Cement, Energy and Environment

·..J - . J -1 \ Environment friendly design Fugitive emissions - The plant has a bi-cable aerial ropeway for transporting about 6000 to 7000 metric tonnes (MT) of limestone daily from the lease mines located some 10 km away. As an alternative to either a battery of belt conveyors or a fleet of trucks, this has aided in totally eliminating fugitive emissions, which would otherwise have arisen from belt transfer points or from continuous plying of trucks through such a long distance. In addition, the conveyor belts for transportation of raw materials, intermediate and finished products, within the plant are totally covered. Also, all u. For uninterrupted power supply, especially to the kiln/ cooler sections, a 10MW captive thermal power plant was set up (1993). Cost Rs 3.5 crore.ln addition, dust collectors are installed in the plant's coal handling circuit to minimise fugitive emissions. The two boilers in this plant are equipped with 2 nos. Flakt ESPs. 111. Installation of latest Roller Press grinding unit for cement grinding (1995). This unit also has an ESP for mill vent gases and a number of dust collectors on various auxiliary equipment. material storages, i.e. shale, laterite, coaC Retrofitting gypsum, clinker, are covered. Further, use of modern packaging machines, wagon loaders 1. Kiln/raw mill ESP's (1997). Cost about Rs and truck loader entails little fugitive emission. Process-related gas emissions- Generation of toxic oxides is considerably lower, since about 60 per cent of the pulverised coal is burnt in the precalciner at around 900° C. The preheater exit gases a t 360-380 oc are totally used for drying raw materials in raw mills and coal mill, so 2 crore. 11. The entire internals of the cement mills' ESPs for improving the collection efficiency (2000), Cost Rs. 36 lakh. m. Cooler ESP internals (September 2000). Cost Rs. 30 lakh. much so, the vent gas temperature from these 1v. Modifica tion of belt conveyors into flow mills is 100-105° C and 80-85° C respectively. conveyors for cooler ESP discharge. Upgradations and retrofitting While it is a fact that the plant started with the latest equipment and technology then available, the management has never hesitated to upgrade them for better energy efficiency and Pollution control Wide ranging measures as below have been undertaken to control pollution in and around the plant. env ironmen tal protec tion, and that a t The fly ash generated from the captive power considerable cost. Following is a lis t of the plant is totally being consumed, part as a raw upgradations and retrofitting carried out. mix component and part as additive for the Upgrada tion i. Replacement of the Norrie dust collector on cooler vent with a hi gh efficiency ESP (1993). Cost Rs 3.5 crore. manufacture of Portland pozzolana cement. This has eliminated the problems related to disposal/ dumping of ash. Table 3 gives the trend of fl y ash consumption by the plant from 1998 to 2001