A Study on the Sintering of High Performance Humidity Control Ceramic of Green Building Material by MSWI Boiler Ash, Palygorskite and Waste Glass

• Main Authors: Chi-Bin Huang, 黃啟賓
• Other Authors: SI-HUAI GAU
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/70076661910234247234

碩士 === 淡江大學 === 水資源及環境工程學系碩士班 === 103 === Municipal solid waste incinerator (MSWI) will produce fly ash which contains a large amount of heavy metals and the leaching concentration usually doesn’t meet the regulatory limits of EPA. Therefore, the fly ash is considered to be hazardous waste. Fly ash divided into reaction ash and boiler ash. Many studies have found that the reaction ash always contains large amount of alkalinity and heavy metals. However, sintering process will decompose the components and it will also generate lots of gas that like the foaming characteristics. Leaching concentrations of heavy metals of boiler ash are lower than reaction ash, and they have the similar chemical and physical characteristics. Palygorskite has a large amount of specific surface area, which has high efficiency to absorb heavy metals. Glass is easy to generate a liquid phase during the sintering process. This phenomenon could increase the mechanical strength of the sintered specimens. Therefore, this study would investigate the feasibility of sintering the mixtures of boiler ash, palygorskite and waste glass as a humidity-controlling ceramic. Nowadays, humidity-controlling ceramic is high value structure material. The humidity-controlling ceramic made by the mixture will offer a cheaper substitute and also solve the problem of MSWI fly ash. In this study, mixtures of boiler ash, palygorskite and waste glass were sintered to make as humidity-controlling ceramic at different sintering temperature, heating rate and sintering atmosphere. CNS3299-4 was used as the bending test. All the synthesized materials have to conform with JIS A 1470-1 of the humidity-controlling test：2008 Determination of water vapor adsorption/desorption properties for building materials Part 1: Response to humidity variation find the best. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to identify the crystal species and explore the pore feature. The product must be ensured to meet the No. 1010094463A which was announced by Taiwan EPA in 2012. The results of this experiment indicate that the mixture of waste glass (70%), palygorskite (20%) and boiler ash (GAF-721) sintering at 750 oC in air and nitrogen atmosphere, the absorption moisture content of the sintered specimens were 65.26 g/m2 and 59.59 g/m2 and the removal were 75.32 and 80.3%, which were meet with humidity-controlling materials standard level 2 (50g / m2 of moisture content, 70% of removal). The bending strengths were 6.12 and 6.93Mpa (standard: 6.12 MPa). The steady rate of Lead, Zinc, Copper and Chrome were 73%, 90%, 99% and 99%, respectively. Furthermore, all of the toxicity characteristic leaching procedure (TCLP) leaching concentrations of the heavy metals were meted with regulation limits of Taiwan EPA. Therefore, the products of the experiment have been reached non-hazardous and that can be recycling.