɗin kalmomi:ether cellulose; sulfoaluminate ciminti; ruwa; hydration kayayyakin

0,Gabatarwa

Cellulose ether, wanda aka sarrafa daga cellulose na halitta ta hanyar jerin matakai, wani abu ne mai sabuntawa kuma koren sunadarai. Ana amfani da ethers na yau da kullun kamar methylcellulose (MC), ethylcellulose (HEC), da hydroxyethylmethylcellulose (HEMC) a cikin magunguna, gini da sauran masana'antu. Ɗaukar HEMC a matsayin misali, zai iya inganta haɓakar ruwa da daidaiton simintin Portland, amma yana jinkirta saitin siminti. A matakin ƙananan ƙananan, HEMC kuma yana da tasiri mai mahimmanci akan ƙananan ƙananan ƙwayoyin cuta da tsarin pore na manna siminti. Misali, samfurin hydration ettringite (AFt) ya fi zama ɗan gajeren siffa mai siffar sanda, kuma yanayin sa yana ƙasa; a lokaci guda, an shigar da adadi mai yawa na rufaffiyar rufaffiyar a cikin simintin siminti, rage yawan adadin masu sadarwa.

Yawancin binciken da ake yi kan tasirin ethers na cellulose akan kayan da aka gina a siminti suna mayar da hankali kan simintin Portland. Sulphoaluminate siminti (CSA) siminti ne mai ƙarancin carbon carbon wanda aka haɓaka da kansa a cikin ƙasata a cikin ƙarni na 20, tare da calcium sulphoaluminate mai anhydrous a matsayin babban ma'adinai. Saboda babban adadin AFt za a iya haifar da bayan hydration, CSA yana da fa'idodin ƙarfin farko, babban rashin ƙarfi, da juriya na lalata, kuma ana amfani dashi sosai a cikin fagagen bugu na 3D na kankare, aikin injiniya na ruwa, da gyare-gyare mai sauri a cikin ƙananan yanayin zafi. . A cikin 'yan shekarun nan, Li Jian et al. yayi nazarin tasirin HEMC akan turmi na CSA daga ra'ayoyin ƙarfin matsawa da yawan rigar; Wu Kai et al. yayi nazarin tasirin HEMC akan tsarin samar da ruwa na farko na siminti na CSA, amma ruwan da ke cikin simintin CSA da aka gyara ba a sani ba. Dangane da wannan, wannan aikin yana mai da hankali kan rarraba lokacin shakatawa na tsaka-tsaki (T2) a cikin slurry CSA ciminti kafin da kuma bayan ƙara HEMC ta amfani da ƙaramin filin makaman nukiliya na maganadisu, kuma yana ƙara yin nazarin ƙaura da canza dokar ruwa a cikin slurry. An yi nazarin canjin abun da ke ciki na siminti manna.

1. Gwaji

1.1 Kayan danye

An yi amfani da siminti sulphoaluminate guda biyu na kasuwanci, waɗanda aka nuna su a matsayin CSA1 da CSA2, tare da asara akan kunnawa (LOI) na ƙasa da 0.5% (jashi mai yawa).

Ana amfani da hydroxyethyl methylcelluloses daban-daban guda uku, waɗanda aka nuna su a matsayin MC1, MC2 da MC3 bi da bi. Ana samun MC3 ta hanyar hada 5% (masu juzu'i) polyacrylamide (PAM) a cikin MC2.

1.2 Hadawa rabo

An gauraya nau'ikan ethers na cellulose guda uku a cikin ciminti na sulphoaluminate bi da bi, allurai sun kasance 0.1%, 0.2% da 0.3% (jari mai yawa, iri ɗaya a ƙasa). Matsakaicin simintin ruwa mai tsafta shine 0.6, kuma simintin ruwa na simintin ruwa na simintin ruwa yana da kyakkyawan aiki kuma babu zub da jini ta hanyar gwajin amfani da ruwa na daidaitattun daidaito.

1.3 Hanya

Ƙananan kayan aikin NMR da aka yi amfani da su a cikin gwaji shine PQ⁃001 NMR analyzer daga Shanghai Numei Analytical Instrument Co., Ltd. The Magnetic filin ƙarfi na dindindin maganadisu ne 0.49T, da proton resonance mita ne 21MHz, da kuma zafin jiki na maganadisu ana kiyaye akai a 32.0.°C. A lokacin gwajin, an saka ƙaramin kwalban gilashin da ke ɗauke da samfurin silindi a cikin injin binciken na'urar, kuma an yi amfani da jerin CPMG don tattara alamar shakatawa na manna siminti. Bayan jujjuyawar ta software na bincike na daidaitawa, an sami juzu'in juyarwar T2 ta amfani da sirt inversion algorithm. Ruwa tare da digiri daban-daban na 'yanci a cikin slurry za a kwatanta shi da nau'i-nau'i daban-daban na shakatawa a cikin nau'i na shakatawa mai zurfi, kuma yankin na shakatawa yana da dangantaka da adadin ruwa, dangane da nau'in da abun ciki na ruwa a cikin slurry. ana iya yin nazari. Domin samar da karfin maganadisu na makamashin nukiliya, wajibi ne a tabbatar da cewa cibiyar mitar O1 (raka'a: kHz) na mitar rediyo ta yi daidai da mitar maganadisu, kuma O1 ana daidaita shi kowace rana yayin gwajin.

TG?DSC ne yayi nazarin samfuran tare da STA 449C hade mai nazarin zafi daga NETZSCH, Jamus. An yi amfani da N2 azaman yanayin kariya, yawan dumama ya kasance 10°C/min, kuma kewayon zafin dubawa ya kasance 30-800°C.

2. Sakamako da tattaunawa

2.1 Juyin Halitta na ruwa

2.1.1 cellulose ether mara nauyi

Za'a iya lura da kololuwar shakatawa guda biyu (wanda aka bayyana azaman kololuwar shakatawa na farko da na biyu) a sarari a tsakar lokacin shakatawa (T2) na simintin sulphoaluminate guda biyu. Ƙwaƙwalwar shakatawa ta farko ta samo asali ne daga cikin tsarin flocculation, wanda ke da ƙananan 'yanci da ɗan gajeren lokacin shakatawa; kololuwar shakatawa na biyu ya samo asali ne daga tsakanin tsarin flocculation, wanda ke da babban matakin 'yanci da dogon lokacin hutu mai tsayi. Sabanin haka, T2 wanda ya yi daidai da kololuwar shakatawa na farko na siminti guda biyu yana kwatankwacinsa, yayin da kololuwar shakatawa na biyu na CSA1 ya bayyana daga baya. Daban-daban da sulphoaluminate siminti clinker da siminti da aka yi da kai, kololuwar shakatawa biyu na CSA1 da CSA2 sun mamaye wani bangare daga yanayin farko. Tare da ci gaban hydration, kololuwar shakatawa na farko a hankali yakan kasance mai zaman kanta, yanki a hankali yana raguwa, kuma yana ɓacewa gaba ɗaya a kusan mintuna 90. Wannan yana nuna cewa akwai wani madaidaicin musanyar ruwa tsakanin tsarin flocculation da tsarin flocculs na fakitin siminti guda biyu.

Canjin yankin kololuwar kololuwar shakatawa na biyu da canjin ƙimar T2 wanda ya dace da koli na kololuwar bi da bi yana nuna canjin ruwan kyauta da abun ciki na ruwa da aka ɗaure ta jiki da canjin matakin 'yancin ruwa a cikin slurry. . Haɗin waɗannan biyun na iya ƙara yin nuni ga tsarin hydration na slurry. Tare da ci gaba na hydration, ƙananan yanki yana raguwa a hankali, kuma canjin darajar T2 zuwa hagu yana ƙaruwa a hankali, kuma akwai wata dangantaka mai dacewa tsakanin su.

2.1.2 Ƙara ether cellulose

Ɗaukar CSA2 gauraye da 0.3% MC2 a matsayin misali, ana iya ganin bakan shakatawa na T2 na ciminti sulphoaluminate bayan ƙara ether cellulose. Bayan ƙara cellulose ether, na uku shakatawa kololuwa wakiltar adsorption na ruwa ta cellulose ether ya bayyana a wurin da transverse shakatawa lokaci ya fi 100ms, da kuma kololuwa yankin ya karu a hankali tare da karuwa da cellulose ether abun ciki.

Adadin ruwan da ke tsakanin tsarin flocculation yana shafar ƙaurawar ruwa a cikin tsarin flocculation da kuma adsorption na ruwa na ether cellulose. Saboda haka, adadin ruwa tsakanin tsarin flocculation yana da alaƙa da tsarin pore na ciki na slurry da ƙarfin adsorption na ruwa na ether cellulose. Yankin mafi girman shakatawa na biyu ya bambanta da abun ciki na ether cellulose ya bambanta da nau'ikan siminti daban-daban. Yankin kololuwar shakatawa na biyu na CSA1 slurry ya ragu ci gaba tare da haɓaka abun ciki na ether cellulose, kuma shine mafi ƙanƙanta a cikin 0.3% abun ciki. Sabanin haka, yanki kololuwar shakatawa na biyu na CSA2 slurry yana ƙaruwa tare da haɓaka abun ciki na ether cellulose.

Lissafin canjin yanki na kololuwar shakatawa na uku tare da haɓaka abun ciki na ether cellulose. Tun lokacin da ingancin samfurin ya shafi yankin kololuwa, yana da wuya a tabbatar da cewa ingancin samfurin da aka ƙara daidai yake yayin ɗaukar samfurin. Sabili da haka, ana amfani da rabon yanki don kwatanta adadin sigina na kololuwar shakatawa na uku a cikin samfurori daban-daban. Daga canjin yanki na kololuwar shakatawa na uku tare da haɓakar abun ciki na ether cellulose, ana iya ganin cewa tare da haɓakar abun ciki na ether cellulose, yanki na hutun hutu na uku a zahiri ya nuna haɓakar haɓaka (a cikin). CSA1, lokacin da abun ciki na MC1 ya kasance 0.3%, ya fi girma Yankin shakatawa na uku ya ragu kadan a 0.2%), yana nuna cewa tare da karuwar abun ciki na ether cellulose, ruwan da aka shayarwa kuma a hankali yana karuwa. Daga cikin slurries CSA1, MC1 yana da mafi kyawun sha ruwa fiye da MC2 da MC3; yayin da tsakanin CSA2 slurries, MC2 yana da mafi kyawun sha ruwa.

Ana iya gani daga canjin yanki na kololuwar shakatawa na uku a kowace raka'a taro na CSA2 slurry tare da lokaci a cikin abun ciki na 0.3% cellulose ether cewa yanki na hutu na uku kololuwa a kowace naúrar taro yana raguwa tare da hydration, yana nuna cewa Tun da yawan hydration na CSA2 ya fi sauri fiye da na clinker da ciminti da aka yi da kansa, cellulose ether ba shi da lokaci don ƙarin tallan ruwa, kuma ya sake fitar da ruwa mai ban sha'awa saboda saurin karuwar yawan lokaci na ruwa a cikin slurry. Bugu da ƙari, ƙaddamar da ruwa na MC2 ya fi karfi fiye da na MC1 da MC3, wanda ya dace da ƙaddarar da ta gabata. Ana iya gani daga canji na kololuwar yanki a kowace naúrar taro na uku shakatawa kololuwa na CSA1 tare da lokaci a daban-daban 0.3% allurai na cellulose ethers cewa canjin mulkin na uku shakatawa ganiya na CSA1 ya bambanta da na CSA2, kuma yankin CSA1 yana ƙaruwa kaɗan a farkon matakin hydration. Bayan karuwa da sauri, ya ragu don bacewa, wanda zai iya zama saboda tsayin lokaci na clotting na CSA1. Bugu da ƙari, CSA2 ya ƙunshi ƙarin gypsum, hydration yana da sauƙi don samar da ƙarin AFt (3CaO Al2O3 3CaSO4 32H2O), yana cinye ruwa mai yawa na kyauta, kuma yawan yawan ruwa ya wuce adadin tallan ruwa ta hanyar cellulose ether, wanda zai iya haifar da The yanki na kololuwar shakatawa na uku na CSA2 slurry ya ci gaba da raguwa.

Bayan shigar da ether cellulose, kololuwar shakatawa na farko da na biyu suma sun canza zuwa wani matsayi. Ana iya gani daga kololuwar nisa na kololuwar shakatawa na biyu na nau'ikan siminti guda biyu da slurry sabo bayan ƙara ether cellulose cewa girman nisa na kololuwar hutu na biyu na sabon slurry ya bambanta bayan ƙara ether cellulose. karuwa, siffar kololuwar tana yin yaduwa. Wannan yana nuna cewa shigar da ether na cellulose yana hana haɓakar barbashin siminti zuwa wani ɗan lokaci, yana sa tsarin flocculation yayi sako-sako, yana raunana matakin dauri na ruwa, kuma yana ƙara ƙimar ƴancin ruwa tsakanin tsarin flocculation. Duk da haka, tare da karuwa na sashi, karuwar girman girman ba a bayyane yake ba, kuma mafi girman nisa na wasu samfurori ma yana raguwa. Yana iya zama cewa karuwa na sashi yana ƙara danko na lokaci na ruwa na slurry, kuma a lokaci guda, adsorption na cellulose ether zuwa simintin siminti an inganta don haifar da flocculation. Matsayin 'yancin danshi tsakanin tsarin yana raguwa.

Za a iya amfani da ƙuduri don kwatanta matakin rabuwa tsakanin kololuwar shakatawa na farko da na biyu. Za'a iya ƙididdige matakin rarrabuwa bisa ga matakin ƙuduri = (Afirst component-Asaddle)/Afirst bangaren, inda Afirst bangaren da Asaddle ke wakiltar iyakar girman kololuwar hutun farko da girman mafi ƙasƙanci tsakanin kololuwar biyu, bi da bi. Ana iya amfani da matakin rarrabuwar kawuna don siffata ƙimar musayar ruwa tsakanin slurry flocculation tsarin da tsarin flocculation, kuma ƙimar ita ce gabaɗaya 0-1. Mafi girman darajar Rabuwa yana nuna cewa sassan biyu na ruwa sun fi wahalar musanya, kuma darajar daidai da 1 tana nuna cewa sassan ruwa biyu ba za su iya musanya ba kwata-kwata.

Ana iya gani daga sakamakon ƙididdiga na digiri na rabuwa cewa matakin rabuwa na siminti guda biyu ba tare da ƙara cellulose ether ba daidai yake, duka biyun kusan 0.64 ne, kuma darajar rabuwa ta ragu sosai bayan ƙara cellulose ether. A gefe guda, ƙuduri yana raguwa tare da ƙara yawan adadin, kuma ƙudurin kololuwar biyu har ma ya ragu zuwa 0 a cikin CSA2 gauraye da 0.3% MC3, yana nuna cewa ether cellulose yana inganta musayar ruwa a ciki da tsakanin flocculation Tsarin . Dangane da gaskiyar cewa shigar da ether cellulose ba shi da wani tasiri a kan matsayi da yanki na farkon shakatawa na farko, ana iya yin la'akari da cewa raguwa a cikin ƙuduri ya kasance wani ɓangare na karuwa a cikin nisa na mafi girman shakatawa na biyu, kuma tsarin flocculation maras kyau yana sa musayar ruwa tsakanin ciki da waje ya fi sauƙi. Bugu da ƙari, haɗuwa da ether na cellulose a cikin tsarin slurry yana ƙara inganta yanayin musayar ruwa tsakanin ciki da waje na tsarin flocculation. A daya hannun, ƙuduri rage sakamako na cellulose ether a kan CSA2 ne karfi fiye da na CSA1, wanda zai iya zama saboda da karami takamaiman surface area da ya fi girma barbashi size of CSA2, wanda shi ne mafi kula da watsawa sakamakon cellulose ether bayan. hadewa.

2.2 Canje-canje a cikin abun da ke ciki na slurry

Daga TG-DTG spectra na CSA1 da CSA2 slurries hydrated don 90 min, 150 min da 1 rana, ana iya ganin cewa nau'ikan samfuran hydration ba su canza ba kafin da bayan ƙara ether cellulose, kuma AFt, AFm da AH3 duk sun kasance. kafa. Littattafan sun nuna cewa kewayon lalata na AFt shine 50-120°C; kewayon lalata na AFm shine 160-220°C; kewayon bazuwar AH3 shine 220-300°C. Tare da ci gaban hydration, asarar nauyi na samfurin ya karu a hankali, kuma halayen DTG na AFt, AFm da AH3 a hankali sun bayyana a hankali, yana nuna cewa samuwar samfuran ruwa guda uku a hankali ya karu.

Daga yawan juzu'i na kowane samfurin hydration a cikin samfurin a shekarun hydration daban-daban, ana iya ganin cewa AFt ƙarni na samfurin blank a shekarun 1d ya wuce na samfurin da aka haɗe da ether cellulose, yana nuna cewa ether cellulose yana da tasiri mai yawa akan. hydration na slurry bayan coagulation. Akwai takamaiman tasirin jinkiri. A cikin mintuna 90, samar da AFm na samfurori guda uku ya kasance iri ɗaya; a minti 90-150, samar da AFm a cikin samfurin da ba shi da kyau ya kasance da hankali fiye da na sauran ƙungiyoyi biyu na samfurori; bayan 1 rana, abun ciki na AFm a cikin samfurin blank ya kasance daidai da na samfurin da aka haɗe da MC1, kuma abun ciki na AFm na samfurin MC2 ya ragu sosai a wasu samfurori. Amma ga hydration samfurin AH3, tsarar kudi na CSA1 blank samfurin bayan hydration na 90 minutes ya muhimmanci a hankali fiye da na cellulose ether, amma tsara kudi da aka muhimmanci da sauri bayan minti 90, da AH3 samar da adadin uku samfurori. yayi daidai da rana 1.

Bayan da CSA2 slurry aka hydrated ga 90min da 150min, adadin AFT samar a cikin samfurin gauraye da cellulose ether ya muhimmanci kasa da na blank samfurin, nuna cewa cellulose ether kuma yana da wani retarding sakamako a kan CSA2 slurry. A cikin samfurori a 1d shekaru, an gano cewa abun ciki na AFt na samfurin blank ya kasance mafi girma fiye da na samfurin da aka haɗe da ether cellulose, yana nuna cewa ether cellulose har yanzu yana da wani tasiri na raguwa a kan hydration na CSA2 bayan saitin karshe. kuma matakin jinkirtawa akan MC2 ya fi na samfurin da aka ƙara tare da ether cellulose. MC1. A cikin minti 90, adadin AH3 da aka samar da samfurin mara kyau ya kasance ƙasa da na samfurin da aka haɗe da ether cellulose; a cikin mintuna 150, AH3 da aka samar da samfurin mara kyau ya wuce na samfurin da aka haɗe da ether cellulose; a ranar 1, AH3 da samfurori guda uku suka samar ya kasance daidai.

3. Kammalawa

(1) Cellulose ether na iya inganta musayar ruwa tsakanin tsarin flocculation da tsarin flocculation. Bayan shigar da ether cellulose, ether cellulose yana tallata ruwa a cikin slurry, wanda aka kwatanta a matsayin kololuwar shakatawa na uku a cikin lokacin hutu mai jujjuyawa (T2). Tare da karuwar abun ciki na ether cellulose, shayarwar ruwa na ether cellulose yana ƙaruwa, kuma yanki na kololuwar shakatawa na uku yana ƙaruwa. Ruwan da ether cellulose ke sha yana fitowa a hankali a cikin tsarin flocculation tare da hydration na slurry.

(2) Haɗin haɗin ether na cellulose yana hana haɓakar ƙwayoyin siminti zuwa wani ɗan lokaci, yana sa tsarin flocculation yayi sako-sako da; kuma tare da haɓakar abun ciki, ƙarancin lokaci na ruwa na slurry yana ƙaruwa, kuma ether cellulose yana da tasiri mai girma akan ƙwayoyin siminti. Ingantattun tasirin adsorption yana rage ma'aunin ƴancin ruwa tsakanin sifofin flocculated.

(3) Kafin da kuma bayan haɓakar ether cellulose, nau'ikan samfuran hydration a cikin sulphoaluminate ciminti slurry bai canza ba, kuma an kafa AFt, AFm da manne aluminum; amma cellulose ether dan jinkirta samuwar samfurin hydration sakamako.