Substance description/characteristics
The substance Waste solids, lead silver anode is a UVCB (origin: inorganic)
Public name: Lead-Silver Oxides; Pb-Ag Oxide Drosses
| EC number: | 305-449-9 |
| EC name: | Waste solids, lead silver anode |
| CAS number (EC inventory): | 94552-05-3 |
| IUPAC name: | Residues remaining after recovering, melting and alloying of electrolytic lead/silver anodes. Consists primarily of lead, lead compounds, manganese oxides as well as minor amounts of other metals and/or their compounds. |
| Description: |
During the Zinc electrolysis, the Lead-anodes need to be regularly cleaned and maintained. At the end of their service life, anodes need to be recycled. They are taken to a melting/casting shop where the Pb.Ag anodes are melted and recast A scum/dross is formed on the melt surface, containing Lead oxide, manganese dioxide and some entrained metallic Pb-Ag alloy The residues are isolated, from the molten metallic bath, by mechanical separation (rattling) and collected from the baghouse-filters The separated material is collected into small containers near the furnace, the casting line and/or the filters This Intermediate is typically used in production units of Lead metal or Lead compounds. |
| Molecular formula: | n.a. |
| Molecular weight range: | n.a. |
| Physical state: | solid (massive) at 20°C, 1013 hPa |
2. Source, process and conclusion
| Source |
Lead/silver anodes (recovery, melting and alloying of electrolytic lead/silver anodes) |
| Process |
During the Zinc electrolysis, the Lead-anodes need to be regularly cleaned and maintained. At the end of their service life, anodes need to be recycled. They are taken to a melting/casting shop where the Pb.Ag anodes are melted and recast. A scum/dross is formed on the melt surface, containing Lead oxide, manganese dioxide and some entrained metallic Pb-Ag alloy. The residues are isolated, from the molten metallic bath, by mechanical separation (rattling) and collected from the baghouse-filters. The separated material is collected into small containers near the furnace, the casting line and/or the filters. Further transfer of the PbAg Anode residue to enclosed or covered buildings in i.e. big-bags or containers, in accordance with legislation. The PbAg Anode residue is a mixture of lumpy and dusty products with an average Lead-content of 60-90% w/w with significant quantities of other metal-oxides (up to 25% Mn). |
| Conclusion |
Waste solids, lead silver anode are residues remaining after recovering, melting and alloying of electrolytic lead/silver anodes. They mainly consists of lead, lead compounds, manganese oxides. |
3. Composition of the substance
The Waste solids, lead silver anode boundary composition is detailed here below.
Elemental composition - boundary:
| Core | min (% w/w) | max (% w/w) | Typical (% w/w) |
| Pb | 60 | 90 | 70 |
| Mn | 2 | 25 | 2.77 |
| Ag | 0.1 | 0.5 | 0.34 |
| Zn | 0 | 2 | 0.46 |
Mineralogical composition - boundary:
| Core | min (% w/w) | max (% w/w) | Typical (% w/w) |
| PbSO4 | 7 | 11 | 8.54 |
| Pb | 10 | 45 | 35 |
| PbO2 | 29 | 43 | 33.67 |
| Ag2O | 0.05 | 0.27 | 0.25 |
| MnO2 | 3 | 40 | 5 |
| Ag | 0.05 | 0.25 | 0.17 |
| ZnSO4 | 0 | 4.9 | 1.14 |
4. Classification
| The classification is always based on the worst case. For the generic grade Waste solids, lead silver anode, this corresponds to: | |
| Acute toxicity - inhalation | Acute inhal. 4 |
| Eye Irritation/corrosion | Eye damage 1 |
| Carcinogenicity | Carc. 2 |
| Reprotoxicity | Repr. 1A |
| Specific target organ toxicity - repeated: | STOT RE 1 |
| Hazards to the aquatic environment (acute/short-term): | Aquatic Acute 1 |
| Hazards to the aquatic environment (long-term): | Aquatic Chronic 1 |