Extracting method for lead in silver separating residues

Abstract

The invention provides an extracting method for lead in sliver separating residues, and relates to the technical field of non-ferrous metallurgy. The method mainly comprises the following steps: adding the sliver separating residues into waste alkali liquor for pressure-leaching lead; adding lead-containing leach liquor into a vulcanizing agent for precipitating and preparing lead sulfide, and carrying out alkali liquor regeneration on lead-precipitated liquor; and returning the regenerated alkali liquor to the step 1 as leaching mother liquor for recycling. The extracting method has the characteristics of treating waste with waste, being high in lead recovery rate, low in cost, less in investment and easy to realize industrial production.

Description

technical field [0001] The invention belongs to the technical field of nonferrous metal metallurgy, and in particular relates to a method for extracting lead from silver-separating slag. Background technique [0002] Silver separation slag is the residual slag after copper electrolytic anode slime is processed by semi-wet process, and the lead content in it is as high as 15%. If it is not handled properly, it will not only cause waste of resources, but also have a serious impact on the natural environment and people's lives. The wet processes for lead removal mainly include chloride salt method, amine leaching method, sodium carbonate conversion-nitric acid leaching method, and alkali leaching method. Chloride method is in NaCl-HCl-MCl n Under the acidic chloride salt system, generally Cl - The concentration is above 6mol / L, and the lead is leached at a temperature of 70~95°C. The lead-containing leaching solution is replaced by active metals to replace it with sponge lead...

AI Technical Summary

Problems solved by technology

Chloride method is in NaCl-HCl-MCl n Under the acidic chloride salt system, generally Cl - The concentration is above 6mol / L, and the lead is leached at a temperature of 70~95°C. The lead-containing leaching solution is replaced by active metals to replace it with sponge lead, or NaOH is added to prepare PbOHCl, or (NH 4 ) 2 CO 3 Preparation of basic lead carbonate, etc. This process has problems such as low lead recovery rate, poor selectivity, and difficult treatment of high-chlorinated wastewater; the amine leaching method uses amine-based agents and PbSO 4 , PbCl 2 The reaction produces a soluble compound. Commonly used agents are ethylenediamine (EDA) and diethylenetriamine (EDTA). This process has a high lead leaching rate, but there are problems such as high production costs, difficult regeneration of leaching agents, and difficult treatment of amine-containing wastewater. Problem; sodium carbonate conversion - nitric acid leaching method, first add sodium carbonate to remove PbSO 4 , PbCl 2 Converted to PbCO 3 , then wash and filter sulfate and chloride, and then add nitric acid to leach lead. This process has high lead leaching rate and good selectivity, but there are problems such as high production cost, cumbersome process, long production cycle, and equipment corrosion.

Alkali leaching method is a method of leaching lead with NaOH solution. The concentration of lye (NaOH) generally needs to reach 150g / above. The lye has not been recycled, and there is a problem of large alkali consumption; Pressure leaching has the problems of low lead leaching rate and slow reaction speed

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