A method for extracting Zn, Mn, Pb, Ag from zinc electrolysis anode slime

Abstract

The invention relates to the technical field of wet metallurgy, in particular to a method for extracting Zn, Mn, Pb and Ag from zinc electrolysis anode mud. By means of the total six steps of washing, ball milling, electrolyzing, leaching, replacement and liquid waste treatment, the process of extracting zinc, manganese, lead and silver from the zinc electrolysis anode mud is completed, the separation effect is remarkable, the cost is low, the metal recovering rate is high, the quality is good, waste residues and liquid waste are fully utilized in the whole process, and little pollution is caused.

Description

technical field [0001] The invention relates to the technical field of hydrometallurgy, in particular to a method for extracting Zn, Mn, Pb and Ag from zinc electrolysis anode slime. Background technique [0002] Zinc electrolytic anode slime generally contains Mn30-40%, Pb10-20%, Ag several hundred grams / t to several kilograms / t, ZnSO 4 More than 15%, also contains a small amount of sulfuric acid and calcium sulfate, among which Mn is mainly manganese dioxide, and Pb is mainly PbSO 4 , PbO and lead-silver alloy, Ag is mainly metal Ag and lead-silver alloy; because manganese dioxide is insoluble in acid and alkali, the traditional treatment method is to return the zinc electrolytic anode slime and mix it with zinc raw materials for ball milling sulfuric acid leaching. Only zinc sulfate and sulfuric acid and a small amount of Mn enter the leaching solution, most of the manganese dioxide along with PbSO 4 , lead-silver alloy into the leaching slag cannot be recovered; in ord...

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Problems solved by technology

[0002] Zinc electrolytic anode slime generally contains Mn30-40%, Pb10-20%, Ag several hundred grams / t to several kilograms / t, ZnSO 4 More than 15%, also contains a small amount of sulfuric acid and calcium sulfate, among which Mn is mainly manganese dioxide, and Pb is mainly PbSO 4 , PbO and lead-silver alloy, Ag is mainly metal Ag and lead-silver alloy; because manganese dioxide is insoluble in acid and alkali, the traditional treatment method is to return the zinc electrolytic anode slime and mix it with zinc raw materials for ball milling sulfuric acid leaching. Only zinc sulfate and sulfuric acid and a small amount of Mn enter the leaching solution, most of the manganese dioxide along with PbSO 4 , lead-silver alloy into the leaching slag cannot be recovered; in order to recover Mn, Pb, Ag with high efficiency, people have studied the mixture of zinc electrolytic anode slime and reduced coal for reduction roasting, so that manganese dioxide can be reduced to manganese oxide, and then leached with sulfuric acid to obtain Manganese sulfate, Pb, Ag enter the leaching slag and separate from Mn; since the addition of reduced coal is more than 1.5 times the amount of Mn, the excess coal does not participate in the reduction reaction, and also enters the lead sulfate slag during leaching to reduce the lead sludge (lead sulfate slag), and during reduction roasting, the exhaust gas contains a large amount of sulfuric acid and sulfur dioxide, which corrodes the roasting equipment and pollutes the environment; so someone has studied the sulfuric acid reduction leaching process, adding sulfite (mainly Sodium sulfite or zinc sulfite) or lead into sulfur dioxide to carry out reduction leaching, obtain manganese sulfate and lead mud, the reduction leaching rate of manganese dioxide is not high, about 50-70%, gained manganese sulfate when using sodium sulfite as reducing agent, Containing a large amount of sodium ions, manganese sulfate must be crystallized to have economic value; and zinc sulfite is used as a reducing agent, because there is no market product and needs to be self-made by the enterprise, so its economic value is not large, and Pb and Ag in the lead sludge need additional Treatment can only be separated and recovered, so the cost of reduction leaching is high, the amount of waste water is large, and the recovered manganese sulfate cannot offset the production cost, and has no economic benefits; some scholars have studied the use of flotation and re-election to treat zinc electrolysis anode slime, although The content of manganese dioxide flotation concentrate is as high as 80%, but the flotation rate is not high, and a large amount of flotation ore and tailings are still difficult to handle. When zinc electrolysis anode slime is used to reduce and smelt lead-silver alloys, because manganese dioxide is an oxidant , to consume a large amount of reducing agent, Mn enters the smelting slag and cannot be recovered