Electrowinning (also called electrolytic recovery) is the process of plating dissolved gold and silver out of strip solution onto cathodes by passing direct current through the solution. In an ADR plant it is the final metal-recovery step before smelting.
How It Works
After the strip step releases gold back into solution, the pregnant strip solution flows into electrolytic cells. Direct current is passed through the cell — typically 2–4 volts at 200–500 amps. At the cathode (stainless steel wool), gold and silver ions are reduced to metallic form and plate out as a sponge. At the anode (stainless steel), oxygen is generated.
Why Stainless Steel Wool
Stainless steel wool has enormous surface area — gold plates uniformly across the wool fibers rather than as a dense layer that would limit further deposition. After plating, the loaded wool is removed, the gold/silver is recovered by burning off the steel or by acid digestion, and the residue goes to smelting.
KCA Cell Design
KCA fabricates electrolytic cells from laboratory scale up to the Model EC-420-SS — 88 gpm flow capacity, 170 ft³ volumetric, the largest in our standard lineup. Stainless and polypropylene tank options. Extended flow-path designs place anodes in series with cathodes to maximize recovery efficiency.
Integration with Gold Room
Loaded cathodes are sent to the gold room where the cellulose / wool is burned off, the precious-metal residue is mixed with flux, melted in a tilting-crucible furnace, and poured into a doré bar mold. Full integration with KCA smelting furnaces and mercury retorts.
Have a project that involves Electrowinning?
KCA’s engineering bench and Reno metallurgical laboratory have done this before. Let’s talk about your project.
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