gold processing plant flow chart in Zimbabwe
Gold Processing Plant Flow Chart in Zimbabwe
Gold processing in Zimbabwe involves several stages to extract pure gold from ore. The process begins with mining and ends with refined gold ready for market. Below is a detailed flow chart outlining the key steps in a typical gold processing plant in Zimbabwe.
1. Mining and Ore Delivery
The process starts with extracting gold-bearing ore from underground or open-pit mines. The ore is transported to the processing plant using trucks or conveyors. High-grade and low-grade ores are often separated at this stage to optimize processing efficiency.
2. Crushing and Grinding
The raw ore undergoes primary crushing to reduce large rocks into smaller fragments. Secondary crushing further breaks down the material before it enters a grinding mill, where it is pulverized into fine powder. This step increases surface area for better chemical reactions in subsequent stages.
3. Gravity Separation (Optional)
Some plants use gravity separation methods like centrifugal concentrators or shaking tables to recover coarse gold particles before chemical processing. This step improves overall recovery rates and reduces load on leaching circuits.
4. Leaching (Cyanidation or Alternative Methods)
The ground ore is mixed with a leaching solution—typically cyanide—to dissolve gold particles into liquid form (gold cyanide complex). Heap leaching or tank leaching methods may be used depending on ore characteristics and plant capacity.
5. Adsorption (Carbon-in-Pulp or Carbon-in-Leach)
The gold-laden solution passes through activated carbon columns, where gold adheres to carbon particles while impurities remain dissolved. Loaded carbon is then separated for further treatment, while barren solution is recycled back into the leaching circuit.
6. Elution and Electrowinning
Gold-loaded carbon undergoes elution, where high-temperature and pressure strip gold from carbon into a concentrated solution. The solution then enters an electrowinning cell, where electric current deposits pure gold onto steel wool cathodes, forming sludge-like material called “gold mud.”
7. Smelting and Refining
The gold mud is dried, mixed with fluxes, and smelted in a furnace at high temperatures to remove impurities like silver and base metals. Molten gold is poured into molds to form doré bars (typically 90–95% pure). Further refining via chlorination or electrolysis produces 99.99% pure bullion bars ready for sale or exportation by Zimbabwean authorities under local regulations such as Fidelity Printers