The Unglamorous Reagent That Keeps a Circuit Running
Hydrated lime doesn’t get the attention that flotation reagents or leaching chemicals do, but in a cyanide gold circuit it performs one of the most safety-critical functions: controlling pH. Cyanidation needs to run under alkaline conditions, and hydrated lime is the standard, cost-effective way most operations get there.
Why pH Control Isn’t Optional
Running a cyanide circuit at insufficiently alkaline pH risks the generation of hydrogen cyanide gas — a serious worker safety hazard. Hydrated lime addition, properly controlled, keeps the circuit in a safe and effective operating range while also supporting gold dissolution chemistry. This is one of those reagents where under-dosing isn’t just inefficient, it’s dangerous.
Beyond pH: Other Roles in the Circuit
Depending on the plant design, hydrated lime may also contribute to water treatment, neutralization of acidic process streams, and certain precipitation reactions. Its low cost relative to other alkalis is part of why it remains the default choice across so many gold operations worldwide.
Quality and Consistency Matter More Than People Expect
Not all hydrated lime is equal. Reactivity, particle size, and impurity content affect how quickly and completely it neutralizes acid and raises pH. Inconsistent lime quality from batch to batch can show up as pH swings that are hard to diagnose if you’re not tracking reagent quality alongside process data.
Sourcing Checklist
- Confirm reactivity/particle size specifications relevant to your dosing system
- Request current TDS and SDS documentation
- Ask about packaging options suited to your consumption rate (bulk bags vs. bulk silo delivery)
- Establish a consistent supply relationship to avoid quality variability between batches
Contact us for current availability, specifications and bulk pricing on hydrated lime for your gold processing operation.
