3. In pit crusher conveyor technology•The drilled & blasted OB is loaded by shovels and transported by dumpersto Crushers. The crushed OB is then transported by a series of conveyorsinto a spreader for dumping.•Can be used in steep seams where laying of transport roads for the trucksis difficult.•While S.R indicates volumes, cut off ratio indicates depth and reflects indumper haulage cost, which increase with depth and may becomeprohibitive where in alternative haulage system may have to thought off.•Ideally suited where material has to be transported over a longer distance& high lift.
3.IN-PIT CRUSHER CONVEYOR TECHNOLOGY• Haulage costs have been an area that have risen significantly with the increase of diesel prices.• One alternative to reduce haulage costs is to shorten the truck haul distance by bringing the dump point into the pit using an in pit movable crusher/ crushers and conveying the Over burden out of the pit can reduce the haul cost.• When the gradient is too steep, dumping the material within the mine is not practicable as the dumped OB slides on to the coal face. In such cases in pit crushing is preferred.• The flow of material utilising an inpit movable crusher and conveyor system starts with OB material being dumped into crushers by dumpers. The material is crushed and fed on to horizontal transfer belts within the pit or directly on to a major up slope belts taking the material out of the pit. There may be one or more belts depending on the pit Geometry and depth. The conveyed material is dumped as per Video the requirement and the dump design by using spreaders.
In pit crusher conveyor technology: • Can be used in steep seams where laying of transport roads for the trucks is difficult. • Ideally suited for large capacity projects. • Ideally suited where material has to be transported over a large distance with huge lift. • Requires huge capital. • The transport cost will be much less than compared to shovel dumper combination. • Requires heavy equipment like crushers, conveyor distribution point and spreaders.
Ramagundam OC-II with Inpit Crushing & Conveying TechnologyDepth and gradients makes dumper haulage prohibitive due to high operatingcost. The alternate choice is ICC where material has to be transported over alarge distance & lift.The drilled & blasted OB is loaded by shovels and transported by dumpers toCrushers. The crushed OB is then transported by a series of conveyors into aspreader for dumping.
Salient features of RG OC-II ProjectNo.of seams- 10Gradient- 1 in 3.6 to 1 in 4Depth planned- 400mCapacity of the project- 4 MTPATechnology- Shovel dumper combination with ICC technologyLife of the project- 27 yearsStripping Ratio- 7.73 Cum/T (107.46 Mt of coal and 808.46 M.Cum of OB)Grade of the coal- ‘D’OMS- 6.88 plannedCost of production in Rs/T - 1606.94Total Capital outlay of the project is estimated at Rs 896.32Slope stability is a vital aspect in this project, as final highwalls will have a heightof up to 400 m which need to be planned as steep for better economics.The 120m high dumps with crushed OB(low cohesion) will pose differentproblems in dump stability which needs a comprehensive study on design,maintenance, monitoring and stabilisation altogether.
Ramagundam OC-II Mine with Inpit Crushing & Conveying TechnologyCompacted floor sloped 2-3°towards toe of the upper deck to direct the water to thedrain to avoid seepage into the dump. Better we provide lined drains/channels.
The spreader can rotate with an angle of 120 degrees. In SCCLtd, the inpit crushing and conveying system introduced in RG OC II, Ramagundam. The capacity of each crusher-conveyor system is 1200 cum/hour. There are 3 such systems in addition to coal conveying system in RG OC II mine.
4) Continuous Miner Technology:- Bucket Wheel Excavators•Presently being used in Naveyali, Lignite Opencast mines,having soft strata.•The bucket wheel excavates the material without blastingwhich is transported by a series of belt conveyors tospreader.
BUCKET WHEEL EXCAVATOR(BWE)This machine is suitable for excavating soft and non sticky material inlarge quantities.Lignite deposits usually associated with soft over burden. Most lignitemines in world use these BWEs for both OB and Lignite, as is the caseof “Nyveli Lignite Corporation” of India.Semi hard material also be made suitable for BWEs by small blastings.The BWE is a continuous excavating machine and capable of removingof OB up to 1200 cum / per hour.The excavation component of BWE is a large rotating wheel mounted onan arm/boom.On the outer edge of wheel is a series of scoops/ buckets as the wheelturns, the Bucket removes soilAs the wheel turns, the bucket removes OB/Coal from the target areasand carries it around to the back side of the wheel, where it falls on to aconveyor which carries the material to the identified destination.BWE are generally worked in combination with crusher & conveyingsystem.
Structural Components of the BWE – Side ViewHoist Unit for Bucket Maintenance Crane Counterweight Boom Maintenance Crane Wheel Boom Pylon Operator’s Cabin Bucket Wheel Boom E-House Bucket Wheel Slewing PlatformDischarge Boom Discharge Boom Slew with Conveyor Arrangement System Rotary Plate and Drive Crawler Travel Crawler Undercarriage Main Ball Race
Equipments Installed on BWECrawler DriveBucket wheelRotary PlateBoom Conv. SystemsSlew SystemsBoom Hoist System
LIGNITE FIELDS OF INDIA NLC is also the Nodal agency 4 for Exploration of Lignite Deposits in India. The Lignite Reserves in various states of India was 2 proved and estimated by NLC.3 Lignite Reserves (as of April 2009) Sl. State In MT % No. 1 Tamilnadu & 31818.42 81.7 Pondicherry 2 Rajasthan 4443.65 11.4 3 Gujarat 2662.25 6.8 1 4 Jammu & Kashmir 27.55 0.07 5 5 Kerala 9.65 0.02 6 West Bengal 1.15 0.003 Total 38963.17 100.0
Safety Department – Mine-II & Expn. MAJOR MINING EQUIPMENTS FOR MINE-II . Mines-2 Mines-2Description (10.5 MTPA ) (15.00MTPA)1400 Lit. STANDARD BWEs 2 51400 Lit. STANDARD BWEs- BRIDGE TYPE 3 3700 Lit. STANDARD BWEs 3 4700 Lit. STANDARD BWEs- Bucket rever. Type 2 311000 TPH MTC 3 64700 TPH MTC/4420Cu.mPH 2 320000 TPH SPREADER 2 320000 TPH CRAWLER MOUNTED TRIPPER 2 311000 TPH SPREADER 2 211000 TPH CRAWLER MOUNTED TRIPPER 2 26000TPH STACKER 1 12800 TPH RECLAIMER 2 2TRANSPORT CRAWLER 2 4
METHOD OF MINING Opencast continuous mining system using • Bucket Wheel Excavators • Spreaders • Conveyor Systems Refilling Mine Advancing Side NSBS NSBS SBSSBS TBS TBSSpoil Bank MBS MBS OB bench Avg. Height – 25 m Spoil Bank BBS Av. Height – 15 m Spoil Bank BBS Lignite Bench Maximum Height = 22 m
1400 LITRE BRIDGE TYPE BWERated Production : 2250 m3/hrOutreach from BW boom to Discharge boom : 130 ± 12 metresMaximum High Cut height : 30 metresService Weight : 3193 Tonnes
1400 LITRE BWERated Production : 2250 m3/hrOutreach from BW boom to Discharge boom : 61.3 metresMaximum High Cut height : 26 metresService Weight : 2170 Tonnes
700 LITRE BWE WITH DEEP CUT FACILITY Rated Production : 1100 m3/hr Outreach from BW boom to Discharge boom : 63.8 metres Maximum High Cut height : 18 metres Service Weight : 1450 Tonnes
EXCAVATION WITH LOCAL DEPRESSURISATION GROUND WATER PUMPING FROM MINES - 110 Mm3 / ANNUM 45 NUMBERS OF 1000 GPM PUMPS (20” DIA) ARE IN OPERATION
Rock breakerRock breaker technology can be applied for breaking of rock/coal/oreeven about 500 kg/sq.cm.It can be used wherever it is not possible to go for blasting – nearvicinity of structures and habitations.
Technical Parameters of Mega – BreakerMake : INDECOModel : 8500 UPWeight : 4500 KgDia of tool : 195 mmHP : 120 HPStriking rate : 350-450 Blows / MinPressure to Breaker : 150-160 barEnergy Class / Blow : 10,000 joules
Working Parameters of Mega BreakerProduction / Hour : 190 – 200 tonsProduction / Month : 55,000 tonsDiesel Consumption : 30 Lit./ HrLife of Moil point : 275-300 hoursOptimal Bench Ht. : 3 to 4 M
AdvantagesLocked-up reserves can be mined easilyReduction in Man powerSump-deepening an easy affairDigging of foundation pits adjoining the kiln /valuable structuresMore environmental friendly working &maintaining better social relationship withvillagersEffective working hours compared toconventional working methods
LimitationsFloor-level will not be uniform ascompared to Surface MinerNot suitable for mining huge reservesHave to be dependent on a singlemachine
Cost ParticularsTotal Capital Investment = 330 LakhsCost of consumables = 1.2 LakhsCost / ton of Limestone (Rs./MT) : Owning Cost = 17.77 Operating Cost = 12.25 Total Cost = 30.02Cost of Conventional Mining (Rs./MT) : Total Cost = 24.80