longwall for deep seam

8/16/2019 Longwall for Deep Seam

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UNDER GROUND MINING TECHNOLOG

ASSIGNMENT-1

TOPIC:-CRITERIA FOR SELECTION OF ADVANCED LONGWALL M

TECHNOLOGY

FOR DEEP SEAMS EXCEEDING 800 M. DEPTH COVERS A

STUDY

NAME-TARINI GAUTAM

ROLL NO.-114MN0274

NATIONAL INSTITUTE

TECHNOLOGY,

ROURKELA


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INTRODUCTION Longwall mining is a form of underground coal mining where a

wall of coal is mined in a single slice (typically 0.6 – 1.0 m thick

The longwall panel (the block of coal that is being mined) is typ

– ! km long and "#0 – !00 m wide.

The factors are influenced by geographical distribution with $u

wise abundance% depth wise a&ailability of coal deposits and

economic mining options.

'ith impro&ed technology of mining instrumentation% numerica

models computer applications for analysis of data in&estigato

gained enhanced satisfaction through obser&ational approaches


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THE LAYOUT OF LONGWALL MINING

SYESTEM


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*+traction is an almost continuous operation in&ol&ing the use of sel

ad&ancing hydraulic roof supports% a coal shearing machine% and an

armored con&eyor paralleling the coal face.

'orking under the mo&able roof supports% the shearing machine ridethe con&eyor as it cuts and spills coal onto the con&eyor for transpo

of the mine. 'hen the shearer has tra&ersed the full length of the c

face% it re&erses direction and tra&els back along the face taking the

cut.

,s the shearer passes each roof support% the support is mo&ed close

the newly cut face.

The steel canopies of the roof supports protect the workers and e$u

located along the face.


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ANALYSIS

OF THE

PROBLEM

Geo-mining Conditions

Faulty Planning

Improper Selection

Management of Face

Longwall SupportSelection Deficiencies

Large expansion inopencast mining

Researc needs


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-/T*/, 2 *3*-T/4

,5T7*4T T* 8/T/5T/4

2 99T

:*4T/33,T/4

;*3;/- 3/7/T,T/4


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ABUTMENT STRESS DISTRIBUTION ,ny massi&e stratum is labeled


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2 99T upport resistance

oof and floor pressure distribution

-utting height range

-ollapsed and transport height

Tra&elling access through the supports

The setting and yield pressure

peed of operation


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:*4T/33,T/4 nce past the face the air is no longer fresh air% but return air carrying

away coal dust and mine gases such as methane% carbon dio+ide% depen

on the geology of the coal.

The thinner the seam% the more difficult the challenge becomes.

eturn air is e+tracted by &entilation fans mounted on the surface and

&entilation methods can be used where intake air also passes the main g

and back return road reducing gas emissions from the goaf onto the fac

5ut this entails high capital and operating costs and is not always an op

in seams liable to spontaneous combustion.

There are basic ways of &entilating a longwall panel.


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! "#$%IL&%I'$ (! "entilation( where intake air comes in the main gate and

returns in the tailgate there is no connection to any airways

behind the face line. /f a longwall ad&ancing face is e&er used%

this is the only means of &entilation a&ailable.


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R "#$%IL&%I'$ (R "entilation( in which the main &entilation circuit is as

for &entilation% but there is another connection

(a ()leed() maintained to return airways behind the face.


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* 'R + "#$%IL&%I'$

(* or + "entilation( where both main and tailgates carry intake air

and all the return air is carried to main returns behind the face. 'ith

this system a &ariable regulator on the main gate intake is often used

to ad?ust the balance between face flow and main gate intake flow.

G#'L'GIC LIMI%&%I'$S


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G#'L'GIC LIMI%&%I'$S

-oalbeds that are e+tensi&e% fairly flatlying% generally uniform

thickness% and free of discontinuities% such as large faults or ot

geologic features. The mine floor must pro&ide a firm base for the mo&eable roof

supports used in longwall mining.

/deally% the strata o&erlying the coalbed should ca&e behind the

roof supports soon after the coal is e+tracted. /f the strata han

and break into large blocks% the high stresses placed on the roo

supports may lock them in place and interfere with their

operation.

'hen large sections of hardtoca&e roof strata e&entually fall

dangerous working conditions can occur due to &iolent air blast

ground &ibrations% and related conditions.

,8:,4T,;*


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,8:,4T,;* :ery efficient coal producing techni$ue.

-ontinuous operation re$uiring fewer workers and

allowing a high rate of production to be sustained. ,lso concentrates miners and e$uipment in fewer

working sections% which makes the mine easier to

manage.

afety impro&es through better roof control.

*liminates roof bolting at the working face to support

the mine roof.

/t in&ol&es no blasting% with its conse$uent dangers.

The coal haulage system is simpler% &entilation is bette

controlled.

8/,:,4T,;*


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8/,:,4T,;* @igh capital costs. -osts for e$uipment and installation are

substantially.

e$uires &ery e+pensi&e shields% cutters% and con&eyors. , large initial capital outlay is re$uired.

3ongwall mining is also comple+% with many mo&ing parts% all of

which must operate as an integrated system.

2ailure of one part can disrupt the entire operation% delaying

production and causing contractual difficulties.

8ust le&els often e+ceed the ma+imum allowable limit despite the

use of ad&anced dust control technology.


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34;',33 98-T/4 /4 -/3 ,48 --3


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:A.B /4-3/4* 3ongwall e$uipment with !+60T -on&entional supports

was introduced in Top seam in 1CD#.

D panels of 1"0m face length and B panels of 60m face length ha&e been worked

successfully.

econd set(!+!#0T/2) shifted from ;8A.11,/nc in 1CC! E

is presently in operation.

*+perience in–&aried face lengths %uphill transport%crossing the de&eloped gallery% working in between

goa&es% fault running across the panel.

7ain 9roblems–nderrated capacity of supports% -a&ity

formation.


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D panels of 1"0m face length ha&e completed 'ith !+60T

supports by producing around .67T and daily production

&aried from !00 to1D00T. B panels of 60m face length ha&e completed 'ith !+!#0T

supports by producing around 1.67T and daily production

&aried from1000 to100T.


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5*@

*-T/

@'/4

*,7 (7

*-T/

CONCLUSION


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CONCLUSION

8ue to re$uirement of mining at greater e+ceeding D00m. depths

future in /ndia by long wall method it is suggested to perform the

critical e&aluation for /ndian geomining conditions using different

approaches and conducting e+perimental trials% including stress

relie&ing techni$ue% and e+tensi&e use of inno&ati&e strata beha&

monitoring methods.


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PRESENT

ACTIONS AND

FUTURE

NEEDS

Planning

Standardisation

of #uipment

Monitoring of

Performance

.or/sops and'0erauling Facilities

7anpower8e&elopment

REFERENCES


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REFERENCES http://www.coalage.com/features/3120-ultra-thic-

seam-longwall-mining-in-china.html!."u#$2fl%&'(

https://en.wiipe)ia.org/wii/*ongwall+mining

http://www.un)ergroun)coal.com.au/p)f/longwall+mitc

hell

http://we,app1.)li,.in)iana.e)u/irtual+)is+li,rar/in)

e.cgi/2&0/F'1&4/p)f/coal+nuc/tr044

https://www.whitehaencoal.com.au/enironment/)ocs/section-2-)escription-of-the-longwall-pro5ect

http://www.minesu,si)ence.com/in)e+files/files/'ntro+

*ongwall+6ining+an)+Su,s

http://www.ct.ufrgs.,r/laprom/(n)ergroun)7206ining

7206etho)s


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longwall for deep seam

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