湿式ボールミル法を用いた無機性汚泥の再資源化技術の開発

The possibility of material recycling of inorgamic sludge by wet ball milling with distrilled water and an ethylenediaminetetraacetic acid disodium salt dehydrate (EDTA・2Na・2H(2)O)reagent was investigated. The inorganic sludge consisted of 14.1mass% of the heat-treated sludge obtained after drying and heat treatment, 20.1mass% of active carbon, and 65.9mass% of water. The wet ball milling of the heat-treated sludge was performed using a ball pot and balls in air for 40 h at room temperature with the rotational speed fixed at 200rpm. The fractions of Mn, Fe, Ni, Cu, and Zr in the specimens obtained by wet-ball-milling the heat-treated sludge decreased and those of Si and Al increased. Appropriate content of distilled water and weight of the heat-treated sludge for wet ball milling were 150-250 ml and 4.5 g or less, respectively. When the wet ball milling of the heat-treated sludge was perfomed twice,the fractions of Mn, Fe, Ni, Cu, and Zr in the specimen obtained after repeated wet ball milling remarkably decreased and that of Si increased in comparison with those in the specimens wet-ball-milled once. This suggests that the repeat of wet ball milling of the heat-treated sludge leads to a colorless specimen without colored ions such as Mn, Fe, Ni, and Cu.

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