Method for preparing zinc oxalate as zinc oxide powder precursor from middle/low-grade zinc oxide ore

Abstract

The invention relates to a method for preparing zinc oxalate as a zinc oxide powder precursor from middle / low-grade zinc oxide ore and belongs to the technical field of wet method metallurgy. The method comprises preparing a deep eutectic solvent-type ionic liquid from choline chloride and oxalic acid, fragmenting and fine grinding middle / low-grade zinc oxide ore, adding the middle / low-grade zinc oxide ore powder into the deep eutectic solvent-type ionic liquid, carrying out stirring leaching, adding distilled water into the leached ore pulp, carrying out stirring to obtain a uniform mixture, carrying out standing, carrying out solid-liquid separation to obtain a filtrate A and a zinc oxalate-rich filter residue B, preparing a deep eutectic solvent-type ionic liquid, adding the zinc oxalate-rich filter residue B into the deep eutectic solvent-type ionic liquid, carrying out leaching, carrying out solid-liquid separation to obtain a filtrate C and filter residue D, adding distilled water into the filtrate C, wherein the volume of the distilled water is 2-10 times that of the filtrate C, carrying out filtration after white precipitates are precipitated, washing the filter residue and carrying out drying to obtain zinc oxalate crystals. The method realizes effective utilization of middle / low-grade zinc oxide ore and provides a novel approach for deep eutectic solvent use.

Description

technical field [0001] The invention relates to a method for preparing zinc oxalate precursor zinc oxalate by utilizing middle and low-grade zinc oxide ore, and belongs to the technical field of hydrometallurgy. Background technique [0002] Zinc oxide ore has low grade and complex composition. The zinc in zinc oxide minerals is mainly zinc oxide (ZnO), smithsonite (ZnCO 3 ), hydrozincite (ZnCO 3 ·Zn(OH) 2 ), Willemite (Zn 2 SiO 4 ), hemimorphite (Zn 4 (Si 2 o 7 )(OH) 2 ·H 2 O) and other forms exist, and the minerals also contain a considerable amount of metal impurities, such as compounds of lead, iron, cadmium, copper, etc., and the main components of gangue are calcite, dolomite, quartz, clay, etc. At present, there are mainly two types of zinc oxide ore processing methods: one is to smelt zinc oxide ore to obtain metal zinc after beneficiation and enrichment; the other is to directly smelt zinc oxide ore to obtain metal zinc. However, the beneficiation and enr...

AI Technical Summary

Problems solved by technology

The concentration of zinc in the leaching solution obtained from the treatment of low-grade zinc oxide ore by sodium hydroxide leaching process is low, and the effect of direct electrodeposited zinc is not ideal. Generally, for low-grade zinc oxide ore, zinc sulfide concentrate can be prepared by sulfidation precipitation or hydrolysis precipitation. and zinc oxide concentrate, but it is difficult to return and utilize the liquid after zinc precipitation

Ammonia-ammonium salt leaching process is based on NH 3 As a ligand, Zn with zinc oxide ore 2+ Form complex ions to leach zinc in minerals. This method can prevent impurities such as calcium, magnesium, iron, and silicon that coexist in minerals from being leached in large quantities. The leaching process is short, but there is still ammonia gas in the leaching process. Volatilization is harmful to the human body and the environment, and the leaching solution needs to be recovered by distilling ammonia, the energy consumption of the process is high, and the ammonia distillation tower is seriously scarred.

Therefore, it is difficult to directly smelt zinc oxide ore by traditional technology, and the production operation and recycling of valuable metals are difficult, and the production cost is relatively high.

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