Beneficiation method for recovering zinc, lead and silver from zinc leaching residue

Abstract

The invention discloses a beneficiation method for recovering zinc, lead and silver from a zinc leaching residue. The method basically comprises the following steps of: recovering water-soluble zinc by a washing, zinc leaching and precipitating method to obtain a zinc concentrate; and recovering lead and silver to obtain a lead-silver concentrate by a disperse, size mixing, surface modifying and floating method. When the zinc content in the precipitate obtained by the washing, zinc leaching and precipitating method is lower, selective floating and enriching are carried out on the precipitate to obtain the zinc concentrate; and selective size mixing and floating are carried out on the leaching residue to recover indissoluble zinc in the leaching residue and then the indissoluble zinc is sent to a lead and silver recovery system. The method has the advantages that the process is simple, and required equipment investment is less; the production cost is low to ensure that an economical treatment method is found for the zinc leaching residue with a low zinc content; roasting with coal is not needed, thus the smoke pollution problem is avoided; return water can be recycled; and floatingtailings are subjected to low-toxicity treatment, and dry stockpiling can be used for replacing full size tailings library stockpiling, therefore, potential safety hazards of the full size tailings library are eliminated.

Description

technical field

[0001] The invention relates to a beneficiation method for recovering lead, zinc and silver, in particular to a beneficiation method for recovering lead, zinc and silver from zinc leaching slag. Background technique

[0002] The raw material of the zinc smelter - zinc concentrate generally contains about 50% zinc (existing as ZnS) and about 1.5-3% lead (existing as PbS). The slag rate of the raw material is about 50%, so the grade of lead in the leaching slag will be more than doubled than the original enrichment, reaching more than 3-6% (mainly converted into PbSO 4 form). The leaching slag of this hydrometallurgy plant is an important secondary resource of lead.

[0003] The leaching slag of the wet zinc smelting plant also contains zinc metal with recycling value. The zinc minerals contained in the leaching slag are mainly acid insoluble zinc minerals, the most common being zinc ferrite, followed by zinc silicate. When the zinc sulfide concentrate cont...

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