隨著人口的增加與經濟的快速發展，廢棄物之妥善處理與處置已成為世界各國面臨的重要課題。台電燃煤電廠每年有近200萬公噸的煤灰產量，分別為80%的飛灰，及20%的底灰。如何將這大量的廢棄物做好回收及再利用，以期減少煤灰對環境之衝擊，相關各界莫不投注龐大之人力及物力。以民國88年為例，飛灰利用率已高達89.7%。然而相較之下，底灰之再利用卻相當少，僅有6.2%。底灰內所含豐富的化學元素，正是製造玻璃所需要的原料。故本研究以底灰為原料製成玻璃陶瓷，不但可以將廢棄物回收利用，更能舒解電廠煤灰處置之困境，具環保及資源再生之功效。
本研究所使用之燃煤底灰主成份為SiO2及Al2O3，經添加10～40%重量百分比的MgCO3後，熔製為玻璃(10MG～40MG)，以DTA分析得到一玻璃轉移溫度及三至四個結晶放熱峰，玻璃經一階段及二階段的熱處理之後，經X光繞射分析證實，所得到的結晶有α-堇青石(Indialite, 2MgO．2Al2O3．5SiO2) 、鈣長石(Anorthite, CaO．Al2O3．2SiO2)、頑火輝石(Enstatite, MgO．SiO2)、含鐵頑火輝石((Mg, Fe)O．SiO2)、鐵尖晶石(Hercynite, FeO．Al2O3)、白矽石(Crystobalite, SiO2)等相。經過SEM顯微分析，結晶顆粒大小及分佈之控制尚可繼續研究改進。
此外，以預成核熱處理及DTA分析得知，40MG的最佳成核溫度在780°C附近，最佳成核時間為4小時。40MG經780°C，4小時的預成核熱處理後，長晶活化能由未預成核的449.9 kJ/mol降低為343.7 kJ/mol。
於基本物理性質方面，添加MgCO3的量愈多，玻璃及玻璃陶瓷的體密度及視比重愈大，而孔隙率及吸水率則愈小。實驗結果顯示，熱處理過後所得到玻璃陶瓷之微硬度均比玻璃高，且經二階段熱處理所得的玻璃陶瓷可獲得比一階段熱處理者更高的微硬度值。

With the rapidly growing populations and economy, proper disposal of wastes has become an urgent subject confronted by the world. Taipower’s coal-fired power plants generate two million tons of coal ashes annually, of which are 80% fly ash and 20% bottom ash respectively. All units related have invested large labor power and material resources studying how to recover and reuse this large quantity of wastes in order to decrease their impact against environment. For example, the amount utilized of fly ash has reached 89.7% in 1999 while that of bottom ash is only 6.2%. The abundant chemical elements in bottom ashes are just the raw materials of producing glasses. This research takes the bottom ashes of thermal power plants as a major starting raw material to make glass ceramics, which not only reuse and recover the wastes but also easing the disposal of power plant coal ash, having the benefits of environmental protection and resources recycling.
The major composition of the bottom ash used in this study is SiO2 and Al2O3. After adding 10 to 40% of MgCO3, melt it to glass (10MG~ 40MG). In the DTA analysis the glass shows one glass transition point and three to four crystallization exothermic peaks. After heat treated on the glass and analyzed by X-ray diffraction, it’s crystal phases are indialite (2MgO．2Al2O3．5SiO2), anorthite (CaO．Al2O3．2SiO2), enstatite (MgO．SiO2), ferroan enstatite ((Mg, Fe)O．SiO2), hercynite (FeO．Al2O3), and crystobalite (SiO2).
SEM micro-structure analysis shows the control of crystal grain size and distribution still leaves room to be desired.
After a pre-nucleate heat treatment and DTA analysis, the temperature of maximum nucleation rate of 40MG is 780°C and the best time for nucleation is 4 hours. When heated at 780°C for 4 hours, the activation energy for crystal growth lowers to 449.9 kJ/mol from the non-nucleated 343.7 kJ/mol.
As for the basic physical properties of glasses and glass ceramics, the more MgCO3 added to bottom ash, the higher the bulk density and apparent specific gravity and the lower porosity and water absorption is. Experiment shows the micro hardness of glass ceramics is higher than that of glasses. Also, two stage heat treatment leads to higher micro hardness than that of one stage heat treatment.

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