Influence of Minor Elements in Waste Lead Battery Recycling
579
Fig. 11 Results of sulfuric acid coloring test by calcination of lead electrode components
Influence of Organic Substances (Separator)
As shown in Fig. 4, a separator is used for the lead battery. The separator has a
role of preventing a short circuit between the positive electrode and the negative
electrode, allowing each ion related to the reaction to pass through and holding the
electrolytic solution in the separator. As a material for the separator, generally, a
mixture of hydrophilic PE fibers and SiO 2 powder is used. In our refinery, sulfuric
acid is produced from SO 2 gas generated in the sintering process. In-house dust
containing organic components recovered from the cupola furnace exhaust gas is
processed in the sintering process. As a characteristic of the furnace of the sintering
machine, there is a preheating process of raw materials at the raw material charging
stage. The organic substances are not completely burned in the furnace, and the
gaseous organic components that cannot be washed in the sulfuric acid gas refining
equipment are transferred to the sulfuric acid process. As a result, the gaseous organic
matter is absorbed and carbonized in an absorption tower in the sulfuric acid process,
and the product acid becomes brown. Figure 11 shows the photograph of the various
test results of the coloring condition when the combustion conditions in the sintering
machine are simulated. In the case of a gas produced from a lead electrode plate
separator and from in-house dust including dust generated from cupola exhaust gas
sulfuric acid, the acid is colored, while in the case of concentrate, which is the main
raw material of a sintering machine, sulfuric acid is less colored. From the above
results, the cause of sulfuric acid coloring is considered to be due to the influence of
organic substances due to the lead electrode plate treatment.
Conclusion
In this paper, the influence of the minor elements in waste lead battery such as adhered
sulfuric acid, organic matter, and alloy components was described. Regarding the
attached sulfuric acid, the corrosion of the water cooling jacket in the cupola furnace
is caused and the generated SO 2 gas causes an increase in the desulfurization load in
the desulfurization process. As for the separator (organic substance), coloring of the
579
Fig. 11 Results of sulfuric acid coloring test by calcination of lead electrode components
Influence of Organic Substances (Separator)
As shown in Fig. 4, a separator is used for the lead battery. The separator has a
role of preventing a short circuit between the positive electrode and the negative
electrode, allowing each ion related to the reaction to pass through and holding the
electrolytic solution in the separator. As a material for the separator, generally, a
mixture of hydrophilic PE fibers and SiO 2 powder is used. In our refinery, sulfuric
acid is produced from SO 2 gas generated in the sintering process. In-house dust
containing organic components recovered from the cupola furnace exhaust gas is
processed in the sintering process. As a characteristic of the furnace of the sintering
machine, there is a preheating process of raw materials at the raw material charging
stage. The organic substances are not completely burned in the furnace, and the
gaseous organic components that cannot be washed in the sulfuric acid gas refining
equipment are transferred to the sulfuric acid process. As a result, the gaseous organic
matter is absorbed and carbonized in an absorption tower in the sulfuric acid process,
and the product acid becomes brown. Figure 11 shows the photograph of the various
test results of the coloring condition when the combustion conditions in the sintering
machine are simulated. In the case of a gas produced from a lead electrode plate
separator and from in-house dust including dust generated from cupola exhaust gas
sulfuric acid, the acid is colored, while in the case of concentrate, which is the main
raw material of a sintering machine, sulfuric acid is less colored. From the above
results, the cause of sulfuric acid coloring is considered to be due to the influence of
organic substances due to the lead electrode plate treatment.
Conclusion
In this paper, the influence of the minor elements in waste lead battery such as adhered
sulfuric acid, organic matter, and alloy components was described. Regarding the
attached sulfuric acid, the corrosion of the water cooling jacket in the cupola furnace
is caused and the generated SO 2 gas causes an increase in the desulfurization load in
the desulfurization process. As for the separator (organic substance), coloring of the