Cement Energy and Environment

• would ori ginal!) have been ven ted to the mmosphere is relea sed. Contrary to what happen s in dedicated incinerators. wherein the combustible waste is burnt all by itself. th at 1 . the fuel con. titutes 100 per cent of the input. in a cement ki ln . it accounts forjust I 0 per cent of the in put. the balance bei ng made up or other raw ma teri als. li enee. cement industry is a zero waste industry from thi. 'iewpoint. Fuel- Waste oil rMio for complete combustion - The waste oil is J?Umpcd along with coal in the burner pipe under steady stat e conditions of kiln. For an average feed as we do. of I 0 tonnes/hr of coa l and one barrel ( 180 kg)/hr of waste. the fuel to waste oil ratio works out to 55.55: I . The waste oil thus constitutes less than 2 per cent of the total fuel. With the high temperature of material inside the kiln, a complete combustion of the waste takes place. Operational Measures Fugitive dust s uppression -Where the fugitive dust of materi al be ing conveyed creates fire hazards, toxic effects or nuisance in the prox imity, provision of proper enclosures in conjunction with mechanica l ventilation system at transfer po ints, bunker fl oors and near surge bins have reduced these hazards. Where the nature of materia I penn it s wetting, spraying ofwater effectively suppresses the du st. Stack emission control- The CO analysers provided at th e inl et and 2nd stage preheatcr outlet guide the personn el ope rating the kiln in ensuri ng complete combustion. The maximum predicted levels of NOx and S0 2 in stack emiss ion are 620 mg/Nm 3 and I 00 mg/Nm' respective ly. Noise abatement- Noise levels are regu larly monitored. Noise generating sources have been isolated by housing them in enclosures. Whenever entry is necessitated, in such areas ea r plugs/muffs are used. Material Conservation Measures Oils- Electrostatic oil cleaner has been procured for oi l cleaning and prolonging oil li fe. For cement mi ll gear boxes, high performance gear oil is used which is based on Mox active tec hnology and has a li fe of 30,000 working hours against the normal life of 5.000 hours. Oil removed from vital gear boxes, after the specified number of hours, will be used in smaller gea r boxes. Oil is periodi call y tested to know its conditi on for rcplacemen t. 6 Fly Aslt - The plant consumes the entire fl) ash and cinder ash generated at its captive th ermal power plant in the production of OPC and PPC. Additionally fl y ash is being procured from the nearby Raichur Therma l Power Station. \\ ater Since the coo ling water has to be of uni fo rm qua lity and preferab ly con form to requirements in thi s regard as we ll as its temperature. but the plant' s raw'' ater supp ly was inadequate. coo li ng tower has been installed with open recirculating type coo ling water system for the cement pl ant. After coo ling in the coo ling tower, the same vvater is re-circulated. Apart from this. the plant's coa l based thermal power plant has its ownwater circuit the waste water !'romwhich is used for dust suppression in the ash handli ng system and for spray ing on roads. The mined-out pit is used as reservoir to store water for supply during the lean period, i.e. mid February to mid June. As a further water conservation measure, effluent from the sewage treatment plant (STP) is used on land for irrigation . The drip irrigation system has been adopted to save water. Among other measures, the drinking water for the colony is sterilised with ultrav iolet rays in stead of by chlori nation for ki lling the pathogens. Se\\a~<.· Treatment Plant The plant proper, along with the road network and the plant's surroundings. are ma intained neat, tidy and well illuminated. Pesticides are sprayed and whitewashing done regularl y to keep off cobwebs and other insects, as also prevent the growth ofgrass in the sludge drying beds. Afforestation Planting an appropriate number of the right species of trees, and tend ing them properl y thereafter has been adopted by the industry as an integral pmt of its ecological preservation endeavour. Accordingly, and for fulfillin g the conditions laid down in the letter of consent for cement plant expansions. a tree plantation programme was formul ated and is being imp lemented in close consultation with the concern ed officia ls and under the supervision of experts in th e field . Trees have been planted along the periphery ofthe plant and the colony's avenues. While the taller and evergreen type trees are used along boundary walls, med ium size flowering and fruit bearing trees have been preferred for pl anting in the colony. Furthermore, lush green lawns have been laid out in the parks. •