Method for Extracting and Recovering Gold from Aqueous Solution

Abstract

The present disclosure provides a method for extracting and recovering gold from an aqueous solution, the method including: (1) gold extraction from an aqueous solution through electrocoagulation, in which an electrocoagulation reaction is performed in an electrolytic cell to produce iron hydroxide in-situ, so as to capture gold in the aqueous solution and reduces the gold into gold nanoparticles in-situ; (2) pickling and liquefaction of the precipitated iron sludge, in which the obtained precipitate is dissolved in nitric acid to dissolve iron flocs after washing treatment; and (3) separation and recovery of gold through a nanofiltration membrane system, in which the resulting solution after pickling the precipitated iron sludge is subjected to cut-off treatment using a nanofiltration membrane to separate nano-sized elemental gold from the solution, and then the resultant is washed with water to obtain elemental gold. The extraction and recovery method of the present disclosure has characteristics of high gold extraction efficiency (up to 100%), low cost, simple process, good stability and environmental protection, and can recover high-grade elemental gold (with a comprehensive recovery rate greater than 95%). The method is of an important significance for technical guidance and practical engineering application for the extraction and recovery of gold in various gold smelting and extraction processes.

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