General Principles and Processes of Isolation of Elements - Notes, Topics, Formula, Books, FAQs

“The Pessimist Sees Difficulty In Every Opportunity. The Optimist Sees Opportunity In Every Difficulty.” – Winston Churchill

This chapter deals with the processes and isolation of metals from their sources. Metals are always obtained from their respective ores. These ores are found in the earth's crust and they obtained by mining. These ores contain some form of impurities known as gangue. Thus, metals are obtained in their purified form by following several steps. Majorly, the general principles and processes of isolation of elements from their ores follow the given steps:
(i) Concentration of the ore
(ii) Isolation of the metal from its ore
(iii) Purification of the metal

This chapter is all about the extraction and purification of metals. There are various types of methods and processes specified for particular metals are described in this chapter. It is a very important chapter as it gives you learning about how these metals that you use in your daily life are actually purified. From the practical and real-life applications point of view if we talk about then these metals are highly important for all of us. Some of the applications are described below:

• Metals like iron and steel are widely used in the construction of homes and buildings. They are hard metals and have the strength to withstand the heavyweights of these buildings and houses. They are commonly used in pillars, grilling, fencing, etc.
  
• In jewellery, metals like gold, silver, and platinum are used widely to make these ornaments.
  
  

• In farming as well, there are many tools that they use for farming. Most of these equipment are made of iron and steel, etc.
  
  

There are various other applications as well as related to metallurgy. In this article, you will get complete information about this chapter. This article will also help you regarding how to prepare for this chapter and the best-described books for preparation.

Notes for General principles and processes of Isolation of Elements

In this section, you will study about the important topics of the chapter, overview, formulae and some important tips and guidelines for the preparation of the chapter at the best.

General Principle and Process of Isolation of Metals- Topics

• Occurrence of Metals
• Hydraulic Washing
• Magnetic Separation
• Froth Floatation Method
• Leaching
• Extraction of crude metal from Concentrated Ore
• Refining
• Uses of Aluminium, Copper, Zinc and Iron

Overview of the General Principle and process of Isolation of metals

In this chapter, there are various important topics as given below that you must understand carefully. Basically, this chapter gives you the knowledge of the occurrence of various elements and how they get extracted through various procedures. First, the ore needs to be concentrated with some processes like hydraulic washing, magnetic separation, etc. then finally the isolation of pure metal is done.

Concentration of Ores
This is the process of isolation of ore from the gangue. This involves various processes that depend on the properties of the metal ore and the gangue. There are the following available methods that we use for the concentration of ore.

(i) Hydraulic Washing: This method is based on the gravity differences of the ore and the gangue. In this process, an upward stream of running water is used. The lighter gangue particles are washed away with water and the heavier ore particles get suspended on the surface.

(ii) Magnetic Separation: In this method, the ore and the gangue are separated on the basis of their magnetic properties. Either the ore or the gangue is capable of being attracted by the magnetic field and thus they able to be get separated from each other as shown in the figure.

(iii) Froth Floatation Method: In this method, gangue is separated from the sulphide ores. Water is used to make a suspension of powdered ore. Then oil is used to wet the mineral ore and water is used to wet the gangue. Now a shaft is rotated at the bottom which creates forth and this froth takes the mineral with it which thus separated later.

(iii) Froth Floatation Method: In this method, gangue is separated from the sulphide ores. Water is used to make a suspension of powdered ore. Then oil is used to wet the mineral ore and water is used to wet the gangue. Now a shaft is rotated at the bottom which creates forth and this froth takes the mineral with it which thus separated later.

(iv) Leaching: This process is used when the ore is soluble with some solvent. Leaching of alumina from bauxite is one of the major examples of leaching. In this process, the concentration of bauxite ore is done by digesting it with a solution of NaOH at high temperature and pressure. Thus in this way, Al₂

Extraction of crude metal from concentrated ore: In this process, the concentrated ores are further converted into a form which is suitable for reduction. Thus complete isolation of metal from concentrated ore is done in two steps:
(i) Conversion of concentrated ore into the oxide
(ii) Reduction of oxide to its metal.

Now, this conversion of concentrated ore to its oxide is done into two different ways:

(i) Calcination: In this process, the ore is heated due to which the unwanted matter leaves and we only left with the metal oxide. This process is illustrated with the following reactions:
(ii) Roasting: In this method, the ore is heated below the melting point of the metal and thus forms the metal oxide. This is illustrated in the following reactions.

(b) Reduction of oxide to the metal: In this method, metal oxides are heated in the presence of a suitable reducing agent to give the pure metal. this process occurs according to the following reaction.

We use Gibbs energy to predict which must be the best reducing agent for this process.

Refining:
After extracting the metal from the various methods as discussed above, it is still contaminated with some impurity. For removing these impurities and obtaining the metal of high purity, we use various techniques as follows:
(i) Distillation: This method is particularly important for metals like zinc and mercury. In this method, the metals are boiled and the impure metal is evaporated and the pure metal is obtained.
(ii) Liquation: This technique is specifically useful for tin and other low melting metals. In this method, low melting metal moves on the sloping hearth and high melting impurities do not move, in this way, the metal is purified.
(iii) Electrolytic refining: In this method, the principle of electrolysis is used. The impure metal acts as anode and a strip of pure metal is used as cathode. The electrolytic solution of the soluble salt is also of the same metal. For eg., copper and zinc are purified in this way.
(iv) Zone refining: In this method, a mobile heater is fixed at one end of the impure metal rod. The molten zone moves along with the heater. In this way pure metal gets crystallize and the impurities pass into the adjacent molten zone. This process is repeated several times. Germanium, silicon, etc. are purified in this way.
(v) Vapour phase refining: This process is done in two steps, first, the metal is converted into its volatile compound and then this volatile compound is decomposed to give pure metal. There are two important techniques i.e, "Mond Process for Refining Nickel" and "van Arkel Method for Refining Zirconium or Titanium" for purification of zinc and zirconium respectively.
(vi) Chromatographic methods: In this method, a column is used as a adsorbent which has the property to adsorb the different components. The mixture of various components is passed through this column. As this mixture pass through the column, its different components adsorb at the different levels of the column. Later another solvent is used as eluant to remove these components and purified.

Uses of Aluminium, Copper, Zinc and Iron

• Aluminum is used for a variety of purposes like wrappers of chocolates, electricity wires, paint and in the extraction of chromium and manganese.
• Copper is used for making electrical wires, steam pipes and utensils. It is also used to make alloys like brass and bronze.
• Zinc is used in batteries. It is used as a reducing agent in dye-stuffs and paints. It is also used for galvanizing iron.
• Iron is used for various purposes like in the manufacture of steel, toys, pipes, utensils, etc. Wrought iron is used in making of wires, bolts, chains, etc.

How to prepare for General Principle and process of Isolation of metals?

• This chapter is a part of inorganic chemistry. It is completely theory-based and very easy to learn. There are only processes for the separation of metals that only you need to learn.

• Most importantly, the diagrams are very important. Practice each process with the diagram, this would help a lot in board exams

• This chapter is very different from every other chapter of the complete chemistry syllabus, so it does not require any pre-requisite for its preparation.

• Rest this complete chapter is very simple, just be regular and be consistent in your numerical practice.

Prescribed Books for General Principle and process of Isolation of metals

First, you must finish the class XI textbook and solve each and every example and unsolved question given in it. Then for advanced level preparation like JEE and NEET, you must follow O.P. Tandon or Solomons and Fryhle. You must definitely solve the previous year papers. Meanwhile, in the preparation, you must continuously give the mock tests for the depth of knowledge. Our platform will help you to provide with the variety of questions for deeper knowledge with the help of videos, articles and mock tests.