Detoxification of municipal solid waste incineration fly ash and recycle for producing concrete and glass

• Main Authors: HU,JHIH-HAO, 胡智豪
• Other Authors: JHANG,KUN-SEN
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/52766170059253874289

碩士 === 國立聯合大學 === 環境與安全衛生工程學系碩士班 === 105 === Abstract Almost of municipal solid waste incineration (MSWI) fly ash in Taiwan was treated by cement solidification/stabilization and final disposed, which does not meet the principles of waste minimization and reutilization. In this research, two MSWI fly ashes from M and H plants were studied in two parts: (1) detoxification of M fly ash and mixing with textile sludge to produce cement mortar. (2) inediblenormal glass made fromH fly ash and crystal glass made from H fly ashextractedlead-containing sludge. The results of detoxification of M fly ash show that water extraction of L/S (1.2) + 2 days of aging + acid stabilization combined with aging was the best method. TCLP-Pb of M fly ash couldbe reduced from 10.3 mg/L to all heavy metals passing the regulatory limits and water soluble chloride content reduced from 23.6% to 0.77%. In the detoxified fly ash mixing with textile sludge to produce cement mortar, textile sludge was pretreatedat 550°C to remove organics.Thereafter, cement mortarswere made of different ratios of textile sludge ash + cement + sand, and the best compressive strength of 271 kgf/cm2(higher than the governmental standard for structural concrete, 210 kgf/cm2) was carried out with the composition was22%textile +53%cement +25%sand). Furthermore, cement was replaced with0, 5, and 10% detoxified fly ash to test the variation of compressive strength.A best compressive strength of 278 kgf/cm2at 91th day, higher than the former mortar because of detoxified fly ash playing as apozzolanicmaterial,was found withthe composition of 22% textile sludge ash + 10% detoxified fly ash + 43% cement + 25% sand. In addition, leaching test show that all heavy metal concentrations were far lower than regulatory limits. In the normal glass made from H fly ash, the best result was R-3 (30% reacted fly ash + 30% Na2CO3 + 40%SiO2/1% activated carbon /1,300 °C) with Na-Ca-Si structure; moreover, no porosity, and leaching concentrations of Cd and Pb were below regulatory limits in accordance with ISO 7086-2:2000; density and refractive index (nD) were 2.67 g/cm3 and 1.573 respectively, better than that of market normal glass (density of 2.67 g/cm3 and refractive index of 1.573). In the crystal glass made from lead-containing sludge was P-3 (20% fly ash extracted sludge + 40% K2CO3 + 40%SiO2 + 5%TiO2/1,300 °C) with K2O-PbO-SiO2 structure. Additionally, no porosity and leaching concentrations of Cd and Pb were ND; density and refractive index were 2.75 g/cm3 and 1.600 respectively, better than that of the former normal glass made of H fly ash, and achieve the multiple purposes of saving the Earth's resources and resources reutilization. Keyword: MSWI fly ash; Detoxification; Chloride ion; Lead-containing sludge; Glass