摘要
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.
Thar煤田是巴基斯坦的一个新煤田,估计褐煤资源超过1750亿吨。资源规划是战略规划的重要组成部分,是优化和经济开发Thar褐煤的重要组成部分。本研究的主要目的是将Thar煤田作为单一矿床进行评价,并确定适合在Thar煤田进行地表开采、地下开采和排土场开采的区域。为Thar煤田编制了累积剥蚀比分布图,覆盖面积达1691.04 km^2,有12个勘探区块。利用693个钻孔的岩性资料,计算了每个钻孔的累积剥蚀率(3.7–88.1 m:m),平均值为12.85 m:m。累计剥蚀率分6个范围,分别为4–6,6–8,8–10,10–15,15–20和>20。所有钻孔周围的等高线都被数字化,显示出不同的剥离比范围。从累积剥蚀率分布图可以看出,665.72 km^2的面积(占评估总面积的39.37%)适合地表开采,989.82 km2的面积(占58.53%)适合于地下开采和外部废物堆放。而2.1%的地区不属于煤区,只适合于外部倾倒废物。所开发的累积剥蚀率分布图可作为制定Thar煤田开采总体规划的指导图。
