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Battery recycling

General

A battery is a source of electrical energy that consists of one or more primary cells (not rechargeable), or one or more secondary cells (rechargeable). Batteries convert chemical energy into electrical energy. This allows electrical or electronic equipment to be operated independently of the power grid, and can be used to fill in for failures in the power supply. We can distinguish three basic types of batteries:

  • Device batteries: Used to operate electrical or electronic equipment. A further distinction is made here between primary batteries (not rechargeable) and secondary batteries or accumulators (rechargeable).
  • Vehicle batteries: Batteries or accumulators for vehicle lighting, starters and ignition systems.
  • Industrial batteries: Batteries and accumulators for industrial or commercial purposes, or for electric vehicles. Industrial batteries are not used in private homes, and are therefore not discussed any further here.

 

Processing device batteries

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Collecting device batteries

The Saubermacher company operates a battery sorting facility in Trofaiach (Styria). Batteries are sorted at this site to ensure that device batteries can be reused as effectively as possible. About 80% of the device batteries collected are primary batteries (not rechargeable), most commonly zinc-carbon and alkaline manganese batteries. Until fairly recently, these batteries were processed at a recycling facility in Austria operated by the Fernwärme Wien district heating utility. The other 20% or so are secondary batteries or accumulators (rechargeable), most commonly nickel-cadmium, nickel-metal hydride, and Li-ion batteries. The secondary batteries and lithium batteries are passed along to processing facilities in Europe (Germany, Netherlands, France), since there are no facilities for processing these types of batteries in Austria. Despite a substance ban on mercury in the EU, there are still batteries that contain this heavy metal. A special exemption for button-cell batteries allows for their continued production, but with a maximum content of two percent by weight. As of 1 October 2015, the upper limit has been reduced to 0.0005% by weight. The existing limit may be maintained for hearing aids. Other primary batteries contain between 100 and 150 ppm of mercury and other heavy metals. As of 1 January 2017, the use of cadmium is also banned for wireless electric tools (max. 0.002% by weight). The battery technology for these devices must transition to nickel-metal hydride or lithium-ion batteries by that date. Batteries and accumulators produced prior to that date can still be used after the substance ban goes into effect. It is critical that these substances be prevented from escaping into the environment during the recycling process. At the Fernwärme Wien facility, zinc-carbon and alkaline manganese batteries were therefore processed for about an hour in a rotary furnace at over 700° C. In the course of this process, the batteries were broken down into their component parts. Valuable recyclable metals (zinc, manganese, and iron) were recovered, while the hazardous heavy metals were separated out with Fernwärme Wien’s sophisticated filter technology. The Simmeringer Haide facility met the EU’s strictest threshold values in this regard. The following table presents the approximate proportion of different materials recovered in the processing of zinc-carbon and alkaline manganese batteries. The metal portions (zinc, manganese, and iron) can be reused as essential raw materials. In terms of energy consumption, this is far more efficient than acquiring new raw materials, and therefore makes an important contribution to protecting our climate and environment.

Device batteries Mass [t] Proportion [%]
Ferrous metals 261 15,0
Zinc metals 295 17,0
Manganese metals 539 31,0
Remainder 643 37,0
Total 1.738 100,00

 

Processing vehicle batteries

MINOLTA DIGITAL CAMERA

Collecting vehicle batteries

The majority of vehicle batteries processed in Austria are recycled by BMG Metall und Recycling GmbH in Arnoldstein (Carinthia). Since vehicle batteries contain substances that can be harmful to people and the environment (e.g. sulphuric acid), all used batteries must be disposed of properly. Collecting used batteries also serves another purpose, however: the recovery of valuable resources. Vehicle batteries contain lead, which can be reused in new vehicle batteries once it has been recycled. Vehicle batteries dropped off by consumers are placed in a bin and stored. The sulphuric acid separated from them is stored in a sealed temporary bin, cleaned with a filter press, and then processed into sodium sulphate, which is used in the production of laundry detergents and glass. After going through the crusher, what remains is a mixture of metal plates (lead), lead paste, housing material (polypropylene, hard rubber) und miscellaneous plastic. The extracted paste is desulphurised before going into the short rotary furnaces. The reusable polypropylene housing material is sent off for recycling. The plate material and the lead paste are processed into raw lead in the short rotary furnaces. The short rotary ovens (SRFs) are used to smelt the products of the separation phase (and other recycling products that contain lead) into raw lead. The exhaust air from the SRFs is cleaned by passing it through high-quality fabric filters. The raw lead produced in the furnaces is then smelted again in the refinery, in two 130 t vessels. Depending on the customer’s needs, unwanted elements are removed and desired elements are added to the molten lead. The finished molten lead alloy is poured out in batches of up to 80 – 90 t in bars weighing 40-44 kg each, which are then bundled (see BMG Metall und Recycling GmbH). The following table and graph present the approximate quantity of raw materials recovered each year in the processing of vehicle batteries, and the proportion of different specific materials that are recovered.  The lead paste portion consists of up to 70% lead, and the lead plates are almost entirely pure lead. The lead portion can be reused as a valuable raw material. In terms of energy consumption, this is far more efficient than acquiring new raw materials, and therefore makes an important contribution to protecting our climate and environment.

Vehicle batteries Mass [t] Proportion [%]
Lead paste 4.792 44,0
Lead plates 3.050 28,0
Propylene housing 545 5,0
Separators 327 3,0
Acids 2.178 20,0
Total 10.892 100,00