Lead Acid: Lead acid led 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. As a result, over 50 percent of the lead supply comes from recycled batteries. Other battery types are not being returned as readily as lead acid, and several organizations are working on programs to make collection of spent batteries more convenient. Only 20 to 40 percent of cellular phone and consumer batteries are currently recycled.
The main objective for recycling batteries is to prevent hazardous materials from entering landfills. Lead acid and nickel-cadmium batteries are of special concern, and although Li-ion is less harmful, the aim is to include all batteries in the recycling programs. Do not store old lead acid batteries in households where children play. Simply touching the lead poles can be harmful. [ See Health Concerns with Batteries BU-703 ]
Even though they are environmentally unfriendly, lead acid batteries continue to hold a strong market niche. 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 Auxiliary Power Unit (APU) of commercial airplanes and power 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 we properly dispose of them. Europe banned NiCds in consumer products because there is a suitable replacement, the NiMH battery. Controlling the disposal of NiCds from consumer products is difficult because many users do not know that the retiring equipment includes this battery. The long-term environmental damage if the world’s NiCds were improperly disposed of could be devastating.
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 such 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. Regulatory discipline will lead to a cleaner environment for the next generations.
Nickel-metal-hydride: Nickel-metal-hydride batteries contain nickel and electrolyte, which are considered semi-toxic. If no disposal service is available in an area, individual NiMH batteries can be discarded with other household waste. When accumulating 10 or more batteries, the user should consider disposing of the packs in a secure waste landfill. The better alternative is bringing the spent batteries to a neighborhood drop-off bin for recycling.
Primary lithium: Primary lithium batteries contain metallic lithium that reacts violently when in contact with moisture and the batteries 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 cause 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 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: In many territories, alkaline batteries can be disposed of as regular domestic waste. This was made possible with the mercury reduction in 1996. California and Europe considers all batteries as hazardous waste and alkaline cells cannot be disposed with domestic waste. Most stores selling batteries are also required to accept old batteries for recycling. Since there is little valuable materials in alkaline batteries, disposal is a liability that incurs cost.
In North America,Toxco and Rechargeable Battery Recycling Corporation (RBRC) collect spent batteries and recycle them. While Toxco has its own recycling facilities, RBRC is in charge of collecting batteries and sending them to recycling organizations. Toxco 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. Toxco also recycles retired lithium batteries from the Minuteman missile silos and tons of Li-ion from the war in Iraq. Other divisions at Toxco 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. The raw material lithium can also be retrieved and re-used repeatedly. [ See Battery Recycling as a Business BU-705a ]
Recycling begins 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, and 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.
Toxco uses liquid nitrogen to freeze lithium-based batteries before shredding, crushing and removal of the lithium, as well as 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.
Battery recycling is energy-intensive. Reports reveal that it takes 6 to 10 times more energy to reclaim metals from some recycled batteries than it does to produce it through other means, including mining. The exception to the rule is lead acid for its large lead content and perhaps NiMH for its nickel recovery. Let’s explore who pays for the recycling of batteries.
Each country imposes their own rules and fees to make recycling feasible. In North America, some recycling plants invoice on weight, and the rates vary according to chemistry. Nickel-metal-hydride yields the best return, as recycling produces enough nickel to pay for the process. The highest recycling fees apply to nickel-cadmium and lithium‑ion, because the demand for cadmium is low and lithium‑ion contains little in retrievable metal.
Rather than calculate the cost according to battery chemistry, some countries deal in tonnage. The flat cost to recycle a ton of batteries is $1,000 to $2,000, and 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 still must provide subsidies to support the battery recycling programs. This is underwritten by a tax added to each manufactured cell. RBRC receives funding from such a program.
|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: 04/07/2014