Leaching behavior of heat-treated waste ash
| Autor: | Junya Nishino, Yoshiaki Matsuzawa, Nobuhiko Kubota, Shigeru Kitano, Kazuhiro Mae, Shunichiro Ueno, Satoshi Yoshihara |
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| Rok vydání: | 2006 |
| Předmět: |
General Chemical Engineering
Organic Chemistry ash Energy Engineering and Power Technology chemistry.chemical_element Mineralogy Thermal treatment heavy metal engineering.material Combustion Incineration leaching Chromium Fuel Technology chemistry Fly ash Environmental chemistry engineering Limiting oxygen concentration Leaching (metallurgy) Gehlenite |
| Zdroj: | Fuel. 85:401-409 |
| ISSN: | 0016-2361 |
| DOI: | 10.1016/j.fuel.2005.07.016 |
| Popis: | The leaching behavior of heat-treated waste ash was studied to verify the possibility of the thermal treatment of waste incineration ash in existing incinerators and boiler combustion chambers. The influence of temperature, oxygen concentration and treatment time on the leaching behaviors of harmful heavy metals, especially lead (Pb) and chromium(VI) (Cr (VI)) were studied to clarify effective treatment conditions to suppress leaching. By examining the leaching behavior of Pb and Cr from ash heat-treated under various conditions, it was found that leaching can be suppressed by heat-treating the ash under conventional combustion conditions of around 900–1000 °C at 5–10% oxygen concentration. The leaching behaviors of Pb and Cr (VI) from real ash with different particle sizes and from model samples were also investigated in detail to find an effective method to suppress Pb leaching. It was found that the formation and growth of gehlenite (SiO 2 ·2CaO·Al 2 O 3 ) in the ashes led to the decrease in the amount of Pb leaching. Therefore it was considered that the addition of an inorganic matrix with a high silica content that can promote gehlenite growth in the ash, for example, coal ash or waste glass is effective to suppress of Pb leaching. |
| Databáze: | OpenAIRE |
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