The most important raw materials used in the manufacture of cement are

examrobotsa's picture
Q: 77 (NDA-II/2012)
The most important raw materials used in the manufacture of cement are

question_subject: 

Science

question_exam: 

NDA-II

stats: 

0,33,21,3,33,3,15

keywords: 

{'important raw materials': [0, 0, 1, 1], 'cement': [0, 0, 1, 4], 'limestone': [2, 0, 1, 0], 'sodium carbonate': [0, 0, 0, 1], 'potassium': [1, 0, 0, 2], 'silica': [1, 0, 5, 9], 'charcoal': [1, 1, 1, 4], 'gypsum': [0, 0, 1, 3], 'clay': [2, 0, 1, 7], 'transition metal oxides': [0, 0, 0, 1], 'sodium': [10, 2, 12, 23]}

The correct answer is option 2: limestone, clay, and gypsum.

Limestone is the primary raw material used in the manufacture of cement. It is a sedimentary rock that is mainly composed of calcium carbonate. Limestone undergoes a process called calcination, where it is heated to high temperatures, to form a substance called quicklime. This quicklime is then mixed with other materials to produce cement.

Clay is another important raw material in cement manufacturing. It contains silica, alumina, and other minerals. Clay is typically extracted from quarries and is mixed with limestone in the manufacturing process. It helps to bind the materials together and provides strength to the final cement product.

Gypsum is a mineral that is added to the cement mixture to control the setting time and improve its workability. It helps to delay the setting of cement, allowing enough time for it to be poured and shaped. Gypsum also enhances the strength and durability of the final cement product.

Option 1, which includes potassium nitrate, charcoal, and sulfur, is incorrect. These materials are not used in the manufacture of cement.

Option 3, which suggests transition metal oxides, sodium hydroxide, or potassium hydroxide, is also incorrect. These materials are not commonly used

Practice this on app