Effect of Cooling Rate on base Metals Recovery from Copper Matte Smelting Slags
Slag sample from copper smelting operation in a
water jacket furnace from DRC plant was used. The study intends to
determine the effect of cooling in the extraction of base metals. The
cooling methods investigated were water quenching, air cooling and
furnace cooling. The latter cooling ways were compared to the
original as received slag. It was observed that, the cooling rate of the
slag affected the leaching of base metals as it changed the phase
distribution in the slag and the base metals distribution within the
phases. It was also found that fast cooling of slag prevented
crystallization and produced an amorphous phase that encloses the
base metals. The amorphous slags from the slag dumps were more
leachable in acidic medium (HNO3) which leached 46%Cu, 95% Co,
85% Zn, 92% Pb and 79% Fe with no selectivity at pH0, than in
basic medium (NH4OH). The leachability was vice versa for the
modified slags by quenching in water which leached 89%Cu with a
high selectivity as metal extractions are less than 1% for Co, Zn, Pb
and Fe at ambient temperature and pH12. For the crystallized slags,
leaching of base metals increased with the increase of temperature
from ambient temperature to 60°C and decreased at the higher
temperature of 80°C due to the evaporation of the ammonia solution
used for basic leaching, the total amounts of base metals that were
leached in slow cooled slags were very low compared to the
quenched slag samples.
[1] Arslan, C. and F. Arslan, Recovery of copper, cobalt, and zinc from
copper smelter and converter slags. Hydrometallurgy, 2002. 67(1-3): p.
1-7.
[2] Baghalha, M., V.G. Papangelakis, and W. Curlook, Factors affecting
the leachability of Ni/Co/Cu slags at high temperature.
Hydrometallurgy, 2007. 85(1): p. 42-52.
[3] Banza, A.N., E. Gock, and K. Kongolo, Base metals recovery from
copper smelter slag by oxidising leaching and solvent extraction.
Hydrometallurgy, 2002. 67(1-3): p. 63-69.
[4] Das, B., et al., An overview of utilization of slag and sludge from steel
industries. Resources, Conservation and Recycling, 2007. 50(1): p. 40-
57.
[5] Gorai, B., R.K. Jana, and Premchand, Characteristics and utilisation of
copper slag--a review. Resources, Conservation and Recycling, 2003.
39(4): p. 299-313.
[6] Kuo, Y., et al., Effect of water quenching and SiO2 addition during
vitrification of fly ash: Part 1: On the crystalline characteristics of slags.
Journal of Hazardous Materials, 2008. 152(3): p. 994-1001.
[7] Lin, K.L., and Chang, C.T. (2006). "Leaching characteristics of slag
from the melting treatment of municipal solid waste incinerator ash."
Journal of Hazardous materials,135(1-3), 296-302.
[8] Maweja, K., T. Mukongo, and I. Mutombo, Cleaning of a copper matte
smelting slag from a water-jacket furnace by direct reduction of heavy
metals. Journal of Hazardous Materials, 2009. 164(2-3): p. 856-862.
[9] Mukongo, T., et al., Zinc recovery from the water-jacket furnace flue
dusts by leaching and electrowinning in a SEC-CCS cell.
Hydrometallurgy, 2009. 97(1-2): p. 53-60.
[10] Piatak, N.M., R.R. Seal, and J.M. Hammarstrom, Mineralogical and
geochemical controls on the release of trace elements from slag
produced by base- and precious-metal smelting at abandoned mine
sites. Applied Geochemistry, 2004. 19(7): p. 1039-1064.
[11] Saffarzadeh, A., et al., Characterization study of heavy metal-bearing
phases in MSW slag. Journal of Hazardous Materials, 2009. 164(2-3):
p. 829-834.
[12] Shen, H. and E. Forssberg, An overview of recovery of metals from
slags. Waste Management, 2003. 23(10): p. 933-949.
[13] Tossavaine, M., Engstrom, F., Yang, Q., Menad, N., Lidstrom Larsson,
M., and Bjorkman, B. (2007). " Characteristics of steel slag under
different cooling conditions." Waste Management, 27(10), 1335-1344.
[1] Arslan, C. and F. Arslan, Recovery of copper, cobalt, and zinc from
copper smelter and converter slags. Hydrometallurgy, 2002. 67(1-3): p.
1-7.
[2] Baghalha, M., V.G. Papangelakis, and W. Curlook, Factors affecting
the leachability of Ni/Co/Cu slags at high temperature.
Hydrometallurgy, 2007. 85(1): p. 42-52.
[3] Banza, A.N., E. Gock, and K. Kongolo, Base metals recovery from
copper smelter slag by oxidising leaching and solvent extraction.
Hydrometallurgy, 2002. 67(1-3): p. 63-69.
[4] Das, B., et al., An overview of utilization of slag and sludge from steel
industries. Resources, Conservation and Recycling, 2007. 50(1): p. 40-
57.
[5] Gorai, B., R.K. Jana, and Premchand, Characteristics and utilisation of
copper slag--a review. Resources, Conservation and Recycling, 2003.
39(4): p. 299-313.
[6] Kuo, Y., et al., Effect of water quenching and SiO2 addition during
vitrification of fly ash: Part 1: On the crystalline characteristics of slags.
Journal of Hazardous Materials, 2008. 152(3): p. 994-1001.
[7] Lin, K.L., and Chang, C.T. (2006). "Leaching characteristics of slag
from the melting treatment of municipal solid waste incinerator ash."
Journal of Hazardous materials,135(1-3), 296-302.
[8] Maweja, K., T. Mukongo, and I. Mutombo, Cleaning of a copper matte
smelting slag from a water-jacket furnace by direct reduction of heavy
metals. Journal of Hazardous Materials, 2009. 164(2-3): p. 856-862.
[9] Mukongo, T., et al., Zinc recovery from the water-jacket furnace flue
dusts by leaching and electrowinning in a SEC-CCS cell.
Hydrometallurgy, 2009. 97(1-2): p. 53-60.
[10] Piatak, N.M., R.R. Seal, and J.M. Hammarstrom, Mineralogical and
geochemical controls on the release of trace elements from slag
produced by base- and precious-metal smelting at abandoned mine
sites. Applied Geochemistry, 2004. 19(7): p. 1039-1064.
[11] Saffarzadeh, A., et al., Characterization study of heavy metal-bearing
phases in MSW slag. Journal of Hazardous Materials, 2009. 164(2-3):
p. 829-834.
[12] Shen, H. and E. Forssberg, An overview of recovery of metals from
slags. Waste Management, 2003. 23(10): p. 933-949.
[13] Tossavaine, M., Engstrom, F., Yang, Q., Menad, N., Lidstrom Larsson,
M., and Bjorkman, B. (2007). " Characteristics of steel slag under
different cooling conditions." Waste Management, 27(10), 1335-1344.
@article{"International Journal of Chemical, Materials and Biomolecular Sciences:64575", author = "N. Tshiongo and R K.K. Mbaya and K Maweja and L.C. Tshabalala", title = "Effect of Cooling Rate on base Metals Recovery from Copper Matte Smelting Slags", abstract = "Slag sample from copper smelting operation in a
water jacket furnace from DRC plant was used. The study intends to
determine the effect of cooling in the extraction of base metals. The
cooling methods investigated were water quenching, air cooling and
furnace cooling. The latter cooling ways were compared to the
original as received slag. It was observed that, the cooling rate of the
slag affected the leaching of base metals as it changed the phase
distribution in the slag and the base metals distribution within the
phases. It was also found that fast cooling of slag prevented
crystallization and produced an amorphous phase that encloses the
base metals. The amorphous slags from the slag dumps were more
leachable in acidic medium (HNO3) which leached 46%Cu, 95% Co,
85% Zn, 92% Pb and 79% Fe with no selectivity at pH0, than in
basic medium (NH4OH). The leachability was vice versa for the
modified slags by quenching in water which leached 89%Cu with a
high selectivity as metal extractions are less than 1% for Co, Zn, Pb
and Fe at ambient temperature and pH12. For the crystallized slags,
leaching of base metals increased with the increase of temperature
from ambient temperature to 60°C and decreased at the higher
temperature of 80°C due to the evaporation of the ammonia solution
used for basic leaching, the total amounts of base metals that were
leached in slow cooled slags were very low compared to the
quenched slag samples.", keywords = "copper slag, leaching, amorphous, cooling rate", volume = "4", number = "10", pages = "675-5", }