Lead- and cadmium-based batteries pose the largest environmental concerns.
Lead acid paved the way to the success of recycling. The recycling process is simple and 70 percent of the battery’s weight is reusable. Other battery types are not as economical to recycle and are not being returned as readily as lead acid. EP WASTE MANAGEMENT is working on programs to make the collection of all batteries convenient and affordable. Only 20 to 40 percent of batteries in mobile phones and other consumer products are currently recycled. The goal of recycling is to prevent hazardous materials from entering landfills and to utilize the retrieved materials in the fabrication of new products.
Spent batteries should be removed from the household. Old primary cells are known to leak and cause damage to the surrounding area. Do not store old lead acid batteries where children play. Simply touching the lead poles can be harmful. Also, keep button cells hidden from small children as they can swallow these batteries.
Even though environmentally unfriendly, lead acid batteries continue to hold a strong market niche, especially as a starter battery. Wheeled mobility and UPS systems could not run as economically if it were not for this reliable battery.
Batteries with toxic substances will continue to be with us and there is nothing wrong in using them as long as they are being disposed of properly. Each battery chemistry has its own recycling procedure and the process begins by sorting the batteries into the correct categories.
Nickel-cadmium: When NiCd batteries are disposed of carelessly, the metallic cell cylinder eventually corrode in the landfill. Cadmium dissolves and seeps into the water supply. Once contamination begins, authorities are helpless to stop the carnage. Our oceans already show traces of cadmium (along with aspirin, penicillin and antidepressants) but scientists are not certain of its origin.
Nickel-metal-hydride: Nickel and the electrolyte in NiMH are semi-toxic. If no disposal service is available in an area, individual NiMH batteries can be discarded with other household waste in small quantities; however, with 10 or more batteries, the user should consider disposal them in a secure waste landfill.
Primary lithium: These batteries contain metallic lithium that reacts violently when in contact with moisture and must be disposed of appropriately. If thrown in a landfill in a charged state, heavy equipment operating on top could crush the cases and the exposed lithium could ignite a fire. Landfill fires are difficult to extinguish and can burn for years underground. Before recycling, apply a full discharge to consume the lithium content. Primary lithium batteries (lithium-metal) are used in military combat, as well as in watches, sensors, hearing aids and memory backup. A lithium-metal variety also serves as alkaline replacement in AAA, AA and 9V formats. Li-ion for mobile phones and laptops do not contain metallic lithium.
Lithium-ion: Li-ion is reasonably harmless but spent packs should be disposed of properly. This is done less to retrieve valuable metals, as is the case with lead acid, than for environmental reasons, especially with the growing volume used in consumer products. Li-ion contains harmful elements that are at the toxicity level of electronic devices.
Alkaline: After lowering the mercury content in alkaline batteries in 1996, many territories now allow disposing these batteries as regular domestic trash; however, California and Europe consider all batteries as hazardous waste. Most stores selling batteries are also required to take back spent batteries. Alkaline batteries contain the reusable materials of zinc and manganese but the retrieval process is a liability.
In Port Elizabeth, EP WASTE MANAGEMENT collect spent batteries and recycle them. EP WASTE MANAGEMENT is in charge of collecting batteries and sending them to recycling organizations.
The recycling process begins by removing the combustible material, such as plastics and insulation, with a gas-fired thermal oxidizer. Polluting particles created by the burning process are eliminated by the plant’s scrubber before release into the atmosphere. This leaves the clean and naked cells with metal content.
The cells are then chopped into small pieces and heated until the metal liquefies. Non-metallic substances are burned off, leaving a black slag on top that a slag arm removes. The alloys settle according to weight and are skimmed off like cream from raw milk while still in liquid form.
Cadmium is relatively light and vaporizes at high temperatures. In a process that appears like a pan of water boiling over, a fan blows the cadmium vapour into a large tube that is cooled with water mist. The vapours condense to produce cadmium that is 99.95 percent pure.
Some recyclers do not separate the metals on site but pour the liquid metals directly into what the industry refers to as “pigs” (65 pounds, 24kg) or “hogs” (2,000 pounds, 746kg). Other battery recyclers use nuggets (7 pound, 3.17kg). The pigs, hogs and nuggets are shipped to metal recovery plants where they are used to produce nickel, chromium and iron for stainless steel and other high-end products.
To reduce the possibility of a reactive event during crushing, some recyclers use a liquid solution or freeze lithium-based batteries with liquid nitrogen; however, mixing Li-ion starter batteries with the common lead acid type still remains a problem as a charged Li-ion is far more explosive than lead acid.
Battery recycling is energy intensive. Reports reveal that it takes 6 to 10 times more energy to reclaim metals from some recycled batteries than from mining. The exception is the lead acid battery, from which lead can be extracted easily and reused without elaborate processes. To some extent, nickel from NiMH can also be recovered economically if available in large quantities.
Each country sets its own rules and adds tariffs to the purchase price of a new battery to make recycling feasible. In South africa, some recycling plants invoice by weight and the rates vary according to chemistry. While NiMH yields a fairly good return with nickel, the spent NiCd battery is less in demand because of soft cadmium prices. Due to poor metal retrieval value, Li-ion commands a higher recycling fee than most other battery types.
Most batteries today are recyclable through EP WASTE MANAGEMENT with the preservation of the environment in mind. EP WASTE MANAGEMENT will supply the source client with cradle to grave certification and dispose of these batteries in the correct manner. To motivate the safe disposal of batteries and preserving the environment, EP WASTE MANAGEMENT will minimise the collection, disposal and certification fees and with large volumes even offer rebates.