Question

The molten limestone combines with sand and other impurities and floats. This phenomenon is called as:
1. Flux
2. Slag
3. Silver oxide
4. Zinc oxide

Answer 1

Correct Answer - Option 2 : Slag

Explanation:

Slag:

• Slag is a product of Flux and impurity.
• Slag is a waste matter separated from metal during smelting and other metallurgical and combustion processes from impurities in the metals. 
• The iron and silica is an example of slag that is removed during copper and lead smelting.
• Similarly, molten limestone combines with sand and other impurities and floats. This phenomenon is Slag.
• In steel-making furnaces, during the separation of the molten steel from impurities produced steel slag.
• Slags are divided into two parts blast furnace slag and metallurgical slag.
• The slag consists mostly of mixed oxides of elements such as silicon, sulfur, phosphorus, and aluminum.​​

Flux:

• These are the substances used to remove impurities such as slag in metallurgical processes.
• Common examples of flux are silica, dolomite, lime, borax, fluorite, etc.