Cement, Energy and Environment

Hg emissions are lower in raw mill 'on' conditions compared to raw mill 'off conditions. In cement plants, Raw mill normally runs for more than 20 hours and hence emissions would be low. (iii) Normalizing of measured Mercury emissions to standard oxygen level: Measured emiSSions are required to be normalized to 10% oxygen levels. As the oxygen levels at the time of measurements are not reported, it is not possible to compare the measured emissions with expected Limit value. (iv) Mercury in cooler stack & clinker: One of the findings of the study shows that mercury emission from cement process is mainly from cooler stack. It is necessary that this finding is relooked at and validated. Emission measurement studies carried out in past have reported that there is very low (if any) retention of Mercury in the clinker. No Hg measurements are reported from cooler stack. Mercury and its compounds entering the process through raw materials and fuels are almost entirely vaporized in the kiln or in the pre-heater and therefore exit from pre– heater with the hot gas stream. Very low levels/ practically no mercury ends up in clinker or exits from cooler stack. (v) Mercury circulation loop: Kiln gases are used for drying in raw mill. With decrease in temperature in th e raw mill, mercury compounds condense on the raw meal in raw mill on operation. Similarly mercury gets adsorbed on dust in bag house and on solid fuel forming mercury circulation loop. It is necessary that sampling and determination of Hg is carried out in these streams for realistic mass balance. (vi) Mass balance: Mass balance needs to be incorporated in the study, for which details of gas volumes and other process parameters need also t o be simultaneously monitored/ meas ured/ noted, to va lida te the Mercury measurements fo r report ing. - As no details of gas volumes or process parameters were available, an approx. mass balance with certain assumptions using gas quantities during raw mill 'on' j 'off conditions, reveals that output Hg was substantially higher compared to input. This needs to be further investigated/ analyzed. Possible areas where error could creep in are gas sampling where maintaining !so– kinetic conditions are crucial for accuracy. Interference due to sulfide, chlorides or any other element during Hg determination while using CVAAs may have to be looked into. (vii) To crystallise the findings, all interferences need to be accounted for to justify each data reported. CMA have also requested the Member Secretary, Central Pollution Control Board, to take into account our above observations, while taking any further action. CMAAS CSI COMMUNICATION PARTNER A workshop on biodiversity management was organized for CSI member companies in India in New Delhi on 9 & 10 May 2014. Shri Priya Ranjan Sinha, Country Head of International Union for Conservation of Nature (IUCN) India, presented an overview of the wealth of natural capital in terms of biodiversity that India possesses and set the scene for the workshop. Ms Seema Arora, Executive Director of CII-ITC Cent re of Excellence for Sustainable Development, presented the r ecently developed programme: "India Business & Biodiversity Initiative (IBBI)" to the participants. The IBBI is part of Global Partnership for Business and Biodiversity (GPBB) ' .~