Step 1: Firstly the raw materials iron ore (Haematite, Fe 2 O 3), coke (carbon) and limestone (calcium carbonate, CaCO Step 2: As you can see from the diagram, hot air is blasted from both sides at the bottom. This heats up the inside of Step 3: The extra heat energy released from the above. Jul 23, · Isolation of elements in Chemistry class 12 aims to teach the students about various processes of extraction of metals from ores. Very few metals such as the noble metals, i.e., Gold, Silver, and Platinum etc. are present in their original metallic forms in nature.
Unreactive metals how to extract metals from their ores as gold are found in the Earth's crust as uncombined elements. However, most metals are found combined with other elements to form compounds. An ore is a rock that contains enough of a metal or a metal compound to make extracting the metal worthwhile, eg either:.
It is more expensive and wasteful to extract a metal from a low grade ore, but most high grade ores have already been used. In theory, any metal could be extracted from its compounds using electrolysis. However, large amounts of electrical energy are needed to do this, so electrolysis is expensive. If a metal is less reactive than carbon, it can be extracted from its oxide by heating with carbon. The carbon displaces the metal from the compound, and removes the oxygen from the oxide. This leaves the metal.
The table summarises the extraction methods used for different metals. Although an unreactive metal is found as an uncombined element, chemical reactions are often needed to remove other elements that might contaminate it.
Zinc mostly occurs as sulfide ores, which are heated in air to convert them to zinc oxide. Molten zinc can then be made from zinc oxide by heating with carbon:. Zinc oxide loses oxygen. It is reduced. Carbon gains oxygen. It is oxidised. Carbon acts as a reducing agent. Carbon has displaced the metal from the oxide. The carbon monoxide is oxidised further to produce the less harmful carbon dioxide, CO 2.
Copper may what happened to jan jeffcoat extracted from copper oxide by reaction with carbon. State which substance has been oxidised and which reduced. Carbon has been oxidised. Copper oxide has been reduced. Extracting metals Ores Unreactive metals such as gold are found in the Earth's crust as uncombined elements.
An ore is a rock that contains enough of a metal or a metal compound to make extracting the metal worthwhile, eg either: low grade ores contain a small percentage of the metal or its compound high grade ores contain a larger percentage It is more expensive and wasteful to extract a metal from a low grade ore, but what are the 11 dimensions high grade ores have already been used.
Carbon is a non-metal but can be placed in the reactivity series Although an unreactive metal is found as an uncombined element, chemical reactions are often needed to remove other elements that might contaminate it. Extraction of zinc Zinc mostly occurs as sulfide ores, which are heated in air to convert them to zinc oxide. Question Copper may be extracted from copper oxide by reaction with carbon. Reveal answer up.
Uses of Metals
In theory, any metal could be extracted from its compounds using electrolysis. However, large amounts of electrical energy are needed to do this, so electrolysis is expensive. If a metal is less. Different metals are extracted from their ores using different methods depending on their position in the reactivity series. Electrolysis of molten compounds is used to extract the most reactive. Metals are usually extracted from ores using a combination of heating and reduction with carbon in the form of charcoal or coke. Not all metals can be extracted from their ores in this manner and may need to be extracted by a process called electrolysis. Metals with low chemical activity, such a gold and silver are normally found in their pure buylevitraonline.co Size: KB.
Metals are everywhere. Look around you and try to find something which contains no metal at all! Even the latest iPhone and Samsung phones have an aluminum casing.
The cars and buses are made of steel. The wires embedded within the walls of your home are made of copper. It is very hard to imagine life without metals. Before we start to discuss how to obtain metals from their ores, we are going to learn about their uses first. You would be more interested to know how industries extract metals once you are aware of their importance. There are many metals in this universe but we only use a few of them!
We are simply going to discuss some of the common metals and their uses. The important ones are copper, iron, aluminum. Copper: Copper is an amazing metal. All the electricity and you are enjoying now is due to copper. The electricity cables are made of copper. Copper is even embedded inside electrical devices such as power circuit boards to conduct electricity. In some countries, copper is used to making hot water pipes as they do not react with water.
The coaxial cable of your TV also has copper inside it. Iron: Pure iron does not have a variety of uses.
But alloys of iron such as steel are highly useful. Alloys are nothing but a mixture of different types of metals. Alloys of Irons are used to make cars, nails, bridges etc. We are going to discuss in details about the different types of iron in the extraction of the iron part. Aluminium : This metal is very important. Aluminium is usually recycled as it is very expensive to extract. Aluminum used to make cooking pots, airplanes, overhead wires and also cans for soft drinks and canned foods.
We are going to have an in-depth look later on this blog of how Aluminium metal is ectracted. Metal such as gold and silver are usually used to make pieces of jewelry. Though gold and silver are better electrical conductors than copper but copper is used instead as it is cheaper.
Before we even start scratching the surface of the top of extraction of metals from their ores. We must clear up our concept about the reactivity series. Because of all the concepts of metal extraction is based on this. Keep note about the position of the following elements iron, aluminum, and carbon. Note that iron is less reactive than carbon while aluminum is more reactive than carbon. From where come carbon come from?
Get this concept clear about the displacement reaction, a more reactive metal is able to displace a less reactive metal. But a less reactive metal is not able to displace a more reactive metal. A is a more reactive metal, B is a less reactive metal and C is the anion. Here, solid zinc metal displaces iron from aqeous solution of iron II chloride because zinc is more reactive than iron.
Because less reaction iron is not able to displace more reactive zinc. I hope this concept is clear because both the extraction of Iron and Aluminum uses the concept of the reactivity series.
If you are still finding it difficult to grasp the concept of Reactivity series, then check out this cool Reactivity of metals Poster on Amazon. This poster contains colorful charts and diagrams which help you understand the concept of Reactivity series better. Industries extract metals from their ores. What are ores? Let me explain in a simple way. Usually, less reactive metals such as gold and silver are found in their pure form in the soil.
But this is not the case with more reactive iron or aluminum. Usually iron and aluminum exist as compounds, with oxygen, also known as oxides. Some other mineral or other compound is also present. But the majority is a metal oxide. In conclusion, in most cases, ores are simply metal oxides along with other small amounts of minerals. But not in all cases ores are metal oxides.
For example, ZnS, Zinc Sulfide or also known as zincblendes is an ore of zinc. Iron is a fairly reactive metal, hence we cannot find iron in its pure form. We have to obtain iron from its ores. Iron has three ores from which we can obtain it from. Industries usually use Haematite to extract iron from, but they can also use Magnetite too.
Here we are going to see an example of the extraction of iron from Haematite. To have iron from haematite we must remove the attached oxygen. We can do this by a displacement reaction. We can react a more reactive metal such as zinc with haematite, which will displace iron from the oxygen. Then it will be possible to collect the iron. But if we use zinc to extract iron, then the zinc is gone! Remember we need to extract zinc too from its ore to extract iron.
But carbon, on the other hand, is a better alternative. Carbon is more reactive than iron, plus also it is cheaper and available in plenty. Carbon comes in the form of coal, in industrial level, it is also known as coke. Please do not mistake this coke as the soft drink coca cola , or cocaine drug. The carbon in the coke reduces the iron III oxide to iron. But the carbon does not reduce it directly, but in several steps, I will discuss that later on this blog.
In order to extract iron industries use a structure called Blast Furnace. Have a look at the diagram below:. Looks scary and difficult right?! It might look scary but not a difficult concept to digest. I will be explaining this process step by step so it will be clear to you. Step 1: Firstly the raw materials iron ore Haematite, Fe 2 O 3 , coke carbon and limestone calcium carbonate, CaCO 3 is added from the top of the blast furnace.
I will discuss the reason for adding limestone later on. Just to give a simple idea, for now, it helps to remove some of the impurities. Step 2: As you can see from the diagram, hot air is blasted from both sides at the bottom. This heats up the inside of the blast furnace. This heat causes the oxygen in the hot air to react with the carbon in coke.
The reaction between carbon and oxygen is highly exothermic. This releases more heat inside the blast furnace. So the reaction between carbon and oxygen is mainly used to generate heat. Note: The body of the blast furnace is covered with heat-resistant bricks. This ensures that a minimum amount of heat is lost through the conduction process. This high temperature causes carbon dioxide to react with oxygen in the air to produce carbon monoxide CO. Step 4: Carbon monoxide is a powerful reducing agent.
This carbon monoxide reduces the iron III oxide to iron metal. But in some places of the blast furnace, the temperatures are very high. In those high-temperature regions, carbon directly reduces the ore to iron. The iron settles at the bottom of the furnace in a molten state. It is impure too. As I mentioned before, the limestone CaCO 3 helps to remove impurities.
The main impurity in this process is sand or Silicon dioxide SiO 2. Under the heat of the blast furnace, the limestone decomposes to form carbon dioxide and calcium oxide. The calcium silicate is also known as slag. It is in molten form and floats above the molten iron.
It is based on their amount of carbon content they have.