processing desorption electrolysis system professional

A Desorption Electrolysis System (DES) is an advanced technology used primarily for the recovery of precious metals (like gold, silver, platinum) from loaded activated carbon or other adsorbents in industries such as mining and wastewater treatment. Below is a professional breakdown of its processing stages:

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1. System Overview

The DES combines desorption (stripping metals from carbon) and electrolysis (recovering metals in pure form) into an integrated system. It replaces traditional cyanide-based methods with an eco-friendly, efficient approach.

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2. Key Processing Stages

(1) Desorption Stage

• Purpose: Remove adsorbed metals (e.g., gold cyanide complexes) from activated carbon.
• Process:

– The loaded carbon is fed into a desorption column.
– A hot (~130–160°C), pressurized (~350 kPa) solution of NaOH/NaCN mixture or alternative eluents (e.g., thiosulfate for non-cyanide processes) circulates through the column.
– Metals desorb into the solution, leaving the carbon regenerated for reuse.

(2) Electrolysis Stage

• Purpose: Recover pure metal from the pregnant eluent solution.
• Process:

– The metal-rich solution flows through an electrolytic cell with cathode (e.g., stainless steel wool) and anode.
– Under controlled voltage/current, metal ions (e.g., Au⁺) are reduced and deposited on the cathode:
\[
\text{Au(CN)}_2^- + e^- \rightarrow \text{Au} + 2\text{CN}^-
\]
– Impurities remain in solution or form slimes.

(3) Carbon Regeneration

• The stripped carbon is rinsed, dried, and thermally reactivated (~700°C in a rotary kiln) for reuse.

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3. Advantages of DES

• High Recovery Rate: >99% metal recovery efficiency.
• Eco-Friendly: Minimizes cyanide use; closed-loop system reduces waste.
• Cost-Effective: Lower operational costs vs. conventional methods (e.g., Zadra process).
• Automation: Continuous processing with PLC control.

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4. Applications

• Gold/silver recovery in mining (CIP/CIL circuits).
• Recycling electronic waste (PCBs).
• Industrial wastewater treatment.



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5. Technical Considerations

• Electrolyte Composition: Optimize pH/temperature to avoid passivation.
• Current Density: Typically 10–50 A/m² to ensure dense metal deposition.
• Maintenance: Regular cleaning of electrodes to prevent fouling.

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6. Leading Manufacturers

Companies like APT (Africa), Mintek (South Africa), and Sepro Systems offer commercial DES units tailored to scale.

Would you like details on specific components (e.g., electrolytic cell design) or operational protocols?