Extraction of Metals from Ores

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Learn How the Extraction of Metals from Ores is Done 

Metallurgy is a fascinating chapter of chemistry students like to study. In this chapter, the different types of metals, their ores and different extraction processes are taught. The inorganic reactions used to extract metals from their ores and purified should be elaborately studied so that you can build a strong foundation of metallurgy and progress to the higher concepts later. To make sure you are on the right path, you can refer to this concept page that will help you clear your doubts related to the extraction of metals. 

When you reach Class 12, this will become a crucial chapter to study. Your depth in inorganic chemistry will then be tested. Learn how to extract metals that are used in the industries to manufacture different finished goods. You will also learn how the metals are purified using the most efficient methods. Refer to this concept page and find out how ore is treated step by step to collect a particular metal.

What is the Extraction of Metals?

We all know that the metals exist mostly in the form of salts along with other minerals to form an ore. These impurities should be removed with the help of different inorganic separation techniques. Every step takes us to a purer content of metal in the ore. In this concept page, every process involved in the extraction of metals will be discussed step by step.

The main aim of designing an extraction process is to minimize the cost and gather the purest form of the metal as much as possible. The conventional metal extraction processes will be discussed elaborately on this concept page. The simpler the process, the better and more cost-effective it is for the industries to extract metals from their ores. It all depends on the principles of metallurgy we use to check the inorganic chemical properties of the constituents of an ore. This is how an extraction process is designed. Every constituent is analyzed and then the most suitable process of separating it from the rest is chosen. The basic extraction of metals from ores has the following steps.

1. Grinding and Crushing

The bigger chunks of the ore extracted are crushed and ground in ball mills and crushers. It helps to increase the surface area of the chunks for better chemical actions later. In technical terms, it is called pulverization.

2. Concentrating the Ore

This step concentrates the ore by performing the removal of impurities. It is also called ore dressing. This process is quite elaborate and is named according to the equipment or technique used. Let us take a quick look.

  • Hydrolytic Method: 

In this method, the ground ore particles are poured over a vibrating table with a slope or inclination. A water jet is used to flow on the ground particles. The impurities are lighter than the metal-containing ore particles. They wash down while the heavier particles settle down on the grooves of the inclined table. This is generally used when the metal ore is much heavier than the impurities.

  • Magnetic Separation: 

The name of the concentration process is enough to explain. This technique is used to separate the ferromagnetic metal ore from the impurities after pulverizing. The ground ore particles are carried on a conveyor belt with two wheels. One of these wheels is magnetic. The ferromagnetic ore particles will then get attracted and separated from the impurities easily.

  • Froth Floatation: 

This is one of the methods of extraction of metals from ores by using two mediums together. Both oil and water are used to separate impurities. It can only be done when the ore forms froth when compressed air is passed in this medium. The frothed ore collects on the oil section whereas the impurities settle down in the water medium.

3. Calcination and Roasting

Once the ore is concentrated using the above methods, it is then either heated in the presence or absence of air. It all depends on the element and its chemical properties. For instance, sulfide ores are heated in presence of oxygen. It is called roasting. On the other hand, carbonated metal ores are heated in a vacuum for easy extraction of metals. This is called calcination. This is how a concentrated ore is again refined to gather purer metals.

This is a gist of how the extraction of metals ores and minerals is performed based on the physical and chemical properties of the impure ores. This concept page will also describe how metals in the lower part of the activity series can be extracted from their ores.

FAQ (Frequently Asked Questions)

Q1. Why are Ores Purified First?

The ores are first purified to make the next steps easier to accomplish. It is done to remove the impurities present in the ore particles apart from the metal we want to collect.

Q2. How is the Extraction Process Defined?

The extraction process depends on the physical and chemical properties of the constituents of an ore. The extracting metals low in the activity series will differ from those which are higher in the series.

Q3. How Metal is Extracted from Refined Ore?

If you study the concept page, you will find that there are three main methods of metal extraction. One of them is the extraction of metals by electrolysis.