As HW31 lead-containing hazardous waste, waste lead-acid batteries are widely used in automobiles, communications, energy storage and other fields. Scientific classification and standardized crushing recycling are the keys to realizing the regeneration of resources such as lead and plastics, while avoiding environmental risks such as acid leakage and lead dust pollution from the source.
Core Classification of Waste Lead-Acid Batteries
According to application scenarios and recycling characteristics, the mainstream types can be divided into four categories, with significant differences in recycling priorities for each category:
- Starting Batteries: Mainly used as starting power sources for automobiles and motorcycles, with a high proportion of electrolyte. The core of recycling is to prevent acid leakage and efficiently extract lead and sulfuric acid.
- Stationary Batteries: Suitable for communication base stations and UPS backup power supplies. The electrolyte is fixed by colloidal/AGM separators. Priority is given to testing for cascade utilization, and overall dismantling is carried out after scrapping.
- Power Batteries: Specialized for electric bicycles and low-speed electric vehicles, with thick and corrosion-resistant plates. Those with a remaining capacity of ≥60% can be used for cascade energy storage, and then crushed and recycled after scrapping.
- Energy Storage Batteries: Battery packs for photovoltaic and power grid peak shaving energy storage need to be disassembled into single cells first, and waste batteries and supporting electronic components are handled separately.
Standardized Crushing Recycling Process
The crushing and recycling of scrapped lead-acid batteries must be carried out in a closed workshop with a hazardous waste operation license, with fully mechanized operations throughout. The core process consists of four steps to achieve full resource utilization of materials:
- Pre-crushing and Acid Separation: Disassemble the battery case through a pre-crusher, collect the discharged waste electrolyte, and store it separately in an acid storage tank to avoid sulfuric acid volatilization.
- High-intensity Crushing and Separation: The solid materials after pre-crushing are deeply crushed by a heavy hammer crusher, then sorted by vibrating screens and gravity/hydraulic separators. Plastic cases float on the water surface and are collected separately, while heavy materials such as lead grids and lead paste sink for separation.
- Fine Material Processing: Plastics are cleaned, dried and granulated into recycled plastic pellets, which can be reused to make battery cases and other products. After desulfurization, lead grids and lead paste are processed by pyrometallurgical or hydrometallurgical smelting to extract pure lead and lead alloys, which are used in the production of new battery plates.
- Electrolyte Resource Utilization: Waste sulfuric acid is neutralized to produce sodium sulfate, which is used in papermaking and textile industries. It can also be purified and regenerated into industrial sulfuric acid to realize electrolyte recycling.
Core Recycling Principles
Manual dismantling and open-air stacking of waste lead-acid batteries are strictly prohibited, and they shall not be collected together with lithium batteries and nickel-metal hydride batteries. Repairable batteries should be given priority for cascade utilization through pulse repair and electrolyte supplementation to reduce resource waste. Scrapped batteries must strictly follow the standardized process of mechanized crushing and classified recycling to maximize lead recovery rate, with the whole process complying with environmental protection standards.
The standardized recycling of waste lead-acid batteries not only enables the closed-loop regeneration of resources such as lead and plastics, replacing the development of some primary mineral resources, but also fundamentally solves the environmental problems of hazardous waste disposal. It is a win-win situation for environmental protection and resource recycling, and an important part of green industrial development.
