| 摘要: | 本研究旨在探討三種不同組成的固體再生燃料（Solid Recovered Fuel, SRF）與煤炭混燒所產生的飛灰特性及其再利用的可行性。主要關注可反應性鋁金屬和游離氧化鈣對混燒飛灰體積穩定性及水泥基材料工作性的影響。
研究結果混燒飛灰中的可反應性鋁金屬會在水泥基材料中產生氫氣，導致體積不穩定。而飛灰中的游離氧化鈣在遇水後放熱生成氫氧化鈣，造成體積膨脹和工作性不佳。為此研究探討水泥固化法對飛灰的處理效果，以期改善其體積穩定性和工作性，並根據飛灰特性（如可反應性鋁金屬含量、游離氧化鈣含量、強度活性指數等）提出適當的再利用方案。
在水泥漿料材製程中，不同混燒飛灰的試體展現不同的特性。CCFA(A)飛灰因高含量的可反應性鋁金屬及游離氧化鈣，出現顯著的體積膨脹和強度發展問題。CCFA(B)飛灰則因游離氧化鈣的放熱反應，雖產生較少氫氣但仍影響試體強度。CCFA(C)飛灰含有低量的可反應性鋁金屬及高游離氧化鈣。對於塑性材製程，CCFA(A)和CCFA(C)混燒飛灰在震動壓實後展現良好的抗壓強度和體積穩定性。破碎材製程顯示，將固化體破碎成粒料可控制粒料尺寸且物理性質良好，適合作為工程填築材料。
研究進一步提出基於可反應性鋁金屬含量、游離氧化鈣含量及強度活性指數的混燒飛灰再利用使用建議，包括塑性材製程、漿料材製程及破碎材製程的適用條件，並強調檢測的重要性以確保再利用成效。本研究為混燒飛灰的處理和再利用提供了新穎技術路徑，有助於減少環境開採並促進資源的持續利用。
;This study investigates the characteristics and reuse feasibility of fly ash produced from co-combustion of coal and three different compositions of Solid Recovered Fuel (SRF). It pri-marily focuses on the impact of reactive aluminum and free calcium oxide (CaO) on the volu-metric stability and workability of cement-based materials.
The results indicate that reactive aluminum in the fly ash generates hydrogen gas when used in cement-based materials, leading to volumetric instability. Meanwhile, free CaO in the fly ash reacts exothermically with water to form calcium hydroxide (Ca(OH)₂), causing volumetric expansion and poor workability. The study examines the effectiveness of cement solidification in treating fly ash to improve its stability and workability. It also proposes appropriate reuse strategies based on fly ash characteristics, such as reactive aluminum content, free CaO content, and strength activity index.
In the cement paste formulation, different types of co-combusted fly ash exhibit distinct properties. CCFA(A) fly ash, with high reactive aluminum and free CaO content, shows signif-icant volumetric expansion and strength development issues. CCFA(B) fly ash produces less hydrogen gas but is still affected by the exothermic reaction of free CaO, impacting strength. CCFA(C) fly ash, containing low reactive aluminum but high free CaO, causes specimen rup-ture at high temperatures. For plastic materials, CCFA(A) and CCFA(C) fly ashes exhibit good compressive strength and volumetric stability after vibratory compaction. The crushed material formulation demonstrates that breaking down the solidified material into granules allows for size control and good physical properties, making it suitable for engineering fill.
The study further proposes reuse guidelines for co-combusted fly ash based on reactive aluminum content, free CaO content, and strength activity index. It includes recommendations for plastic material formulation, paste formulation, and crushed material formulation, emphasiz-ing the importance of testing to ensure safe and effective reuse. This research offers novel tech-nical pathways for the treatment and reuse of co-combusted fly ash, contributing to environ-mental pollution reduction and promoting sustainable resource utilization. |
