Learn about disposal and how toxic material can continue to be used in batteries if recycled.
Lead acid contributed to the success of early recycling and today more than 97 percent of these batteries are recycled in the USA. The automotive industry should be given credit for having organized recycling early on. The recycling process is simple and 70 percent of the battery’s weight is reusable lead.
Over 50 percent of the lead supply comes from recycled batteries. Other battery types are not as economical to recycle and are not being returned as readily as lead acid. Several organizations are working on programs to make collection of all batteries convenient. Only 20 to 40 percent of cellular phone and consumer batteries are currently recycled.
The goal to recycle batteries is to prevent hazardous materials from entering the landfills and to turn the material retrieving process into a viable business. Lead acid and nickel-cadmium batteries are of special concern because of their toxicity. Li-ion and alkaline are less harmful but the aim is to recycle all batteries.
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 the children. [ See Health Concerns with Batteries BU-703 ]
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. NiCd also continues to hold a critical position among rechargeable batteries. Large flooded NiCds start the big jets on airplanes and propel sightseeing boats in rivers of larger cities, pollution-free.
Toxic batteries will continue to be with us for a while longer because we have no practical alternatives. There is nothing wrong in using these batteries as long as they are properly disposed. Europe banned NiCds in consumer products because there was a suitable replacement, the NiMH battery. Controlling the disposal of NiCds from consumer products was difficult because many users do not know that the retiring equipment may include NiCd.
Nickel-cadmium: Let’s look at what happens when NiCds are carelessly disposed of in landfills. The metallic cylinder of the cell eventually begins to corrode and the cadmium gradually dissolves, seeping into the water supply. Once contamination begins, the authorities have few options 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, however, when accumulating 10 or more batteries, the user should consider disposal in a secure waste landfill. The better alternative is bringing the spent batteries to a neighborhood drop-off bin for recycling.
Primary lithium: These batteries contain metallic lithium that reacts violently when in contact with moisture and must be disposed of appropriately. If thrown in the landfill in a charged state, heavy equipment operating on top could crush the cases and the exposed lithium would 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. Non-rechargeable lithium batteries (lithium-metal) are used in military combat, as well as watches, hearing aids and memory backup. Li-ion for cell phones and laptops do not contain metallic lithium.
Alkaline: With the reduction of mercury in 1996, many territories allow disposing alkaline 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 old batteries. There is little valuable materials in alkaline and disposal is a cost-incurring liability.
In North America, Retriev, formerly Toxco, and Rechargeable Battery Recycling Corporation (RBRC) collect spent batteries and recycle them. While Retriev has its own recycling facilities, RBRC is in charge of collecting batteries and sending them to recycling organizations. Retirev in Trail, British Columbia, claims to be the only company in the world that recycles large lithium batteries. They receive spent batteries from oil drilling in Nigeria, Indonesia and other places. Retriev also recycles retired lithium batteries from the Minuteman missile silos and tons of Li-ion from wars. Other divisions at Retriev recycle nickel-cadmium, nickel-metal-hydride, lead, mercury, alkaline and more.
Europe and Asia are also active in recycling spent batteries. Among other recycling companies, Sony and Sumitomo Metal in Japan and Unicore in Belgium have developed technology to retrieve cobalt and other precious metals from spent lithium ion batteries. Lithium can also be retrieved and is thereafter sold for non-battery usages. [ See Battery Recycling as a Business BU-705a ]
Recycling starts by sorting the batteries into chemistries. Collection centers place lead acid, nickel-cadmium, nickel-metal-hydride and lithium ion into designated drums, sacks or boxes. Battery recyclers claim that if a steady stream of batteries, sorted by chemistry, were available at no charge, recycling would be profitable.
The recycling process generally begins by removing the combustible material, such as plastics and insulation, with a gas-fired thermal oxidizer. The plant’s scrubber eliminates the polluting particles created by a burning process before releasing them into the atmosphere. This leaves the clean and naked cells with their valuable 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 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 vapor into a large tube cooled with water mist. The vapors 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 the 7-pound nuggets (3.17kg). The pigs, hogs and nuggets are then shipped to metal recovery plants where they are used to produce nickel, chromium and iron for stainless steel and other high-end products.
Retriev uses liquid nitrogen to freeze lithium-based batteries before shredding, crushing and removal of the lithium and other battery components. The lithium is dissolved in a solution to make the metal non-reactive and is sold for producing lubricating greases. Similarly, the cobalt is separated, collected and sold. Some crushers use a liquid solution to prevent reactive events and reduce emission when crushed. A salt bath in a flooded chamber is a common practice. Discharge before the battery is crushed reduces the effect.
Evers so often a Li-ion starter battery gets mixed in with the common car batteries. A charged Li-ion is more explosive than lead acid and an event occurs. Efforts are being made to separate Li-ion from the regular starter batteries.
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 lead acid because of its profitable lead content, and perhaps also NiMH for its large nickel recovery.
Each country sets its own rule and adds tariffs to the purchase price to make recycling feasible. In North America, some recycling plants invoice by weight and the rates vary according to chemistry. NiMH yields a good return for its high nickel recovery. Due to soft cadmium prices and poor yields, NiCd and Li-ion command higher recycling fees.
The flat cost to recycle a ton of batteries is $1,000 to $2,000; Europe hopes to achieve a cost per ton of $300. Ideally, this would include transportation, but moving and handling the goods is expected to double the overall cost. To simplify transportation, Europe is setting up several smaller processing plants in strategic geographic locations. Manufacturers, agencies and governments must still provide subsidies to support the battery recycling programs and recyclers receive funding from such programs.
|Under no circumstances should batteries be incinerated, as fire can cause an explosion. Wear approved gloves when touching electrolyte. On exposure to skin, flush with water immediately. If eye exposure occurs, flush with water for 15 minutes and consult a physician immediately.|
Last Updated 4/8/2015
Comments are intended for "commenting," an open discussion amongst site visitors. Battery University monitors the comments and understands the importance of expressing perspectives and opinions in a shared forum. However, all communication must be done with the use of appropriate language and the avoidance of spam and discrimination.
If you have a question, require further information, have a suggestion or would like to report an error, use the "contact us" form or email us at: email@example.com. While we make all efforts to answer your questions accurately, we cannot guarantee results. Neither can we take responsibility for any damages or injuries that may result as a consequence of the information provided. Please accept our advice as a free public support rather than an engineering or professional service.