In the tide of industrial production and resource recycling, the zinc oxide rotary kiln has become a "Green Pearl" in the field of zinc smelting with its effective and environmentally friendly technical advantages. It not only transforms industrial waste into high value-added products, but also promotes the sustainable development of the industry with low-carbon processes. Today, Henan Zhengzhou Mining Machinery Co., Ltd. (here after called “ZK” unveiled the mystery of this equipment and explored its core technology and application value.
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Zinc Oxide Rotary Kiln: "Resource Alchemy" at High Temperature
The secondary zinc oxide rotary kiln is a core equipment for treating zinc-containing materials through high-temperature calcination. Its principle is based on the physical and chemical properties of zinc compounds. In the high temperature environment of 1100-1250℃ in the kiln, the zinc element in the zinc-containing slag (such as steelmaking dust, lead-zinc slag, etc.) reacts with the reducing agent (such as coke) to generate secondary zinc oxide and gas products. This process not only realizes the effective recovery of zinc, but also can simultaneously extract valuable metals such as lead and cadmium, truly achieving "eating up and squeezing out".
Technical Highlights:
Selective reduction: Zinc has a low boiling point (907℃) and is volatilized first in a reducing atmosphere, and then oxidized to generate secondary zinc oxide dust, achieving precise separation.
Waste heat utilization: A waste heat boiler is installed at the end of the kiln to recover the heat of high-temperature flue gas for power generation or heating, reducing energy consumption by more than 15%.
Intelligent control: Hydraulic stopper wheels, infrared scanners and other devices are used to monitor the temperature of the calcining zone in real time to ensure process stability.
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From waste to treasure: the "road to rebirth" of zinc oxide
The secondary zinc oxide rotary kiln process integrates physical calcination and chemical reactions to form a closed-loop production chain:
Raw material pretreatment:
Zinc-containing waste slag (such as steel mill fly ash and ferromanganese slag) is mixed with coke in appropriate proportions to form 8-15mm pellets, improving reaction efficiency.
High-temperature calcination:
The material undergoes three stages within the kiln: drying, medium-temperature reduction, and high-temperature oxidation. Zinc vapor combines with oxygen to form secondary zinc oxide, which enters the dust collection system along with the flue gas.
Environmental treatment: The flue gas undergoes surface cooling, pulse dust removal, desulfurization, and denitrification before meeting emission standards. The dust recovery rate exceeds 95%. The slag is then quenched with water and reused in the downstream process, achieving zero pollution.
Application scenarios:
Metallurgical industry: recovery of valuable metals from lead-zinc slag and hydrometallurgical zinc slag.
Environmental protection: treatment of industrial hazardous waste (such as zinc-containing sludge, electronic waste) to reduce environmental load.
New material manufacturing: production of rubber reinforcing agents, ceramic glazes, electronic components, etc.
3. The "Core Advantages" of the Zinc Oxide Rotary Kiln
Effective Energy Saving: A waste heat boiler is used to recover heat from high-temperature flue gas (efficiency ≥ 65%).
Intelligent Operation and Maintenance: Equipped with a DCS control system, the kiln speed, air volume, and temperature are adjusted in real time, with fault warning accuracy exceeding 90%.
A hydraulic throttle device extends equipment life and reduces annual maintenance costs by 20%.
Environmental Compliance: Flue gas undergoes four-stage treatment, with dust emissions ≤ 10mg/m³ and SO₂ ≤ 35mg/m³, complying with the "Hazardous Waste Incineration Pollution Control Standard" (GB18484-2020).
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Future Outlook: Green Intelligent Manufacturing's "Kiln Revolution"
As the "dual carbon" goals advance, sub-zinc oxide rotary kilns are accelerating their upgrades toward intelligent and low-carbon development.
Digital twin technology: Optimizing calcination parameters through virtual modeling reduces energy consumption by another 10%.
Sub-zinc oxide rotary kilns are not only a "converter" for resource recycling but also a "booster" for industrial green transformation. Through technological innovation, they address the challenge of balancing environmental protection and profitability, opening up a new path for sustainable development in energy-intensive industries. In the future, with technological advancements and policy support, this equipment will shine even brighter in the global resource recycling sector.
Consult now: Get a customized sub-zinc oxide rotary kiln solution and begin your journey into green intelligent manufacturing!
