Learn about disposal and how toxic material can continue to be used in batteries if recycled.
Lead and cadmium-based batteries pose the largest environmental concerns, so much so that nickel-cadmium was banned in Europe in 2009. Attempts are being made to also ban the lead-based battery but no suitable replacement is available as was the case by substituting nickel-cadmium with nickel-metal-hydride. For the first time, lithium-ion is added to the list of pollutants. This chemistry was classified as only mildly toxic, but the sheer volume requires tighter scrutiny.
Lead acid paved the way to the success of 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; however, business reasons rather than environmental concerns may have been the driving force. 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 the collection of all batteries convenient. Only 20 to 40 percent of batteries in mobile phones and other consumer products are currently recycled. The goal to recycle is preventing hazardous materials from entering landfills and utilizing the retrieved materials for 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 the children as they often get swallowed. [ See BU-703: Health Concerns with 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. NiCd also continues to hold a critical position among rechargeable batteries as large flooded NiCds start jet airplanes and propel sightseeing boats in rivers of larger cities, pollution-free, but they are in decline.
Batteries with toxic substances will continue to be with us and there is nothing wrong in using them as long as they are properly disposed. Each battery chemistry has its own recycling procedure and the process begins by sorting the batteries into the correct category.
Lead Acid: Recycling of lead acid began with the introduction of the starter battery in 1912. The process is simple and cost-effective as lead is easy to extract and can be reused multiple times. This led to many profitable businesses and the recycling of other batteries.
In late 2013, smelters started to report an increased number of Li-ion batteries being mixed in with lead acid, especially starter batteries. This can cause fires, leading to explosion and personal injury. The physical appearance of lead acid and Li-ion packs are similar and sorting at high volume poses a challenge. For consumers, a battery is a battery and folks are enticed to recycle all batteries, never mind the chemistry. As more lead acid are being replaced with Li-ion, the problem will only escalate. There has been a 10-fold increase in reported incidents from 2010 to 2013 in infiltration of Li-ion with lead acid.
The Society of Automotive Engineers (SAE) and the International Electrotechnical Committee (IEC) initiate action through increased awareness, employee training, battery identification and labelling. X-ray technologies to separate batteries are being explored and “who carries the liability?” is being asked. Battery manufacturers put the responsibility on the recyclers who in turn argue that the burden and sustainability of a product must be borne by the manufacturer. The courts may become the arbitrator.
Nickel-cadmium: When careless disposing NiCd batteries, 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, 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 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 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. [ See also BU-106: Advantages of Primary Batteries ]
Lithium-ion: Li-ion is reasonably harmless but spent packs should be disposed of properly. This is done less to retrieve valuable metals as with lead acid, but 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 1996, many territories now allow disposing of 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 spent batteries back. Reusable materials are zinc and manganese but the retrieval process is a liability. Efforts are made to increase the recycling of alkaline cells from the low 4 percent in 2015 to 40 percent in 2025.
In North America, Retriev, formerly Toxco, and the 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. They also recycle retired lithium batteries from the Minuteman missile silos and tons of Li-ion from war efforts. 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 Umicore in Belgium have developed technology to retrieve cobalt and other precious metals from spent lithium ion batteries. [ See BU-705a: Battery Recycling as a Business ]
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 recycling can be made profitable if a steady stream of batteries, sorted by chemistry, is made available.
The recycling process begins by removing the combustible material, such as plastics and insulation, with a gas-fired thermal oxidizer. Polluting particles created by a 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 vapor into a large tube that is 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 seven-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.
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 where 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 North America, 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.
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. This, in part, is due to the Basel Convention that prohibits the export of complete but spent lead acid batteries. As the volume of discarded batteries increases, new technologies are being tried to make recycling profitable without the support of agencies and governments.
|Caution:||Under no circumstances should batteries be incinerated, as fire can cause an explosion. Wear approved gloves when touching the 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 2016-01-12
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