Reuse Technology and Process Improvement Analysis of Bottom Ash in the Municipal Solid Waste Incinerator

• Main Authors: Ming-Chou Chen, 陳明州
• Other Authors: Hsiao-Kan Ma
• Format: Others
• Language: zh-TW
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/63459685919690995130

碩士 === 國立臺灣大學 === 機械工程學研究所 === 93 === The waste incineration ratio in Taiwan has reached 57%. After the completion of the 32 metropolis-scale incineration plants, the amount of waste incineration will reach 8.07 million tons per year, and the amount of bottom ash will reach 1.66 million tons. Such enormous amount, along with the limit to the capability of waste landfill and difficulty in developing new landfills, the reuse of bottom ash becomes an urgent issue. This study used 3-E (engineering, Economy and Regulation, and environment) and 6-risks (technical risk, commercial risk, economic risk, legal risk, environmental risk, and health risk) to evaluate the sintering, melting, and selective/stabilizing technologies. The results showed that separation/stabilizing is more advantageous in recycling technology. The separation /stabilizing technology has been applied in one plant in Taiwan, but problems concerning the equipment and product channels will have to be resolved. “Dismantling” and “separation” are important segments in the bottom ash reuse technology. This study discussed the operation of “dismantling” and “separation”, and measured the water content of the bottom ash produced by the seven incineration plants in northern Taiwan, by sampling three specimens each before sending to the separation plants. The bottom ashes were processed by magnetic separation, sieving, and eddy current separation. The gradation was about 88%-92%, the iron content was 6%-10%, the non-iron and substances from incomplete combustion were half of the residue. The heavy metal content was analyzed to explored the impact on the environment. Lastly, this study discussed the flaw charts in the design of Plant A and new plant, offered modification to the design, and calculated the mass balance, thus, to provide as a design reference for the new plants.