Description
Recycling box/container for used batteries and accumulators:
How are the different types of batteries recycled?
Batteries, cells and accumulators are devices that store electrical energy using electrochemical processes and subsequently return it. It is generally understood that batteries are a finite source of energy, since they are depleted and cannot be recharged. Batteries, on the other hand, can be recharged.
These batteries contain heavy metals and chemical compounds, which are very harmful to the environment. It is very important not to throw them in the trash (in most countries this is not allowed), and take them to a clean point.
Types of batteries:
- Dry batteries: Also called “saline” or “zinc-carbon”, they contain very little mercury (0.01%). Degree of toxicity: Very low.
- Alkaline batteries: They have a mercury content of 0.5%. Degree of toxicity: Toxic.
- Rechargeable batteries: Contain cadmium. They do not contain mercury. Toxicity level: Toxic.
- Button cells: Some contain up to 30% mercury. Degree of toxicity: Very high.
- Green” batteries: They are free of cadmium and mercury, although some of their components are unknown. Degree of toxicity: unknown.
A single button cell can contaminate more than 600,000 liters of water. Mercury and cadmium, together with other metals, are not destroyed by incineration: they are emitted into the atmosphere.
Battery recycling process:
Generally, the recycling of batteries and cells can be divided into two major phases, once sorting has been carried out correctly;
First shredding or grinding phase:
In this mechanical phase the waste cells and batteries are subjected to a fragmentation process where the size is reduced facilitating the separation of the materials that make up the battery. This first step makes it possible to classify the materials obtained according to their composition and then send them to specific processes.
The materials that will be obtained in the recycling processes:
- Plastics that will be subsequently recycled and plastic groats will be obtained.
- Ferrous metals from the metal casings, which will be sent to the iron and steel industry to obtain new steel.
- Intermediate fractions that will be treated in a second phase.
Second treatment phase:
In the second phase we can find two types of treatments:
Pyrometallurgical:
Treatments at high temperatures that allow recovering the metals contained in the cells and batteries by their gasification and subsequent purification and sedimentation. Some examples: Waelz furnaces treatment of the “black mass”, non-ferrous fraction of the saline/alkali batteries:
Waelz furnaces are installations in which zinc dust residues and other wastes from this industry are treated. Due to the high zinc content of the salt/alkali batteries, it is possible to recycle them in this facility, obtaining different products with high zinc and manganese content.
Lead smelting: lead plates are subjected to a melting and purification process after which lead ingots are obtained that are suitable to be used again as raw material, in most cases for the manufacture of new batteries.
Hydrometallurgical:
Physical-chemical treatments that recover metals through dissolution processes with additives and subsequent concentration or purification.
Some examples: Black mass (non-ferrous fraction of saline/alkali batteries) can also be treated with this technology, obtaining high purity fractions of Zinc and manganese. As a result of this second phase, depending on the technology being treated, the chemical components that make up the batteries will be obtained in different chemical states (zinc, manganese, lithium, cobalt, lead, nickel, cadmium…) some of them are used again in the production of new batteries and others are destined to steelmaking or other processes.
