Assessment of traffic noise at Kolar Gold Fields, India.

Traffic noise produces environmental problems on surroundings. At Kolar Gold Fields (KGF), traffic load at different locations can cause noise pollution. Therefore, a detailed study was carried out at KGF in commercial, residential and silence zone. Different monitoring locations were identified in these zones and A-weighted equivalent sound pressure levels (L(eq)) were measured. The study was conducted on different weekdays and weekend for different periods of the day and compared with ambient noise standards. Since many variables were noted during noise monitoring, therefore, a multiple regression analysis was also carried out to develop a regression model for prediction of L(eq). Stepwise regression procedure was followed for the selection of most influencing variables. Model adequacy was checked using normal distribution with zero mean and constant variance, difference between F-observed and F-critical, and correlation between measured and predicted noise levels.

Use of gold mill tailings in making bricks: a feasibility study.

Mill tailings dumps at Kolar Gold Fields, Karnataka, are creating environmental problems. One of the solutions to these problems is to use the mill tailings for some useful purpose. This study examined the possibility of making bricks from the mill tailings with some additives in laboratory experiments. Samples of the mill tailings and the additives were analysed for particle size distribution, Atterberg limits and specific gravity. The plasticity index of the mill tailings being zero, they could not be used directly for making bricks. Therefore some additives that had plasticity or binding properties were mixed with the mill tailings. Ordinary Portland cement, black cotton soils and red soils were selected as additives. Each of the additives was mixed separately with the mill tailings in different proportions by weight and a large number of bricks were prepared using metallic moulds. The bricks were termed as cement-tailings bricks or soil-tailings bricks, depending on the additives used. The cement-tailings bricks were cured for different periods and their corresponding compressive strengths were determined. The bricks with 20% of cement and 14 days of curing were found to be suitable. The soil-tailings bricks were sun-dried and then fired in a furnace at different temperatures. The quality of bricks was assessed in terms of linear shrinkage, water absorption and compressive strength. The cost analysis revealed that cement-tailings bricks would be uneconomical whereas the soil-tailings bricks would be very economical.