3.3 Extracting metals: Displacement reaction & metal issues
Displacement Reaction
A more reactive metal will displace a less reactive metal in the compound, if given the opportunity. For example, you can place a more reactive metal into a solution of a dissolved metal compound with the metal being less reactive than the metal that you are placing into the solution. The more reactive metal pushes out the less reactive metal because the more reactive metal is able to form a stronger bond. Suppose that we have copper sulphate in a solution. We then add magnesium into the solution. The magnesium displaces the copper and leads to copper sitting at the bottom of the solution. The displacement reaction leaves us with copper sitting at the bottom of the solution and magnesium sulphate.
A more reactive metal will displace a less reactive metal in the compound, if given the opportunity. For example, you can place a more reactive metal into a solution of a dissolved metal compound with the metal being less reactive than the metal that you are placing into the solution. The more reactive metal pushes out the less reactive metal because the more reactive metal is able to form a stronger bond. Suppose that we have copper sulphate in a solution. We then add magnesium into the solution. The magnesium displaces the copper and leads to copper sitting at the bottom of the solution. The displacement reaction leaves us with copper sitting at the bottom of the solution and magnesium sulphate.
Copper is also commonly displaced by putting scrap iron into the copper sulphate solution.
If we put a less reactive metal into the solution (e.g. gold), then nothing would happen because copper is more reactive than gold. We would still have a copper sulphate solution and gold sitting at the bottom of the solution.
If we put a less reactive metal into the solution (e.g. gold), then nothing would happen because copper is more reactive than gold. We would still have a copper sulphate solution and gold sitting at the bottom of the solution.
Limited Supply
There is only a finite supply of metals in the world. Copper is one element that scientists and economists are concerned that we could run out of soon. Copper is in demand for a variety of different uses, such as building construction, electrical products, transportation equipment and many more. The demand for copper is also increasing as the world is becoming more developed and the global population is rising. Scientists are considering new ways of extracting metals from ores that have a lower concentration of the desired metal.
One way of extracting copper is Phytomining. Some plants absorb copper compound through their roots. Extractors place some of the ores in the soil. The plants are unable to use the copper or get rid of it, which means that the copper gradually builds up in the leaves. The leaves of the plant can be harvested, dried and then burnt in a furnace. The copper is then able to be collected from the ash that is left in the furnace.
Another method of extraction is bioleaching. Bioleaching uses bacteria that can eat the metal content out of the ore. Bioleaching is a slow but clean and effective process. It is fairly efficient with over 90% of the metal in an ore being recovered.
Recycling can be used to stop metals being extracted from newly mined ores. This slows down the rate at which we approach the limiting supply of metals in ores. Also, recycling metals uses a small fraction of the energy that is needed for obtaining a metal from an ore. By using less energy, we are producing less harmful chemicals that would result in global warming and acid rains, which is good. Furthermore, if the metals were not recycled then they would go to landfill and pollute the surrounding landscape. With modern technology, pretty much all metals can be recycled.
There is only a finite supply of metals in the world. Copper is one element that scientists and economists are concerned that we could run out of soon. Copper is in demand for a variety of different uses, such as building construction, electrical products, transportation equipment and many more. The demand for copper is also increasing as the world is becoming more developed and the global population is rising. Scientists are considering new ways of extracting metals from ores that have a lower concentration of the desired metal.
One way of extracting copper is Phytomining. Some plants absorb copper compound through their roots. Extractors place some of the ores in the soil. The plants are unable to use the copper or get rid of it, which means that the copper gradually builds up in the leaves. The leaves of the plant can be harvested, dried and then burnt in a furnace. The copper is then able to be collected from the ash that is left in the furnace.
Another method of extraction is bioleaching. Bioleaching uses bacteria that can eat the metal content out of the ore. Bioleaching is a slow but clean and effective process. It is fairly efficient with over 90% of the metal in an ore being recovered.
Recycling can be used to stop metals being extracted from newly mined ores. This slows down the rate at which we approach the limiting supply of metals in ores. Also, recycling metals uses a small fraction of the energy that is needed for obtaining a metal from an ore. By using less energy, we are producing less harmful chemicals that would result in global warming and acid rains, which is good. Furthermore, if the metals were not recycled then they would go to landfill and pollute the surrounding landscape. With modern technology, pretty much all metals can be recycled.
The Effects of Mining Ores
Mining ores out of the ground can have positive and negative effects. We can split these effects into economic, social and environmental. The positives are that people are provided with jobs, useful products can be made with the metals and both of these effects improve the quality of life of individuals. However, mining ores is noisy, creates dust and destroys habitats and landscapes. These are the same effects as mining for limestone.
Mining ores out of the ground can have positive and negative effects. We can split these effects into economic, social and environmental. The positives are that people are provided with jobs, useful products can be made with the metals and both of these effects improve the quality of life of individuals. However, mining ores is noisy, creates dust and destroys habitats and landscapes. These are the same effects as mining for limestone.