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:

• 

  Collection container for lithium-ion-batteries (© EAK, 2018)

  Device batteries (e.g. zinc-carbon and alkaline manganese 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).

  • Device batteries – Lithium Batteries
    At present, Lithium batteries and Lithium accumulators are increasingly being used as device batteries. Damaged Lithium batteries present increased health and fire hazards. Important information about using and disposing of Lithium
    batteries and accumulators is available at www.elektro-ade.at/en/collection/key-facts-about-lithium-batteries/.
• 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

Sorting of device batteries at Saubermacher (© Saubermacher, 2018)

The company Saubermacher Dienstleistungs AG (see www.saubermacher.at) operates battery sorting and processing facilities in Trofaiach (Styria/Austria), and at various locations in Germany with its subsidiary Redux GmbH (see www.redux-recycling.com). 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. The other 20% or so are secondary batteries or accumulators (rechargeable), most commonly nickel-cadmium, nickel-metal hydride, and Lithium batteries.

Despite a substance ban on mercury in the EU, batteries containing mercury are still being discarded, and are also still being produced in many countries. Many primary batteries contain between 100 and 150 ppm of mercury and other heavy metals. Therefore, any emissions of mercury and other heavy metals during the recycling process must be prevented at all costs.

Collection of device batteries at Saubermacher (© Saubermacher, 2018)

The collection and processing of Lithium batteries represents a particular challenge. Lithium batteries contain many hazardous substances. Another issue is their characteristically high voltages and energy densities. In combination with extreme heat, mechanical impact or short circuits, these batteries are subject to an uncontrolled, strongly exothermic (heat-releasing) reaction known as “thermal runaway” that poses an acute fire risk.

Lithium batteries and accumulators must therefore always be collected separately, transported in special containers, and discharged before processing. They are then deactivated (thermally processed, heated) and sent along to the recycling process. These processing steps are now being carried out at the Redux GmbH facility in Bremerhaven (Germany).

In the course of the recycling processes, batteries are broken down into their components through mechanical, hydrometallurgical, and pyrometallurgical processes.

The following table and graph present the approximate quantity of raw materials recovered each year in the processing of device batteries, and the proportion of different specific materials that are recovered. The non-ferrous metals portion (zinc, manganese, cadmium, aluminium, nickel, cobalt, copper) and the ferrous metals portion can be reused as valuable 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.

Lithium cannot be recovered at a reasonable financial and energy cost using currently available technologies.

Materials recovered from device batteries (2017 data)

Materials recovered from device batteries (2017 data)

Processing vehicle batteries

Collection and recycling of vehicle batteries (© BMG, 2017)

The majority of vehicle batteries processed in Austria are recycled by BMG Metall und Recycling GmbH in Arnoldstein (Carinthia) (see www.bmg-recycling.at). 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) and miscellaneous plastic (cellulose, PE, PVC). 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 (Patent Production of lead paste, see patents.google.com/patent/EP0127060B1/de) 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.

Lead recycling (© EAK, 2017

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 www.bmg-recycling.at).

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.

Materials recovered from vehicle batteries (2017 data)

Materials recovered from vehicle batteries (2017 data)