淨水污泥再利用於水泥生料

Reuse of water treatment plant sludge as cement raw materials

林志鴻(Chih-Hung Lin)

指導教授 ： 曾迪華

國立中央大學/工學院/環境工程研究所/碩士(2010年)

摘要

本研究以淨水廠常見PAC與硫酸鋁污泥為研究對象，於平日及颱風天分別進行採樣，初步評估其再利用於水泥生料之可行性後，以水泥生料之理論配比設計分析的結果燒製環保水泥，探討其在水硬係數=1.7、2.0、2.3；矽氧係數=1.9、2.6、3.2；鋁鐵係數=1.5、2.0、2.5與不同取代率下（0％、50％、100％）對環保水泥品質的影響。
研究結果顯示，不同出處之淨水污泥，其化學組成都在一定範圍內，且灰分均達80％以上。此外，在化學組成與晶相方面，也都與黏土相似，因此均適合替代黏土作為水泥生料。本研究發現，含淨水污泥之生料經燒結冷卻程序後所製成之熟料，在礦物生成上與純水泥相同並無差異，在不同水泥係數值條件下也發現，水硬係數＝2.3時生成最多的C3S（74.4％）；水硬係數＝1.7時生成最多的C2S（59.27％），另外，實驗燒製之12組水泥熟料其游離石灰皆小於1％，且製程燒失量介於31％~37％間，符合實場品管規範，研究中所燒製水泥熟料皆與卜特蘭一型水泥類似，其單礦物組成均含有C3S、C2S、C3A及C4AF。本研究進一步選擇對照組及C2S、C3S生成量最多之水硬係數系列，探討燒結之升溫速度的影響，結果顯示在1210~1410℃時，升溫速率愈快，愈能提高C2S、C3S晶相強度與生成量，故此，後續以最佳升溫速率20℃/min所燒製而成的水泥熟料，進行水泥漿體及微觀分析。由實驗結果發現，水硬係數＝2.3時以C3S為主，因此在養護7天後，即可發生良好的水化反應，發展強度也是最佳；水硬係數＝1.7則因熔流點下降，造成熟料熔融，結晶效果不佳，以致28天抗壓強度仍不足。

關鍵字

環保水泥 ； 水泥漿體 ； 水化反應 ； 水泥係數 ； 淨水污泥

並列摘要

The objective of this study was initially aimed to evaluate the feasibility of using PAC and alum sludge, obtained individually in ordinary days and typhoon period from water treatment plants, as raw material for cement production. Then, based on the results of theoretical mixing design analysis of cement raw materials, the cement clinker was prepared when hydraulic modules (H.M.) = 1.7、2、2.3, silicate modules (S.M.) = 1.9、2.6、3.2, and iron modules (I.M.) = 1.5、2、2.5, respectively, and at different substitution rates (0%、50%、100%) of sludge for clay. Finally, the effects of various modules on the qualities of eco-cement were investigated.
The experimental results indicated that the percentage of major chemical compositions of sludge from various water treatment plants were all within a certain range and the ash content was above 80%. In addition, the chemical compositions and crystalline phases of water treatment plant sludge (WTPS) were similar to those of clay. Therefore, the WTPS were appropriate to replace clay as one of cement raw materials. It also found that the mineral contents of clinker after sintering and cooling processes had no difference between cement raw materials with and without WTPS. However, at the condition of different cement modules, when hydraulic module was 2.3 produced the maximum amount of C3S (74.4%), while hydraulic module was 1.7 generated the maximum of C2S (59.27%). Furthermore, the contents of free lime in the 12 series cement clinker of this study were all less than 1％, and the weight loss after sintering were in the range of 31%~37%. These results meet the quality requirements for sintered cement clinker and resemble to Portland Type- I cement contained mineral substances of C3S, C2S, C3A, and C4AF.
Moreover, this study selected the control group and hydraulic module groups that produced the maximum amount of C2S and C3S to further investigate the effect of temperature rising rate during the period of sintering process on the quality of eco-cement. The results revealed that the faster rate of temperature rising in the range of 1210 to 1410℃, the more intensity and production of crystalline phase of C2S and C3S occurred. Consequently, cement pastes were prepared from the clinkers sintered at a temperature rising rate of 20℃/min, and the microscopic analysis of the specimens was carried out. The experimental results found that C3S was the major product when hydraulic module = 2.3 and that lead to well hydration reaction and the best strength development at 7 days curing of the cement paste. However, due to the decrease of melting point when hydraulic module = 1.7, the cement clinker had melting phenomenon with ineffective formation of crystalline phase, which resulted in the lowest compressive strength of cement paste at the curing age of 28 days.

並列關鍵字

cement moduli ； water treatment plant sludge ； hydration reaction ； cement paste ； ecocement

參考文獻

Altun, I. "Effect of CaF2 and MgO on sintering of cement clinker." Cement and Concrete Research, 29, 1847-1850(1999).

Ampadu, K. O., and Kazuyuki Torii."Characterization of ecocemment pastes and mortars produced form." Cement and Concrete Research, 31, 431-436(2001).

Aldeeb, A. A., Qasim, S. R., Puppala, A. J., and Anderson, C. F."Physical and Engineering Properties of Treatment Plant Residuals and Disposal." Journal / American Water Works Association, 95(8), 127-137(2003).

Beretka, J., B. de Vito, L. Santoro, N. Sherman., and G. L. Valenti,"Utilisation of industrial wastes and by-products for the synthesis of special cements." Resources, Conservation and Recycling, 9, 179-190(1993).

Basta, N., and Dayton, E. A."Characterization of Drinking WaterTreatment Residuals for Use as a Soil Substitute." Water Environment Research, 73(1), 52-57(2001).