Jurnal f the Krean Ceramic Sciety Vl. 48, N. 1, pp. 80~85, 2011. DOI:10.4191/KCERS.2011.48.1.080 Effect f HF Treatment n the Crystallizatin Behavir f the Glass Cntaining Cal Bttm Ashes Sinae J and Seunggu Kang Department f Materials Engineering, Kynggi University, Suwn 443-760, Krea (Received December 30, 2010; Revised January 15, 2011; Accepted January 17, 2011) k ƒ sw y p e HF z üá» w œw (2010 12 30 ; 2011 1 15 ; 2011 1 17 ) ABSTRACT The crystallizatin behavir and micrstructural change f the glass-ceramics were analyzed as a functin f cncentratin and etching time f the HF slutin in rder t enhance the degree f crystallinity induced by hetergeneus nucleatin f glass f bttm ash cntaining 15 wt% Li 2 O. The nucleatin site seemed t be generated where the Si in was eluted. The main crystal phases in the glass-ceramics fabricated in this study were β-spdumene and Li 2 SiO 3. The specimens etched with HF f 0.5 vl% within 0~60 secnds shwed increased crystalline peak intensities in XRD pattern with etching time cmpared t n-etched ne. Als the crystal size and crystal ccupancy in the glass matrix bserved by SEM were increased with etching time. Fr the glass-ceramics etched with 1.0 and 2.0 vl% HF slutin, the etching time ver 10 s was nt effective t increase the crystallinity. Frm this study, it was fund that the glass-ceramics with the higher crystallinity culd be btained by HF-etching fllwed by heat treatment prcess, even thugh the nucleating agent r 2-stages thermal treatment prcess were nt used. Key wrds : Glass, HF etching, Glass-ceramics, Nucleatin site, Cal bttm ash 1. ü y k 6 m, 1) ey w» w ƒƒeƒ t w w w ƒ y w š. 2) k k ƒ w š ³ w w x w y. w m yw w m w ƒ y š, 3,4) w y j ù w y (glass-ceramics) w w š. 5) k l y w t yƒ ù š. 2) t yƒ r m y ƒ û,» ƒ û Crrespnding authr : Seunggu Kang E-mail : sgkang@kgu.ac.kr Tel : +82-31-249-9767 Fax : +82-31-244-8241 wš ü y(bulk crystallizatin) w» w š. ƒ wx ƒw y w w. w wx w w 2 (2-stages) š. 6) mw wx (T N ) (T P ) d w, û T N w wx jš z T P w x w j. k w w, wx ƒw ù 2 w š, r HF w wx (site) ƒ k r y. w k w ƒw û š, HF y p wš w HF ƒ y e w š w. 80
k ƒ sw y p e HF z 81 Table 1. Weight Percent f Cnstitutinal Oxides f Calcined Cal Bttm Ash and Glass Specimen (wt%) Oxide grups Acids Neutrals Bases Others Raw Materials SiO 2 ZrO 2 TiO 2 Al 2 O 3 Fe 2 O 3 K 2 O Na 2 O MgO CaO MnO Li 2 O P 2 O 5 Calcined bttm ash 58.6 0.4 1.7 23.9 10.4 0.6 0.3 1.0 2.8 0.1 0.0 0.1 Glass 49.8 0.3 1.4 20.3 8.8 0.5 0.2 0.9 2.4 0.1 15.0 0.1 2. x XRF mw k (cal bttm ash) y w Table 1 ùkü. k k ƒ 18 wt%ƒ w w» w 1000 C» 3 w w. w k 45 µm j» ü z Li 2 O 15 wt% yww g w 24 w. yw ù ƒ 1350 C» 20 min w z ƒ,, ƒ ƒ 1cm š T g (glass transitin temperature) 10 C 516 C ƒ w þƒ w w w. T g DTA mw x d w. wx (site)» w 0.5 ~ 2.0 vl% HF 0~60 ü r e(etching)w. r 45 µm w z DTA(Differential Thermal Analysis; STA 409 C/CD, Netzsch C.) mw p w. DTA l l l r y j» w w. r y w» w XRD(Xray Diffractmeter; D/MAX-C, Rigaku C.), w w FESEM(Field Emissin Scanning Electrn Micrscpe;cSM-6500F, JEOL C.) w. HF e w» w ICP-AES (Inductive Cupled Plasma- Atmic Emissin Spectrphtmeter, ICP 2070, LEEMAN LABS, Inc.) w x ww. 3. š w k 15 wt% Li 2 O ƒw y r w XRD Fig. 1 ùkü. Fig. 1 w k quartz(sio 2 ) mullite(3al 2 O 3 2SiO 2 ). k mullite k SiO 2 Al 2 O 3 w x ƒ. ƒ w» w /» Fig. 1. XRD patterns f (a) calcined cal bttm ash and (b) glass cntaining 85 wt% cal bttm ash and 15 wt% Li 2 O. Table 2. The Acid/base Oxides Rati and Basicity Calculated Based n Ml Fractin f Calcined Cal Bttm Ash and Glass Specimen Acid/base xides rati* Basicity Calcined bttm ash 11.46 0.07 Glass 1.47 0.52 * Acid/base xides rati = (RO 2 )/(R 2 O+RO) Basicity = (R 2 O+RO)/(SiO 2 +Al 2 O 3 +Fe 2 O 3 +TiO 2 ) y» w Table 2 ùkü. Andrews v p(frit)ƒ» w /» y 1~3 w frit rule w. k /» y 7) 11.46 frit rule ù j» ƒ. Li 2 O 15 wt% ƒw /» y 1.47 frit rule ƒ, x w d. w» (basicity)ƒ ƒ š,». 8) Basicity = (R 2 O + RO)/(SiO 2 +Al 2 O 3 +Fe 2 O 3 +TiO 2 )» R=1 2. 48«1y(2011)
82 üá Fig. 2. DTA curve fr glass specimen measured at heating rates f 20 Cmin 1. üy d w» ƒ 0.01 w» w ( )ƒ 50 C û š. k» 0.07 m 9) 0.03~0.06 ƒà. ù Li 2 O 15 wt% ƒw» 0.52 j š, ƒ. k 1600 C ù Li 2 O 15 wt% ƒw 1350 C š, w û x w. Li 2 O 15 wt% ƒw r XRD (Fig. 1) vjƒ x ùkù x (nn-crystalline) ql ùkü. l w k y w. Li 2 Oƒ 15 wt% ƒ wš þ k r w DTA x ww Fig. 2 ùkü. 506 C vj (T g ) ùkü š, 668 C vj yƒ ù w. r y j» w vj 668 Cƒ óù (732 C) 5 ww. DTA w» y kinetics w. (1) txw Jhnsn- Mehl- Avrami(JMA). 10,11) n lnα( 1 x) kt =» α DTA d ƒ š, x t (1) Fig. 3. XRD peak patterns f glass-ceramics sintered at 732 C/ 5 hrs as a functin f varius HF-etching times at 0.5 vl% HF slutin. Fig. 4. XRD peak patterns f glass-ceramics sintered at 732 C/ 5 hrs as a functin f varius HF-etching times at 1.0 vl% HF slutin. y v, n (Avrami). n 1 ƒ¾ t yƒ wš 3~4 ü y w š. 10) Chi k n 1.97 w, l ü y t yƒ w š šw. 2) r ü y» w r w (site) š HF ww., ³ w (hetergeneus nucleatin) w yƒ w. w r w» 0.5, 1.0 š 2.0 vl% HF 10~60 e(etching)w. w wz
석탄바닥재가 포함된 유리의 결정화 특성에 미치는 HF 처리 효과 83 한편, 1.0 vl% HF에 10초 처리된 시편들의 경우 (Fig. 4) 전혀 처리하지 않은 경우에 비해 β-spdumene 피크가 증 가되었으나, 60초 이상이 되면 β-spdumene 및 Li SiO 결정피크 강도가 다시 줄어드는 것으로 나타났다. 2.0 vl% HF 용액에 10초 처리된 시편(Fig. 5) 역시 HF 처리되지 않은 경우에 비하여 결정상 피크들의 강도가 증가되었다. 그러나 처리 시간을 60초로 늘리면 오히려 β-spdumene 및 Li SiO 의 주피크 강도가 크게 줄어드는 것으로 나타 났다. 이처럼 1.0 내지 2.0 vl% HF 용액으로 처리한 경 우 60초 동안 에칭한 것이 10초에 비해 오히려 결정화도 가 낮아지는 이유에 대한 정량적 해석은 추가연구가 필 요하다고 생각된다. Fig. 6은 여러 조건으로 HF 처리한 유리를 결정화시킨 시편의 미세구조 관찰 사진이다. 먼저 HF 처리를 전혀 하 지 않은 결정화 유리의 미세구조를 보면, 0.1 µm 크기의 결정입자들이 생성되었으나 유리 모상(martix)에서의 결정 점유율은 크지 않은 것을 알 수 있다. 농도에 관계없이 HF로 10초간 처리된 시편들의 모상 내 결정 점유율이 HF 처리되지 않은 시편에 비해 높아진 것을 관찰할 수 있다. 또한 0.5 vl% HF 용액으로 처리된 경우, 처리시간을 60 초로 늘리면 10초간 처리된 시편에 비해 결정 점유율이 매우 높아졌다. 1.0 vl% HF 용액으로 10초간 처리된 시편의 미세구조 는 처리하지 않은 것에 비해 결정입자의 크기가 증가하 2 2 Fig. 5. XRD peak patterns f glass-ceramics sintered at 732C/5 h as a functin f varius HF-etching times at 2.0 vl% HF slutin. Figs. 3~5는 유리시편을 농도 및 처리시간을 변수로 HF 용액으로 에칭한 후 열처리하여 결정화된 시편들의 XRD 측정결과이다. 0.5 vl%의 HF로 처리된 시편의 경우(Fig. 3) 유지시간이 길어질수록 결정화가 증가하는 것을 볼 수 있 었다. 즉, 0.5 vl% HF에 60초간 처리된 시편의 경우, 처 리되지 않은 시편에 비해 β-spdumene 및 Li SiO 결정상 피크 강도가 더 증가된 것을 볼 수 있다. 2 Fig. 6. 3 3 3 Micrstructures f glass-ceramics bserved by SEM as a functin f treatment time and cncentratin f HF slutin. 제 48 권 제1호(2011)
84 üá Table 3. The Cncentratin f Catins Eluted frm the Glass by 1.0 vl% HF Slutin fr 30 s (ppm) Si Ca Al Li Fe 78.80 0.34 1.03 0.73 0.97 š ü ƒ. ù 60 j»ƒ ƒ ¼ w ù. w w 2.0 vl% HF r ùkû. 60 r 10 w ƒw. r ü ƒ 0.5 vl% HF 60., HF 10 w ƒ, 60 ƒ z 0.5 vl% ùkû. HF ƒ w û Figs. 3~5 XRD vj ew. r 1.0 vl% HF 30 ew ICP ww Table 3 ùkü. ƒ Si 78.8 ppm. 11.84 ml%ƒ w Al 1.03 ppm. Si ƒ r HF j F - Si w(nuclephilic) k H + O (electrphilic) g òsi-o-siò w ñ». 12,13) ü Al mle» Si 50% (Table 1) ù Si w. 4 Al òal-o-siò w òsi-o-siò w Al e w w. w ICP l HF w Si ù wx ƒ. mw 0.5~2.0 vl% HF 10~60 w 15 wt% Li 2 O w w w XRD l ü yƒ w w. p 0.5 vl% HF 60 w r, wx ù 2 œ w š k HF e w w y ƒ y (glass-ceramics) w y w. w wz 4. k 15 wt% Li 2 O yww û w, 0.5~ 2.0 vl% HF 10~60 ew wx (site) ƒ k r y. HF e ƒ Si l wx Si ù e. r β-spdumene Li 2 SiO 3ƒ. 0.5 vl% HF r ¼ β-spdumene Li 2 SiO 3 vj ƒ ƒ w. wr, 1.0 2.0 vl% HF 10 r x w w β-spdumene v jƒ ƒ ù, 60 β-spdumene Li 2 SiO 3 vj ƒ., HF w y 0.1 µm j» ù (martix) j. HF 10 r ü HF r w. 0.5 vl% HF, 60 10 r w ù, 1.0 2.0 vl% HF r 60. mw 0.5~2.0 vl% HF 10~60 w 15 wt% Li 2 O w w wx ù 2 œ w š HF e w w y ƒ y (glass-ceramics) w y w. REFERENCES 1. Krea Electric Pwer Crpratin, The Mnthly Reprt n Majr Electric Pwer Statistics, Krea, N. 334, 2006. 2. C. P. Chi and S. G. Kang, Crystallizatin Behavir at Nucleatin Sites n the Surfaces f Vitreus Materials Laded with Cal Bttm Ash, J. Kr. Phys. Sc., 54 [3] 1320-4 (2009). 3. K. D. Kim and S. G. Kang, Manufacturing Artificial Lightweight Aggregates Using Cal Bttm Ash and Clay, J. Kr. Cryst. Grw. and Cryst. Tech., 17 [6] 227-82 (2007). 4. J. T. Sng, S. D. Yun, D. W. Ryu, and K. S. Han, Manufacture and Prperties f Cal Fly Ash-Clay Bdy, J. Kr. Ceram. Sc., 33 [7] 771-8 (1996). 5. S. J. Jang and S. G. Kang, Micrstructural Analysis f Hybrid Materials Cmpsed f Nepheline Crystals and a Glass Matrix Fabricated frm Cal Bttm Ash, J. Ceram. Pr. Res., 10 [1] 59-63 (2009).
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