In every gold elution plant, carbon is both your workhorse and your hidden cost. It quietly does the heavy lifting, adsorbing gold from solution, surviving multiple elution cycles, and enduring intense heat and caustic conditions.
But like anything under pressure, it wears out.
The good news? With proper handling and maintenance, you can double or even triple the lifespan of your activated carbon, and improve gold recovery while you’re at it.
1. Why Carbon Quality Matters
Your carbon determines how efficiently gold transfers through the entire recovery process. Poor-quality or overused carbon doesn’t just reduce adsorption, it slows elution, increases fouling, and produces dull or incomplete gold plates.
In simple terms: good carbon saves money twice, once through higher adsorption and again through fewer replacements.
If you’d like to see where carbon fits into the overall elution process, here’s a breakdown: How the Elution Process Works: From Loaded Carbon to Pure Gold.
2. Avoid Thermal and Chemical Shock
Carbon hates sudden changes. Switching rapidly between hot and cold, or between acidic and caustic conditions, causes micro-fractures that weaken the pellets. Over time, the carbon begins to attrit, breaking into smaller particles that pass through screens or clog the system.
Prevention Tips:
✅ Always preheat carbon gradually before elution.
✅ Don’t switch from acid washing to hot caustic without a rinse cycle.
✅ Keep thermal gradients below 50°C when possible.
Depending on whether you use a ZADRA or AARL system, your heating and rinsing cycles will differ slightly. Here’s a quick comparison: ZADRA vs AARL: Which Gold Elution System Performs Better in Zimbabwe.
3. Keep Carbon Clean Between Cycles
Fouled carbon is one of the most common causes of reduced gold loading. Oils, organic matter, or fine solids from slurry circuits stick to the pores, blocking adsorption sites and preventing gold from attaching properly.
What to Do:
✅ Use proper acid washing (usually with 3–5% HCl) to remove inorganic buildup.
✅ Follow up with a caustic rinse to strip organics.
✅ Store carbon in clean water if not being used immediately.
Dirty or degraded carbon is one of the main reasons for low elution performance — we covered that here: Top 5 Problems That Reduce Gold Elution Efficiency (and How to Fix Them).
4. Monitor Attrition and Replace Proactively
Many operators wait until they see visible breakdown before replacing carbon, but by that point, recovery has already suffered. Fine carbon not only escapes into solution but also holds onto gold that never gets stripped.
At Bulawayo Elutions, we recommend carbon activity testing after every 10–15 cycles. Once activity drops below 85%, replace at least a portion of the bed. Mixing fresh and used carbon helps maintain consistent performance.
If you’re new to elution and want to understand how carbon fits into the gold recovery chain, start here: What Is Gold Elution and Why It’s the Heart of Gold Recovery.
5. Protect Carbon During Storage and Handling
Carbon is highly porous, which means it absorbs more than just gold. If left exposed, it can take in oil, dust, and moisture from the air, contaminating your next batch.
Best Practices:
✅ Store carbon in sealed, clean containers.
✅ Avoid contact with diesel, grease, or flotation reagents.
✅ Keep it submerged in water if possible.
At Bulawayo Elutions, we supply and regenerate carbon using tested cleaning cycles to ensure it arrives ready for high performance. Properly managed, carbon can last for up to 200 cycles, saving significant costs over time.
Final Thoughts
Activated carbon isn’t cheap, but neglect is far more expensive. When handled right, it rewards you with consistent recovery, smoother elution cycles, and better gold purity.
If your carbon losses are climbing or recovery is dipping, it’s not always your system, sometimes it’s just tired carbon that needs a second life.
