We prefer synthetic rather than natural materials. Natural products are almost too valuable. Wood is much harder to produce than metal. And metal is recyclable, while wood isn’t.”

Helmut Jahn, Architect

What Is Metal Waste and Metal Recycling?

Several kinds and also large amounts of metals are used in industrial processes every day.

Since the industrial revolution period has taken place, our consumption levels skyrocketed due to the mass production of goods and the resulting low unit price.

The most consumed metal worldwide is aluminum, followed by copper, zinc, lead and nickel.

Moreover, some precious materials like gold are used for our computers and other electronic devices.

Metal is therefore crucial to sustaining our living standard.

However, metals are resources that are limited.

The depletion of metals can be a big issue in the future since the world population grows rapidly and thus also the demand for goods made out of metal will increase.

To mitigate the problem of metal depletion, we have to look out for effective measures.

One of those measures could be metal recycling.

Through the recycling process, we can use resources more efficiently and therefore slow down the depletion process.

In the following, all kinds of questions regarding metal trash and the recycling of metals are answered.

Audio Lesson

Why is the Recycling of Metals important?

Due to the increase in world population and the increasing demand for metals, we have to take measures to make sure that we do not run out of metal resources in the future.

Moreover, the recycling of metals also saves energy.

Thus, it is more economical to recycle metals instead of extracting them out of the ground.

If we want to maintain our lifestyle which heavily relies on electronics and therefore on metals, we have to develop sophisticated metal recycling processes.

What are Causes for Metal Trash?

  1. Industry
  2. Wrappings
  3. Cars
  4. Toys
  5. Bicycles
  6. Electronics
  7. Batteries
  8. Deodorants and cosmetics
  9. Food
  10. Mining


Metal trash is caused by many different kinds of industrial processes.

In many cases, specific forms for the end-product are required.

However, in order to accomplish this form, the remaining material has to be removed.

Therefore, there is a certain amount of leftovers that are usually disposed of in the trash bin or recycled in later stages.


Wrappings are another contributor when it comes to metal trash.

Aluminum is contained in many wrappings since it is light and relatively easy to process.

Therefore, companies and stores like aluminum-based wrappings and use them in large amounts.


There is also a significant number of toys that are made out of metals or at least partly contain metal components.

This is especially true when it comes to technology-based toys like helicopters, remote-controlled cars, etc.


Many parts of our cars are made out of metal.

If we replace our cars with newer versions, large amounts of metal garbage are the result.

This problem has become worse over the last decades since people use their cars for shorter periods of time compared to decades ago since the average income of people is higher now and they are able to afford more items and are also able to replace their cars faster by new ones.


Many components of bicycles are also made out of metals.

This includes the frame as well as some other components like brakes.

Therefore, if we do not use our bicycles anymore, we also cause significant amounts of metal garbage.


Electronics are a big part of the metal trash we produce worldwide.

Metal is used for all kinds of electronics, including our smartphones, TVs or computers.

Since our society is quite technology-driven and always strives for the newest electronic articles with the best features, large amounts of metal trash result from this consumption behavior.


Batteries also contain metal components.

Since many of our devices run by batteries, significant amounts of metal trash are produced over time.

This problem will become even worse when electric cars replace conventional cars since more batteries will be used and the trash resulting from batteries will grow significantly.

Deodorants and cosmetics

Cosmetics and deodorants are often packaged in metal wrappings or metal containers in order to prevent the ingredients to evaporate.

However, this leads to significant amounts of metal trash that could be avoided using other kinds of wrapping techniques.


Food wrappings are often made out or at least contain some part of metals.

For example, if you buy kebab and you want to carry it home, it is often wrapped into aluminum foil to keep it warm, resulting in large amounts of metal waste over time.


Significant amounts of metal waste can also be caused by mining processes.

In the extraction process of resources, large machines are used to support workers.

However, these machines will often suffer from damages and some parts have to be replaced over time, resulting in metal trash.

Moreover, in the separation process, heavy metals like mercury are sometimes used which leads to additional metal trash.

What are the Effects of Metal Trash?

  1. Depletion of natural resources
  2. Global warming
  3. Deforestation
  4. Soil pollution
  5. Destruction of habitats
  6. Visual pollution
  7. Air pollution
  8. Water pollution

Depletion of natural resources

The production of metal trash results in a significant depletion of natural resources.

Metals are non-renewable resources which are limited.

Through the production of metal waste, these precious metals are wasted.

If we continue to produce large amounts of metal waste, we are likely to deplete our metals quite soon in the future.

This would heavily impact our daily life since without metals, we would no longer be able to sustain our convenient lifestyle.

Moreover, we would not be able to sustain our sophisticated technologies since almost all of them rely on metals.

Imagine a world without smartphones, computers or the internet!

Global warming

Metal waste also indirectly contributes to the global warming problem.

Since the production of waste can be regarded as inefficient production behavior and the production of goods requires electricity, the production of metal waste implies a waste of electricity.

Electricity production currently relies on coal and other fossil substances. In the combustion process of coal, significant amounts of greenhouse gases are released into the air which in turn contributes to global warming.


Deforestation can be another effect of metal waste and the implied metal extraction.

Since metal has to be extracted out of the ground, mining often requires to cut down forests in order to get new mining areas.

Therefore, the consumption of metals also contributes to deforestation.

Soil pollution

In the process of mining for metals, the soil is often polluted with harmful substances.

For example, for the extraction of certain metals, chemicals have to be used in order to separate metal from dirt.

If these chemicals are not disposed of in an environmentally-friendly manner, they can cause significant soil pollution.

Destruction of habitats

Moreover, mining often causes the destruction of habitats of many animals and plants.

Since for the set up of new mines, large areas of land have to be used, many animals have to relocate since their natural environment is destroyed by human intervention.

Visual pollution

Metal trash can also cause visual pollution. In many countries, metal trash is not just dumped into landfills, it is often just dumped on the streets.

This is not a pretty picture and the life quality for people living near the polluted spots will decrease.

Air pollution

The production of garbage made out of metal can also lead to air pollution.

In the recycling process of metals, fuel has to be used. By burning fuel, harmful gases are emitted into the air, resulting in air pollution and often also contributing to global warming.

Water pollution

Moreover, metal waste can also lead to water pollution.

Since metal trash is often dumped into landfills, harmful compounds are released over time.

If the landfills are not set up properly, these substances can reach the soil and eventually will end up in the groundwater.

Moreover, in many developing countries, illegal dumping is a big problem.

Metal waste is often just disposed into rivers or lakes where harmful compounds are likely to contaminate the water.

Step-by-step Approach for Metal Recycling

  1. Collecting
  2. Sorting
  3. Processing
  4. Shredding
  5. Melting
  6. Purification
  7. Solidifying
  8. Transportation
  9. Use for different industrial processes
  10. Start the recycling loop again

Step 1: Collecting

Depending on the value of the metals, scrap metals can either be collected for recycling purposes or end up in landfills.

Metals not valuable enough will be dumped into landfills while precious metals will be collected in order to recycle them.

In order to be able to collect these metals, people have to contribute their part.

For example, if people just dispose of their metal trash in the regular trash bin, it will likely not be recycled and rather burned which leads to a significant waste of resources.

People have to make sure that they separate their waste in a way that their precious metal trash can be recycled.

This could be accomplished by bringing this kind of trash to scrap yards where they can then be sorted and processed.

Step 2: Sorting

In the next step, the different metals have to be separated and sorted.

This is often done with the help of magnets or other devices, using the different characteristics of different metals to separate them.

These characteristics include the weight and the color of the trash.

For example, when it comes to separating gold, it is clear that gold is pretty heavy and has a quite unique color.

By using these kinds of characteristics and methods, the metal trash can be sorted in an efficient manner before it is reprocessed further.

Step 3: Processing

Since the metal trash usually is quite bulky and space-consuming, it has to be made more compact in order to make it suitable for shredding purposes in the next step.

Step 4: Shredding

With the help of the processing step, the scrap metals are now ready to be shredded.

By using big machines, metal waste is disassembled into small pieces of metal.

By doing so, the material is prepared for the melting phase.

Step 5: Melting

The metal that was previously shredded into small pieces is now ready to be melted.

The melting process involves very high temperatures and is done in furnaces which are specifically designed for melting metals and therefore are able to endure the high temperatures.

The temperature is subject to the specific metal that should be melted.

For example, while aluminum has a rather low melting point of 1220 degrees Fahrenheit (660 degrees Celsius), gold has a much higher melting point of 1945 degrees Fahrenheit (1063 degrees Celsius).

While melting metals is quite energy-consuming, it is still more efficient to melt and recycle metals compared to the extraction of metals out of the ground.

Step 6: Purification

After the melting step is finished, the metals have to be purified in order to make them suitable for further use.

This purification can be done through various processes like electrolysis or other methods, depending on the metal type.

The purification step has the goal to guarantee high quality and to make sure that the recycled product is free from any contaminants.

Step 7: Solidifying

After the metal has been melted and purified, it is time to cool it down and bring it in shape so that it has the right form to process it further.

Depending on the purpose of the recycled material, this form can vary from small units of metal up to big solid metal blocks.

However, it should be assured that the end-product is suitable for transportation purposes.

Thus, solid metal blocks should be not too big or too heavy in order to be able to transport them by conventional trucks.

Step 8: Transportation

In the next step, the solidified and formed metals have to be carried to different kinds of factories where they can then be used for the manufacturing of new goods.

Step 9: Use for different industrial processes

After the recycled metal has been transported to the respective factories, they are usually melted and reprocessed into certain shapes and forms, sometimes certain ingredients are added to make the metal more robust, depending on the specific end product.

Since the recycling processes are quite sophisticated in our current time, people will not even be able to recognize that their products are made out of recycled metals.

Step 10: Start the recycling loop again

The previous steps have shown in detail how metal is recycled efficiently and how it is used in further steps.

However, this is not the end.

Even the new items made of recycled metals will eventually become old and end up in the trash bin.

From there on, the recycling cycle continues and starts again.

What are the Advantages of Metal Recycling?

  1. Efficient use of resources
  2. Save energy
  3. Mitigate many sorts of pollution
  4. Stop deforestation
  5. Slow down global warming
  6. Slow down landfill growth
  7. Protect habitats
  8. Economic upside

Efficient use of resources

Through the recycling of metals, we can use our natural resources more efficiently.

Moreover, metals are a limited resource.

In order to sustain our consumption behavior which involves the consumption of significant amounts of metals, we have to make the metal recycling processes quite efficient.

Save energy

Even if the recycling process needs plenty of energy, especially in the melting process, it is still more energy-consuming to extract metals out of our ground than to recycle them.

Therefore, through the recycling process, we can save energy that would otherwise be necessary to extract metals through mining.

Mitigate many sorts of pollution

As we have seen in the previous analysis, the extraction of metals leads to significant pollution of many sorts.

With the help of recycling, we reduce the need for metal extraction and therefore we can also mitigate the adverse effects of mining activities on our environmental system.

Stop deforestation

Deforestation is a big problem which is partly caused by mining activities.

Mining is crucial in order to extract metals.

Thus, with the support of metal recycling, we can reduce the overall amount of metals that have to be extracted out of the ground and can in turn mitigate the issue of deforestation.

Slow down global warming

Through the recycling of metals, we can also indirectly slow down the global warming process.

On the one hand, we can save energy. On the other hand, we can mitigate deforestation.

Since trees are natural storage spaces for greenhouse gases like CO2, cutting down forests leads to significant emissions of CO2 into the atmosphere.

Thus, by improving recycling processes for metal, we can significantly mitigate the global warming problem.

Slow down landfill growth

Part of the metal trash, especially metals that are of low economic value, are often disposed of into landfills rather than recycled.

If we are able to improve recycling processes and make them more efficient, it will be profitable for industries to also recycle these low-value metal trash items.

Therefore, we could slow down the growth of and the need for landfills.

Protect habitats

Extracting metals out of the ground often involves mining activities.

For those activities, large areas of land have to be used.

However, those areas of land are the habitats for many animals which now have to leave their natural living spaces and relocate to other places.

Thus, the recycling of metals can also lead to saving habitats for many animals and also plant species.

Economic upside

Apart from the environmental upsides of metal recycling, there is also an economic incentive to recycle metal.

Some metals are quite precious and are traded at high prices at the worldwide commodity exchanges.

Therefore, it can be quite profitable for firms to recycle metals and to sell them after the recycling process has been finished.

What are the Problems of Metal Recycling?

  1. Energy and time consuming
  2. Labor-intensive
  3. Bad working conditions
  4. Health issues
  5. Recycled products may be of low quality

Energy and time consuming

The recycling of metals can be energy and time-consuming.

This is especially true in countries where the processes regarding metal recycling are still quite inefficient.

Therefore, in those countries, part of the metal recycling may not be profitable and thus significant amounts of metal trash may be disposed into landfills instead.


The recycling of trash can also be quite labor-intensive, especially in countries where the process is not fully automated by machines.

Thus, plenty of work is needed to recycle metals which in turn can be quite costly.

Bad working conditions

In many developing countries, there are quite bad working conditions when it comes to metal recycling.

Workers are often exposed to harmful substances and may not even wear protection measures like gloves.

Health issues

Moreover, safety requirements may also be quite low which means that workers are exposed to significant health risks.

For example, people may not wear helmets or other forms of protection.

If metal parts fall down on their hats during the separation process, workers may suffer from severe long-term health issues or may even die.

Recycled products may be of low quality

Even if in many countries, recycling processes are quite sophisticated and therefore deliver high-quality products, in some countries, recycled products may significantly vary in quality.

For instance, if the separation of metals is not done in a proper way, there may be harmful by-products contained in the recycled products.

This could mean that items made of recycled steel are more likely to corrode or that durability of a product may be lower.


The consumption of metals and the resulting metal waste is a huge environmental problem.

Metal waste imposes several adverse effects on our planet.

Therefore, it is crucial to develop processes in order to mitigate the problem.

One effective measure against the problem of metal waste is metal recycling.

By doing so, we can use our resources more efficiently and also mitigate several kinds of environmental problems.

It should be noted that the recycling of metals also has some downsides.

However, through the improvement of recycling processes, these weaknesses can be prevented.

By reducing our consumption of metal items, we can also make our contribution on a daily basis and therefore ensure a livable future for the next generations.





About the author

My name is Andreas and my mission is to educate people of all ages about our environmental problems and how everyone can make a contribution to mitigate these issues.

As I went to university and got my Master’s degree in Economics, I did plenty of research in the field of Development Economics.

After finishing university, I traveled around the world. From this time on, I wanted to make a contribution to ensure a livable future for the next generations in every part of our beautiful planet.

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