2. ABOUT BCCL It occupies an important place in as much as
itproduces bulk of the coking coal mined in the country.BCCL meets
almost 50% of the total prime coking coalrequirement of the
integrated steel sector. Currently, the Company operates 81 coal
mines whichinclude 40 underground, 18 opencast & 23 mixedmines.
The Company also runs 6 coking coal washeries, 2non-coking coal
washeries. The total manpower as on 01.03.2010 is 72,222. 3.
P.B.PROJECTo The project report of Putkee Balihari Project for
targetedproduction of 3.00 Mte/annum was sanctioned by Govt.ofIndia
on 19.12.1983 for a capital of Rs. 199.8721 Crore.o The object of
the Project was to produce 3 Mte Coal .Butdue to geological
disturbances and un-favourableconditions the project is derated to
1.00 Mte/annum on16.05.1995.o Finally for certain constrains the
Putkee Balihari Projecthas been derated to 0.68 Mte/annum in
September1999. 4. LOCATIONo Putkee Balihari Area situated at 10 KMs
awayfrom Dhanbad Railway Station in North West side& KM away
from NH 32 Road in south side. 5. MINE SCHEDULE ANDPERFORMANCE The
mine works in three shifts daily.timing:First shift - 8am 4
pmSecond shift - 4pm 12midnightThird shift - 12midnight - 8 am. The
total manpower of the mine is 430. The development and the
maintenance both are done simultaneouslyin all the shifts. The
production details of last five years2005-2006 - 359269
tonnes2006-2007 - 390148 tonnes2007-2008 - 402099 tonnes2008-2009 -
304048 tonnes2009-2010 - 279324 tonnes 6. FINANCIAL STATUSYear
Amount (Rs.in 000)2000 01 (-) 13988492001 02 (-) 12094772002 03 (-)
9869402003 04 (-) 10471672004 05 (-) 18826132005 06 (-) 8550522006
07 (-) 7257382007 08 (-) 12370702008 09 (-) 24110072009 10 (-)
1610145 7. METHOD ADOPTED FOREXTRACTION AT P.B.PROJECTo BORD AND
PILLAR METHOD is adopted for theextraction of coal.o Mine still is
in the development phase i.e.extraction of coal from pillars is not
yet started.o Height of the pillars is around 2.5 3.0 metre .o
Development operation of the P.B.Project willreach upto the
boundary in financial year 2011-12and then depillaring ,with the
hydraulic sandstowing ,with SDLs will be started in P.B.Project. 8.
DETAILS OF BORD AND PILLARMININGThis diagram shows the traditional
method of Bord and Pillar mining. Miners firstextracted coal along
roadways or bords, while the coal in between the bords acts as
pillarsholding up the roof. 9. DETAILS OF BORD AND PILLARMININGo
The fundamental concept of bord and pillar method ofmining is that
the coal seam is divided into regular blockslike array by driving
through it primary headings which areintersected at regular
intervals by connecting cutthroughs.The blocks of coal bounded by
them are the "pillars".o The pillars support the overlying strata
during the "firstworkings" as the bords are driven.o Then finally
coal is extracted from the pillars in thedepillaring phase. 10.
SCHEMATIC DIAGRAM OF BORDAND PILLAR MINING 11. ADVANTAGES OF BORD
ANDPILLAR MINING To develop the pillars, bords and/or panels to
enable theirsubsequent extraction. To develop multiple main entries
for access to the coalreserves. These entries are supported in the
long term bythe pillars consequently formed. Mine capacity. Pillar
and /or pillar and panel system relating to depth ofworking,
productivity and panel extraction system, Number of continuous
miner units operating, Coal clearance system is good. Men and
material transport and Ventilation. 12. DRILLING AND BLASTING
PATTERNAT P.B. PROJECT 13. DRILLING AND BLASTING PATTERNAT P.B.
PROJECT The fifteen hole method is adopted for blasting . Holes are
drilled with a platinum carbide rod,chargedwith P5
explosives(PENTADYNE-HP) and then blastedwith some time lag between
them about 10-20ms. 14. STATS OF THE EXPLOSION No of holes - 15
Effective pull - 1.2-3 m Tonnage of coal - 15 tonne Bottom row
charge - 500-550 gm of P5 Other rows - 350-450 gm of P5 Total
charge - 6-7 kg Powder factor - 2-2.5 tonnes/kg Detonation factor -
1 tonne/detonation 15. CONVEYANCE 16. CONVEYANCE In underground
mining ,a hoist or winder is used to raiseand lower conveyances
within the mine shaft . Winderused in P.B. project is D.C. MINE
WINDER manufacturedby SIEMENS AG which is German engineering
company. The winder rope is connected to a cage through a pulley .
The cage is divided into four different levels. The same cage is
used for taking the man and the materialto the mine . Each level in
the cage has a capacity to carry 20 persons at atime. 17. SDL-Side
Discharge Loader 18. INTRODUCTION TO SDL Side discharge loader is a
crawler mounted machine. It is used in underground mines for
transferring thecoal from one place to other. The machine in use at
P.B.Project is manufactured byEIMCO-ELECON India. The machine is a
hydraulic based . 19. Working conditions required forSDL Minimum
seam thickness is 1.25 m. It can work over weak floor condition as
the machineis crawler mounted. Seam Gradient should be 1 in 4 or
flatter. 20. Specifications of the SDL at the PBProjectEIMCO ELECON
625 SDL is in use . Overall Length - 4216 mm Maximum width - 1778
mm Caging Height - 1790 mm Dumping Height (45 degree tip) - 2300mm
Pay Load Capacity - 2032 kg Bucket Capacity - 1 cu.mtr Track width
- 300mm 21. Specifications of the SDL at the PBProject Weight -
8450 kg Speed - 2.59 km/hr electric Motor Power - 65 hp or 47 kw at
1470 rpm Trailing Cable - 25sq.mm(5core cable) Fan Speed -
1950-2050 RPM Filter Micron Rating - 10 microns 22. WORKING OF THE
HYDRAULICSYSTEM OF SDL. 23. WORKING OF THE HYDRAULICSYSTEM OF SDL.
There are two tanks : a hull tank and a header tank. From the
header tank a filter is attached whichpurifies the hydraulic fluid.
From the filter the hydraulic fluid reaches the mainpump which is
operated by an electric motor. From the pump the pressurized
hydraulic fluidreaches various parts of the SDL. The traction
motors which are responsible for thelocomotion of the machine . 24.
WORKING OF THE HYDRAULICSYSTEM OF SDL. Pressurized fluid is sent to
the fan motor and servicevalve. From there the fluid is sent to
various RAMS andfinally to the hull tank. Then in the final step
the fluid flows from the hulltank to the header tank and the same
process isrepeated again and again. 25. LOCOMOTION OF SDL The SDL
moves with the help of two crawlers. The crawlers are rotated with
the help of two tractionmotors and a gear box. The motors are
operated by the pressurized fluid whichcomes from the header tank.
The volume flow rate in the hydraulic traction motor is 59cc/rev.
The locomotion of the SDL is controlled by two RAMS if the SDL is
to be moved in forward direction both themotors are rotated in same
direction 26. LOCOMOTION OF SDL- if it is to be turned one motor is
working and theother is ideal during the revolution.- If the SDL is
to be rotated with zero turning radiusthen both the motors are
operated in oppositedirection. 27. DISCHARGING METHOD 28.
DISCHARGING METHOD The bucket movement is controlled by a
hydraulicmotor and cylinder piston assembly. For the bucket
movement the volume flow rate of thefluid in the motor must be
44cc/rev or 65 lpm . The name Side Discharge Loader is given to
themachine because the side door of the bucket opensand the belt
runs within the bucket and the material isdropped from the side of
bucket. 29. DISCHARGING METHOD The door of the bucket is controlled
by piston cylindermethod . When the side door is to be opened
,thefluid rushes into the cylinder and the piston is movedfrom the
bottom dead centre to the top dead centerand it remains in that
position until all the material isdischarged out and then the
hydraulic fluid is drawnout of cylinder of the bucket. The material
can be discharged from both sides of thebucket depending upon the
direction of rotation of thebelt. 30. COOLING SYSTEM The hydraulic
fluid used in SDL is HFB-68.HFB 68 is invert emulsion
(water-in-oil) type fire resistanthydraulic fluid specially
developed for use in hydraulicsystems in mining equipments working
under severeoperating conditions. It imparts fire resistance as
well asproper lubrication to hydraulic equipments. The cooling of
the hydraulic fluid is essential because theflash point , i.e. the
temperature at which the liquidvaporizes forms a combustible
mixture with air, is very lessand is approximately 65 degrees
Celsius. The cooling fan is operated by the same motor which
drivesthe belt inside the bucket. The rpm of the cooling fan is
about 2000 rpm. 31. DIMENSIONS OF THE SDL
