Method for producing high-purity zinc oxide by ammonia method using low-grade zinc oxide ores

Abstract

The invention discloses a method for producing high-purity zinc oxide by an ammonia method using low-grade zinc oxide ores. The method comprises the following steps of: adding 3-5% of slaked lime to low-grade zinc oxide ores to be treated for performing mixing and activation before leaching, controlling water in the mixture at 8-10% by mass percentage, adding 0.3-0.5kg of sodium fluorosilicate to per cubic meter of leaching agent, and preferably adding surfactant and dicyandiamide, wherein an ammonia pre-distillation step can be further added simultaneously, therefore, on the one hand, the leaching speed and the leaching rate of zinc in the low-grade zinc oxide ores are increased, and on the other hand, a lower calcination temperature is preferred, zinc oxide with a greater specific surface area and with the purity up to 99.7% and more can be obtained, and the obtained zinc oxide has high economic value; in addition, the treatment method is low in energy consumption and high in efficiency, and the leaching agent can be recycled. The final leaching residues after performing leaching treatment do not damage the original composition and structure of minerals and can still be used to brick-making, thereby achieving economical and environmental-friendly dual purposes.

Description

technical field

[0001] The invention relates to a production method of zinc oxide, in particular to a production method of high-purity zinc oxide. Background technique

[0002] At present, the production of zinc oxide products generally uses ore with high zinc content to be roasted into zinc calcine as raw material, because its zinc content is relatively high, and leaching is relatively easy. With years of mining, high-grade ore sources have become less and less, and the grade has gradually decreased. People have begun to pay attention to the utilization of zinc oxide ore. However, zinc oxide ore usually has a low zinc content (valuable element content Zn below 30%; Pb 0.15%; Cu 0.008%; Mn 0.06%), and the composition is complex, mostly smithsonite, zinc iron spinel and heteropolar The ore exists, and the gangue components in the ore are high in iron oxide, silicon oxide, calcium oxide, and magnesium oxide (about Fe 2 o 3 4-7%; SiO 2 3-5%; CaO30-32%; MgO 7-8%). The value...