The miracle of the metal's rebirth is performed daily in an array of electrolytic tanks glowing with
an ethereal blue light. Anode plates weighing up to 300 kilograms gradually melt in the electrolytic
solution, and electrolytic copper foil of 99.99% purity grows on the cathode rolls, a modern-day
alchemy that underpins the lifeblood of industries ranging from power transmission to electronics
manufacturing. Globally, more than 25 million tons of refined copper are produced through
electrolysis each year, accounting for 85% of total copper production. This centuries-old process
is being revitalized through intelligent and cleaner transformation. (Keywords: electrolytic
copper production, refined copper purification, green metallurgy)
Atomic Reconstruction of Electrolytic Refining
The anode plate preparation process determines the electrolysis efficiency. The anode plate containing
99% copper obtained by fire refining needs to be precisely milled so that the surface roughness is
controlled within Ra3.2μm. The grain size of the plate surface is adjusted to 50-100μm by
temperature-controlled casting, and this microstructure stabilizes the electrolytic dissolution rate
at 25g/(m²-h).
The electrolyte dynamic balance system is the core of the production. The copper sulfate solution
concentration is maintained at 135-200g/L, and the free acid concentration controls the migration
rate of copper ions. Arsenic, antimony and other impurities are removed through a three-stage
counter-current filtration system, and the electrolyte circulates up to 500m³/h in a three-dimensional
circulating system to ensure that the temperature difference in the tank does not exceed 0.5℃.
The cathode deposition control technology is continuously revolutionized. The surface treatment
technology of titanium master plate reduces the stripping force of the starting pole piece by 40%,
and the pulse current technology allows copper crystals to grow along the (220) crystal surface
optimally. When the current density is increased to 380A/m², the cathode copper growth rate can
reach 0.8mm/h, and the surface finish is improved by 2 levels.
Process revolution of intelligent manufacturing
The digital monitoring system of electrolysis workshop realizes precise control. voltage fluctuation of
1600 electrolysis tanks is controlled at ±5mV, temperature sensor network collects data every 10
seconds, and machine learning algorithms optimize additives proportion in real time. Intelligent
transformation reduces DC power consumption from 2200kWh/t to 1950kWh/t.
New electrode materials break through the efficiency limit. Nano-coated anode reduces oxygen
precipitation overpotential by 300mV, and mixed metal oxide anode life is extended to 8 years.
Flexible cathode roll technology realizes the continuous production of 6μm ultra-thin copper foil,
and the width breaks through the 1.5m mark.
The waste liquid regeneration system builds a circular ecology. The copper recovery rate of electrolysis
poor liquid is increased to 99.8% after extraction and electrowinning treatment, and the reuse rate of
regenerated sulfuric acid reaches 95%. The anode sludge treatment workshop recovers 12 tons of
gold and 800 tons of silver annually, and the types of rare and precious metals extracted
are expanded to 18.
The future picture of green production
Clean energy power supply system rewrites carbon footprint. Photovoltaic direct supply direct current
electrolysis technology saves 15% conversion loss, wind power coupled with energy storage system
reduces carbon emission from tons of copper production to 0.8tCO₂e, and hydrogen roasting anode
furnace realizes zero carbon emission from metallurgical process.
The closed-loop management of water resources has created a new standard. The three-stage gradient
water recycling system reduces water consumption from 25 tons to 3.8 tons per ton of copper, and the
purity of condensate recovered by membrane separation technology reaches the electronic grade
standard. The roof water collection system of the electrolysis workshop collects 200,000 cubic meters
of rainwater annually.
High-value utilization of by-products forms a new industry. The output rate of copper oxide nano
technology prepared from electrolysis waste acid is 92%, and the recovery rate of platinum group metals
is increased by 40% by anode sludge bioleaching technology. Electromagnetic shielding materials prepared
from copper electrolysis sludge have been used in the construction of 5G base stations.
When the last piece of copper cathode completes 48 hours of electrodeposition, the metallic luster
reflected on its surface reflects the perfect fusion of traditional metallurgy and modern technology.
From the super electrolysis plant in the Chilean desert to the intelligent workshop on the coast of
East Asia, the copper electrolysis production process is writing a new era of metal purification
technology with an annual energy efficiency improvement rate of 3%.