I. Beneficiation Solutions for Various Gold Ore Types
Oxidized Gold Ore: Heap Leaching & Carbon-in-Leach (CIL) Processes
Oxidized gold ore has undergone long-term weathering, and most sulfides within the ore have been oxidized. Limonite and hematite are typical associated minerals. Gold in this type of ore is relatively easy to recover via leaching, making leaching the mainstream recovery method.
- Low-grade oxidized ore with good permeability: Heap leaching is preferred.
- Ore suitable for leaching after grinding: Carbon-in-Leach (CIL) or Carbon-in-Pulp (CIP) processes are adopted.
- Ore containing coarse free gold: A gravity separation stage is added at the front of the process to recover coarse gold in advance.
Sulfide-Bearing Gold Ore: Flotation-Dominated Process
Gold in this type of gold ore is mostly embedded in sulfide minerals such as pyrite and arsenopyrite. It is difficult to fully liberate and recover gold encapsulated in sulfides by gravity separation or conventional cyanide leaching alone.
Typical process: Run-of-mine crushing → Grinding and classification → Flotation concentration → Gold concentrate dewatering → Subsequent smelting / gold extraction from concentrate.
For refractory sulfide gold ore, pre-treatment procedures are required, including roasting, pressure oxidation and bio-oxidation, to break the encapsulation structure of sulfides.
Quartz Vein Gold Ore: Combined Gravity Separation + Flotation + Leaching Process
Quartz vein gold ore is a common type of lode gold deposit. Gold may occur as free native gold or be associated with sulfide minerals. The final process depends on gold particle size and mineral liberation degree.
Typical processes:
- Coarse free native gold: Recovered by gravity separation.
- Gold associated with sulfides: Concentrated by flotation.
- Fully liberated gold minerals with good leachability: Gold extracted by cyanide leaching.
Many concentrators adopt a combined gravity separation and flotation flowsheet to maximize the overall gold recovery rate.
Carbonaceous Gold Ore: Pre-treatment + Leaching Process
Carbonaceous gold ore contains natural organic carbon, which can adsorb dissolved gold in the solution. This phenomenon is known as “preg-robbing” in the industry. Direct conventional leaching will lead to a sharp drop in gold recovery.
For such ore, it is necessary to first test the carbon content and preg-robbing capacity of carbonaceous matter. Then select flotation concentration, carbon passivation or other pre-treatment methods to eliminate preg-robbing interference before leaching.
Placer Gold Ore: Gravity Separation Process
Gold in placer gold deposits exists in the form of free native gold particles, mostly hosted in riverbeds and alluvial gravel layers. Separation relies on the density difference between gold and gangue minerals, with gravity separation as the core.
Typical process: Run-of-mine ore washing → Classification and screening → Jig / sluice roughing → Shaking table cleaning.
This flowsheet features simple structure and low reagent consumption, and is a mature solution for placer gold.
II. Core Procedures for Determining Gold Beneficiation Process
Beneficiation schemes cannot be copied directly from similar mines. The following work shall be completed sequentially in the early stage of a new concentrator project:
- Run-of-mine assay: Test gold grade and associated elements to clarify the basic composition of ore.
- Mineralogical process study: Identify the occurrence state and grain size of gold, and check whether gold is associated with pyrite, arsenopyrite and other minerals.
- Beneficiation test work: Carry out gravity separation, flotation, grinding and leaching tests to verify the suitable process route.
- Techno-economic evaluation: Evaluate capital investment and operating cost comprehensively based on processing capacity, equipment selection, energy consumption, reagent cost and tailings disposal requirements, so as to select the scheme balancing technical feasibility and economic benefits.
Post time: Nov-13-2026
