The raw materials used for the manufacture of Portland cement are

examrobotsa's picture
Q: (NDA-II/2019)
The raw materials used for the manufacture of Portland cement are

question_subject: 

Science

question_exam: 

NDA-II

stats: 

0,56,51,31,12,56,8

keywords: 

{'portland cement': [0, 0, 0, 3], 'raw materials': [0, 0, 0, 1], 'silica': [1, 0, 5, 9], 'lime': [1, 0, 5, 12], 'carbon dioxide': [2, 0, 5, 6], 'alumina': [0, 0, 1, 2], 'boric acid': [0, 0, 0, 1], 'sulphur dioxide': [0, 0, 0, 1], 'manufacture': [1, 0, 6, 10]}

The correct answer is option 3: Lime, silica, and alumina. Portland cement is the most commonly used type of cement in construction. It is made by heating a mixture of limestone (which contains lime), silica, alumina (derived from clay or shale), and iron oxide. Here is a breakdown of each option:

1) Lime, silica, and sulfur dioxide: Sulfur dioxide is not one of the essential raw materials for manufacturing Portland cement. Lime and silica are correct components, but sulfur dioxide is not.

2) Lime, silica, and carbon dioxide: While lime and silica are needed to make Portland cement, carbon dioxide is not a primary raw material in its production.

3) Lime, silica, and alumina: This is the correct option. Alumina, derived from clay or shale, is a crucial ingredient in the production of Portland cement.

4) Lime, silica, and boric acid: Boric acid is not typically used as a raw material in the manufacturing of Portland cement. It is not one of the essential components required for its production.

Therefore, the correct answer is option 3: Lime, silica, and alumina.

Practice this on app