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C10 C) Reuse, Recycle & Extracting Metals
C10 C) Reuse, Recycle & Extracting Metals
Societies need to make sure that they behave in a sustainable way. Sustainability means meeting the needs of the current generation without harming the ability of future generations to meet their needs. One way that societies can become more sustainable is to do the 3 R’s; reduce, reuse and recycle.
Reduce is all about reducing the quantity of resources that we use and the waste that we produce. For example, we can purchase fewer new goods, such as clothes (fast fashion clothes).
Reuse means that we reuse products for a longer period of time. For example, we can use a reusable coffee cup an unlimited number of times. Reusable coffee cups are better for the environment because fewer single use coffee cups will be produced, which uses fewer resources, thus being more sustainable. Another example is glass milk jars that are washed after use and then refilled with new milk.
Recycle means that we use materials from old/ waste products to make new products. For example, we can melt down used glass milk bottles to make a different shaped container out of glass (such as a wine bottle) or to make glass wool insulation for homes. Another example is recycling old appliances (such as phones) to extract the metals inside them, which can be used to make new appliances (new phones). A final example is the recycling of the materials from an old car to make a new car; we can use steel from the body of an old car to make the body of a new car.
Reduce is all about reducing the quantity of resources that we use and the waste that we produce. For example, we can purchase fewer new goods, such as clothes (fast fashion clothes).
Reuse means that we reuse products for a longer period of time. For example, we can use a reusable coffee cup an unlimited number of times. Reusable coffee cups are better for the environment because fewer single use coffee cups will be produced, which uses fewer resources, thus being more sustainable. Another example is glass milk jars that are washed after use and then refilled with new milk.
Recycle means that we use materials from old/ waste products to make new products. For example, we can melt down used glass milk bottles to make a different shaped container out of glass (such as a wine bottle) or to make glass wool insulation for homes. Another example is recycling old appliances (such as phones) to extract the metals inside them, which can be used to make new appliances (new phones). A final example is the recycling of the materials from an old car to make a new car; we can use steel from the body of an old car to make the body of a new car.
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The Advantages of Recycling
There are many advantages of making a new product from recycled materials rather than extracting new materials. Here are some of the advantages:
There are many advantages of making a new product from recycled materials rather than extracting new materials. Here are some of the advantages:
- Fewer mines and quarries are needed to extract resources/ metal ores. This is especially a positive if the resources are finite because by leaving the finite resources in the ground, it conserves the resources for future generations. Also, as we do not need mines and quarries, less waste products are produced and less land needs to be cleared.
- Less energy is required to recycle materials compared with processing/ producing new materials. Most energy comes from fossil fuels, so as recycling uses less energy, fewer fossil fuels are burnt, thus meaning that a lower quantity of greenhouse gases are produced. For example, the recycling of aluminium uses 92% less energy compared with the extraction and processing of new aluminium from its ore.
- The recycling of materials from old products means that less waste goes to landfill sites, which reduces the amount of pollution from landfill sites and means that less land has to be cleared for new landfill sites.
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The Disadvantages of Recycling
However, there are some disadvantages of recycling and here are some of the disadvantages:
- Old products that are going to be recycled need to be collected and transported. This costs money, needs organisation and requires fuel.
- It can be quite hard to sort all of the different materials from an old product. For example, it can be hard to sort all of the different metals from an old phone.
- The amount of sorting required depends on what the recycled material is being used for. For example, if we are obtaining recycled copper that will be used for electrical wiring, we need to make sure that the recycled copper is as pure as possible. This is because any impurities in the copper wiring will add resistance, which will mean that the wiring is less effective. Ensuring that the recycled copper is as pure as possible for wiring requires more steps in the recycling process. Other metals do not need to be as pure and are therefore easier to recycle. For example, steel is iron with a little bit of carbon. We can easily recycle waste steel by placing it into a blast furnace. Recycling steel requires less energy and keeps iron ores in the ground for future generations.
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Extracting Metals – Higher Tier Only
Metals in metal ores are finite resources, which means that there is a fixed quantity of them on earth. The majority of high grade metal ores have been extracted and processed to produce metals (a high grade metal ore is a rock that has a high quantity of a desirable metal). This has meant that for quite a few metals, it is becoming harder to find high grade metal ores. This has led scientists to come up with alternative ways to extract metal from low grade metal ores using living organisms. The alternative ways that we are going to look at are bioleaching and phytoextraction. We are going to look at the extraction of copper from low grade copper ores.
Bioleaching
Bioleaching involves using bacterial to break down the low grade copper ore to produce an acidic solution containing soluble copper ions – this solution is known as the leachate. We then extract the copper from the leachate by electrolysis or a displacement reaction with a more reactive metal.
A positive of bioleaching is that it has a smaller impact on the environment compared to the traditional way of extracting copper from its ore. Another positive is that it allows us to extract copper from lower grade copper ores.
The extraction of copper in this way does have a few drawbacks. One of the drawbacks is that the process is very slow – you have to wait a long time for the bacteria to produce the leachate that contains the copper ions. Another negative is that it creates sulfuric acid, which can be damaging to the environment if it is not disposed of correctly.
Metals in metal ores are finite resources, which means that there is a fixed quantity of them on earth. The majority of high grade metal ores have been extracted and processed to produce metals (a high grade metal ore is a rock that has a high quantity of a desirable metal). This has meant that for quite a few metals, it is becoming harder to find high grade metal ores. This has led scientists to come up with alternative ways to extract metal from low grade metal ores using living organisms. The alternative ways that we are going to look at are bioleaching and phytoextraction. We are going to look at the extraction of copper from low grade copper ores.
Bioleaching
Bioleaching involves using bacterial to break down the low grade copper ore to produce an acidic solution containing soluble copper ions – this solution is known as the leachate. We then extract the copper from the leachate by electrolysis or a displacement reaction with a more reactive metal.
A positive of bioleaching is that it has a smaller impact on the environment compared to the traditional way of extracting copper from its ore. Another positive is that it allows us to extract copper from lower grade copper ores.
The extraction of copper in this way does have a few drawbacks. One of the drawbacks is that the process is very slow – you have to wait a long time for the bacteria to produce the leachate that contains the copper ions. Another negative is that it creates sulfuric acid, which can be damaging to the environment if it is not disposed of correctly.
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Phytoextraction
This method can also be referred to as phytomining. Phytoextraction involves growing plants in soil that contains low grade copper ores. As the plants grow, they absorb the copper from the soil. The absorbed copper builds up in the leaves of the plants. The plant is then harvested, dried and burnt. The ash that is left behind contains soluble copper compounds. The copper can be extracted from these copper compounds by electrolysis or by a displacement reaction with a more reactive metal.
A positive of phytoextraction is that it has a smaller impact on the environment compared to the traditional way of extracting copper from its ore. Another positive is that it allows us to extract copper from lower grade copper ores.
A negative of phytoextraction is that it is a very slow way to obtain copper from the low grade copper ores.
This method can also be referred to as phytomining. Phytoextraction involves growing plants in soil that contains low grade copper ores. As the plants grow, they absorb the copper from the soil. The absorbed copper builds up in the leaves of the plants. The plant is then harvested, dried and burnt. The ash that is left behind contains soluble copper compounds. The copper can be extracted from these copper compounds by electrolysis or by a displacement reaction with a more reactive metal.
A positive of phytoextraction is that it has a smaller impact on the environment compared to the traditional way of extracting copper from its ore. Another positive is that it allows us to extract copper from lower grade copper ores.
A negative of phytoextraction is that it is a very slow way to obtain copper from the low grade copper ores.
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