高嶺石鋁矽酸鹽聚合材料之研究

A Study on Geopolymerization of Kaolinite Aluminosilicate Materials

戴詩潔(Shih-Chieh Tai)

指導教授 ： 鄭大偉

國立臺北科技大學/工程學院/材料及資源工程系所/碩士(2005年)

https://doi.org/10.6841/NTUT.2005.00057

摘要

無機聚合物主要由富含矽、鋁之原料、鹼性溶液與鹼金屬矽酸鹽溶液混合製成。由於高嶺石富含Si、Al離子，在高鹼性環境中，於高嶺石表面會析出Si、Al離子，加入矽酸鈉溶液，開始產生凝結反應，經由乾燥脫水作用後，即可硬化形成具有架狀結構之聚合物。高嶺石經由高溫焙燒形成之變高嶺石，於鹼性溶液中，較高嶺石更易析出Si、Al離子，故高嶺石中表面析出Si、Al離子的多寡及膠體鍵結的形式、鹼性溶液的種類、鹼性溶液pH值及濃度、高嶺石之焙燒溫度與持溫時間，皆會影響無機聚合物之最終性質。此外，SiO2/M2O莫耳比、養護溫度與養護時間也會影響無機聚合物之性質。

本研究主要以高嶺石或變高嶺石與不同濃度的鹼性溶液混合進行溶出試驗，探討Si、Al離子溶出量對無機聚合物抗壓強度之影響。同時針對高嶺石不同焙燒溫度與持溫時間，及鹼性溶液與矽酸鈉溶液中SiO2/M2O莫耳比對無機聚合物之影響進行探討，並以鹼度測定探討其與無機聚合物表面生成重碳酸鹽之關係，以尋求無機聚合物最佳製作條件。

研究結果顯示鹼性溶液之濃度與種類、溶出時間均會影響高嶺石與變高嶺石中矽、鋁膠體之溶出量，進而影響無機聚合物各項性質。無機聚合物之抗壓強度與Si、Al離子溶出量呈正比；於高嶺石焙燒溫度與持溫時間方面，以焙燒溫度650℃持溫3小時所得之變高嶺石製成無機聚合物有較佳性質。此外，SiO2/M2O莫耳比過高或過低，對無機聚合物之影響較大，其中SiO2/M2O莫耳比範圍於0.29∼0.5可得最佳性質之無機聚合物。

關鍵字

無機聚合物 ； 高嶺石 ； 變高嶺石 ； 重碳酸鹽

並列摘要

Geopolymer, an inorganic polymer, has been gradually attracting world attention as potentially innovative materials due to their great physical/mechanical properties. Three basic sources are needed for geopolymer synthesis, i.e. raw materials, active filler, and alkaline liquor. Many studies have used the metalaolinite as main supporting Al ion material, and most of these metakaolinite were produced by calcining kaolinite at the temperature of 750℃ for several hours. Little work has been undertaken to determine the properties of geopolymers on the relationship between different temperatures sintered metakaolinite. The current research work is fundamentally investigated the effect of various temperatures sintered metakaolinite on the properties of geopolymers. Metakaolinites by different temperature sintered were measured by DTA, XRD and BET. It is interesting to found from DTA results that the maximum mass loss of dehydration of kaolinite occurs at the sintering temperature of 650℃ and reached to 11wt%. The compressive strength of the geopolymer manufactured by using 650℃ sintered metakaolinite also obtained the best strength result.

After fabricating geopolymer for few weeks, it sometimes can be found white materials on the surface of geopolymer. From XRD results, this surface salt is trona that was found due to excess of K or Na ions reacted with CO2 from the atmosphere. Alkali titration tests were carried out to measure hydroxide, carbonate and bicarbonate in various geopolymers in order to understand that the interrelationship between different temperatures sintered metakaolinite and mechanical properties. Experimental results show that the amount of hydroxide in geopolymer decreased with increasing curing days and kaolinite sintering temperature. The higher the compressive strength of the geopolymer, the less of the hydroxide contains in the geopolymer. Carbonate contents are increasing while kaolinite sintered at lower temperatures and short heat treatment times. It is also interesting to found that the quantity of bicarbonate will decrease when the geopolymer compressive strength increase. This could because geopolymers have better structures, therefore, lower content of the residues of K and Na ions on the surface to produce bicarbonate.

並列關鍵字

Geopolymer ； Kaolinite ； Metakaolinite ； Bicarbonate

參考文獻

[1] Xu H. and Van Deventer, J.S.J., The geopolymerisation of alumino-silicate minerals, International Journal Minerals Process, Vol. 59, pp. 247-266, 2000.

[6] Van Jaarsveld, J.G.S., Van Deventer, J.S.J. and Schwartzman, A., The potential use of geopolymeric materials to immobilise toxic Metals：Part Ⅱ. Minerals and characteristics, Minerals Engineering, Vol. 12, No. 1, pp. 75-91, 1999a.

[9] Chakraborty, K.A., DTA study of preheated kaolinite in the mullite formation region, Thermochimica Acta, Vol. 398, pp. 203-209, 2003.

[11] Phair, J.W. and Van Deventer, J.S.J., Effect of silicate activator pH on the leaching and material characteristics of waste-based inorganic polymers, Minerals Engineering, Vol. 14, No. 3, pp. 289-304, 2001.

[12] Van Jaarsveld, J.G.S., Van Deventer, J.S.J. and Lukey, G.C., The effect of composition and temperature on the properties of fly ash-and kaolinite-based geopolymers, Cemical Engineering Jouranl, Vol. 89, pp. 63-73, 2002.