Zotsatira za ma cellulose ethers pakusintha kwamadzi ndi zinthu za hydration za sulphoaluminate simenti paste.

Zigawo zamadzi ndi kusintha kwa microstructure mu cellulose ether modified sulphoaluminate simenti (CSA) slurry anaphunzira ndi otsika kumunda nyukiliya maginito resonance ndi matenthedwe analyzer. Zotsatira zake zidawonetsa kuti pambuyo pakuwonjezera kwa cellulose ether, idatulutsa madzi pakati pazigawo za flocculation, zomwe zidawoneka ngati nsonga yachitatu yopumula mu mawonekedwe a transverse relaxation time (T2), komanso kuchuluka kwa madzi adsorbed kumalumikizidwa bwino ndi mlingo. Kuphatikiza apo, ether ya cellulose idathandizira kwambiri kusinthana kwamadzi pakati pamitundu yamkati ndi yapakati-floc ya CSA flocs. Ngakhale Kuwonjezera kwa mapadi ether alibe mphamvu pa mitundu ya mankhwala hydration wa sulphoaluminate simenti, izo zidzakhudza kuchuluka kwa mankhwala hydration a m'badwo winawake.

Mawu ofunikira:cellulose ether; simenti ya sulfoaluminate; madzi; mankhwala a hydration

0,Mawu Oyamba

Ma cellulose ether, omwe amapangidwa kuchokera ku cellulose yachilengedwe kudzera m'njira zingapo, ndiwongowonjezedwanso komanso wobiriwira wosakanikirana ndi mankhwala. Ma cell cellulose ethers monga methylcellulose (MC), ethylcellulose (HEC), ndi hydroxyethylmethylcellulose (HEMC) amagwiritsidwa ntchito kwambiri mu zamankhwala, zomangamanga ndi mafakitale ena. Kutenga HEMC monga chitsanzo, ikhoza kupititsa patsogolo kusungirako madzi ndi kusasinthasintha kwa simenti ya Portland, koma kuchedwetsa kukhazikitsa simenti. Pamlingo wa microscopic, HEMC imathandizanso kwambiri pakupanga ma microstructure ndi pore ya phala la simenti. Mwachitsanzo, hydration product ettringite (AFt) imakhala yowoneka ngati ndodo yayifupi, ndipo mawonekedwe ake ndi otsika; panthawi imodzimodziyo, ma pores ambiri otsekedwa amalowetsedwa mu phala la simenti, kuchepetsa chiwerengero cha pores kulankhulana.

Ambiri mwa maphunziro omwe alipo pa chikoka cha ma cellulose ethers pazinthu zopangira simenti amayang'ana pa simenti ya Portland. Simenti ya Sulphoaluminate (CSA) ndi simenti yotsika kaboni yokhazikika yomwe idapangidwa mdziko langa m'zaka za zana la 20, yokhala ndi anhydrous calcium sulphoaluminate monga mchere waukulu. Chifukwa kuchuluka kwa AFt kumatha kupangidwa pambuyo pa hydration, CSA ili ndi zabwino zake zoyambira mphamvu, kusasunthika kwakukulu, komanso kukana dzimbiri, ndipo imagwiritsidwa ntchito kwambiri posindikiza konkire ya 3D, zomangamanga zam'madzi zam'madzi, ndikukonzanso mwachangu m'malo otentha. . M'zaka zaposachedwa, Li Jian et al. adasanthula chikoka cha HEMC pa matope a CSA kuchokera pamalingaliro amphamvu yopondereza ndi kachulukidwe konyowa; Wu Kai et al. anaphunzira zotsatira za HEMC pa njira yoyambirira ya hydration ya simenti ya CSA, koma madzi mu simenti ya CSA yosinthidwa Lamulo la kusinthika kwa zigawo ndi slurry kapangidwe sichidziwika. Kutengera izi, ntchitoyi imayang'ana pa kugawa nthawi yopumula (T2) mu slurry ya simenti ya CSA isanayambe komanso itatha kuwonjezera HEMC pogwiritsa ntchito chida chotsika cha nyukiliya cha nyukiliya, ndikuwunikanso kusamuka ndikusintha lamulo la madzi mu slurry. Kusintha kwapangidwe kwa phala la simenti kunawerengedwa.

1. Yesani

1.1 Zopangira

Simenti ziwiri za sulphoaluminate zogulitsidwa zinagwiritsidwa ntchito, zomwe zimatchedwa CSA1 ndi CSA2, ndi kutaya pamoto (LOI) osachepera 0.5% (gawo la misa).

Ma hydroxyethyl methylcellulose atatu osiyanasiyana amagwiritsidwa ntchito, omwe amatchedwa MC1, MC2 ndi MC3 motsatana. MC3 imapezeka posakaniza 5% (chigawo chambiri) polyacrylamide (PAM) mu MC2.

1.2 Chiŵerengero cha kusakaniza

Mitundu itatu ya ma cellulose ethers idasakanizidwa mu simenti ya sulphoaluminate motsatana, Mlingowo unali 0.1%, 0.2% ndi 0.3% (gawo la misa, lomwe lili pansipa). Chiŵerengero chokhazikika cha simenti yamadzi ndi 0,6, ndipo chiŵerengero cha simenti cha madzi cha simenti yamadzi chimakhala ndi ntchito yabwino ndipo palibe kutuluka kwa magazi kudzera muyeso la kumwa madzi la kugwirizana kofanana.

1.3 Njira

Zida zotsika za NMR zomwe zimagwiritsidwa ntchito poyesera ndi PQ⁃001 NMR analyzer yochokera ku Shanghai Numei Analytical Instrument Co., Ltd. Mphamvu ya maginito ya maginito okhazikika ndi 0.49T, ma frequency a proton resonance ndi 21MHz, ndipo kutentha kwa maginito kumakhala kosasintha pa 32.0°C. Panthawi ya mayesero, botolo la galasi laling'ono lomwe lili ndi chitsanzo cha cylindrical linayikidwa mu probe coil ya chida, ndipo ndondomeko ya CPMG inagwiritsidwa ntchito kusonkhanitsa chizindikiro chotsitsimula cha phala la simenti. Pambuyo pakutembenuzidwa ndi pulogalamu yowunikira ma correlation, curve ya T2 inversion idapezedwa pogwiritsa ntchito algorithm ya Sirt inversion. Madzi okhala ndi magawo osiyanasiyana aufulu mu slurry adzakhala ndi nsonga zopumula mosiyanasiyana, ndipo malo opumula amalumikizana bwino ndi kuchuluka kwa madzi, kutengera mtundu ndi zomwe zili m'madzi mu slurry. akhoza kufufuzidwa. Kuti apange nyukiliya maginito resonance, m'pofunika kuonetsetsa kuti pakati pafupipafupi O1 (unit: kHz) wa ma frequency wailesi n'zogwirizana ndi pafupipafupi maginito, ndi O1 calibrated tsiku lililonse mayeso.

Zitsanzozi zidawunikidwa ndi TG?DSC yokhala ndi STA 449C kuphatikiza matenthedwe analyzer ochokera ku NETZSCH, Germany. N2 idagwiritsidwa ntchito ngati malo otetezera, kutentha kwapakati kunali 10°C/mphindi, ndi kusanthula kutentha osiyanasiyana anali 30-800°C.

2. Zotsatira ndi zokambirana

2.1 Kusintha kwa zigawo za madzi

2.1.1 Ma cellulose ether osatsegulidwa

Nsonga ziwiri zopumula (zotanthauzidwa ngati nsonga zotsitsimula zoyamba ndi zachiwiri) zitha kuwoneka bwino mu nthawi yopumula (T2) yamitundu iwiri ya simenti ya sulphoaluminate. Chiyembekezo choyamba chotsitsimula chimachokera mkati mwa mawonekedwe a flocculation, omwe ali ndi ufulu wochepa komanso nthawi yochepa yopumula; nsonga yachiwiri yopumula imachokera pakati pa mapangidwe a flocculation, omwe ali ndi ufulu wambiri komanso nthawi yayitali yopumula. Mosiyana ndi izi, T2 yofanana ndi nsonga yoyamba yopumula ya simenti ziwirizo ikufanana, pomwe nsonga yachiwiri yopumula ya CSA1 imawonekera pambuyo pake. Zosiyana ndi klinka ya simenti ya sulphoaluminate ndi simenti yodzipangira yokha, nsonga ziwiri zopumula za CSA1 ndi CSA2 zimadutsana pang'ono ndi momwe zinalili poyamba. Ndi kupita patsogolo kwa hydration, nsonga yoyamba yopumula pang'onopang'ono imakhala yodziyimira payokha, dera limachepa pang'onopang'ono, ndipo limasowa kwathunthu pafupifupi mphindi 90. Izi zikuwonetsa kuti pali kusinthana kwamadzi pakati pa mawonekedwe a flocculation ndi mawonekedwe a flocculation a phala la simenti iwiri.

Kusintha kwa nsonga ya nsonga ya nsonga yachiwiri yopumula ndi kusintha kwa mtengo wa T2 womwe umagwirizana ndi nsonga ya nsonga motsatana kukuwonetsa kusintha kwa madzi aulere ndi madzi omangidwa ndi thupi komanso kusintha kwa kuchuluka kwa ufulu wamadzi mu slurry. . Kuphatikizika kwa ziwirizi kumatha kuwonetsa momveka bwino njira ya hydration ya slurry. Ndi kupita patsogolo kwa hydration, gawo lapamwamba limachepa pang'onopang'ono, ndipo kusuntha kwa mtengo wa T2 kumanzere kumawonjezeka pang'onopang'ono, ndipo pali ubale wina wofananira pakati pawo.

2.1.2 Anawonjezera cellulose ether

Kutenga CSA2 yosakanikirana ndi 0.3% MC2 mwachitsanzo, mawonekedwe opumula a T2 a simenti ya sulphoaluminate atawonjezera cellulose ether amatha kuwoneka. Pambuyo powonjezera ma cellulose ether, nsonga yachitatu yopumula yoyimira kutengeka kwa madzi ndi cellulose ether idawonekera pamalo pomwe nthawi yopumula yodutsa inali yayikulu kuposa 100ms, ndipo chigawo chapamwamba chinawonjezeka pang'onopang'ono ndikuwonjezeka kwa cellulose ether.

Kuchuluka kwa madzi pakati pa mapangidwe a flocculation kumakhudzidwa ndi kusamuka kwa madzi mkati mwa dongosolo la flocculation ndi madzi adsorption a cellulose ether. Choncho, kuchuluka kwa madzi pakati pa flocculation nyumba zimagwirizana ndi mkati pore dongosolo slurry ndi madzi adsorption mphamvu ya mapadi ether. Chigawo chachiwiri chopumula chimasiyana ndi Zomwe zili mu cellulose ether zimasiyana ndi mitundu yosiyanasiyana ya simenti. Dera la nsonga yachiwiri yopumula ya CSA1 slurry idatsika mosalekeza ndi kuchuluka kwa cellulose ether, ndipo inali yaying'ono kwambiri pa 0.3%. Mosiyana ndi izi, gawo lachiwiri lopumula la CSA2 slurry limawonjezeka mosalekeza ndi kuchuluka kwa cellulose ether.

Lembani kusintha kwa dera lachitukuko chachitatu chopumula ndi kuwonjezeka kwa zomwe zili mu cellulose ether. Popeza kuti malo okwera kwambiri amakhudzidwa ndi khalidwe lachitsanzo, n'zovuta kutsimikizira kuti khalidwe lachitsanzo lowonjezera ndilofanana poika chitsanzo. Choncho, chiŵerengero cha dera chimagwiritsidwa ntchito kusonyeza kuchuluka kwa chizindikiro cha nsonga yachitatu yopumula mu zitsanzo zosiyanasiyana. Kuchokera pakusintha kwa gawo la nsonga yachitatu yopumula ndi kuchuluka kwa zomwe zili mu cellulose ether, zitha kuwoneka kuti pakuwonjezeka kwa zomwe zili mu cellulose ether, gawo la nsonga yachitatu yopumula likuwonetsa kuchulukirachulukira (mu. CSA1, pamene zili MC1 anali 0,3%, anali zambiri Dera lachitatu zosangalatsa pachimake amachepetsa pang'ono pa 0.2%), kusonyeza kuti ndi kuwonjezeka zili mapadi ether, madzi adsorbed nawonso pang'onopang'ono kumawonjezeka. Pakati pa CSA1 slurries, MC1 inali ndi mayamwidwe abwinoko amadzi kuposa MC2 ndi MC3; pomwe pakati pa CSA2 slurries, MC2 inali ndi mayamwidwe abwino kwambiri amadzi.

Zitha kuwonedwa pakusintha kwa gawo la nsonga yachitatu yopumula pamlingo wa CSA2 slurry ndi nthawi yomwe ili ndi 0.3% cellulose ether kuti dera lachitatu lopumula pachimake pa unit misa limachepa mosalekeza ndi hydration, kuwonetsa. kuti Popeza mlingo wa hydration wa CSA2 ndi mofulumira kuposa clinker ndi kudzipangira simenti, mapadi etere alibe nthawi zina madzi adsorption, ndi kumasula madzi adsorbed chifukwa mofulumira kuwonjezeka madzi gawo ndende mu slurry. Kuphatikiza apo, ma adsorption amadzi a MC2 ndi amphamvu kuposa a MC1 ndi MC3, omwe amagwirizana ndi zomwe zidachitika kale. Zitha kuwoneka kuchokera pakusintha kwa malo okwera pachimake pa nsonga ya chiwongolero chachitatu cha CSA1 ndi nthawi yosiyana 0.3% ya milingo ya cellulose ethers kuti kusintha kwa lamulo lachitatu lakupumula kwa CSA1 ndi losiyana ndi la CSA2, ndipo dera la CSA1 limawonjezeka mwachidule kumayambiriro kwa hydration. Pambuyo pakuchulukirachulukira, idatsika ndikuzimiririka, zomwe zitha kukhala chifukwa cha kutsekeka kwanthawi yayitali kwa CSA1. Komanso, CSA2 lili gypsum zambiri, hydration n'zosavuta kupanga kwambiri AFt (3CaO Al2O3 3CaSO4 32H2O), amadya madzi ambiri aulere, ndi mlingo wa kumwa madzi kuposa mlingo wa madzi adsorption ndi cellulose ether, zomwe zingachititse The gawo la nsonga yachitatu yopumula ya CSA2 slurry idapitilira kuchepa.

Pambuyo pakuphatikizidwa kwa cellulose ether, nsonga zopumula zoyamba ndi zachiwiri zidasinthanso pang'ono. Zitha kuwonedwa kuchokera pachimake m'lifupi mwake nsonga yachiwiri yopumula ya mitundu iwiri ya simenti yotayirira komanso slurry yatsopano mutawonjezera mapadi a cellulose kuti m'lifupi mwake pachimake chachiwiri chopumula cha slurry yatsopano ndi yosiyana pambuyo powonjezera cellulose ether. kuwonjezeka, mawonekedwe a nsonga amatha kufalikira. Izi zikusonyeza kuti kuphatikizika kwa mapadi efa kumathandiza agglomeration wa particles simenti kumlingo wakuti, zimapangitsa dongosolo flocculation ndi lotayirira, kufooketsa kumanga digiri ya madzi, ndipo kumawonjezera mlingo wa ufulu wa madzi pakati pa nyumba flocculation. Komabe, ndi kuwonjezeka kwa mlingo, kuwonjezeka kwa m'lifupi mwake sikukuwonekera, ndipo m'lifupi mwake mwa zitsanzo zina zimachepa. Zingakhale kuti kuwonjezeka kwa mlingo kumawonjezera mamasukidwe akayendedwe a madzi gawo la slurry, ndipo pa nthawi yomweyo, ndi adsorption wa mapadi efa kuti particles simenti kumatheka chifukwa flocculation. Mlingo wa ufulu wa chinyezi pakati pa mapangidwewo umachepetsedwa.

Kutsimikiza kungagwiritsidwe ntchito kufotokoza kuchuluka kwa kulekana pakati pa nsonga zopumula zoyamba ndi zachiwiri. Mlingo wa kulekana ukhoza kuwerengedwa molingana ndi mlingo wa chisankho = (Chigawo cha Afirst-Asaddle) / gawo la Afirst, pamene gawo la Afirst ndi Asaddle likuyimira matalikidwe apamwamba a nsonga yoyamba yopuma komanso matalikidwe a malo otsika kwambiri pakati pa nsonga ziwirizo, motsatira. Mlingo wa kulekana ungagwiritsidwe ntchito kuwonetsa kuchuluka kwa kusinthana kwa madzi pakati pa slurry flocculation structure ndi flocculation structure, ndipo mtengo wake nthawi zambiri ndi 0-1. Mtengo wapamwamba wa Kulekanitsa umasonyeza kuti magawo awiri a madzi ndi ovuta kusinthanitsa, ndipo mtengo wofanana ndi 1 umasonyeza kuti magawo awiri a madzi sangathe kusinthanitsa konse.

Zitha kuwoneka kuchokera ku zotsatira zowerengera za digiri yolekanitsa kuti digiri yolekanitsa ya simenti ziwiri popanda kuwonjezera mapadi a cellulose ndi ofanana, onse ndi pafupifupi 0,64, ndipo digiri yolekanitsa imachepetsedwa kwambiri pambuyo powonjezera cellulose ether. Kumbali imodzi, chigamulocho chimachepetsanso ndi kuwonjezeka kwa mlingo, ndipo kuthetsa kwa nsonga ziwirizo kumatsikira ku 0 mu CSA2 kusakaniza ndi 0,3% MC3, kusonyeza kuti cellulose ether imalimbikitsa kwambiri kusinthana kwa madzi mkati ndi pakati pa flocculation mapangidwe . Kutengera kuti kuphatikizika kwa cellulose ether sikukhala ndi zotsatirapo pa malo ndi malo a pachimake chotsitsimula choyamba, titha kunena kuti kuchepa kwa chigamuloko kumakhala chifukwa cha kuchuluka kwa m'lifupi mwa nsonga yachiwiri yopumula, komanso mawonekedwe omasuka a flocculation amachititsa kusinthana kwa madzi pakati pa mkati ndi kunja kukhala kosavuta. Kuphatikiza apo, kuphatikizika kwa cellulose ether mu kapangidwe ka slurry kumapangitsanso kusinthana kwamadzi pakati pamkati ndi kunja kwa kapangidwe ka flocculation. Komano, chigamulo kuchepetsa zotsatira za mapadi efa pa CSA2 ndi wamphamvu kuposa CSA1, amene angakhale chifukwa ang'onoang'ono enieni pamwamba m'dera ndi lalikulu tinthu kukula kwa CSA2, amene ali tcheru kwambiri kubalalitsidwa zotsatira za mapadi efa pambuyo. kuphatikiza.

2.2 Kusintha kwa kapangidwe ka slurry

Kuchokera pazithunzi za TG-DTG za CSA1 ndi CSA2 slurries hydrated kwa 90 min, 150 min ndi 1 tsiku, zikhoza kuwoneka kuti mitundu ya mankhwala a hydration sinasinthe isanayambe komanso itatha kuwonjezera cellulose ether, ndipo AFt, AFm ndi AH3 zonse zinali. anapanga. Zolembazo zikuwonetsa kuti kuwonongeka kwa AFt ndi 50-120°C; Kuwola kwa AFm ndi 160-220°C; Kuwonongeka kwa AH3 ndi 220-300°C. Ndi kupita patsogolo kwa hydration, kulemera kwa chitsanzo kunakula pang'onopang'ono, ndipo khalidwe la DTG nsonga za AFt, AFm ndi AH3 pang'onopang'ono zinakhala zoonekeratu, zomwe zimasonyeza kuti mapangidwe atatu a hydration akuwonjezeka pang'onopang'ono.

Kuchokera ku gawo lalikulu la mankhwala a hydration mu chitsanzo pa mibadwo yosiyana ya hydration, zikhoza kuwoneka kuti AFt mbadwo wa zitsanzo zopanda kanthu pa zaka za 1d zimaposa chitsanzo chosakanikirana ndi cellulose ether, kusonyeza kuti cellulose ether imakhala ndi chikoka chachikulu pa. hydration wa slurry pambuyo coagulation. Pali kuchedwa kwina. Pamphindi 90, kupanga kwa AFm kwa zitsanzo zitatu kunalibe chimodzimodzi; pa 90-150 mphindi, kupanga AFm mu chitsanzo chopanda kanthu kunali kochepa kwambiri kusiyana ndi magulu ena awiri a zitsanzo; pambuyo pa tsiku la 1, zomwe zili mu AFm m'chitsanzo chopanda kanthu zinali zofanana ndi za chitsanzo chosakanikirana ndi MC1, ndipo zomwe AFm zili mu MC2 zinali zochepa kwambiri mu zitsanzo zina. Ponena za mankhwala a hydration AH3, chiwerengero cha mbadwo wa CSA1 wopanda kanthu pambuyo pa hydration kwa mphindi 90 chinali chochepa kwambiri kuposa cha cellulose ether, koma chiwerengero cha m'badwo chinali mofulumira kwambiri pambuyo pa mphindi 90, ndi AH3 kupanga kuchuluka kwa zitsanzo zitatu. zinali zofanana ndi tsiku limodzi.

Pambuyo pa CSA2 slurry hydrated kwa 90min ndi 150min, kuchuluka kwa AFT komwe kunapangidwa mu chitsanzo chosakanikirana ndi cellulose ether kunali kochepa kwambiri kusiyana ndi chitsanzo chopanda kanthu, kusonyeza kuti cellulose ether nayenso anali ndi zotsatira zina zochepetsera pa CSA2 slurry. Mu zitsanzo pa zaka 1d, anapeza kuti AFt zili mu chitsanzo chosoweka akadali apamwamba kuposa chitsanzo osakaniza mapadi ether, kusonyeza kuti mapadi efa akadali ndi zina retardation zotsatira pa hydration wa CSA2 pambuyo kukhazikitsidwa komaliza, ndipo kuchuluka kwa kuchedwa pa MC2 kunali kwakukulu kuposa kwachitsanzo chowonjezeredwa ndi cellulose ether. MC1. Pamphindi 90, kuchuluka kwa AH3 kopangidwa ndi chitsanzo chopanda kanthu kunali kochepa pang'ono kusiyana ndi chitsanzo chosakanikirana ndi cellulose ether; pa maminiti a 150, AH3 yopangidwa ndi chitsanzo chopanda kanthu inaposa chitsanzo chosakanikirana ndi cellulose ether; pa tsiku la 1, AH3 yopangidwa ndi zitsanzo zitatu inali yofanana.

3. Mapeto

(1) Ma cellulose ether amatha kulimbikitsa kwambiri kusinthana kwa madzi pakati pa kapangidwe ka flocculation ndi kapangidwe ka flocculation. Pambuyo pa kuphatikizika kwa cellulose ether, cellulose ether imakondera madzi mu slurry, yomwe imadziwika ngati nsonga yachitatu yopumula mu sipekitiramu ya transverse relaxation (T2). Ndi kuchuluka kwa zomwe zili mu cellulose ether, kuyamwa kwamadzi kwa cellulose ether kumawonjezeka, ndipo gawo lachitatu lopumula limawonjezeka. Madzi otengedwa ndi cellulose ether amamasulidwa pang'onopang'ono mu dongosolo la flocculation ndi hydration ya slurry.

(2) Kuphatikizidwa kwa cellulose ether kumalepheretsa kuphatikizika kwa tinthu tating'ono ta simenti kumlingo wina, kupanga kapangidwe ka flocculation kukhala kotayirira; ndi kuchuluka kwa okhutira, ndi madzi gawo mamasukidwe akayendedwe a slurry ukuwonjezeka, ndi mapadi ether ali ndi yaikulu kwambiri pa simenti particles. The kumatheka adsorption zotsatira amachepetsa mlingo wa ufulu madzi pakati pa flocculated nyumba.

(3) Isanayambe komanso itatha kuwonjezeredwa kwa cellulose ether, mitundu ya mankhwala a hydration mu sulphoaluminate simenti slurry sinasinthe, ndipo AFt, AFm ndi aluminium guluu zinapangidwa; koma cellulose ether anachedwetsa pang'ono mapangidwe hydration mankhwala zotsatira.