Q&A Processing Waste Batteries
So what happens once the batteries have been collected and sorted?
- What are the different processes for recycling the chemistries in batteries?
- What is involved in pre-treatment and recycling process?
- How do the two types of recycling processes differ?
- Which recycling process do we use in the UK and why?
- What happens to them when they are recycled - what can they be turned into?
- How much does it cost to collect and recycle one tonne of batteries?
What are the different processes for recycling the chemistries in batteries?
Each battery chemistry has a different recycling process, and some may even have a choice of processes.
There is not space or time to go into detail here of all the processes available. The choice comes down to one of cost versus recycling efficiency – the more material you recover for re-use the more it costs.
The batteries directive will stipulate an efficiency that must be reached, which is likely to rule out some of the more inefficient (but cheaper) processes.
Back to topWhat is involved in pre-treatment and recycling process?
The pre-treatment stage is to remove the steel case or plastic outer pack of the batteries, so that the metal-containing inner parts can be processed.
Back to topHow do the two types of recycling processes differ?
The two basic processes are:
Pyrometallurgical – where the batteries are put in a furnace to extract some of the metals, and
Hydrometallurgical – where the contents of the batteries are dissolved in acid and the metals recovered chemically
Back to topWhich recycling process do we use in the UK and why?
For alkaline and zinc carbon batteries, which are the most common types, the UK hasn’t got a full process yet, but a hydrometallurgical system is being developed.
The reasons for this are:
- Hydrometallurgy can readily achieve the recycling efficiency target expected to be set by the directive.
- The hydrometallurgical process is very flexible; it is easy to increase the size and throughput of the process as volumes grow, whereas furnaces are of a fixed size.
- There are few emissions to atmosphere with a hydrometallurgical process, where as a furnace will always have gaseous emissions (CO2 etc).
- There are still small amounts of mercury in some very old batteries, and it is much easier to cope with mercury in the cold hydrometallurgical process, than in the hot processes.
What happens to them when they are recycled - what can they be turned into?
Each battery type has its own constituents; the key ones are:
- Alkaline/Zinc Carbon containing Steel, Manganese, Zinc
- Li-ion rechargeable containing Steel, Cobalt, Nickel, Copper
- Nickel Cadmium containing Steel, Nickel, Cadmium
- Nickel Metal Hydride containing Steel, Nickel, Cobalt
As to what these metals can be used for, the list is endless – more batteries certainly, and most of the others tend to get used in the steel industry.
Back to topHow much does it cost to collect and recycle one tonne of batteries?
The results of the WRAP trials will help to establish the real (full) costs of collecting waste portable batteries and sorting them into the different types ready for recycling.
As the Batteries Directive is a 'producer responsibility' directive, ultimately producers of batteries will be financially responsible for the collection and recycling of batteries.
Back to top
