Leach residues, zinc ore-calcine, zinc cobalt (EC 273-769-5)
Zinc Substances > Zinc UVCBs

Substance description/characteristics

1. Name and other identifiers of the substance:

The substance Leach residues, zinc ore-calcine, zinc cobalt is a UVCB (origin: inorganic)

Substance identity:
EC number: 273-769-5
EC name: Leach residues, zinc ore-calcine, zinc cobalt
CAS number (EC inventory): 69012-72-2
IUPAC name:  
Description: Insoluble cobalt-nickel containing residue after reduction of those elements from pregnant solutions
Molecular formula:  n.a.
Molecular weight range:  n.a.
Physical state: solid at 20°C and 1013 hPa


2. Source, Process and Conclusion

Source

Cobalt-Nickel loaded zinc sulphate solution

Process

A reducing agent is added (e.g. Zinc powder, PbO and As/Sb salts ...) to the Cobalt and Nickel loaded Zinc Sulphate solution and precipitation (cementation) of a Cobalt/Nickel-rich metallic precipitate ensues. After that 'cementation' reaction, separation of the precipitate occurs in dedicated settler. The precipitate is optionally re-pulped in a second reaction tank with a slightly acidic sulphate solution in order to dissolve the excess of un-reacted zinc powder and potentially co-precipitated Cadmium. Eventually, the Cobalt/Nickel-rich filter-cake is washed and filtered out of the suspension using press-filters. The Co/Ni rich filter-cake is stored (covered) before being transferred as Intermediate to the special treatment unit, typically used in production units of Cobalt and Nickel recovery. In case of transport to other premises, the Intermediate will be loaded in ADR-regulated big-bags or containers (barrels, small containers, bulk containers, silo-trucks, …). The ‘Cobalt/Nickel cement’ is optionally blended with other Cobalt / Nickel -containing primary or secondary materials.
The mixture is continuously or semi-continuously fed:
=> In hydrometallurgical uses, to leaching tanks (closed loop of acidic solution, mostly sulphate) used in the production of (Intermediate) Cobalt / Nickel salt
=> In pyrometallurgical uses, to furnaces, i.e. ISA, Blast... used in the smelting and extraction of Cobalt / Nickel metal

Conclusion

Insoluble cobalt-nickel containing residue after reduction of those elements from pregnant solutions, typically used in production units of Cobalt and Nickel recovery.

3. Composition

The boundary composition of Leach residues, zinc ore-calcine, zinc cobalt is detailed here below.

Elemental composition - boundary:

Core min (% w/w) max (% w/w) typical (% w/w)
Zn 1 30 11,6
Cu 1 80 18,8
Cd 0,1 20 0,53
Co 1 15 4,02
Ni 0,5 40 2,53
Fe 0,1 15 0,97
Pb 0,3 30 15,7
Si 0 1,4 0,57
As 0 3 0,006
Sb 0,1 3 0,4
Ca 0 0,6 0,14

Mineralogical composition - boundary:

Core min (% w/w) max (% w/w) typical (% w/w)
PbSO4 0,35 35,13 18,38
CuSO4 1,35 99,9 25,47
Cu(OH)2 0,23 18,44 4,33
Zn(OH)2 0,3 9,12 3,53
ZnSO4 1,73 51,85 20,05
Zn 0,1 3 1,16
Cu 0,4 32 7,52
CdSO4 0,18 37,09 0,98
Co2O3 1,4 21,1 5,66
NiO 0,63 50,9 3,22
Fe(OH)2 0,16 24,14 1,56
Pb 0,06 6 3,14
SiO2 0 1,4 1,23
As2O3 0 3,96 0,008
Sb2O3 0,12 3,59 0,4
CaSO4 0 2 0,47

4. Classification

The classification is always based on the worst case. For the Leach residues, zinc ore-calcine, zinc cobalt, this corresponds to:  

Acute toxicity - oral

Acute oral 3

Acute toxicity - inhalation

Acute inhal. 4

Skin corrosion / irritation

Skin irrit. 2

Serious eye damage / eye irritation

Eye damage 1

Skin sensitisation

Skin sens. 1A

Respiratory sensitisation

Resp. sens. 1B

Germ cell mutagenicity

Muta. 2

Carcinogenicity

Carc. 1A

Reproductive toxicity

Repr. 1A

Specific target organ toxicity - repeated (STOT-RE)

STOT RE 1

Hazardous to the aquatic environment (acute / short-term)

Aquatic Acute 1

Hazardous to the aquatic environment (long-term)

Aquatic Chronic 1