The Battery Process: From Collection to Recycling

Alkaline Batteries

Alkaline batteries that have been sorted out from other battery types, are not classified as hazardous waste. When the batteries come in, they are crushed, and their metal casing etc. is separated from the black mass. The metal casing (iron) makes up about 20% of the battery’s weight and is recycled. The black mass is sent to a metallurgical company (i.e. a smelter) where it passes through a so-called Waelz process where the zinc-oxide of the material is extracted. As a residual product from the Waelz process, a material is obtained which contains e.g. manganese-oxide and iron. This is used in various ways as filling material or construction material, but according to legislation cannot be regarded as material recycling. The recycling rate for alkaline batteries is 50–55%, and the statutory requirement is 50%.

This is what an alkaline battery consists of:

Manganese (cathode) : 37%
Iron : 23%
Zinc (anode) : 16%
Paper & Plastic: 24%

Nickel-Cadmium Batteries

When the batteries come in, they are crushed, and their metal casing etc. is separated from the black mass. The metal casing is recycled. The black mass is passed through a hydrometallurgical process which extracts the nickel-hydroxide, nickel-iron alloy, and cadmium-carbonate from the material. Nickel-hydroxide is classified as a dangerous substance, but is resold to be used again in new products. Cadmium-carbonate is also classified as a hazardous substance and is finally processed as landfill waste, as the use of cadmium has been banned in Europe since 2010. The remaining waste after the recycling process is disposed of by approved recipients for landfill or incineration. The recycling rate for nickel-cadmium batteries is 75–79%, and the statutory requirement is 75%.

This is what a nickel-cadmium battery consists of:

Iron: 40%
Nickel: 22%
Cadmium: 15%
Paper & Plastic: 23%

Lithium and Lithium-Ion Batteries

When the batteries come in, they are crushed, and their metal casing etc. is separated from the black mass. The metal casing is recycled. The black mass is passed through a hydrometallurgical process which extracts the cobalt-hydroxide, copper-hydroxide, nickel-hydroxide, manganese-hydroxide, and aluminum from the material. The cobalt-hydroxide is sent to other facilities for further chemical treatment, while the rest of the substances are sold to various smelters and become new raw materials. The remaining waste after the recycling process is taken care of by approved recipients for landfill or incineration. As of now, lithium is not separated from manganese or aluminum. The recycling rate for lithium and lithium-ion batteries is 50–61%, and the statutory requirement is 50%.

This is what a litium-ion battery consits of:

Aluminium: 15-25%
Copper: 5-15%
LiPF6 (Lithium): 1-10%
Cobalt: 1-15%
Nickel: 1-15%
Iron: 1-20%
Paper & Plastic: 6-15%

Nickel-Metal Hydride Batteries

Nickel-metal hydride batteries are not classified as hazardous waste as long as they are intact and not damaged. The batteries are first sent to a warehouse and then transported to a metallurgical company that uses a thermometallurgical process to extract metals from the material. Ferro-manganese (an iron alloy consisting of iron and manganese) and zinc-oxide are then resold, while the slag becomes landfill waste. The recycling rate for nickel-metal hydride batteries is 50-60%, and the statutory requirement is 50%.

This is what a nickel-metal hydride battery consists of:

Nickel: 33%
Iron: 30%
Lanthanide: 10%
Cobalt: 3%
Manganese: 1%
Zinc: 1%

Button-Cell Batteries

Button-cell batteries can have different chemical contents, such as lithium or silver-oxide. Button-cell batteries that contain mercury are no longer sold but can still be found among collected batteries, which is why button-cell batteries are classified as hazardous waste. The batteries are stored, and then transported to another facility where they undergo a kind of thermometallurgical process that extracts metallic raw material. Iron and manganese form ferro-manganese which is sold as a new raw material. The zinc evaporates from the material and is extracted in a zinc condenser. These products are then resold. Any mercury also evaporates at high temperature and is then separated into pure mercury. Mercury that remains in gaseous form is purified in filters, and then all extracted mercury is kept in its final disposal in salt mines. The slag also becomes landfill waste. The recycling rate for button-cell batteries is 50–84% and the Swedish target of 98% special disposal of mercury is met.

Lead Batteries

When the batteries arrive at the facility, they are emptied of sulfuric acid, which can be neutralized to water by the addition of sodium-hydroxide. The lead cell is fed into a blast furnace. In this thermometallurgical process, lead, iron-matte and slag are extracted. Lead is alloyed and resold, while slag and iron-matte are deposited in Boliden-Bergsöe’s own landfill. The recycling rate for lead batteries is 65–74%, and the statutory requirement is 65%.