| Significant quantities of mercury have been reclaimed from dental amalgams, oxide and acetate sludges, and battery scrap. |
| Food waste, process waste and non-hazardous sludges are some examples of waste streams where there are serious difficulties, Dr Kelly said. |
| Leaching residues from zinc processing, dusts and sludges such as jarosite, hematite, goethite, etc. |
| Thus, the present invention advantageously avoids the production of tailings sludges caused by clay dispersion. |
| The settled sludges are removed, returned to the beginning of the secondary treatment process, and added to the incoming waste water. |
| Sometimes, however, lead residues, sludges, or flue dusts are mixed with oxides from the battery treatment plant and processed together. |
