The correct answer is D. All of the above.
Firebricks are a type of refractory brick that is used in high-temperature applications, such as furnaces and kilns. They are made from a variety of materials, including silica, alumina, and magnesia. The percentage of absorption for firebricks varies from 5 to 10, depending on the type of brick and the manufacturing process. The percentage of silica in silica bricks is to the extent of about 95 to 97 percent. This is because silica is a very stable material that can withstand high temperatures. Roughly 1 to 2 percent of lime in silica bricks is added to act as a binding material. This helps to keep the bricks together and prevents them from cracking.
Here is a more detailed explanation of each option:
- Option A: The percentage of absorption for firebricks varies from 5 to 10. This means that when firebricks are placed in water, they will absorb between 5 and 10% of their weight in water. This is important because it affects the way that firebricks perform in high-temperature applications. If firebricks absorb too much water, they can become unstable and crack.
- Option B: The percentage of silica in silica bricks is to the extent of about 95 to 97 percent. This is because silica is a very stable material that can withstand high temperatures. Silica is a type of mineral that is found in sand and quartz. It is a very hard material that is resistant to heat and chemical attack.
- Option C: Roughly 1 to 2 percent of lime in silica bricks is added to act as a binding material. This helps to keep the bricks together and prevents them from cracking. Lime is a type of mineral that is found in limestone and chalk. It is a white powder that is used in a variety of applications, including construction, agriculture, and medicine.
In conclusion, the correct answer is D. All of the above.