Construction and operation of high capacity longwall project: Adriyala experience

摘要

In India, lot of coal reserves exist up to 300m depth, are more amenable for extraction by opencast mining. Bulk production is possible with Opencast mining, with low gestation period, more safety and high percentage of extraction compared to underground methods. Hence coal operators are inclined towards opencast mining methods. India is the third largest coal producer in the world and is producing nearly 89% of coal from opencast mining and 11% from underground mining (2014-15)[1]. In India, the gap between the demand and indigenous availability of coal has been rising. Presently, coal imports are about 99 Million tonnes. The import requirement is projected to be 265 Mt by 2016-17. This gap is likely to widen further beyond XII Plan period leading to requirement of hefty imports. This unacceptable gap can be limited only by an all out effort by domestic coal producers [1]. With depletion of shallow reserves, the future emphasis has to be on faster exploration and underground mining. This calls for meticulous identification of coal blocks suitable for high mechanisation and introduction of state-of-the-art technology from overseas, in addition to possible semi mechanisation of the existing mines. Large scale mechanisation shall be sustained by expanding the service base of Equipment manufactures with supplementation of indigenous spares and parts manufacturing in line with 'Make in India policy'. These high capital intensive systems will not be viable unless global operating standards are achieved in equipment maintenance and utilisation. This demands highly skilled and motivated work force. Suitable planning and systems are to be developed for skill development and for adopting best management practices However, as shallow seated seams are exhausting at rapid pace and to meet the future requirement there is an urgent need for development and implementation of bulk production technologies for deep-seated deposits in the depth range of 300m to 600m by underground methods. Coal production at higher rates from underground, particularly at depths more than 300m, is possible with "Longwall Mining Technology", which is a proven technology worldwide[1]. Accordingly, one high capacity longwall project with an annual capacity of 2.817 MTPA has been commissioned with state of art equipment at Adriyala Longwall Project (ALP). After seeing the performance of Adriyala Longwall Project, SCCL is planning to introduce few more longwalls in near future. This paper brings out the constructional and operational experiences of high capacity longwall at Adriyala Longwall Project, SCCL.