Fe^(2+)dissolution method and manual method were used to remove the anode slime and their effects on properties of cast Pb−0.6wt.%Ag anode and zinc electrowinning were compared.The results reveal that the Fe^(2+)disso...Fe^(2+)dissolution method and manual method were used to remove the anode slime and their effects on properties of cast Pb−0.6wt.%Ag anode and zinc electrowinning were compared.The results reveal that the Fe^(2+)dissolution method can avoid mechanical damage to the oxide film layer on the anode surface,which cannot be achieved by traditional manual method.This can lower the anode corrosion rate by 57.14%,thus reducing Pb contamination in electrolyte and zinc products.Meanwhile,compared with manual method,Fe^(2+)dissolution method can significantly improve the electrocatalytic activity of the anode and lower the initial power consumption of zinc electrowinning to 2720 kW·h/t after removing anode slime.展开更多
A process was proposed for removing and stabilizing arsenic(As) from anode slime. The anode slime with high arsenic concentration was pretreated by circular alkaline leaching process. Then, the arsenic in the leaching...A process was proposed for removing and stabilizing arsenic(As) from anode slime. The anode slime with high arsenic concentration was pretreated by circular alkaline leaching process. Then, the arsenic in the leaching solution can be further precipitated as a form of scorodite crystalline(FeAsO4·2H2O). In the precipitating arsenic reaction, in which ferrous ions were oxidized by air gas, the effects of acidity(p H), reaction temperature, air flow rate, initial concentration of arsenic and initial molar ratio of Fe(II) to As(V) on arsenic precipitation were investigated. The results showed that sufficiently stable crystal scorodite could be achieved under the condition of initial arsenic concentration of 10 g/L, pH 3.0-4.0, Fe/As molar ratio of 1.5, the temperature of 80-95 °C, and the air flow rate higher than 120 L/h. Under the optimal condition, more than 78% of arsenic could be precipitated as a form of scorodite crystalline. The As leaching concentration of the precipitates was less than 2.0 mg/L and the precipitates may be considered to be safe for disposal.展开更多
基金supported by Zhejiang Libo Industrial Co.,Ltd.,Shaoxing,China。
文摘Fe^(2+)dissolution method and manual method were used to remove the anode slime and their effects on properties of cast Pb−0.6wt.%Ag anode and zinc electrowinning were compared.The results reveal that the Fe^(2+)dissolution method can avoid mechanical damage to the oxide film layer on the anode surface,which cannot be achieved by traditional manual method.This can lower the anode corrosion rate by 57.14%,thus reducing Pb contamination in electrolyte and zinc products.Meanwhile,compared with manual method,Fe^(2+)dissolution method can significantly improve the electrocatalytic activity of the anode and lower the initial power consumption of zinc electrowinning to 2720 kW·h/t after removing anode slime.
基金Projects(51304251,51374237)supported by the National Natural Science Foundation of ChinaProject(201509050)supported by Special Program on Environmental Protection for Public Welfare,ChinaProjects(2012FJ1010,2014FJ1011)supported by the Key Projects of Science and Technology of Hunan Province,China
文摘A process was proposed for removing and stabilizing arsenic(As) from anode slime. The anode slime with high arsenic concentration was pretreated by circular alkaline leaching process. Then, the arsenic in the leaching solution can be further precipitated as a form of scorodite crystalline(FeAsO4·2H2O). In the precipitating arsenic reaction, in which ferrous ions were oxidized by air gas, the effects of acidity(p H), reaction temperature, air flow rate, initial concentration of arsenic and initial molar ratio of Fe(II) to As(V) on arsenic precipitation were investigated. The results showed that sufficiently stable crystal scorodite could be achieved under the condition of initial arsenic concentration of 10 g/L, pH 3.0-4.0, Fe/As molar ratio of 1.5, the temperature of 80-95 °C, and the air flow rate higher than 120 L/h. Under the optimal condition, more than 78% of arsenic could be precipitated as a form of scorodite crystalline. The As leaching concentration of the precipitates was less than 2.0 mg/L and the precipitates may be considered to be safe for disposal.
