Cement, Energy and Environment July-Sep 2002

the effect ofwind blowing across during the fall. Atomised water spray system is installed also at the belt transfer point before coal stacking at the plant. The total cost ofthe water spray system is Rs 2lac. Crushed limestone transport to cement plant The crushed limestone is transported to the cement plants by means of a 3.8.-km long overland conveyor belt. of 900 tph carrying capacity. This belt is covered to reduce fugitive emissions. As a result, the fugitive emission is nil along the entire 4-km distance, while that at the transfer point is just 50 11g/m 3 • The cost of the total overland conveyor system was Rs 1450 lac. As a result of the ·foregoing efforts, fugitive emissions in the plant premises is 125-330!-Lg/Nm 3 against the prescribed norms of 500 11g/Nm 3 . The figure for the residential area is 90- 155!lg/Nm3 against the norm of200!lg/Nm 3. Stack Emissions The control measures taken for reducing stack emissions and the resulting improvement are summarised in the Table below: Figure 6 Roofwater drain leading to collection pit adjoining a dug-up well. SNo. Control measure Improvement Remarks I Rectification and modification Considerable reduction Carried out during of ESP internals (G.D. screen, in stack emission. plant maintenance. collecting, emitting system and hopper partition walls ext.) in BCW Nil investment kilns I and 2, and cement mill. 2 Fine-tuning ofESP rapping systems Kiln- less than 50 mg/Nm 3 (emitting, collecting and G.D. screen). 3 Fine-tuning of ESP control panels Cement mill - less and T. R. sets In effect, the plants consistently maintain the stacks' emission at 70-90 mg/Nm 3 against the prescribed norms of 150mg/ Nm 3 · Solid Wastes Management Fly ash - Part of the fly ash produced in the captive power plant is collected by nearby brick manufacturers. The balance is stacked away in an isolated area, covered with top soil to prevent than 70mg!Nm 3 leaching by rain water and help tree plantation. Waste oil and grease -These are disposed of to recycling industries approved by the Central Pollution Control Board and the Ministry of Environment · and Forests. Vegetable wastes A compostingpitof4mx5m x4m has been made into which all dry leaves from the plantation are dumped and periodically wetted to make manure. Biomedical waste - Such waste generated at the Health Centre and dispensary at the plant and the colony is delivered to the neighbouring government hospital for incineration once in two days. Optimisation of Water Use Recycling - No used water , whether from the plant or the captive power plant, is allowed to·go waste. All cooling m