You may have wondered when your remote control or flashlight batteries ran out and you wanted to throw them away, what happens next? How are batteries recycled?
So, let's see what the process
of recycling used batteries involves?
Battery recycling is the
process of recycling used batteries from various sources, thus preventing them
from being dumped in landfills or the environment.
Almost all batteries used in a
household can be recycled whether we are talking about remote control
batteries, batteries for children's toys, laptop batteries or car battery.
Batteries contain toxic
substances and heavy metals such as lead, nickel, mercury or cadmium. They can
contaminate soil and surface water or groundwater if dumped in landfills or in
the wild. Therefore, batteries must be recycled in a special battery recycling
unit.
Because batteries are of
different types and contain different substances, they must be separated before
the recycling process begins, as each type of battery has a different recycling
process. Once sorted, the batteries are introduced into the recycling process
itself, obtaining iron, lead, nickel, cadmium, zinc, lithium and other metals
used in the production of batteries.
But let's see more about the path of batteries in the recycling process, from your household to the final products obtained from their recycling.
1. How are batteries collected for recycling?
The process of collecting
batteries for recycling starts from your home. As mentioned above, batteries contain environmentally harmfull substances and cannot be thrown directly in the trash. They must be collected and stored separately from household waste. From the household, they can be taken either to the large electronics stores that usually have special containers for storing used batteries, also you can bring them to the retail stores or to a nearby recycling center.Once in the collection centers, the used batteries are sent to a battery recycling factory where are sorted into categories for recycling.
2. What types of batteries can be recycled?
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In principle, any type of
battery can be recycled. But the most common in home use are: lead-acid
batteries, Li-Ion batteries, Ni-Cadmium batteries (NiCd), Ni-Metal Hydride
batteries (NiMH), primary lithium batteries and alkaline batteries.
Lead-acid batteries
Lithium-ion batteries (Li-ion) & Primary Lithium batteries
Li-Ion batteries are mainly
used for electronics from the smallest (earbuds, watches) to mobile phones,
tablets, laptops, cameras or other electronic gadgets. They are also used to
power cordless tools and other electrical products.
Although lithium itself is not
in principle harmful to the environment, Li-ion batteries must be recycled as
they may also contain metals such as nickel, cobalt or magnesium. Even though
these metals are not as polluting as lead, they are considered toxic heavy
metals and must be recycled.
Primary Lithium batteries
These batteries must be
recycled because the metal lithium in their component is very reactive when it
comes in contact with moisture or when the metal tank of the battery is
perforated.
As the demand for lithium on
the market continues to increase, its recovery through recycling is becoming
increasingly important.
Nickel-Cadmium batteries (NiCd)
Nickel-Cadmium batteries are a
hazard to the environment if they are not disposed of properly. The harmful
effect is so great that the European Union banned the production and use of
Nickel-Cadmium batteries in 2009.
To dispose of these batteries,
they must be isolated from the other batteries.
Ni-Cd batteries are used for
portable electronics, toys, solar garden lamps. Also, special Ni-Cd batteries
are used in cordless phones, mobile phones, emergency lighting and other
applications. Ni-Cd batteries contain chemical elements such as nickel and cadmium
in various compositions and forms that can be recycled.
Nickel-Metal-Hydride batteries
Ni-MH batteries are less
polluting than Ni-Cd batteries, but still pose a risk to the environment if disposed
in large quantities.
Nickel-Metal-Hydride batteries
have similar uses to Li-ion batteries, where more energy is needed such as
power tools or some hybrid vehicles.
Ni-MH batteries contain
nickel-hydroxide, hydrogen absorbing alloys and pottasium-hydroxide.
Alkaline batteries
Alkaline batteries are
currently the most used in household applications, from flashlights, alarm
clocks, battery-powered radios to toys.
Due to restrictions on the use
of mercury in alkaline batteries since 1996, they have become safe for normal
waste disposal (these are considered common waste). Although not a major hazard
to the environment, alkaline batteries can be recycled. Alkaline batteries
contain materials that can be reused such as zinc, magnesium or iron. Although
the recycling process is difficult and dangerous, there are still recycling
plants that accept alkaline batteries.
3. The main battery recycling process
The recycling process begins
with sorting the batteries by their chemical component. Thus, the batteries are
sorted into categories in special containers. The recycling process can become
even more profitable for battery recyclers if the batteries arrive at the
factory already sorted by category.
Depending on the type of
batteries, recycling processes may differ. Next I will detail the recycling
process for each type of battery.
Lead-acid batteries recycling
process
The batteries are chopped in a
hammer mill, turning them into pieces.
Plastic: The plastic particles
are washed, then sent to a plastic recycler that melts them, puts them in an
plastic extruder and turns them into small plastic pellets.
These pellets are then
reintroduced to the market in various industries that use plastic.
Lead: Lead plates are cleaned,
washed, dried and melted in smelting furnaces. The molten lead is poured into
ingot molds. After a few minutes, the impurities are concentrated on the
surface of the molten lead, floating in the molten lead. Impurities are removed
and the resulting lead is left to cool. The resulting lead ingots are then sent
to the battery manufacturers where they will be melted again and used to
produce new lead plates or other parts for the new batteries.
Sulfuric acid:
Sulfuric acid in lead-acid batteries
can be recycled by 2 methods:
Method 1: The acid is
neutralized with an industrial compound similar to baking soda. This compound
converts the acid to water. The water is treated, cleaned and then tested to
meet purity standards for reintroduction into the environment. After the
treatment process, the water is poured into the public sewer.
Method 2: Another method of
recovering sulfuric acid is to process it and turn it into sodium sulfate, an
odorless powder that is used in the production of laundry detergents, in the
production of glass and in the textile industry. Also, the acid can be
recovered in its original form and reused in the lead-acid battery industry.
Li-ion and Ni-MH battery recycling process
Li-ion batteries are recycled
using an ultra-high temperature process. Used batteries are disassembled and
melted in UHT furnaces. The resulting materials are separated into metal alloys
containing copper, nickel, cobalt and slag, a stony waste containing rare
metals. Slag can then be processed to recover lithium, but obtaining a high
purity lithium from this compound would require too much cost, so slag is used
in the construction industry.
Nickel-Cadmium batteries recycling process
The Ni-Cd battery recycling
process is a thermal separation process (TSP). This TSP process is used to
recover valuable metals from used Ni-Cd batteries, using limestone and cullet
additives. Materials resulting from the process: slag, ingot and flue gas.
The slag contains mainly Ca
and Si and the major crystalline phase is CaSiO3.
The ingot has a hight level of
Fe (514,000 mg / kg) and Ni (245,000 mg / kg). The ingot can be refined to
obtain Ni but the compound can be used in this form as an additive in the steel
production process.
Alkaline batteries - the recycling process
As I said, alkaline batteries
contain zinc, manganese, zinc-carbon, potasium or mercury. The batteries are
pyrolyzed at temperatures of 700°C and the mercury is recovered by
distillation.
The other metal components
left after distillation are extracted and melted in a furnace at a temperature
of 1500°C. Following this process, a molten metal compound containing Fe and manganese
is formed, producing a ferromanganese alloy, while zinc vaporizes and can be
recovered by condensation.
4. What are the benefits of battery recycling?
In conclusion, battery
recycling is a beneficial process. Here are some reasons:
- The batteries contain harmful chemicals that must not reach the landfill or the environment.
- Valuable materials are recovered for the production of new batteries, thus reducing the need for the extraction of new materials and automatically reducing the level of pollution
- Ensures safe storage of batteries, reducing the risk of batteries catching fire or exploding compared to their disposal in landfills or the environment.
- There is a growing demand on the market for battery recycling
- Reduce the cost of operating waste for local councils, so less taxes to pay
- It is very easy to recycle batteries
