Method for increasing leaching rate of zinc and indium in secondary zinc oxide

Abstract

A method for increasing the leaching rate of zinc and indium in secondary zinc oxide comprises the following steps that firstly, neutral leaching is carried out, secondary zinc oxide and a sulfuric acid solution are mixed to carry out the leaching reaction, neutral leaching liquor and base flow are obtained through solid and liquid separation, and the base flow is executed in the second step; secondly, low-acid leaching is carried out, the base flow obtained in the first step is mixed with oxygen pressure acid step to carry out the leaching reaction, low-acid leaching residues and low-acid step are obtained through solid and liquid separation, and the low-acid leaching residues are executed in the third step; and thirdly, oxygen pressure acid leaching is carried out, zinc electrolysis waste liquid is added in the low-acid leaching residues for slurrying so that seriflux can be obtained, the obtained seriflux is added in a high-pressure reaction kettle, heating is carried out through high-temperature steam, industrial oxygen is pressurized to participate in the leaching reaction, and oxygen pressure acid leaching residues and oxygen pressure acid leaching liquid are obtained throughsolid and liquid separation. By means of the method, the initial acid concentration of sulfuric acid can be reduced, the reaction temperature is increased, and the reaction time is shortened; interrupted production is changed into continuous production, the material treating cost is reduced, the indium leaching rate can reach more than 92%, and the zinc leaching rate can reach more than 95%.

Description

technical field [0001] The invention relates to the technical field of nonferrous metallurgy, in particular to a method for increasing the leaching rate of zinc and indium in secondary zinc oxide. Background technique [0002] As a rare metal, indium has an abundance in the earth's crust of only 0.11×10 -6 , often associated with zinc, lead, copper, tin and other ores in small amounts, and can only be recovered from the by-products of these non-ferrous metal smelting. Indium has very unique physical and chemical properties, such as low melting point, high boiling point, good conductivity, strong plasticity, etc. It is widely used in high-tech fields such as electronic computers, communications, national defense and military industry, and aerospace. [0003] At present, the domestic treatment of indium-containing materials mostly adopts the two-stage acid leaching technology of low-acid leaching and high-acid leaching. Equipped with professional acid mist absorption equipme...

AI Technical Summary

Problems solved by technology

[0003] At present, the domestic treatment of indium-containing materials mostly adopts the two-stage acid leaching technology of low-acid leaching and high-acid leaching. Equipped with professional acid mist absorption equipment, it is difficult to maintain the temperature for a long time, and the energy consumption is high. In the leaching process, it is necessary to add such as H 2 o 2 、HNO 3 - , MnO 4 - , manganese powder and other oxidants; the total leaching rate of indium in the low-acid process plus high-acid process is still in the range of 60% to 80%, which cannot be further improved, and the traditional low-acid plus high-acid leaching process is intermittent production, the degree of automation Low, high material handling costs