How are Lead Acid Batteries Recycled?

posted on May 16, 2011

Lead-acid batteries have lot more environmental benefits. According to a survey conducted on some of the recycled consumer products, it is found out that 45% of newspapers, 26% of glass bottles, 26% of tires and  55% of aluminum soft drink and beer cans have been recycled. But the recycling of lead-acid batteries has gone up to 97%, which is ahead of them all.

The closed-loop life cycle of lead-acid battery is responsible for most of its environmental success. 60 to 80 percent recycled lead and plastic are there in an unused lead-acid battery. After collecting a used battery, it goes through a permitted recycling process. This processing is carried out under strict environmental regulations and followed by the recovering of lead and plastic to be used by a new battery manufacturer.  The recycling process is indefinite and you must have got an idea that the lead and plastic in the lead-acid battery in our vehicle can be recycled multiple times. So as far as the environmental and economical perspectives are concerned, the disposal of lead-acid battery has been useful in a great way.

Lead Acid Batteries Recycled

A recycling data is provided by the recycling chart for glass bottles, aluminum, tires and newspapers in comparison to lead-acid batteries. A hammer mill is used to break the battery into pieces. Then in a vat, the broken pieces are stored. While the plastic comes out to the top, the heavy materials and lead settle on the bottom. It scoops away the polypropylene pieces and draws off the liquids except the heavy metals and lead. A different stream is used for each of the materials. We can start with plastic or polypropylene.

After washing and drying the polypropylene pieces, these are melted into an almost liquid state by a plastic recycler. Then small plastic pellets are produced from these molten plastic through an extruder. The pellets remain in a uniform size. The battery manufacturers buy these pellets and start their process.

Cleaning and melting of lead oxide, lead grids and other parts are carried out in a melting furnace. The molten lead goes into ingot molds. Larger ingots are also called hogs and they weigh around 2,000 pounds.  Pigs are the smaller ingots carrying around 65 pounds of weight. Wait for few minutes and you will notice the lead is still molten and impurities or dross rising to the top of it in the ingot molds. You can cool the ingots once the dross is scraped away. After cooling is done, the lead can be removed from the molds. The battery manufacturers remelt the lead and produce new lead plates and other parts of a new battery using the lead.

There are two ways to handle an old battery acid. An industrial compound neutralizes acid just like the household baking soda. The acid is turned into water. The water goes through a testing and cleaning process to meet the standards of clean water. Then it is sent to the public sewer system. In the second way the acid is processed and converted into sodium sulfate. Sodium sulfate is an odorless white powder which is used laundry detergent, textile and glass manufacturing. It makes use of a material which is discarded and forms a useful product out of it. This is how most of the discarded matters from Industrial Salvage should be dealt with to keep our environment clean.

*Image credits by: crownbattery.com
Resources and Readings: Fiberglass recycling from Boat Auctions

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