Influences of chemical activators on incinerator bottom ash

被引:22
作者
Qiao, X. C. [1 ]
Cheeseman, C. R. [1 ]
Poon, C. S. [2 ]
机构
[1] Univ London Imperial Coll Sci Technol & Med, Dept Civil & Environm Engn, London SW7 2AZ, England
[2] Hong Kong Polytech Univ, Dept Civil & Struct Engn, Kowloon, Hong Kong, Peoples R China
关键词
GROUND FLY ASHES; CRACKING CATALYST RESIDUE; BLENDED CEMENT PASTES; POZZOLANIC REACTION; MECHANICAL TREATMENT; LIME PASTES; CONCRETE; MORTARS; CLAYS; GFA;
D O I
10.1016/j.wasman.2008.06.026
中图分类号
X [环境科学、安全科学];
学科分类号
08 ; 0830 ;
摘要
This research has applied different chemical activators to mechanically and thermally treated fine fraction (< 14 mm) of incinerator bottom ash (IBA), in order to investigate the influences of chemical activators on this new pozzolanic material. IBA has been milled and thermally treated at 800 degrees C (TIBA). The TIBA produced was blended with Ca(OH)(2) and evaluated for setting time, reactivity and compressive strength after the addition of 0.0565 mole of Na(2)SO(4), K(2)SO(4), Na(2)CO(3), K(2)CO(3), NaOH. KOH and CaCl(2) into 100 g of binder (TIBA+Ca(OH)(2)). The microstructures of activated IBA and hydrated samples have been characterized by X-ray diffraction (XRD) and thermogravimetry (TG) analysis. Thermal treatment is found to produce gehlenite (Ca(2)Al(2)SiO(7) wollastonite (CaSiO(3)) and mayenite (Ca(12)Al(14)O(33)) phases. The thermally treated IBA samples are significantly more reactive than the milled IBA. The addition of Na(2)CO(3) can increase the compressive strength and calcium hydroxide consumption at 28-day curing ages. However, the addition of Na(2)SO(4), K(2)SO(4), K(2)CO(3). NaOH and KOH reduces the strength and hydration reaction. Moreover, these chemicals produce more porous samples due to increased generation of hydrogen gas. The addition Of CaCl(2) has a negative effect on the hydration of TIBA samples. Calcium aluminium oxide carbonate sulphide hydrate (Ca(4)Al(2)O(6)(CO(3))(0.67)(SO(3))(0.33)(H(2)O)(11)) is the main hydration product in the samples with activated IBA, except for the sample containing CaCl(2). (c) 2008 Elsevier Ltd. All rights reserved.
引用
收藏
页码:544 / 549
页数:6
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