ABSTRACT
The underground coal production is decreasing continuously after the nationalisation of the industry. Inspite of over 70% reserve amenable only to underground mining, the share of underground mining 72% in the year 1975–76 changed to 25% in 1994–95 in Coal India. The productivity is also continuously decreasing and has reached from 0.59 in 1975–76 to 0.44 in 1994–95 The drooping trend of underground coal mining production & productivity is attributed to technological vacuum, lack of engineering support and poor planning and development. Over 80% of the total work force contributed only 27.7% production of the coal from underground mine in the year 1991–92. The present boundary condition of underground mining could be defined as virgin seam underneath deeper cover or developed pillars in thick seams and pillars underneath surface and sub-surface features. Developed pillars accounted for large portion of good quality proved reserve. The eco-friendly mining method - wide stalling was developed for conservation of good quality coal, improvement in production, productivity and safety of the workers and workings while working thick seam standing on pillars under protected land.
A tnal was taken on experimental scale at Bartunga Hill mine of Chirimiri Area using bolts and W-strap as support along the roof and ring hole blasting of the band coal from the floor development. The results have been very encouraging in terms of productivity, level of recovery and safety. The ground management system and mining technology could be made techno-economically competitive and may open new vistas for high production and productivity from underground mines in suitable conditions.
