As the world's fourth largest base metal, zinc is irreplaceable in the fields of galvanized steel,
battery manufacturing and alloy production. With the acceleration of global industrialization,
the strategic value of zinc resources continues to rise, and its efficient extraction and recycling
technology is becoming a core direction for the transformation and upgrading of the
metallurgical industry.
Global layout and strategic value of the zinc industry chain
Resource distribution and supply/demand status
The global proven zinc ore reserves are about 250 million tons, with an annual mining capacity of
more than 13 million tons, of which China, Australia and Peru account for more than 60%. Recycled
zinc production accounts for 35% of the total supply, and the annual growth rate of 6% continues
to grow, gradually easing the pressure of primary mining.
Multi-field application deepening
Galvanized steel consumption accounts for more than 50% of zinc consumption, the rapid growth
of demand in the field of new energy - zinc-nickel battery storage density of 300Wh/kg, zinc air
batteries in the Internet of Things devices to expand the application of zinc, to promote the
continued optimization of the structure of global zinc consumption.
Economic environment balance point
Energy consumption of recycled zinc production is 70% lower than that of virgin ore, and each ton
of recycled zinc can reduce carbon emissions by 3.2 tons. The recovery rate of zinc from industrial
waste is increased to 92%, and associated metals such as lead and silver are recovered simultaneously,
maximizing the value of resources.
Zinc extraction technology system and process innovation
1. Evolution of pyrometallurgical process
The traditional vertical pot distillation method has been reformed by oxygen-enriched combustion
technology, with the zinc recovery rate exceeding 97% and energy consumption reduced by 40%.
The new ISP (Imperial Smelting Process) equipment realizes the simultaneous smelting of lead and
zinc symbiotic ores, and the adaptability of raw materials is enhanced to low-grade ores containing
more than 15% zinc.
2. Breakthrough in wet metallurgy technology
Neutral leaching-electrolysis process has become mainstream: adopting high-pressure oxygen leaching
technology, the decomposition efficiency of zinc sulfide ore has been raised to 99.5%; introducing
titanium-based anode plate in electrolysis link, the current efficiency reaches 92%, and the cathode
zinc purity is stable at over 99.995%.
3. Secondary resource regeneration system
Zinc-containing fume is treated by rotary kiln volatilization method, with a zinc recovery rate of over
90%; galvanized steel scrap adopts electrochemical stripping technology, with a metal recovery rate
of 88% and base material intact rate of 95%, significantly reducing downstream processing costs.
Environmental Protection Treatment and Resourcing Technology
Exhaust gas treatment module
Equipped with double alkali desulfurization tower and bag filter, the concentration of sulfur dioxide emission
is controlled below 50mg/m³, and the dust capture efficiency reaches 99.8%. Volatile organic compounds
(VOCs) adopt RTO regenerative thermal combustion device, with purification rate over 98%.
Wastewater recycling system
A graded counter-current washing system is established, heavy metal ions are deeply treated by chelating
resin adsorption, and the zinc content of effluent water is <0.5mg/L. Crystallization and salt separation
technology realizes the resourceization of by-products such as sodium sulfate, sodium chloride, etc., and
the water recycling utilization rate reaches 93%.
Solid waste value-added path
The leaching slag is made into cement retarder or ceramic raw material after extraction of silver, germanium
and other rare metals by flotation; the iron alum slag is made into road base material by high temperature
curing, completely eliminating the risk of stockpiling pollution.
Three major technological trends for industry upgrading
1. Popularization of intelligent control system
Digital twin technology to achieve three-dimensional simulation of the smelting process, real-time
optimization of key parameters; AI algorithms to dynamically adjust the pH value of the leaching solution,
metal recovery rate fluctuations narrowed to ± 0.3%.
2. Low-carbon process innovation
The hydrogen-based direct reduction technology has been successfully tested, and the reduction temperature
of zinc oxide has been lowered from 1,100℃ to 750℃, reducing energy consumption by 55%; bioleaching
technology treats low-grade ores, and the intensity of carbon emission has been reduced by 80%.
3. Refined product development
High-purity zinc (99.999%) preparation technology breakthrough, to meet the demand for semiconductor
targets; zinc-aluminum alloy powder atomization granulation equipment put into production, the market
penetration rate of 3D printing materials increased by 12% per year.
Key elements for synergistic development of the industry
Adaptability of raw materials: have the technical reserves to deal with oxidized ore, sulfide ore, zinc-containing
waste and other multi-source materials
Energy consumption control: establish an energy management platform, with a comprehensive energy
consumption of less than 1.2 tons of standard coal per ton of zinc.
Compliance: Obtained hazardous waste license and ISRI certification system.
Value Chain Extension: Develop zinc-based functional materials to increase product value-added by more than 30%.
Conclusion
Driven by the goal of carbon neutrality, the zinc extraction industry is undergoing a profound change from crude
smelting to green manufacturing. Through process innovation and improvement of resource recycling system,
modern zinc industry not only guarantees the supply of basic materials, but also becomes an important engine
to promote low-carbon transformation of manufacturing industry. Grasping the window of technological upgrading
and building an efficient, clean and sustainable zinc resource utilization model will become the core
competitiveness of the global metallurgical field.