60.溶融飛灰からの重金属揮発挙動に及ぼす炭素源の影響

抄録

In order to obtain fundamental data for developing the efficient recovery process of heavy metals from molten fly ash, volatilization behavior of lead and zinc was investigated for the ash produced from the coke bed melting furnaces. The ash sample was heated at terminal temperatures ranging from 873 to 1073K in a nitrogen stream with a fixed bed reactor. Four kinds of carbon sources, phenolphthalein-derived carbon and raw coals (Barau, Prima and Nanton), were used as chlorination accelerating agents. When a molten fly ash sample was heated at 1073K without the additives, the release extent of 60% was observed for lead. On the other hand, zinc did not volatilize at all The addition of phenolphthalein-derived carbon accelerated the volatilization of lead and zinc. All of zinc was volatilized from solid phase at 1073K The addition of raw coals was effective for lead volatilization more than phenolphthalein-derived carbon at low temperature. Zinc originating from oxide and aluminosilicate was completely volatilized at 1073K by addition of coals.