After being discarded, metals release hazardous gases to health and to the environment. The way out of this problem that has become chronic is the recycling of metals, which is expensive, but vital for sustainability.
Metal recycling must be done at the same pace as the others!
This type of recycling involves the recovery and processing of scrap metal from end-of-life products or structures, as well as from manufacturing scrap so that it can be introduced as a raw material in the production of new goods.
Therefore, scrap metal recycling is more complicated than plastic, paper, tire, and glass recycling. Metals can take hundreds or even thousands of years to disappear. Aluminum, for example, only disappears completely after 100 to 500 years of disposal!
The issue is that some scrap metals have an unknown destination after being discarded!
Solar energy panels, for example, have been multiplying all over the world. The problem is knowing what will happen to them when their useful life ends! The solution could be in thin-film panels, based on plastic solar cells.
"Electronic devices production exponentially increases because people switch their devices each year, only to be up to date! That's dangerous!"
The guy who wants to "be fashionable", never waste time and buy a smartphone, for example, just to show off or because of ego appeals.
Instead of donating or selling the old device (not that old, actually), it goes to a trash or to a drawer! This "disease" of the present times, encourages the constant updating of mobile phones, tablets, computers, TVs and other equipment!
Correct metal recycling follows a standard routine!
The destination of scraps, after disassembling the device:
Carcasses: they are crushed and separated according to their density. Waste can be sold to companies that use their polymers. Other alternatives: are incineration for power generation or being transformed into other plastic objects.
Glasses: they can be found on cell screens and monitors. After selection by type, they undergo a grinding and treatment process. Since glass contains toxic components such as lead and arsenic, it can be sold to companies, where it will be raw material in the manufacture of other appliances.
Batteries: since they have high toxicity, the best destination is specialized companies. The toxic material is stored in prepared tanks that will serve as a raw material in the manufacturing of new batteries.
3 types of metal recycling:
- Mechanical recycling: the first step is to reduce the volume of scrap metal to be recycled. Then it is fragmented through crushing and grinding. Subsequently, the residues pass through sieves or mechanical classifiers, according to their granulometry. The separation is done by magnetic density when the magnetic fragments of the non-magnetic fragments are divided.
- Chemical recycling: it is the extraction of metals, through the process called "leaching", which is the solubilization of the chemical constituents of metal or mineral, by the action of a specific fluid, which facilitates the operation.
- Thermal recycling: this type of recycling metals, converts metals into different states of purity when they pass through high temperatures. The system requires high energy expenditure to incinerate the plates and obtain a concentrated metal that goes to another separation process: the electrostatic.
Before recycling, you must classify metals into two groups:
ferrous: iron and steel, which have a high potential for contamination of nature reduced over time.
non-ferrous: copper, aluminum, nickel, lead, and zinc, long deteriorating, therefore harmful to the environment.
Recycling classification is a very important measure in terms of landfill diversion. It is generally high, due to its value. See some rates:
for cars: 106 percent
for appliances: 90 percent
for steel cans: 66.8 percent
for structural steel: 98 percent
for reinforcement steel: 70 percent
Cans of soft drinks or beers lead the process of recycling metals, which reaches 98%!
Scrap metal has been recycled for thousands of years because it has been long recognized as being a more efficient process than mining and processing new ore.
In mining, metal recycling simply contributes do destroy the environment, causing damages such as:
destruction of vegetation in the surrounding area;
pollution of rivers with chemicals used in extraction;
air pollution with the burning of mercury used in the extraction of various types of ore;
avoidance of the fauna from the extraction area;
risk of dam disruption;
risk of contamination of the population living in the vicinity;