Thar coalfield is a new coalfield in Pakistan with estimated lignite resource of more than 175 billion tons. Resource planning is an essential part of the strategic plan for optimal and economical exploitation of Thar...Thar coalfield is a new coalfield in Pakistan with estimated lignite resource of more than 175 billion tons. Resource planning is an essential part of the strategic plan for optimal and economical exploitation of Thar lignite. Main objective of the present research is to assess Thar coalfield as a single deposit and identify the areas suitable for surface mining, underground mining and waste dump at Thar coalfield. The cumulative stripping ratio distribution map has been developed for Thar coalfield, covering an area of 1691.04 km2 around 12 exploratory blocks. Lithological data of 693 drill holes have been used to calculate the cumulative stripping ratio in every borehole, which varies from 3.7 m：m to 88.1 m：m with an average value of 12.85 m：m. Cumulative stripping ratio is divided into six ranges, viz： 4-6, 6-8, 8-10, 10-15, 15-20 and 〉20 m：m. Contours are digitized around all boreholes showing various ranges of stripping ratios. From the cumulative stripping ratio distribution map, it is concluded that 665.72 km2 area, which constitutes 39.37% of the total assessed area, is suitable for surface mining and 989.82 km2 area, constituting 58.53%, is appropriate for underground mining and outside waste dumps. Whereas, 2.1% area is no coal zone, only suitable for outside waste dumping. The developed map of cumulative stripping ratio distribution may be used as a guide map for the preparation of mining master plan for Thar coalfield.展开更多
A methodology applicable at any phase of a surface mining project for evaluating its current technical and economic feasibility is presented.It requires the typically available quantitative data on the ore-body,with i...A methodology applicable at any phase of a surface mining project for evaluating its current technical and economic feasibility is presented.It requires the typically available quantitative data on the ore-body,with its three-dimensional block model developed upon accurate interpolations.Thus it allows estimations of exploitable reserves in function of various cut-off grades,such as the average grade of mineable ore,the tonnages of ore and waste rock,stripping ratios and proft estimates for different production levels.If cost evaluations of essential mine operations are available(such as ore mining,waste removal,ore concentration,transportation,indirect project costs and expected concentrate selling prices),the methodology will provide clear indications on the economic feasibility of mining,including the best available options at any moment.Simple expressions are developed on the basis of a proft mathematical function and an application example is presented with data available from an existing iron ore deposit.展开更多
This paper analyzes the basic characters of optimum open-pit limit.According to them,following general rule for designing pit limit is obtained.The incremental stripping ratios is not greater than the break-even strip...This paper analyzes the basic characters of optimum open-pit limit.According to them,following general rule for designing pit limit is obtained.The incremental stripping ratios is not greater than the break-even stripping ratios,or the net incremental value is not less than zero.The rule can be used both in traditional and computer methods as direct basis to determine an optimum limit for any kinds of deposit.展开更多
In this study, landfill leachate with and without pre-treatment was co-treated with municipal wastewater at different mixing ratios. The leachate pre-treatment was achieved by air stripping to removal ammonia. The obj...In this study, landfill leachate with and without pre-treatment was co-treated with municipal wastewater at different mixing ratios. The leachate pre-treatment was achieved by air stripping to removal ammonia. The objective of this study was to investigate the effect of landfill leachate on nutrient removal of the wastewater treatment process. It was demonstrated that when landfill leachate was co-treated with municipal wastewater, the high ammonia concentration in the leachate did not have a negative impact on the nitrification. The system was able to adapt to the environment and was able to improve nitrification capacity. The readily biodegradable portion of chemical oxygen demand（COD）in the leachate was utilized by the system to improve phosphorus and nitrate removal.However, this portion was small and majority of the COD ended up in the effluent thereby decreased the quality of the effluent. The study showed that the 2.5% mixing ratio of leachate with wastewater improved the overall biological nutrient removal process of the system without compromising the COD removal efficiency.展开更多
文摘Thar coalfield is a new coalfield in Pakistan with estimated lignite resource of more than 175 billion tons. Resource planning is an essential part of the strategic plan for optimal and economical exploitation of Thar lignite. Main objective of the present research is to assess Thar coalfield as a single deposit and identify the areas suitable for surface mining, underground mining and waste dump at Thar coalfield. The cumulative stripping ratio distribution map has been developed for Thar coalfield, covering an area of 1691.04 km2 around 12 exploratory blocks. Lithological data of 693 drill holes have been used to calculate the cumulative stripping ratio in every borehole, which varies from 3.7 m：m to 88.1 m：m with an average value of 12.85 m：m. Cumulative stripping ratio is divided into six ranges, viz： 4-6, 6-8, 8-10, 10-15, 15-20 and 〉20 m：m. Contours are digitized around all boreholes showing various ranges of stripping ratios. From the cumulative stripping ratio distribution map, it is concluded that 665.72 km2 area, which constitutes 39.37% of the total assessed area, is suitable for surface mining and 989.82 km2 area, constituting 58.53%, is appropriate for underground mining and outside waste dumps. Whereas, 2.1% area is no coal zone, only suitable for outside waste dumping. The developed map of cumulative stripping ratio distribution may be used as a guide map for the preparation of mining master plan for Thar coalfield.
文摘A methodology applicable at any phase of a surface mining project for evaluating its current technical and economic feasibility is presented.It requires the typically available quantitative data on the ore-body,with its three-dimensional block model developed upon accurate interpolations.Thus it allows estimations of exploitable reserves in function of various cut-off grades,such as the average grade of mineable ore,the tonnages of ore and waste rock,stripping ratios and proft estimates for different production levels.If cost evaluations of essential mine operations are available(such as ore mining,waste removal,ore concentration,transportation,indirect project costs and expected concentrate selling prices),the methodology will provide clear indications on the economic feasibility of mining,including the best available options at any moment.Simple expressions are developed on the basis of a proft mathematical function and an application example is presented with data available from an existing iron ore deposit.
文摘This paper analyzes the basic characters of optimum open-pit limit.According to them,following general rule for designing pit limit is obtained.The incremental stripping ratios is not greater than the break-even stripping ratios,or the net incremental value is not less than zero.The rule can be used both in traditional and computer methods as direct basis to determine an optimum limit for any kinds of deposit.
基金funded by the Natural Sciences and Engineering Research Council of Canada (NSERC) under the Engage Grant (EGP 463799-2014) with collaboration with KGS Groups (Winnipeg, Canada)
文摘In this study, landfill leachate with and without pre-treatment was co-treated with municipal wastewater at different mixing ratios. The leachate pre-treatment was achieved by air stripping to removal ammonia. The objective of this study was to investigate the effect of landfill leachate on nutrient removal of the wastewater treatment process. It was demonstrated that when landfill leachate was co-treated with municipal wastewater, the high ammonia concentration in the leachate did not have a negative impact on the nitrification. The system was able to adapt to the environment and was able to improve nitrification capacity. The readily biodegradable portion of chemical oxygen demand（COD）in the leachate was utilized by the system to improve phosphorus and nitrate removal.However, this portion was small and majority of the COD ended up in the effluent thereby decreased the quality of the effluent. The study showed that the 2.5% mixing ratio of leachate with wastewater improved the overall biological nutrient removal process of the system without compromising the COD removal efficiency.
