Technology for extracting zinc, lead and silver step by step by processing zinc-leached residues by full wet process

Abstract

The invention relates to a technology for extracting zinc, lead and silver step by step by processing zinc-leached residues by a full wet process, and belongs to the technical field of zinc-leached residue recycle. The technology comprises the following steps of: preparing sulfuric acid into an appropriate concentration, and performing two-stage acid leaching in an appropriate liquid-solid ratio and at a high temperature to obtain slurry; filtering and separating the slurry to obtain lead-silver residues and a zinc-containing solution; oxidizing, neutralizing and deironing the zinc-containing solution, and depositing zinc by using sodium sulphide; and eluting the lead-silver residues, blending with caustic lye at an appropriate concentration to obtain slurry at a certain concentration, reacting at a certain temperature and in a certain solid-liquid ratio, and filtering and separating to obtain a filter cake and a filtrate, wherein the filtrate is directly added with sodium sulphide for lead deposition and the filter cake returns to a silver cyaniding leaching process. The technology is short in process, simple in operation, low in cost and mild and loose in reaction conditions; an acid solution and an alkali solution at high concentrations are not required; requirements on equipment are low; the extraction rate of metal is higher than that in the conventional method; no additional waste solid, waste liquid and waste gas are discharged; the recycle of the eluate and the filtrate is realized; and environment pollution is avoided from the source.

Description

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AI Technical Summary

Benefits of technology

This patented technology involves extracting metals like zirenium (Zn), Lead(Pb)and Silver (Ag). It uses an overall dry approach that does away with strong acids or bases while also improving efficiency at removing these elements compared to other techniques such as solvent extractions. Additionally, it allows for easy reprocessing without generating any waste materials during processing. Overall, this new technique simplifies the way we recover valuable resources from spent nuclear fuel after use safely.

Problems solved by technology

This patented technical problem addressed in this patent relates to improving the efficiency of recycling zinc from various sources such as hydrometallurgical (HZM) production sites without causing environmental issues due to excessive disposal costs associated therewith. Specifically, current solutions involve expensive processing steps like centrifugating, burning off residual solids, pyrolysis, filtrations, ion exchange resin adsorbption, electrowinning, thermal reduction furnace melting, magnetic separation, and solid state transformation. These approaches require significant capital assets and operating environments, leading to increased operational cost.

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