| abstract |
A part of a cement kiln combustion gas such as chlorine bypass dust is extracted from a cement manufacturing process, and dust contained in the extracted combustion gas is washed at low cost. A part of a cement kiln combustion gas is extracted from a cement manufacturing process, dust contained in the extracted combustion gas is collected, dust collected, and incinerated ash containing metal aluminum and / or metal iron Is dissolved in water and filtered to insolubilize heavy metals such as thallium and lead while using metallic aluminum and / or metallic iron in the incinerated ash as a reducing agent. Because heavy metals contained in the extracted dust are reduced and insolubilized by the reducing agent, heavy metals do not elute in the washing solution that is produced after the extracted dust is washed with water, such as the addition of sodium hydrosulfide to the washing solution. It is not necessary to perform wastewater treatment, and dust can be washed with low cost. [Selection] Figure 1 |