| 摘要 |
<p>PROBLEM TO BE SOLVED: To recover available metals such as zinc, lead in dust in high recovering ratio by supplying the dust together with a pulverized reducing agent into a vacuum vessel and condensing after reducing metallic oxides in the dust. SOLUTION: The reducing agent pulverized with a pulverizing machine 51 together with the dust are charged into a mixer 41. The mixed material is stored in a powder storing hopper 32. The pressure in the hopper 32 and a treating chamber 21 is reduced and the inner part of the treating chamber 21 is heated to a prescribed temp., and the mixed material of the dust and the reducing agent is charged into the treating chamber 21. Vacuum heating treatment is executed while stirring with blades 92, and after vaporizing moisture and fat and oil in the dust, the treated dust is sucked into a condenser 71 and its temp. is lowered in a solidifying chamber 73 kept at a low temp. and recovered. On the other hand, the inner part of a treating chamber 22 is made to vacuum, and the mixed material of the dust and the reducing agent is charged thereinto and heated to reduce the metallic oxides such as ZnO, PbO in the dust with the reducing agent. The reduced metals such as Zn, Pb are vaporized and sucked into a condenser 72 and its temp. is lowered in a solidifying chamber 75 to recover Zn and Pb as the solidified materials.</p> |
