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Dhanbād, India

Ramulu M.,Indian Central Institute of Mining and Fuel Research | Raina A.K.,Indian Central Institute of Mining and Fuel Research | Sinha A.,CIMFR
Journal of Mines, Metals and Fuels

The pace of developments in underground blasting technology is insignificant in contrast to developments in opencast blasting. Blasting practices in underground mines has limited flexibility due to many safety criteria, statutory and field constraints. This has narrowed the scope of major modifications in the solid blasting design vis-à-vis the efficiency and yield per round. However, it is high time to balance the opencast and underground mine production, in view of the exhausting reserves in shallow depth and socio-environmental problems due to opencast mining. With this back-drop, Central Institute of Mining & Fuel Research (CIMFR), Regional Centre, Nagpur developed two new underground blasting techniques with simple modifications in explosive loading patterns. They are: (i) in-hole delay solid blasting technique (ii) bottom hole decking technique. The first technique was in-hole delay solid blasting technique by inserting multiple delay detonators in cut holes to improve the solid blasting efficiency. The conventionally available resources are used in this technique without violating the statutory guidelines. The trial blast results indicated improvements in all the parameters like pull, yield per round, powder factor and detonator factor. The overall improvement in pull per round was 49% with 1.5m deep rounds and 40% with 1.8 m deep rounds. The technique also resulted in reduction of ground vibration intensity by 32-37%. Another blasting method developed was bottom hole decking technique by inserting air-deck at the bottom of the blastholes. In this technique a spacer is to be placed at the bottom of the hole and remaining portion of the hole is conventionally charged. The length of spacer is equal to 10-12% of depth of blasthole. A wooden spacer or any antistatic plastic pipe can also be used for decking. The technique was also applied in both soft and medium hard coal formations while exploiting the thin coal seams. The trial blast results indicated improvements in pull, yield per round and powder factor. The overall progress/pull per round observed was 36% with 1.5m deep rounds and it was up to 22% with 1.8m deep rounds with the powder factor (ton/kg) improvement up to 70%. The technique was also resulted in reduction of ground vibrations by 20-26%. The experimental results also reveal that the in-hole delay solid blasting and bottom hole decking techniques are suitable for relatively harder and softer formations respectively for improving blasting productivity. Source

Gupta R.N.,National Institute of Rock Mechanics | Raina A.K.,CIMFR
Tunnelling in Rock by Drilling and Blasting: Workshop Hosted by FRAGBLAST 10 - The 10th International Symposium on Rock Fragmentation by Blasting

The paper describes a controlled blasting strategy adopted to excavate open cut (for tunnel portal) and a new tunnel near an existing railway tunnel with a parting/barrier of about 16 m. The area lies in highly populated vicinity, with an operational railway track passing through an old tunnel with brick lining, high tension electric traction and small hutments. The objective of the study was to prevent any fly rock from the surface blasting and damage to the existing tunnel from the blasting for the new tunnel. Source

Sahay N.,CIMFR | Haldar A.C.,ECL | Ray S.K.,Coal India Ltd | Kumar N.,Coal India Ltd | Sinha A.,Indian Central Institute of Mining and Fuel Research
Journal of Mines, Metals and Fuels

Occurrence of Fuel-rich open fire is one of the serious threats to safety and productivity of coal mines. Many a times it causes virtual closure of mine for a long period or forever. Recovery of such mine needs to address several technical challenges. It requires careful approaches for safe sealing, avoidance of situation for occurrence of explosion and strategies for quick recovery of the mine. Based on the above, a new comprehensive approach comprising safe sealing, control of fire, ventilation control, quick isolation of fire affected area, cooling of hot coal heaps and treatment of fallen coal by inhibitors suggested and implemented by authors for recovery of Kunustoria colliery (ECL) affected with fuel-rich open fire are briefly discussed in this paper. Source

2012 1st International Conference on Recent Advances in Information Technology, RAIT-2012

The word "cyber law" encompasses all the cases, statutes and constitutional provisions that affect persons and institutions who control the entry to cyberspace, provide access to cyberspace, create the hardware and software which enable people to access cyberspace or use their own devices to go "online" and enter cyberspace. In simple way we can say that cyber crime is unlawful acts wherein the computer is either a tool or a target or both. Cyber crimes can involve criminal activities that are traditional in nature, such as theft, fraud, forgery, defamation and mischief, all of which are subject to the Indian Penal Code. The abuse of computers has also given birth to a gamut of new age crimes that are addressed by the Information Technology Act, 2000. © 2012 IEEE. Source

Sahay N.,Indian Central Institute of Mining and Fuel Research | Sinha A.,CIMFR
Journal of Mines, Metals and Fuels

Problem of coal seam fire due to spontaneous heating is globally recognised by all coal producing countries because it is an inherent property of coal. Since all coals are prone to spontaneous heating provided it is allowed to oxidize in favourable situation, hence proper diagnosis of the problem and application of comprehensive technology is required to address the problem. Authors have conducted a studies in an opencast mine for better understanding of the problem of fire. The findings may be helpful in safe extraction of coal from fire affected developed seams through opencast. Source

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