I own a 400tpd cement plant. Because of a recent reshuffle in government, the state is now asking us prove our pollution-free state of running. How can I prove the technology is a pollution-free one.

You need to begin the process of obtaining ISO 14001 certification for environmental management systems. There are various consulting companies who should be able to help you with this process.

I wish to know if the test of consistency of cement pastes has any significance as regards the quality of cement, eg a cement of lower consistency (<25 per cent) is better than a cement of higher consistency (> 25 per cent water). Secondly: it is observed that most of international cement standards set limits only to mortar compressive strengths although in practice the main usage of cement is in concrete applications. May I know why is that?

To calculate the velocity of the gases at the mill fan inlet you need the static pressure in addition to the dynamic pressure. If the mill fan has a capacity of 133m³/s then you need to divide this by the cross-sectional area of the inlet ducting to arrive at the design gas velocity of the fan