Introduction: The Modern Value of Copper Smelting
As the “blood metal” of modern industry, copper smelting technology has a direct impact on the development
of electronics, construction, new energy and other core areas. The global demand for copper is growing at a rate
of 3% per year, but the ore grade is decreasing year by year to less than 0.6%. How to realize efficient purification
under the premise of environmental compliance has become the focus of the industry's technical attack.
This article will deeply analyze the whole process of copper smelting, technical difficulties and the direction
of future breakthroughs.
The core process of copper smelting: four major stages of the process
in detail
1. Ore pretreatment: from raw ore to concentrate metamorphosis
Crushing and grinding: through the combination of jaw crusher + ball mill, the particle size of the raw ore is reduced
to below 0.074mm, releasing the monomer dissociation degree of copper minerals.
Flotation Separation: Adopting flavonoid trapping agent to realize efficient separation of copper minerals (chalcopyrite,
chalcopyrite) and chalcopyrite in alkaline environment of pH 8.5-9.5, and the grade of concentrate can be up to 20%-30%.
Dehydration and drying: Ceramic filter reduces the water content of concentrate to less than 12%, reducing energy
consumption for transportation and smelting.
Industry pain point: low-grade ore (<0.3% Cu) flotation recovery rate of less than 70%, the urgent need for the
development of new chemicals.
2. smelting process: pyrometallurgical smelting of the three mainstream technology comparison
Technology Type Reaction Temperature (℃) Energy Consumption (GJ/ton Cu) Sulfur Capture Rate
Conventional reflector furnace 1250-1300 28-32 <40
Flash Smelting 1350-1400 18-22 95%-98
Oxygen top-blowing smelting 1200-1250 15-18 99%+
Technological breakthrough: Oxygen-enriched intensive melting (O₂ concentration >85%) increases melting
efficiency by 50% and reduces slag copper content to below 0.5%.
3. Blowing and refining: metamorphosis from crude copper to anode plate
Converter blowing: purify ice copper (containing 50%-75% Cu) to crude copper (98.5% Cu) through
two-stage oxidation in PS converter.
Anode furnace refining: natural gas reduction deoxidization + phosphorus copper deoxidization, copper
purity is increased to 99.3%, casting into anode plate.
Electrolytic refining: 99.99% copper cathode is obtained by 0.3V DC deposition in copper sulfate electrolyte,
and precious metals (gold, silver) are enriched in anode mud.
Environmental challenges: electrolysis produces 3-5 tons of acidic wastewater per ton of copper, which
requires supporting ion exchange resin treatment system.
Direction of technology attack: green smelting and
resource utilization
1. Low-carbon smelting technology breakthrough
Electricity substitution: Combination of mine heat electric furnace + green electricity, carbon emission per ton
of copper is reduced from 2.8 tons to 1.2 tons (EU BAT standard).
Waste heat recovery: smelting flue gas (1000℃) is used to generate electricity through the waste heat boiler,
which meets 30% of the smelter's self-consumption electricity demand.
2. Complex ore processing program
Mixed ore synergistic smelting: copper-nickel ore and copper-cobalt ore are jointly processed, and the
comprehensive metal recovery rate is increased to 92%.
Arsenic pollution control: high-temperature curing method fixes arsenic in glassy slag, leaching toxicity is lower than 0.1mg/L.
3. Tailings resourceization path
Valuable metal extraction: recovery of molybdenum, rhenium and other rare metals from flotation tailings, the added
value of 200 yuan / ton.
Building materials utilization: tailings system microcrystalline glass technology, compressive strength of 150MPa,
alternative to natural stone.
Future trends: intelligence and circular economy
1. Digital twin system landing
Real-time collection of 300+ parameters such as melting temperature, flue gas composition, etc. through IoT sensors,
and dynamic optimization of oxygen material ratio by AI model, the fluctuation range of copper recovery rate is
narrowed from ±2% to ±0.5%.
2. Urban mine development
Waste circuit boards, electric motors and other “urban minerals” provide 30% of copper raw materials, and the energy
consumption of the short-flow smelting process is only 20% of that of primary ore.
3. Hydrogen metallurgy test
Hydrogen-based direct reduction copper refining pilot line has realized 45kg of hydrogen consumption per ton of copper,
reducing CO₂ by 85% compared with the traditional process.
Conclusion: Technology Upgrade Drives Industry Change
Copper smelting is transforming from high energy consumption and high pollution to green and low-carbon. In the next
five years, with the maturity of biometallurgy, plasma smelting and other new technologies, the comprehensive cost of
smelting is expected to drop by 40%, which will provide key materials for the global energy transition. Enterprises need
to focus on process upgrading and circular economy layout to find a balance between compliance and efficiency.