Product Overview
What Are Gold
Doré Bars?
Gold Doré bars are semi-pure gold alloys, typically containing a high concentration of gold along with other metals like silver and copper. These bars are produced at mining sites or by melting gold-bearing scrap material, serving as an intermediate product before refining into pure gold bullion.
Gold Doré bars occupy a crucial position in the gold supply chain — they are neither raw gold ore nor refined bullion, but a convenient, compact, high-gold-content alloy form that facilitates handling, transportation, and onward refinery processing. The Doré format enables miners to realise significant value from their ore at the point of production without requiring on-site refinery infrastructure.
United Metals sources Doré exclusively from verified, non-criminal-origin jurisdictions — ensuring that our supply chain is free from conflict zones and fully compliant with international responsible sourcing standards.
Composition
90–96% Gold Content
Doré bars contain the majority of their mass as gold, with the remaining fraction comprising silver, copper, and other trace metals — reflecting the mineralogy of the source ore body.
Production
Mine-Site Casting
Created by removing non-metallic particles from gold ore through crushing, flotation, and smelting — then casting the molten alloy into compact bar form directly at the mining operation.
Form Factor
1 kg Ingot Units
Standard 1 kg bars (±10%) for ease of handling, security, and logistics. The compact, standardised form enables efficient vault storage, transportation, and assay verification at the receiving refinery.
Origin
Conflict-Free Sourcing
All United Metals Doré is sourced from Algeria, Libya, Ghana, and Uganda under strict compliance with OECD Due Diligence Guidance for Responsible Supply Chains of Minerals from Conflict-Affected Areas.
How It's Made
The Doré Bar
Production Process
From underground ore body to castable alloy — a five-stage process that transforms extracted rock into the standardised intermediate product traded by refineries worldwide.
01
Stage 01
Mining & Extraction
Gold is extracted from gold ore through open-pit and underground mining methods, depending on the deposit geometry and depth. The extracted ore is then processed to separate gold from the surrounding rock matrix through a sequence of physical concentration steps.
Open-pit and underground mining methods selected by deposit geometry
Primary crushing and ball-mill grinding to liberate gold particles from gangue
Gravity concentration or flotation to produce a gold-rich concentrate
Carbon-in-leach (CIL) or heap leach cyanidation for refractory ore types
02
Stage 02
Smelting
After extraction, the gold concentrate is smelted in a furnace to produce a semi-pure gold alloy. This process involves heating the concentrate to temperatures above 1,064°C — gold's melting point — to melt and separate the gold from remaining mineral phases. Fluxes are added to capture slag-forming impurities.
Induction or resistance furnace smelting of the loaded carbon or precipitate
Flux addition (borax, silica, sodium nitrate) to capture iron, sulphide, and oxide impurities
Slag separation — lighter slag floats above the dense molten gold-silver alloy
03
Stage 03
Doré Bar Formation
The smelted gold-silver alloy is cast into standardised Doré bar moulds at the mine site. These bars are the primary physical form in which gold leaves the mine — compact, secure, and amenable to assay. The composition of each pour can vary, reflecting the mineralogy of the ore processed in that campaign.
Molten alloy poured into pre-heated graphite or cast-iron moulds
1 kg bars produced as standard; larger pours possible for high-volume campaigns
On-site fire assay performed to determine provisional gold and silver content
Bar stamping, weight recording, and chain-of-custody documentation applied
04
Stage 04
Transportation to Refinery
Once formed, the Doré bars are transported to a licensed refinery for further purification. Transport is arranged under certified bonded logistics with full insurance, chain-of-custody documentation, and regulatory compliance across each transit jurisdiction. United Metals manages the entire logistics process on behalf of clients.
Bonded transport under armed escort and full cargo insurance
OECD Due Diligence compliant documentation package for each shipment
Umpire assay at loading and outturn assay at refinery for settlement
05
Stage 05
Refining to 99.9% Bullion
At the receiving refinery, Doré undergoes additional purification to produce investment-grade gold bullion. The primary refining routes are the Miller Chlorination Process and electrolytic (Wohlwill) refining — each capable of achieving 99.9% to 99.99% gold purity.
Miller Process: chlorine gas bubbled through molten Doré precipitates impurities as chloride slag — fast, to 99.5%
Wohlwill Electrolysis: gold is dissolved from Doré anodes and plated as 99.99% pure cathode gold
Silver and platinum-group metal by-products recovered from Miller slag and Wohlwill electrolyte
Final product: LBMA Good Delivery bars, coins, grain, or granules at 24-carat purity
Applications
Uses & Benefits of
Gold Doré Bars
Gold Doré represents a crucial link in the global gold supply chain, serving three distinct downstream applications — from investment-grade bullion production to industrial manufacturing.
Application 01
Investment & Wealth Preservation
Gold Doré bars are valued for their stability and versatility — offering investors and sovereign wealth funds a tangible asset that maintains value during economic uncertainties. They serve as the feedstock for LBMA Good Delivery bars and central bank gold reserves worldwide. Their semi-pure form at acquisition allows buyers to verify gold content independently before refining to their required specification.
Economic Stability · Inflation Hedge · Portfolio Diversification
Application 02
Jewellery & Electronics Manufacturing
Gold Doré is used across multiple industries — jewellery manufacturing, electronics, and specialty industrial applications — due to its high gold content and readily refinable form. Electronics applications include bonding wire, contact plating, and connectors in semiconductor and aerospace components, where gold's conductivity and corrosion resistance are essential.
Jewellery · Semiconductors · Aerospace Components
Application 03
Refinery Feed & Bullion Production
The primary use of Doré is as refinery feedstock for the production of pure gold bullion at 99.9% to 99.99% purity. Major bullion banks, sovereign mints, and commodity traders purchase Doré as the most direct route from mine production to marketable gold. The silver content in Doré is simultaneously recovered as a silver by-product, adding incremental value beyond the gold alone.
Bullion Banks · Sovereign Mints · Au & Ag By-Product Recovery