1.5MT Longwall faces in SCCL-Few planning issues

1,051 views
950 views

Published on

fThis paper was presented in MGMI Kothagudem chapter. This maily deals with various options for mechanisation od underground mines and their merits and demerits. The various advantages of Longwall technology and its supremacy in the different geo-mining conditions.

Published in: Technology, Business
0 Comments
3 Likes
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
1,051
On SlideShare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
0
Comments
0
Likes
3
Embeds 0
No embeds

No notes for slide

1.5MT Longwall faces in SCCL-Few planning issues

  1. 1. 1.5 Mtpa Longwall faces inShanthikhani and KK-7. G.Rajendar Reddy GM, Proj.Plng MD. Suresh Kumar Add.Mgr, Proj.Plng
  2. 2. MMR shaft block KK-7 LW Project D B C E A Geo-Reserves 101.57 MTMine Take Area: 857.91 Ha Rated Capacity 1.5MTForest 60.51 Grade F, E, CNo-Forest 797.4BH Density 13/sq.kmSeams 7Seams workable 3 (IA, I,III)Gradient 1 in 3.5 to 5Depth 92 to 606 m
  3. 3. Shanthikhani shaft block SK LW ProjectMine Take Area 1184.3 Ha Geo-Reserves 45.496 MTForest Land 648.11 Ha Ext. Reserves 26.22Non-Forest Land 536.18 Ha Rated Capacity 1.5MTBH Density 13.5 /sq.km Depth 244-662mSeams avble 7 seamsSeams workable 1 (SJ Top&Bot)Rated Capacity 1.5MTGrade D Bolting Practice in Workshop on mines-needs ‘ Review & Policy’ Roof underground Strata Control- Planning issues
  4. 4. Working under Sst roof Past ExperienceLW failures under hard roof in India• LW collapsed at Balrampur, Kumda, Churcha, Kottadi and Gdk9inc, 11A.• Major roof collapse in VK-7 during salvage under Sst roof.• P-21 worked under Sst roof in PVK.Preparedness for working under Sst in PVK• Supports Refurbishment: Around new 200 legs (50% of total legs), all control valve blocks, all bleed valves, all line distribution blocks, all connectors, hoses, filters, advancing rams, rams of extension canopies were replaced with indigenous and imported spares.• New 3rd power pack pump.• Ring-main circuit.• Multi Point Borehole Extensometers (MPBEx) - 2 Nos.• The additional boreholes at 30 and 60m were logged too. 21 P-• The physic-mechanical properties of older/newer boreholes compared and studied in-detail.• Calculation of layer wise cavability index.• Numerical modeling were done with the help of CIMFR.• Around 500 blast holes were drilled & blasted. Roof Bolting Practice in Workshop on mines-needs ‘ Review & Policy’ underground Strata Control- Planning issues
  5. 5. Working under Sst roof Past Experience Actual Situation… 0 10 20 30 40 Support # 50 60 70 80 90 100 120 0• Excessive abutment pressure & loading on Power supports. 100 -5• Floor heaving-AFC got lifted up, Hydraulic run of Legs (cm s) Supports dislodged in gates 80 Hanging Goaf (m ) -10• Change of roof RL within the face: 60 Frequent change of section- AFC -15 damage. 40 Front 24/9• Stone intrusion: had to cut by Rear 24/9 Front 25/9 shearer--Damage to picks, drums, 20 Rear 25/9 -20 gear box, abrasion of AFC Hanging 24/9 Hanging25/9 fleights, chains. 0 -25 Roof Bolting Practice in Workshop on mines-needs ‘ Review & Policy’ underground Strata Control- Planning issues
  6. 6. Working under Sst roof Past ExperienceCoal roof Vs Stone roof Roof Bolting Practice in Workshop on mines-needs ‘ Review & Policy’ underground Strata Control- Planning issues
  7. 7. Selection of seam and sequence of Operation Seams of MMR shaft Block Seams of SK shaft Block 4.5m 2.5m 3.7m 1.7m 2.0m Roof Bolting Practice in Workshop on mines-needs ‘ Review & Policy’ underground Strata Control- Planning issues
  8. 8. Selection of seams and Sequence of Oprn. LW workability options KK-7 SK•Projected Reserves in IA : 33.9 MT (upto750m). •Projected Reserves in SJ Bot: 34.3MT (Upto750m).•No of Cycles =34000 •No of cycles = 34000 LW Unit-1 with 30000 cycles LW Unit-2 with 30000 cycles Thin seams (2.5m) •Projected Reserves in III seam of KK-7 : 8.5 MT (Upto 750m). No of Cycles = 14775 •Projected Reserves in I seam of KK-7 : 6.8 MT (Upto 750m) No of Cycles = 16144 •Projected Reserves in SJ (Top)seam of SK : 9.7 MT (Upto 750m). No of Cycles = 9760 LW Unit-3 with 30000 cycles (1.7 to 2.5 Ht Control- Planning issues Workshop on Strata of Extn)
  9. 9. Selection of Working section DevelopmentTrunksGate Roads Roof Bolting Practice in Workshop on mines-needs ‘ Review & Policy’ underground Strata Control- Planning issues
  10. 10. Selection of Working section Extraction Roof Bolting Practice in Workshop on mines-needs ‘ Review & Policy’ underground Strata Control- Planning issues
  11. 11. Panel Layouts Dip-Rise PanelsWhy Dip-Rise panel in KK-7 ?? Roof Bolting Practice in Workshop on mines-needs ‘ Review & Policy’ underground Strata Control- Planning issues
  12. 12. Panel Layouts Dip-Rise PanelsAdvantages1. Face gradient is 1 in 6. Gate roads gradient is 1 in 6.2. The position of abutment load and tensile load gets shifted from supports towards goaf.3. The intensity of abutment load reduced drastically and the caving is very smooth.4. No abnormal roof convergence and floor heaving are experienced & expected.5. Gate road supports are intact.6. No water problem along bottom gate road ways. a. Min 10 persons/ day/ km gate belt-be avoided. b. Min 4 weak joints/week-avoided c. Reduction in Belt life. d. Advancing of gate end supports, BSL, Gate belt tail end unit becomes easier. e. BSL and gate belt is free of water. f. No rusting & pitting problems of BSL bottom plates, fleights and chain. g. Quality of coal is maintained.Limitations1. Men transport upto face and Advancing of switch train.2. Shear failure of face results in falling of boulders onto AFC and injuring persons working at face.3. Reduction of shearer thrust for cutting the coal in raising direction. Roof Bolting Practice in underground mines-needs ‘ Review & Policy’
  13. 13. Panel Layouts Strike panels Problems to be focused..• Face gradient is 1 in 3.8 to 1 in 4.5. Gate road gradient is 1 in 50.• Power requirement of Shearer: • For cutting the face At 1 in 3.8 gradient is around 900KW for 3.6m/4m Ht of Extrn. • For haulage of shearer at 1 in 3.8 gradient is around 70 KW.• Contours swing for about 500m in few panels towards North. • Straight gate: Gates dipping at 1 in 50, RL difference 10m, Water should be pumped out. • Deviation in Gate (90) : Face has to negotiate deviation with strata problems, time loss.• Possible Roof damage to bottom Gate of Twin gates due to LW retreat.• Maintaining such gates for 1-1.5 years including Pumping, Ventilation, inspection etc., Roof Bolting Practice in Workshop on mines-needs ‘ Review & Policy’ underground Strata Control- Planning issues
  14. 14. Selection of Equipment Power Roof SupportsSupport resistance1. Convergence method2. Bending stress/Moment/ Beam method • Ht of caving is 10T. • Weighted avg of Ts is considered. • Cavability index calculated layer-wise. • Caving beds are assumed as cantilever beams. • Bending stress/moment of Beams calculated and equated. • Main Fall is expected at : 65m • Periodic Fall span : 15.85m • Required Support Density : 129.7 t/m2 (Main weight) 64.7 t/m2 (Periodic Weighting) • Load on Support : 915.4 T (Main weighting) 641.4 (Periodic Weighting) • The recommended Support Capacity is 1000-1100T with support Resistance of 110-120T/m2 Roof Bolting Practice in Workshop on mines-needs ‘ Review & Policy’ underground Strata Control- Planning issues
  15. 15. Selection of Equipment Power Roof SupportsStructural Features • 2 Legged Shield • Base width : 1.7 or 1.8m • Advancing Ram : atleast 60T capacity. • Face frogs • Anti skid + Anti topple • Base lifting rams. • Support Resistance : 110-120T/m2 • Support capacity : 1000-1100T Base Roof Bolting Practice in Workshop on mines-needs ‘ Review & Policy’ underground Strata Control- Planning issues
  16. 16. Coal Evacuation system Belts Vs Skip Roof Bolting Practice in Workshop on mines-needs ‘ Review & Policy’ underground Strata Control- Planning issues
  17. 17. Coal Evacuation system Belts Vs Skip Roof Bolting Practice in Workshop on mines-needs ‘ Review & Policy’ underground Strata Control- Planning issues
  18. 18. Men & material Transport Haulers Vs Monorail Roof Bolting Practice in Workshop on mines-needs ‘ Review & Policy’ underground Strata Control- Planning issues
  19. 19. Men & material Transport Haulers Vs Monorail Roof Bolting Practice in Workshop on mines-needs ‘ Review & Policy’ underground Strata Control- Planning issues
  20. 20. Conclusion
  21. 21. Thank You Sir..

×