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What Is Gold Smelting?
Smelting is the process of applying heat and chemicals to separate gold from other minerals in ore or raw material. It is the critical step between raw mining output and refined, tradeable gold.
Step 1: Pre-Treatment (Amalgamation or Gravity Concentration)
Most artisanal miners in DRC and Uganda use mercury amalgamation (despite health and environmental risks) or simple gravity concentration (sluice boxes, jigs) to pre-concentrate gold before smelting.
Step 2: Smelting
Concentrated gold material is placed in a crucible with flux agents (borax, soda ash, silica). The mixture is heated to 1,064°C (gold's melting point) in a furnace. Base metals oxidise and separate as slag, leaving molten gold.
Output: A rough gold bead or small bar, typically 85–95% pure.
Step 3: Refining
For higher purity (99%+), two main methods are used:
Miller Process
Chlorine gas is blown through molten gold. Impurities form chlorides and float to the surface. Produces 99.5% purity. Used for most commercial gold.
Wohlwill Electrolytic Refining
Gold is dissolved in chloroauric acid and electrolytically deposited as 99.99% pure gold. Used for LBMA Good Delivery Bars.
Artisanal vs Industrial Smelting
| Factor | Artisanal | Industrial | |--------|-----------|------------| | Output purity | 85–95% | 99.5–99.99% | | Scale | Grams–kg per day | Tonnes per month | | Cost | Low | High | | Compliance | Variable | Certified |
What This Means for Buyers
Raw smelted bars from DRC/Uganda artisanal operations (85–95% purity) are ideal for buyers with access to refineries. Full refining adds $15–40/oz to the cost but produces LBMA-grade material at full spot value.
Equator Gold Resources offers partially smelted bars and can coordinate final refining at accredited facilities.
Discuss Your Gold Sourcing Requirements
Interested in discussing legitimate gold sourcing, mining opportunities or African gold supply? Contact Equator Gold Resources to discuss your requirements and the applicable due-diligence process. Availability of gold is always subject to verification, and transactions are subject to applicable regulations.
About the Editorial Team
This article is published by the Equator Gold Resources Editorial Team for general educational purposes and does not constitute legal, tax, investment or professional advice. Gold transactions, mining, licensing, export, taxation, AML/KYC and documentation requirements differ by jurisdiction and change over time. Buyers and investors should confirm current requirements with the relevant government authorities in Uganda, the Democratic Republic of the Congo (DRC), South Sudan and other applicable jurisdictions, and seek advice from qualified legal, customs and assay professionals.
