Study on the Sintering of Municipal Solid Waste Incineration Bottom Ash for Construction Materials

• Main Authors: Zih Xiang Chang, 張祉祥
• Other Authors: Kuen-Sheng Wang
• Format: Others
• Language: zh-TW
• Published: 1999
• Online Access: http://ndltd.ncl.edu.tw/handle/59752375967974482887

碩士 === 國立中央大學 === 環境工程研究所 === 87 === The decreasing availability of landfill sites, the growing amount of municipal solid waste (MSW), and the increasing disposal costs have hastened efforts to adopt incineration technologies and energy recovery strategies. By the year 2004, the completion of 36 MSW incinerators will generate more than 4000 tons incineration ashes each day, which has to be properly treated, disposed of, or recovered. Recognizing the trend toward more usage of bottom ash as constructional materials, the author investigated the feasibility of recovering bottom ash as aggregates, by sintering size-fractioned MSW incinerator bottom ashes (particle size less than 1.41 mm and between 4.76-1.41 mm) at 400-1000 degree C for 60-240 min, to determine their sintered characteristics such as compressive strength, heavy metal leachability, and principal material properties. The results indicate that the pH of the TCLP leachate for the fine and the coarse ashes, ranging from 10.04-11.49, and from 7.49-11.26, respectively, showed a decreasing trend with increasing sintering temperature. Correspondingly, the acid-neutralization capacity for both ashes decreased with increasing sintering temperature. In addition, for both ashes, the compressive strength of the sintered monoliths, ranging from 500-550 kgf/cm2, slightly decreased when the sintering temperature was increased from 400 degree C to 600 degree C. Problems such as deformation may result from the melting of glassy substance in the ash when the bottom ash was sintered at higher than 1000 degree C. Moreover, when sintering between 800 to 1000 degree C, the sintered bottom ash may be destroyed due to the formation of calcium salts and/or aluminum. The decomposition of calcium carbonate at 650degree C, releasing significant amount of carbon dioxide, may also cause the destruction of the monolith. Based on considerations of the loss on ignition, volume change, water adsorption, soundness, bulk density, and the compressive strength of the sintered ash, the general results from the experiments suggest that acceptable aggregates meeting Chinese National Standards(CNS) for permeable block can be developed by sintering the bottom ash between 400 to 600 degree C after removing its coarse impurities.