Solidification and recycling of incinerator bottom ash through the addition of colloidal silica (SiO2) solution.
The possibility of using incinerator bottom ash as a substitute for natural aggregates was investigated. Rough, porous surface of bottom ash, which diminishes the strength of solidified products, was improved by colloidal silica solution. As a result, a significant increase of mechanical strength was accomplished by a slight amount of silica (<1 wt% to total). Moreover, pozzolanic reaction was induced in initial cement hydration due to the nano-particle size of about 20 nm in colloidal silica solution. Cylindrical specimens and bricks were prepared from bottom ash added to a colloidal silica (SiO2) solution and cement, and then their compressive strengths were evaluated. Cylindrical specimens showed an increase of approximately 60% in compressive strength when colloidal solution containing 4 wt% silica particles was sprayed onto the bottom ash. The strength of bricks containing colloidal silica was in excess of 20 MPa, which meets the requirement of construction materials. Results of leaching tests based on Toxicity Characteristic Leaching Procedure (TCLP) proved that the solidified bottom ash possessed good chemical stability.
Park
Jong Soo
JS
School of Environmental Science and Engineering, Pohang University of Science and Technology, San 31, Hyoja-dong, Nam-gu, Pohang, Gyeongbuk, Republic of Korea.
Park
Young Jun
YJ
Heo
Jong
J
D000327:Adsorption; D001151:Arsenic / Q000032:analysis; D002244:Carbon / Q000737:chemistry*; D060729:Coal Ash; D003102:Colloids; D019245:Compressive Strength; D003247:Conservation of Natural Resources; D003252:Construction Materials; D003486:Cyanides / Q000032:analysis; D017745:Incineration; D007220:Industrial Waste / Q000032:analysis; D008670:Metals / Q000032:analysis; D052638:Particulate Matter / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry*; D012996:Solutions; D014874:Water Pollutants, Chemical / Q000032:analysis
D060729:Coal Ash; D003102:Colloids; D003486:Cyanides; D007220:Industrial Waste; D008670:Metals; D052638:Particulate Matter; D012996:Solutions; D014874:Water Pollutants, Chemical; D002244:Carbon; D012822:Silicon Dioxide; D001151:Arsenic