Lead-acid batteries, also known as storage batteries, are mainly composed of lead plates (over 70%) and acid (over 20%), converting chemical energy into electrical energy. As a zero-emission, low-noise, rechargeable green energy source, batteries have long been widely used in various aspects of life. However, batteries are usually scrapped after one or two years of use. How to handle large quantities of used batteries? A battery dismantling machine is a device used to dismantle used batteries. It can cut the battery cover, neatly cut off the battery casing, separate the lead core from the casing, and output the battery cover, casing, and lead blocks separately.
Waste lead-acid battery lead recycling technology is generally divided into three types: pyrometallurgical process, hydrometallurgical process, and solid-phase electrolysis process.
1. Pyrometallurgical Process
Reduction smelting is mainly used for the pyrolysis of waste lead-acid batteries. Besides reducing agents, fluxes such as iron filings, sodium carbonate, limestone, quartz, and fluorite can be added during the smelting process.
2. Hydrometallurgical Process
The battery fragments obtained after the pretreatment of dismantled waste lead-acid batteries are a mixture of metallic lead, lead oxide, lead salts, and other metals such as copper, silver, and arsenic.
Hydrometallurgical technology, also known as electrolysis, uses electrical energy to selectively reduce all lead compounds in the battery fragments to metallic lead. Its main characteristics are that no waste gas or residue is generated during the smelting process, and the lead recovery rate can reach 95%~97%.
The working principle of hydrometallurgical technology is to add a reducing agent to the solution. The reducing agent in the lead reduction process can be prepared from steel pickling wastewater, thus achieving the purpose of “using waste to produce waste”.
3. Solid-Phase Electrolysis Process
The solid-phase electrolysis process uses an aqueous sodium hydroxide solution as the electrolyte. Stainless steel plates are used for the cathode and anode. During electrolysis, solid lead-containing molecules in the lead slurry gain electrons from the cathode surface and are reduced to metallic lead.
Waste lead-acid batteries have a high lead content, and recycling them has significant economic and environmental benefits.
