Recovery of zinc and lead from fly ash from ash-melting and gasification-melting processes of MSW--comparison and applicability of chemical leaching methods.
Recovery of zinc and lead from fly ash from ash-melting and gasification-melting processes of MSW--comparison and applicability of chemical leaching methods.
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DOI：
10.1016/j.wasman.2005.12.006
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发表时间：
2007
期刊：
影响因子：
8.1
通讯作者：
Takashi Okada;Y. Tojo;Nobutoshi Tanaka;T. Matsuto
中科院分区：
文献类型：
--
作者：
Takashi Okada;Y. Tojo;Nobutoshi Tanaka;T. Matsuto
城市生活垃圾灰熔化和气化熔化厂产生的飞灰，称为熔化炉飞灰（MFA），含有大量的重金属，如铅和锌。这些金属可以在“预处理”去除不需要的元素（例如Cl、Sn和Si）后使用熔炼炉回收。过去已经研究了化学方法用于预处理。然而，仅讨论了处理成本和回收的 Pb 和 Zn 浓度，而没有考虑对各种类型 MFA 的适用性和环境影响。本研究从以下角度对酸浸、碱浸和氨/氯浸出方法进行了比较：(1) MFA 的适用性，(2) 回收的 Pb 和 Zn 浓度，(3) 处理成本，(4) 环境影响。收集了 23 个 MFA 样品，根据元素含量分为 4 类。针对这些类型的代表性 MFA 进行了 Pb 和 Zn 回收实验。结果表明：（1）气化熔融装置产生的MFA不能用化学方法处理； (2)其他MFA可以通过现有熔炼炉处理至合格的质量； (3)只有来自电阻熔灰厂的MFA可以很容易地采用水洗法进行处理； (4)碱浸法和氨/氯浸法比酸浸法更有效。
Fly ash generated from MSW ash-melting and gasification-melting plants, known as Melting Furnace Fly Ash (MFA), contains considerable amounts of heavy metals such as Pb and Zn. These metals can be recovered using a smelting furnace after “pre-treatment” for removal of unnecessary elements such as Cl, Sn and Si. Chemical methods have been studied for pretreatment in the past. However, they have been discussed only with regard to treatment cost and the concentration of Pb and Zn recovered, but neither applicability to various types of MFA nor the environmental impact have been considered. In this study, acid, alkaline and ammonia/chloride leaching methods were compared from the standpoints of: (1) applicability to MFA, (2) concentration of Pb and Zn recovered, (3) treatment cost, and (4) environmental impact. Twenty-three samples of MFAs were collected and classified into 4 types based on element contents. A Pb and Zn recovery experiment was conducted for the representative MFA of those types. The results showed: (1) MFA from gasification-melting plants cannot be treated by chemical methods; (2) the other MFA can be treated to an acceptable quality by existing smelting furnaces; (3) only MFA from electric resistance ash-melting plants can be treated easily by the water washing method; and (4) alkaline and ammonia/chloride leaching methods were more effective than acid leaching.