1. Control of chemical treatment agents
Prohibit the use of highly polluting chemicals
Avoid the use of chemical treatment agents containing chromate (such as hexavalent chromium), and give priority to chromium-free passivation agents or low-toxic substitutes to reduce the risk of heavy metal pollution.
Regulate the use of chemicals
Strictly control the concentration and emission of chemical treatment agents to ensure compliance with national heavy metal emission standards (such as chromium, nickel, etc.).
2. Optimize the coating process
Select environmentally friendly coatings
Prioritize the use of coatings with low volatile organic compound (VOC) content to reduce the volatilization of harmful gases during the coating process.
Promote water-based coatings or powder coatings to reduce environmental pollution from solvent-based coatings.
Improve coating efficiency
Optimize the spraying process (such as electrostatic spraying), increase the utilization rate of coatings to more than 80%, and reduce coating waste.
3. Wastewater and waste gas treatment
Wastewater discharge meets standards
Wastewater containing acids, alkalis, and heavy metal ions (such as aluminum ions and zinc ions) must be treated through precipitation, filtration, adsorption and other processes to meet national emission standards.
Direct discharge of untreated polishing wastewater (including polishing wax and metal particles) is prohibited.
Waste gas treatment
The waste gas generated during the painting and passivation process needs to be treated by activated carbon adsorption or catalytic combustion to reduce VOC and dust emissions.
IV. Resource recycling
Waste recycling
Recycle aluminum chips, metal particles and polishing wax in waste liquid and reuse them in production or resource regeneration.
Energy saving
Optimize the treatment process (such as low-temperature passivation, short-time oxidation) to reduce power consumption and heat energy consumption.
V. Alternative technology and process upgrade
Promote chromium-free passivation technology
Use chromium-free passivation liquid to generate dense passivation film, replace traditional chromization process, and take into account anti-corrosion performance and environmental protection requirements.
Combined process application
For highly corrosive environments (such as coastal areas), use anodizing (film thickness ≥ 10μm) combined with fluorocarbon spraying to reduce resource consumption caused by frequent maintenance.
VI. Compliance and Facility Requirements
Environmental protection facilities are required
Wastewater treatment equipment, waste gas purification equipment and hazardous waste temporary storage facilities are required in the production process to ensure compliance of the entire process.
Regular testing and certification
Regularly conduct third-party testing of wastewater and waste gas emissions, and pass ISO 14001 environmental management system certification.
