Abstract
In our country, melting process is utilized for the purpose of the reduction of waste volume and the stabilization of hazardous heavy metals. However Tokyo metropolitan government showed the guideline of the heavy metals content in slag recently, then the separation of heavy metals from molten slag has been becoming much more important than the stabilization of them. In the past research, it was found that a large part of volatile metals emitted into an exhaust gas in ash melting conditions at higher temperature than 1200degC, and the emission was more remarkable under the reducing condition. On the other hand, in the case of gasification melting conditions, a lot of char particles coexist with ash particles, so that the emission behavior might be different from the homogeneous ash melting condition. Then, in this study, simulating the gasification melting condition, the incineration ash melting with carbon particles was experimentally investigated from the viewpoint of melting characteristics and heavy metal emissions. The crucible filled up with the simulated ash sample was installed inside of the reactor tube made of quartz, and it was heated to the melting condition using a high frequency IH power supply. From the results, the addition of carbon into ash was confirmed not only to partially increase emissions of volatile heavy metals, such as zinc and lead, but also to block the ash melting itself.
