• A metallic compound occurring in the earth crust along with impurities is called mineral.


• A mineral from which a metal can be extracted economically and conveniently is called ore.


• The impurity present in the ore is called gangue..


• The substance added to the ore to remove gangue from it is called flux.



• Physical methods adopted in dressing the ore are : hand picking, washing, froth flotation, Magnetic separation etc.


• The methods used for Extracting of Crude metal are Calcination, Roasting, Chemical reduction, Auto reduction, Displacement method, Electrolytic reduction .


• Calcination is a process of heating the ore strongly in the absence of air or oxygen.


• During calcinations, carbonate is converted to its oxide.


• Roasting is a process of heating the ore strongly in a free supply of air or oxygen.


• Calcination and Roasting are carried out in a reverberatory furnace

Reflections on concepts

1. List three metals that are found in nature as Oxide ores.(AS₁)
2. List three metals that are found in nature in un combined form. (AS₁ )
3. Write a note on dressing of ore in metallurgy? (AS₁)
4. How do metals occur in nature? Give examples to any two types of minerals. (AS₁ )
5. When do we use magnetic seperation method for concentration of an ore? Explain with an example. (AS₁)
6. What is the difference between roasting and calcination? Give one example for each. (AS₁ )
7. Draw the diagram showing i) Froth floatation ii) Magnetic separation. (AS₅)
8. Draw a neat diagram of riverboratory furnace and label it. (AS₅ )

1. Magnesium is an active metal, if it occurs as a chloride in nature, which method of reduction is suitable for its extraction? (AS₂)
2. Mention two methods which produce very pure metals from impure metals. (AS₁)
3. Which method do you suggest for extracting of high reactivity metals? (AS₂)
4. Explain Thermite process and mention its applications in our daily life. (AS₇)