The life cycle of a lead-acid battery follows a continuous, closed loop. When a scrap battery is collected and returned to Power Infinity Batteries, its lead and plastic are reclaimed and directed to new battery manufacturing.
The recycling of lead-acid batteries is a multi part process, the basics of which run as follows:
- Initially the battery is broken apart in a hammer mill. The broken pieces go into a vat or flotation pond where the lead and heavy materials sink to the bottom while the plastic remains afloat. At this stage of the process the polypropylene pieces are scooped away and the liquids are drawn off leaving the lead and heavy metals behind.
- The polypropylene, or plastic pieces are washed, air dried and then melted together into an almost liquid state. The molten plastic is then put through an extrude that produces small uniform plastic pellets. These pellets are then used to manufacture new battery cases.
- The lead grids, lead oxide and other lead parts are cleaned and melted together in a smelting furnace along with additives used to help in the removal of impurities. The molten lead is poured into ingot molds. After a couple of minutes, the impurities, or dross, float to the top of the still molten lead in the molds and is scraped away. The ingots are then left to cool. Once they have cooled they are removed and are then ready to be re melted to produce new lead plates and other parts for new batteries.
- Old battery acid is handled in two ways. The one way is to neutralise the acid with an industrial compound similar to household baking soda. This turns the acid into water which is treated, cleaned and tested to ensure that it meets clean water standards. The second way of treating old battery acid is to process it and convert it into sodium sulfate, an odorless white powder used in laundry detergent, glass and textile manufacturing. Thus a potentially noxious substance is transformed into a useful reusable product.
