| 摘要: | 本研究嘗試利用實驗室規模之高溫爐及旋轉窯系統，評估8家鍋爐業者混燒灰渣，作為取代水泥生料之可行性，試驗過程分別控制水泥係數、升溫速率、燒結溫度與時間等條件，探討混燒灰渣取代水泥生料及燒製環保水泥熟料之物化及機械特性，以作為後續混燒灰渣再利用之參考。
研究結果顯示，高溫爐燒製之環保水泥熟料，在抗壓強度方面，對照組各齡期之強度，分別為75.48 kgf/cm2、134.91 kgf/cm2及216.42 kgf/cm2；然而，以混燒灰渣燒製環保水泥之機械強度均不高，經養護後，僅以KYP BA(廣O造紙之混燒底渣)組之抗壓強度，可優於對照組，分別達101.16 kgf/cm2、130.65 kgf/cm2及230.00 kgf/cm2。
為進一步評估旋轉窯系統對燒製環保水泥之影響，試驗結果顯示，旋轉窯燒製之環保水泥熟料，游離氧化鈣含量，由平均1.5%降至平均1.0%；凝結時間平均介於150至250分鐘，相較於高溫爐燒製之熟料而言，凝結時間縮短約50分鐘。抗壓強度方面，對照組各齡期強度分別達到120.00kgf/cm2、191.76kgf/cm2及273.33kgf/cm2，相較於高溫爐熟料亦增加約50%。相較之前KYP BA組之抗壓強度，平均為168.32kgf/cm2、195.03kgf/cm2及263.87kgf/cm2，已可達到CNS 61規範標準。顯示旋轉窯有較佳煅燒效果，可生成水泥熟料之主要礦物組成。
根據水泥熟料試體之水化反應分析結果顯示、養護初期已可觀察到主要水化產物CH及C-S-H膠體的存在，且會隨著養護齡期增加而越趨明顯。另根據XRD、FTIR峰值以及SEM結構變化分析結果可知，對照組與KYP BA組於後期波峰強度可達10,000以上，且水泥熟料表面特性亦有較緊密結構存在，此與抗壓強度明顯增加之分析結果相吻合。整體而言，根據本研究之相關成果，已初步驗證混燒灰渣取代傳統水泥生料，燒製成環保水泥之可行性，可提供作為後續相關技術之發展與政策研擬之參考。
;This research investigates on the feasibility of replacing the cement raw materials with co-fired biomass ash by using laboratory scale fixed-bed furnace and rotary kiln system. The physical, chemical and mechanical characteristics of the cement clinker manufactured by different co-fired ash addition were controlled the cement modulus, heating rate, sintered temperature, and sintered time.
The fixed-bed experimental results showed that the compressive strength of cement clinker manufactured by cement raw materials were 75.48 kgf/cm2 (3 days), 134.91 kgf/cm2 (7 days), and 216.42 kgf/cm2 (28 days). However, compressive strengths of eco-cement produced by different co-fired ash addition were lower than that of the cement clinker. Only one eco-cement (produced by KYP BA) compressive strengths were 101.16 kgf/cm2 (3 days), 130.65 kgf/cm2 (7 days), and 230.00 kgf/cm2 (28 days), respectively, higher than that of cement clinker.
To further assess the effect of eco-cement sintered by rotary kiln system, the results indicated that the f-CaO content of the eco-cement clinker was decreased from 1.5% to 1.0% resulted in applying the rotary kiln system. For the setting time, the initial and final setting time of the eco-cement sintered by rotary kiln system were approximately ranged from 150 minutes to 250 minutes. Comparing with fixed-bed furnace, it could reduce 50 minutes setting time. In the case of the compressive strength of cement clinker produced by rotary kiln system, the compressive strengths were 120.00 kgf/cm2 (3 days), 191.76 kgf/cm2 (7 days), and 273.33 kgf/cm2 (28 days), respectively. However, the compressive strengths of eco-cement sintered by KYP BA were in compliant with CNS 61 standard criteria which there were 168.32 kgf/cm2 (3 days), 195.03 kgf/cm2 (7 days), and 263.87 kgf/cm2 (28 days). It implied that the main mineral composition of the cement clinker was formed by rotary kiln system.
According to the hydration results of clinkers, the main hydration products C-H and C-S-H gel could be observed at the early curing stage. The C-H and C-S-H gel were significantly increased with the curing age increasing. Based on the XRD, FTIR, and SEM analysis results, it can find out the above experimental results were consistent with the trends in compressive strength increasing. Overall, the relevant results of this research has proved the feasibility of eco-cement manufactured from co-fired biomass ash and cement raw materials, but also can provide useful information for the development of related technologies and policy formulation in eco-cement manufacturing. |
