Use of Granulated Slag as a stowing Material for Underground coal mines - A case study

This paper deals in detail the laboratory investigation, model study, field trials and gas emission monitoring studies carried out on SiMn Granulated Slag of Manarashatra Electrosmelt Limited (MEL) during stowing at Durgapur Rayatwari Colliery (DRC) – No. 4 mine of Western Coalfields Limited, Chandrapur area. This study was undertaken to investigate the suitability of slag as a hydraulic stowing material for underground coal mines by comparing results on different properties of slag with the established paradigm of any stowing material. This paper also throws light on the stowing trials carried out at DRC with different proportion of slag and send and its applicability for stowing in anti-gradient. The study revealed that granulated slag has several advantages over river sand with respect to physical, chemical and drainage characteristics, if used as a fill material. The main hurdle, which is apprehended in slag stowing, was its compressibility is within permissible limit. At DRC about 2000 cu.m of SiMn granulated slag was stowed successfully. It is expected that the success of this study will open a new horizon on utilizing Granulated slag as an alternative to sand as a stowing material which is getting scarcer day by day. The result of this study will instill confidence among practicing mining engineer to use granulated slag as an alternative to sand for hydraulic stowing.