Coal Age : devoted to the operating, technical and business problems of the coal-mining industry, Vol. 39, No. 9

C ^{o a l} A ^ge

E stablished 1 9 1 1 — M c G r a w - H ill P u b lish in g C o m p a n y , Inc.

DEVOTED TO THE OPERATING, TECHNICAL A N D BUSINESS PROBLEMS OF THE C O A L-M IN IN G INDUSTRy SY D N E Y A. H A LE , E d ito r

New York, September, 1934

M M B S M iH

CODE

1 9 3 4

Retort Courteous

T h e

T V A

addressed to its outstanding critics in the coal industry, that the Authority is eager to engage in a research program to develop a greater utilization of coal from the Tennessee Valley, moves C. A.

Bockus, president, N ational Coal Association, to observe gently that the T V A power pro­

gram jeopardizes 6,000,000 tons of annual production. This, in a year o f normal activity, would throw 6,000 mine workers out of their jobs. T h e mining industry, which already has planned research on a national scale through Bituminous Coal Research, Inc., naturally wel­

comes any project that has increased consump­

tion as its objective. Sponsorship of such re­

search by an agency actively engaged in a cam­

paign to wreck existing markets for coal, how­

ever, hardly can be expected to move the in­

dustry to wild jubilation.

Underdraw

T h e e x p r e s s i o n

“underdraw” was coined to designate the squeezing of clay from under a big pillar toward its edge, or edges— a move­

ment so commonly recognized that no name seem ed needed for it until it was found how active it was in the very heart o f the pillar.

Underdraw has nothing to do with “draw” ; it does imply the tension o f anything, as draw’

-does, but the word has become so well estab­

lished that search for a more expressive desig­

nation seems futile.

Plastic masses under compression move to­

ward points o f lower pressure. W hat is more natural, therefore, than that the clay would be

squeezed into the goaf, which is often not loaded at all? But if the load on the edge of the pillar is greater than in its heart, that un­

balance would tend to drive the clay not only into the goaf but toward the heart o f the pillar.

In this latter direction it could not wrell travel to any extent, but the tendency to move inward would effectually inhibit any disposition to travel outward. It seems obvious, therefore, that as clay moves from points in the heart of the pillar toward its edges there must be points within the pillar more heavily laden than those at the edge.

T he phenomenon underdraw therefore con­

firms the idea that pressures are greatest some­

where in the pillar and not at the face, and that if safety is sought, headings should avoid these highly stressed areas.

Intermission

W i t h t h e a p p o i n t m e n t

o f John W el­

lington Finch as director o f the U . S. Bureau o f M ines last month the curtain falls on an­

other act in the tragi-comedy which began with the Roosevelt election and rose to a new climax o f absurdity on July 2 when the induc­

tion into office o f the new director was hastily called off on the discovery that his commission had been “held up temporarily because of political objections by P. M . G .” On the basis o f o f training and experience, M r. Finch appears to be well qualified for the post he now holds. Friends o f the mining industry must unite in wishing him every success in re­

storing the Bureau to the position it occupied before curtailed appropriations, decentraliza­

tion and dismemberment, ostensibly undertaken

in the sacred name o f economy, so weakened its service and its influence.

Loud hosannas that the Secretary o f the Interior has snatched the directorship from the patronage bag of the Postmaster General, how­

ever, should not make us indifferent to the fact that the appointment represents a distinct break with the tradition that heads o f tech­

nical bureaus should not fall with a change in national administration. Regardless o f the new incumbent’s admitted qualifications, in the larger sense this break with tradition makes the appointment a political one. W hether there is any greater virtue in M r. Ickes’ poli­

tics than in M r. Farley’s brand remains to be seen. Beyond that, the new precedent having been established, upon another change in ad­

ministration, M r. Finch’s tenure becomes as insecure as that of his predecessor.

Emphasis is placed upon the political aspect o f the situation because, in a technical bureau, policies and plans must flow from the chief of that bureau. I f the position is to be one of the political spoils, long-range planning, so essential in the determination o f a national government policy on mineral resources, be­

comes increasingly difficult. M orale also suffers. It is not too soon for an aroused mining industry to impress upon the politicians o f both major parties that the old tradition and not the new precedent must prevail in the future and that no technical bureau chief should be required to work in the shadow o f the political axe.

Routing

W h o

should receive a report is a question too often left to the man who makes it. I f he makes it to a manager, he is regarded as telling tales. I f he makes it to a superintendent, it may be pigeonholed, if not flouted and disre­

garded. T he man making the report should be able to justify him self for the routing he gives it, and he can keep his action from misrepresen­

tation only by positive orders, given in writing.

H is sole responsibility, if he routes his report as ordered, is for the correctness o f the report.

W ith reports in duplicate or triplicate, his re­

ports get immediate attention, and on prompt­

ness o f reporting depends the value o f any report he may make. W hen a report to the manager is demanded, the superintendent and foreman can regulate his actions to conform

with the fact that the manager has been in­

formed, and he cannot condemn his equal or subordinate for the action he has taken.

Storekeepers kept informed as to the relo­

cation of equipment can keep a record o f the location o f all equipment. Dispatchers prop­

erly informed can be governed in their work by the reports made. W hen writing was an un­

usual accomplishment, written reports were impossible. T oday even the miner can fill requisitions for material. Such written reports can be filed, if the recipient is busy, and used later for making a combined report. W hen forms are furnished, questions can be supplied so that the report maker will not fail to check all items and give answers accordingly and with­

out annoying omissions.

Seasonal Exemptions

I f o b j e c t i o n

to the 7-hour day and the 35-hour week as the norm per shift in bitu­

minous mining still exists, it has ceased to be vocal. But, as the time draws near when fall and winter orders should call for more ton­

nage, particularly from mines leaning heavily upon the domestic market, the question o f sea­

sonal exemptions again becomes pertinent.

Double- or triple-shifting may not be justified by the additional tonnage involved, and em­

ployment o f more men on a single shift, even if practical, may work hardship and injustice to regular workers denied the opportunity o f full-time employment in the spring and summer months. T h e question certainly seems to be entitled to more consideration than it appar­

ently received at the time N R A imposed the new maximums last spring.

Check o f the first 400 codes approved shows that in only ten cases, excluding bitu­

minous coal, was a 7-hour maximum fixed.

M oreover, in each o f these ten cases provision was made for a flexible working week o f 35 to 54 hours. T h at bituminous coal should have been among the few major industries to acquiesce in the establishment o f the shorter work-day and the shorter work-week is a dis­

tinction o f which it may well be proud. It re­

vealed a genuine willingness to go along whole­

heartedly with the recovery movement. But that willingness should not operate as a barrier against consideration o f proper seasonal ex­

emptions which in nowise break down or men­

ace the basic minimums.

336 C O A L A G E —

CONVEYOR MINING

+ Enters Picture in Southern Fields In Response to Changing Conditions

A

m ented w ith co n v ey o r m ining, b u t in A la b a m a on ly d id h an d -lo ad in g into face c o n v ey o rs becom e a re g u la r pra c tic e on a la r g e scale a t several m ines. W ith in th e la s t y ear, how ever, conveyor m in in g h a s m ade trem en d o u s s trid e s in th e g e n e ra l te r r ito r y co m p ris­

in g so u th e rn W e s t V irg in ia , V irg in ia , n o rth e rn T en n essee an d e a ste rn K en ­ tucky. A re c e n t su rv e y of m ines in th is te r r ito r y re p o rte d to be u sin g u n ­ d e rg ro u n d con v ey o rs rev ealed th a t over 100,000 to n s p e r m o n th is th u s being loaded a n d in d ic a te s th a t in a few m o nths th e figure w ill be m o re th an double th a t am ount.

T h e in creased lo a d in g ra te g ra n te d to la b o r by th e code is p o p u larly given a s th e b asic re a so n fo r th is ru s h to con­

v ey o r m ining, b u t in th is su rv e y the p erso n al in te rv ie w s w ith ex ecu tiv es of com panies u sin g co n v ey o rs revealed a n u m b er o f o th e r reaso n s, sev eral of w hich, in som e instances, o u tra n k th a t of red u ced cost. A lth o u g h sev eral com ­ p an ies a d m it a n a ttra c tiv e sav in g , it is sig n ifican t th a t one in s ta lla tio n reputed to be m a k in g a han d so m e red u ctio n in p ro d u c tio n co st w a s p erfected before th e in creased lab o r ra te s w ere in sight.

T h e s u rv e y also rev ealed th a t e x is t­

in g sy stem s of co n v ey o r w o rk in g , as re g a rd s face le n g th an d reco v ery , a re n ow few in n u m b er an d th a t th ree- fo u rth s of the m ines use essentially one system .

N in etee n m in es h av e co n v ey o r equip­

m ent in u se an d officials of m any o th er m ines a r e serio u sly co n tem p latin g its a d o p tio n w ith in a y ear. F o r obvious reaso n s, no a tte m p t w as m ade to obtain a com plete list of m ines fo r w hich co n ­ vey o rs a r e contem plated, b u t a u th o r ita ­ tiv e in fo rm a tio n w as collected fo r eleven m ines w h e re co n v ey o rs a re planned.

F o r room tra n s p o rta tio n , ch ain con­

v ey o rs a re used a t fo u rte e n o f th e m ines, s h a k e r co n v ey o rs a t th re e , a n d both

sh a k e r a n d ch ain ty p es a t tw o. O f th e tw elve in sta lla tio n s m ade since J a n . 1, 1933, tw o a re sh ak er, one is sh a k e r an d chain, an d n in e a re ch ain . T h e p rin c i­

pal reaso n ad v an ced fo r th e selection of the ch ain -ty p e conveyor is th a t it can be rev ersed to c a r r y tim b ers to th e face.

A n o th e r re a so n ad v an ced in sev eral in ­ stan ces is th a t th e m ain ten an ce co st of th is type is low er. A re p o rt is c u rr e n t th a t one m a n u fa c tu re r w ill soon o ffer a rev ersib le sh ak er. A s to th e m ain ­ ten an c e fe a tu re , it should be noted th a t in sev eral in stan ces th e co m p ariso n s w ere based on sh a k e r equipm ent m an u ­ fa c tu re d a n u m b er of y e a rs ago. I t is reaso n ab le to assu m e th a t th e im proved sh a k e r equipm ents now b ein g o ffered can be m a in tain ed a t a m uch lo w er cost th a n th e old er equipm ents.

T h e m in in g system now b ein g fo l­

low ed a t m o re th a n h alf of th e m ines is to d riv e a room 40 to 75 ft. w ide an d 275 to 300 ft. deep, an d ab an d o n th e p illars. R oom w id th depends upon top co n d itio n s an d m ethod of p a y in g the crew . O n ly one of th e m ines w o rk in g the room system is u n ifo rm ly success­

ful in ta k in g th e p illa r w ith th e co n ­ v ey o r upon r e tr e a t fro m th e room . S ev ­ eral o th ers a r e m ak in g th e attem p t, but it is doubtful if th ey w ill m eet w ith success.

B ecause th e conveyors a re used in e v ery in stan ce in low coal, and in m an y cases in coal, o r in a split, so th in as to hav e been co n sid ered u n p ro fitab le to w ork, th e re h as been a tendency on th e p a r t of the lan d lo rd o r lesso r to red u ce m inim um ro y alties o r lo w er th e p e r­

centage of recovery. In c e rta in cases w h ere th e m in in g com pany o w ns the m in eral th e re is no w o rry ab o u t the sm all p illa rs abandoned. Q u o tin g one e x e c u tiv e : “ W h a t do w e ca re a b o u t the sm all p illa rs left if w e can m in e the room coal cheap eno u g h to m ake m ore to tal p ro fit th a n by ta k in g th e p illa r s ? ”

W h e n p ercen tag e of re c o v e ry is co n ­ sidered the longface in sta lla tio n s are

o u tsta n d in g . T h e face len g th s a t these m ines ra n g e fro m 95 to 300 ft. O n the 300-ft. face the w o rk is p ro g re ssiv e an d in su res to tal reco v ery of th e panel. In th e o th e r in stallatio n s, relativ ely sm all p illa rs a re left betw een w ide room s.

T h e s e p illa rs c ru s h as th e top caves fro m one to th re e room s back of the place b ein g w orked. A p p a re n tly only a sm all p e rc e n ta g e of th e m ines h av e roofs sufficiently s tro n g close above th e coal an d y e t sufficiently w eak above so th a t falls o ccu r a t th e r ig h t tim e a n d to suffi­

cien t h e ig h t to m ake th e m ethod based on the w ide room an d n a rro w safety p illa r w orkable.

T h e ra n g e of coal thicknesses being w orked w ith con v ey o rs a t th e nineteen m ines is 18 in. to 52 in., b u t th e lo w er lim it of re g u la r w o rk in g is 22 in. T h e 18-in. coal th a t is w o rk ed a t one m ine o ccu rs only th ro u g h ro lls in a seam th a t ru n s up to 48 in. T h e a v e ra g e th ic k ­ n esses in inches a t each o f th e 19 m ines a r e : 22, 29^, 30, 32, 32, 33, 33, 3 3 i, 36, 36, 37, 37, 39, 40, 40, 42, 42, 42 a n d 52.

I n a n u m b er of cases, th e m a jo r re a ­ son fo r th e in sta lla tio n has been diffi­

cult to sep arate, b u t a n a tte m p t to classify th e first, o r m ost im p o rtan t, re a so n g iv es resu lts, in n u m b er of m ines, a s fo llo w s: five m ines, speed o f p ro ­ d u ctio n o r developm ent to fill o rd e rs to re g u la r cu sto m ers o r han d le new co n ­ tr a c ts ; th re e , lo w er p ro d u ctio n c o st;

th ree, depletion of th ic k e r seam , m ak ­ in g it n e cessary to begin m in in g coal too th in to w o rk w ith c a rs in ro o m s;

tw o, p ro d u c tio n o f clean er coal ; tw o, p ro d u c tio n of la rg e lum p a n d /o r a h ig h e r p e rc e n ta g e of p re p a re d sizes ; one, w eak top, p re v e n tin g th e use of c a rs on tra c k p arallel to slabbing fa c e ; th re e , m iscellaneous reasons.

L o w e r cost of m in in g figures in p ra c ­ tically e v ery case, a lth o u g h m an y of th e in stallatio n s a r e as y e t so new o r in ­ com plete th a t th e re a l a d v a n ta g e o f low cost h as n o t been a ttain ed . A t one m ine a h ig h e r cost ap p e a rs c e rta in , b u t th e in creased re a liz a tio n by re a so n of la r g e r coal exceeds th e d ifference.

M o th e r c o n v ey o rs a r e p lanned fo r sev-

September, 1934

— C O A L A G E 337

v no h io / ) 'o

* Hun+ing+on

C h a r le s to n

O /

•5

W E S T

O Logcin

U C K Y

X? W i l l i a m s o n

/a*Y

V I R G I N I A

B e c k l e y

S. °»7 9* .10

IS

H a z a rd

Harlan o

16 o P i k e v i l l e o Welch

" \ B l u e f i e l d

11

¿5 r . / 12

f * / 3 V I R G I N I A . M i dd les bo rooj^ '~~~'

T E N N E S S E E

gKnoxville

1- R iverton Coal Co., Crown Hill 2 - G reat Kanawha Barge Line, Crown Hill 3 - W in/frede Collieries, W inifrede

4 - d k h o r n Piney Coal M ining Co., Powellton 5 - Gau/ey Mountain Coal Co., P o s te d 6- Saxman Coal 8 Coke Co., Saxman 7- Blue d a y L um ber Co., Blue day 8 - C.C.B. Sm oke/ess Coal Co., Glen W hite l 9 - C.C.B. Smokeless Coal Co., Stotesbury fib - Wihcfing G u lf Collieries ~

i l l - d e w e d R id g e Coal Corp., dew ell Ridge

■ 12- S to n e g a Coke & Coal Co., Derby ) 13- Blue D iam ond Coal Co., B onny B lue ' 14- P ruden Coal & Coke Co., P ruden

15- U n ited S t a t e s Coal S Coke Co., Lynch 16- A ja x Coal Co., Bulan

17- H ardy -Bur/ingham Minina Co., Hardburlv/

I8~ Weds E lkhorn C oal Co., Garret / 19- L eckie Collieries Co., A t lex

L ocations of C onveyor M ines in G en eral T e rrito ry C overed by Survey.

eral m ines, b u t as y e t a re used in only tw o. In each in stan ce, these m o th er conveyors a re belts. I t is th e g en e ra l o pinion th a t th e low est co sts a re realized only w ith a com plete u n it of fo u r to six room co n v ey o rs feed in g on to a m o th er conveyor installed on the panel heading.

F o u r of the co n v ey o r in stallatio n s a re in n ew m ines opened in low c o a l; fo u r a re in old m ines in te r r ito r y so low th a t it w as skipped in the re g u la r m in in g ; tw o a re in old m ines in te r r ito r y w h ere th e p a rtin g is so th ick as to re n d e r ta k ­ in g both benches, o r splits, unprofitable, th ereb y lim itin g m in in g o p e ra tio n s to b u t one b e n c h ; an d one in a m ine w h ere one bench in stead of tw o is w orked, be­

cause th e one bench pro d u ces a m uch h ig h e r q u a lity coal th a n both.

S ix m in es o u t of th e n in eteen pay the face w o rk e rs a d ay ra te , o th e rs pay on a p ie c e -ra te b asis su ch as p er foot of face loaded, p e r c u t o r fo r c o n tra c t o r g a n g w ork. I t is sig n ifican t th a t tw o m ines recen tly w ere ch an g ed fro m th e d a y -ra te to p iece -rate basis. T h is action coincides w ith th e o p in io n voiced by th e m a jo rity of o p e ra to rs th a t th e day ra te is n o t successful. A n ex cep tio n is one m ine w h ere th e to n n a g e p e r m an, in ­ clu d in g th e fo re m a n of th e u n it, is in the h ig h e s t b rack et. A t th is m ine, face m en, e x clu d in g th e m ach in e m an and h elp er, a r e p aid th e unskilled la b o r rate.

A lth o u g h $4.76 is th e m inim um 7 -h o u r ra te specified in sev eral d is tric ts fo r co n v ey o r face m en, th e w o rk e rs a re able to m ake $6 to $7 p er s h ift a t ce rta in

m ines w h e re th e pay is on a n accom ­ p lishm ent basis. In sev eral of th e fields th e w a g e a g re e m e n ts m ake no m en tio n of co n v ey o r loading.

P ro d u c tio n s p e r sh ift p er m a n a t th e face, w h ich includes th e w o rk of co n ­ v ey o r ex ten sio n , c u ttin g , d rillin g , shoot­

ing, tim b e rin g a n d lo ad in g o n to th e co n ­ v eyor, v a ry fro m 4 to n s to 16 to n s a t th e v a rio u s m ines. C o nveyor w o rk in one m ine w ith coal 31 to 33 in. th ick pro d u ces a n a v e ra g e of 10 to n s p er m an p er sh ift, in clu d in g th e fo rem an o f the u n it an d th e m o to rm an w ho d eliv ers the coal to the p a rtin g .

T e n of th e m ines th a t w o rk room s up to 70 ft. in w id th o p e ra te tw o sh ifts an d th re e o p e ra te th r e e sh ifts. O f th e ten, how ever, tw o a re a b o u t to be ch an g ed to th re e sh ifts. T h e co n v ey o r o p e ra ­ tio n s em p lo y in g 180- to 300-ft. faces load on one sh ift a n d re s e rv e th e n ex t sh ift fo r c u ttin g , co n v ey o r m o ving, tim ­ b e rin g a n d o th e r activ ities. A lth o u g h m ost of th e o p e ra to rs a g re e th a t c o n ­ vey o rs m u st be w o rk ed tw o sh ifts to m ake th e in v estm en t in co n v ey o r e q u ip ­ m ent an d e x tr a m in in g m ach in es pay, th e re is a w ide d iv e rsity of o pinion as to w h e th e r it is p ra cticab le to op erate th re e sh ifts. A p p a re n tly it can be done in m o st cases, b u t con sid erab le p lan n in g m ay be n ecessary in o rd e r to w o rk out a sa tisfa c to ry system of d e liv e rin g m a ­ te ria ls an d ta k in g ca re of inspections an d re p a irs betw een shifts.

D u rin g th e su rv ey , o p e ra to rs w ho h a v e h ad ex p erien ce w ith co n v ey o rs

w ere asked fo r th e ir o p in io n s a s to th e h e ig h t of coal below w h ich it w ould pay to equip fo r conveyor m in in g in stead of ta k in g m ine c a rs to th e face. T h e a s ­ su m p tio n w as a ro o f c o n d itio n fav o rab le to con v ey o rs an d th e av a ila b ility of m odern lo w -h e ig h t c a rs a n d locom o­

tives. O n e w as of th e o p in io n th a t co n ­ v ey o rs e n te r th e p ic tu re only w hen the coal is below 30 in., b u t m an y a g re e d on a h e ig h t of a p p ro x im a te ly 36 in. A few feel c e rta in th a t c o n v ey o rs show econom y below 40 in. C h a ra c te r of the coal, as d eterm in ed by size of lum p to be loaded o r dem anded by th e m ark et, h as m uch to do w ith th e h e ig h t w ith in w hich coal can be loaded in to a m in e c a r w ith o u t ta k in g top o r bottom in th e room .

A p p a re n tly th e re is need fo r m ore e x p e rim e n ta tio n a n d stu d y o f th e m ost ad v an ta g eo u s d ep th of u n d e rc u t fo r co n ­ veyor m in in g . In m an y cases, co n sid ­ e ra tio n s o f sh o o tin g o r b re a k in g dow n th e coal, lum p p e rc e n ta g e desirable, and g en e ra l .action of th e face d ic ta te a defi­

n ite ra tio of u n d e rc u t d e p th to coal thickness. H o w e v e r, th e re a re , a p ­ paren tly , m an y in stan ces w h ere these . c o n sid e ra tio n s do n o t apply o r a t least w h ere th ey m ay be o u tw eig h ed by the fa c to r of d ep th of c u t th e crew can clean up once o r tw ice p er sh ift. T h e e x ­ p erien ce of one o p e ra to r in d icates th a t th e sam e c rew can clean up tw o 8-ft.

cu ts p e r sh ift alm o st a s easily a s they handled tw o 5 i- ft. cu ts previously.

O f th e eleven m ines m entioned as can d id a tes fo r convevor m in in g , in s ta l­

338

Left, In d icatin g M e th o d o f W o rk in g Shaker Conveyors at W in d in g G u lf C ollieries M in e ; R ig h t, P la n of W o rk in g a t H ard b u rly . la tio n s a r e classified a s fo llo w s: F o u r

w ill be in new open in g s in th in seam s, tw o a re p ro je c te d to reduce m in in g cost, one to in crease lum p a n d d ecrease cost, one to speed d riv in g ro o m s so d ra w s la te can be held in place, one to m ine one sp lit w h ere th e p a rtin g is too th ick to handle, one to m ine te r r ito r y skipped as being too low, a n d one fo r speeding the d riv ­ in g o f h ead in g s fo r a d ra in a g e p ro je c t in 36- to 48-in. coal.

A t n u m ero u s m ines, th e th ic k e r seam first opened is n e a rin g ex h au stio n , w ith the re s u lt th a t th e com panies m u st soon tu r n to a th in n e r seam av ailab le on th e p ro p e rty . T h is is p a rtic u la rly tr u e of th e W in d in g G ulf field, w h e re m o st of the m ines w e re opened a b o u t the sam e tim e in th e B eckley seam . O ne o f these m ines w as finished w ith in th e last m onth, an d sev eral o th e rs w ill be about th ro u g h in tw o y e a rs. T o m o st of these p lan ts th e P o c a h o n ta s N o. 3 seam , ly in g a t lo w er elev a tio n a n d less th a n 4 ft.

in th ick n ess, is available. C onsiderable co re d rillin g is now being done in the field to p ro v e a re a s to be opened. In n e a rly e v ery case it is the in ten tio n to o p e ra te w ith conveyors.

A s to size of th e n in eteen g o in g co n ­ v ey o r in stallatio n s, th e to ta l o u tp u t per d ay fro m co n v ey o rs a t th ese m ines ra n g e s fro m 40 to 2,000 to n s. T h e a c ­ com p an y in g m ap in d icates th e a p p ro x i­

m ate locations of th ese o p eratio n s.

A t th e R iv e rto n C oal Co. m ine, C row n H ill, W . V a., th e C o a lb u rg seam had been n e a rly ex h au sted , w ith th e resu lt th a t m in in g w as no lo n g e r profitable.

In M ay , 1933, a n ew o p en in g w as s ta rte d in th e C e d a r G ro v e seam , 34 to

cuts a re loaded in 24 h o u rs, a v erag in g 54 ft. of p ro g re ss. R oof is a h a rd blue slate an d only a few safety p osts a re needed in th e room s. T h e m ine bottom also is fav o rab le. In n a rro w w ork, fo u r face m en p ro d u ce 40 to n s p er sh ift an d in room s seven face m en pro d u ce 84 tons. T h is includes conveyor ex ten sio n , c u ttin g , d rillin g , shooting, lo ad in g an d tim b erin g .

In J u ly a n o th e r o p en in g w as m ade in th e B elm o n t seam , c o n sistin g o f a sp lin ty coal 42 in. th ick a n d free of p a r t­

ing. A lth o u g h th e sh a k e r conveyors h av e been q u ite sa tisfa c to ry in th e other, seam , ch ain con v ey o rs h av e been in ­ stalled in th e B elm ont. P re s e n t e q u ip ­ m en t co n sists of one 300-ft. room con­

v ey o r a n d tw o 52-ft. face conveyors.

C h ain c o n v ey o rs w ere given th e p re fe r­

ence because of p ro v isio n fo r rev ersal fo r h a u lin g tim b ers, slig h tly g re a te r cap acity an d p o sitiv e action.

B ecause of ad v erse n a tu ra l conditions, a n e ig h b o rin g sh ak er-co n v ey o r in s ta lla ­ tion, a t th e th e G re a t K a n a w h a B a rg e L in e m ine, h a s n o t been so successful.

A b o u t M ay 1 th e re w as in stalled one 300-ft. sh a k e r u n it to w o rk in th e 42-in.

D o ro th y seam u n d e r ten d er top. T h e conveyor w as first trie d in n a rro w w ork an d is now b ein g trie d in d riv in g a 30-ft. room an d b rin g in g back the p illar on a n a n g le face a b o u t 60 ft. long. B ad top, w a te r an d local g ra d e s h av e been th e p rin c ip a l difficulties. T h e conveyor w ill n o t m ove th e w et coal up th e a d ­ v e rse g ra d e s encountered. A b o u t 25 to n s p e r sh ift w as th e co n v ey o r p ro d u c ­ tio n in n a rro w w ork.

I n 1931, a new com pany, th e W in i-

Scptember, 1934

— C O A L A G E

conveyor

i - 5 - f t . p i l l a r ( a b a n d o n e d )

Plan o f W o rk in g at Leckie C ollieries Co.

O peratio n .

36 in. thick a n d free of p a rtin g . T h e C edar G rove is a h ig h -v o latile coal an d a c o n tra c t w as secured fo r d eliv ery of

10.000 to n s p er m onth to a chem ical concern. B ecause of the th in n e ss of the seam an d the necessity fo r speed to fill the c o n tra c t, conveyor m in in g w as adopted. . E q u ip m en t consists of th ree 10-hp. sh a k e r u n its, each equipped w ith 400 ft. of p an s an d on e 90- an d one 30- deg. an g le tu rn . T h e 30-deg. tu rn s a re angle sw ivels ad ju sta b le betw een 0 and 30 deg.

R oom s a re d riv en 70 ft. w ide, leav in g p illars as n a rro w as is deem ed safe.

T h ese p illa rs a r e abandoned. T h e face pan is d riv en fro m th e room conveyor by m eans of th e 90-deg. tu rn . A b o u t 12.000 tons p er m onth is b ein g loaded w ith th e fo u r conveyor u n its, an d fo r th e m ost p a r t th ese a re w o rk ed th re e shifts. In n a rro w w o rk (2 4 -ft.) six

F o u r m o n th s a g o th e B lue J a y L u m ­ b e r Co., B lue J a y , W . V a., p u rc h a se d a c h a in u n it c o n sistin g of one 300-ft.

room co n v ey o r a n d a 30-ft. face con­

v eyor. T o d a te th is co n v ey o r h as been used in both n a rro w w o rk an d in room s up to 40 ft. in w id th . T h e p u rp o se has been e x p lo ra tio n w o rk th ro u g h B eckley seam te r r ito r y w h e re th e coal v a rie s fro m 18 to 40 in. in th ick n ess. T h e m ine h a s been o p erated b u t a few days p e r m onth an d consequently th e con-*

v ey o r to n n ag e h as been sm all.

block of coal. T h e blocks a re developed by n a rro w room s d riv e n in p a irs w ith ch a in p illa rs betw een. T h e se ch ain p il­

lars, se rv in g as a p ro te c tio n betw een blocks, a r e ab an d o n ed . S ix to 8 in. of d ra w sla te com es dow n a n d is shoveled back o v er th e co n v ey o r. A b o v e th a t, in m ost places, is a b o u t 4 ft. o f w eak slate.

A bout 30 tim b e rs p er c u t a re se t on th e 180-ft. face. C u ttin g , co n v ey o r m oving an d tim b e rin g a r e done o n one s h ift an d loading on a n o th e r sh ift. S ix lo ad ers clean up a face in one shift. In th is fred e C o llieries, reopened th e old W in i-

fre d e ( W . Y a .) m ine, u sin g sh a k e r co n ­ vey o rs to ta k e th e 30-in. sp lit of coal in a te r rito ry w h ich h ad n o t been m ined because th e p a rtin g w as too th ick to handle. E q u ip m en t co n sists o f th re e 10-hp. d riv e e n g in es a n d tw o 300-ft.

p a n lin es w ith 90-deg. tu rn s . F a c e s up to 8 0 ft. w id e w ere trie d , b u t w hen a sp ace 8 0 x 8 0 h ad been m ined th e top fell a n d th e face w as l o s t N o w th e w o rk is confined to 55-ft. room s an d no a tte m p t is m ade to re c o v e r p illars. T h e g re a te s t difficulty h as b een in face p re p a ra tio n . C u ttin g is done in a la m ­ in a tio n below th e coal a n d th e re fo re e v e ry p a rtic le o f th e c u ttin g s m u st be rem o v ed fro m th e k erf. S c ra p in g th is o u t a n d sh o v e lin g th e w aste m a te ria l back o v e r th e co n v ey o r tak es m uch tim e.

T h e m en av ailab le in th e lo cality a re n o t accustom ed to low coal a n d th is h am p ers th e ir a c c o m p lis h m e n t I t h a s n o t been easy to find h ig h -class m achine m en w ho a r e w illin g to lo ad coal.

A t P o w ellto n , W . V a., th e E lk h o rn P in e y Coal M in in g Co., a K o p p ers com ­ p an y , b eg an to use ch ain co n v ey o rs e x ­ ten siv ely in th e 32- to 34-in. bottom sp lit o f th e P o w ellto n seam w h e re th e p a rtin g betw een sp lits is too th ick to h an d le, in N o v em b er, 1933. C onveyors a r e used in bo th n a rro w w o rk an d room s, an d a s y et n o a tte m p t h as been m ade to reco v er p illars. E q u ip m en t co n sists o f tw elve room c o n v ey o rs 310 ft. lo n g a n d , 30 face conveyors. C on­

v ey o r u n its a r e w o rk ed tw o shifts.

F o r a b o u t five y e a rs th e G auley M o u n tain C oal C o., A n sted , W . V a., h as e x p erim en ted w ith c h a in conveyors an d w ith sh a k e r con v ey o rs in 36- to 38-in. coal. T h e m in e-car equipm ent is 23 in. h ig h , w h ich u n d e r th e local co n d itio n s w ill allow th e m in in g of 36-in. coal w ith o u t ta k in g y a rd a g e in ro o m s; th e re fo re little o r n o o v er-all cost a d v a n ta g e has been fou n d w ith conveyors. A t p re s e n t tw o 400-ft.

ch a in con v ey o rs a r e in use d riv in g n a r ­ ro w w o rk w h e re y a rd a g e w ill be tak en la te r w ith th e s h a k e r co n v ey o r o r p e r­

h ap s w ith th e slu sh e r-ty p e sc ra p e r.

T h e low est coal mirled re g u la rly w ith co n v ey o rs is a t th e S a x m a n C oal &

Coke Co. m ine, S a x m a n , W . V a., w h e re th e S ew ell seam ru n s up to 36 in. in h e ig h t b u t in places th in s to a few inches. H e ig h ts dow n to 22 in. a re w o rk ed re g u la rly w ith ch ain co n v ey o rs a n d fo r th e w o rk th e n ew -ty p e m in in g m ach in es 16 in. h ig h a re used. T h e first co n v ey o r u n it w e n t into serv ice in 1929, an d since th a t tim e tw o m o re u n its h a v e been added, th e la st one a b o u t tw o y e a rs ag o . R oom co n v ey o rs a re 300 ft.

a n d face co n v ey o rs a re 30 f t long.

R oom s a r e d riv e n 45 ft. w ide, a n d the p illa rs, w h ic h a r e abandoned, a re le ft as n a rr o w as possible co n sisten t w ith p ro ­ tectio n . S ix m en w o rk on th e 45-ft.

face a n d one a t the lo ad in g head. S ix ­ teen to e ig h te e n posts a re set fo r each 7 - f t cut.

T h e C. C. B . S m okeless Coal Co., a n ­ o th e r K o p p e rs com pany, h a s h ad about a y e a r ’s ex p e rie n c e w ith c h a in co n ­ v e y o rs in its G len W h ite ( W . V a .) m ine. U n til recen tly , tw o room co n ­ v ey o rs an d five 12-ft. face co n v ey o rs w ere in use. In a d d itio n , th e re w ere on h an d an d scheduled fo r in sta lla tio n d u r ­ in g the la tte r p a r t of A u g u s t tw o a d d i­

tio n al ro o m con v ey o rs, tw o 35-ft. face c o n v ey o rs a n d one g a th e r in g o r m o th er conveyor. T h e B eckley seam , 30 to 44 in. th ic k a n d c o n ta in in g a 0-3-in. p a r t­

ing, is o p erated . R oom s a re d riv en 40 ft. w ide, 200 to 300 ft. deep, a n d th e p illa r is b r o u g h t b ack im m ediately w ith ­ o u t m uch difficulty. A sin g le sh ift is w o rk ed an d th e le n g th of c u tte r b a r used is 8 ft. D r a g sc ra p e rs on lo n g faces h a v e been u sed in th is sam e m ine fo r a n u m b er of y ears.

C o n v ey o r w o rk in th e S to te sb u ry N o.

8 m in e of th e sam e com pany d ates back to 1926, b u t th e m in e w as s h u t dow n f o r sev eral y e a rs b efo re b ein g reopened a b o u t Ja n . 1, 1934. T h is m in e is in the P o c a h o n ta s N o. 4 seam , 39 in. th ick an d fre e of p a rtin g s . C h ain co n v ey o rs a re in use a n d these co n sist of fo u r room con v ey o rs, seven 12-ft. face co n v ey o rs an d tw o 35-ft. face conveyors. In A u g u st th e re w as b ein g in stalled a n a d ­ d itio n al ro o m conveyor a n d a g a th e r in g conveyor. T h e w o rk is d ouble-shifted.

C u tte r-b a r le n g th is 64 ft. R oom s a re d riv e n 40 ft. w ide, an d p illa r e x tra c tio n still o ffers difficulties.

A b o u t 1^ y e a rs ag o , th e W in d in g G ulf C ollieries p u t tw o sh a k e r co n ­ v ey o rs into use in th e N o. 1 m in e in a 5 0 0-acre tr a c t of 28- to 31-in. top bench B eckley coal. F o u r s h a k e r u n its a re now o p e ra tin g , th e la s t one h a v in g been in stalled a b o u t six m o n th s ago. T h e co n v ey o rs a r e u sed on 180-ft. angle faces, tw o of w hich b rin g back a 200-ft.

section of tire m ine th e lo w er bench of coal, 14 in. thick, is se p a ra te d fro m th e o th e r b y 12 to 18 in. of p a rtin g . W ith the old eq u ip m en t of cars, a b o u t 40 in.

is th e m inim um h e ig h t of ro o m s into w hich c a rs can be ta k e n fo r h an d - loading.

T h e p rin c ip a l re a so n s fo r tr y in g co n ­ v ey o r m in in g w e re to g a in ex p erien ce, as th e com pany ow ns a la rg e tr a c t of undeveloped lo w -seam coal, a n d to g e t a h ig h e r p e rc e n ta g e of p re p a re d sizes. A la rg e in crease in p re p a re d sizes h as been obtained. O n ly a few v ery lig h t sh o ts a re fired, th ese as a s ta r t fo r th e m en in w e d g in g dow n th e coal. O ne d ra g sc ra p e r is u sed to d riv e n a rro w w o rk . E x c e ssiv e slack p ro d u ctio n , due to th e fria b le n a tu re of th e low -volatile coal, w as th e p rin c ip a l re a s o n fo r the lim ited use of sc ra p e r conveyors. B e­

cau se o f in creased re a liz a tio n , the sh ak e r-c o n v e y o r w o rk is co n sid ered a success.

R ed u ctio n of cap acity by re a so n of th e 7 -h o u r d ay an d 5-day w eek, re s u ltin g in fa ilu re to fill o rd e rs to re g u la r cus­

to m ers, w as th e re a so n b ack of the c h ain -co n v ey o r in s ta lla tio n a t th e Jew ell R id g e C oal C o rp o ra tio n m ine, Jew ell R id g e, V a . I t w a s n e c e ssa ry to speed pro d u ctio n , a n d th e first co n v ey o rs w ere in stalled in M ay of th is y e a r. T h e re a re no w in use s ix room co n v ey o rs a n d six face conveyors, all c h a in type, a n d one m o th er co n v ey o r w ith a 26-in. belt.

T h e coal is 40 to 44 in. th ick and c a rr ie s 2 to 3 in. of d ra w sla te . T h e bottom is a bony m a te ria l. W ith m ine c a rs, c u ttin g w a s done in th is bottom , b u t w ith c o n v ey o rs it is done in the coal. R oom s a r e d riv e n 45 ft. w ide a n d 25-ft. p illa rs a re left. T h e room le n g th is 300 ft. I t is th e idea to com ­ plete tw o cuts p e r sh ift, a n d th re e sh ifts w ill be w orked if possible.

340 C O A L A G E —

T h e D erb y ( V a .) m ine of the S to n eg a Coke & Coal Co. is w orked exclusively by co n v ey o rs a n d is the la rg e st p ro d u c e r of co n veyor-m ined coal studied. In 1930, c o n v ey o rs w ere put to w o rk a t D e rb y in a new o p en in g in a 36-in. seam ly in g below th e h ig h seam . E a rly e ffo rts w e re based on the use of belts on lo n g faces. F o r a w hile tw o 400-ft. faces m ak in g a block 800 ft.

wide w e re advanced. A s t r o n g ' ro o f w hich refu sed to b reak an d reliev e the w eig h t cau sed ab an d o n m e n t of th is m ethod. A t p resen t, room s a re d riv e n 75 ft. w ide a n d the p illa rs a re left in place. F a c e conveyors a re of th e ch ain type, room c o n v ey o rs a re equipped w ith 18^-in. belts a n d m o th e r co n v ey o rs w ith 26-in. belts. C uts a v e ra g e 5 i ft. and ab o u t 18 p o sts a re se t p e r cut. F iv e m en w o rk a t each face an d u n d e r fa v o r­

able con d itio n s com plete tw o c u ts per shift. T h e w o rk goes on fo r th re e sh ifts a day.

E a r ly th is y e a r a co n v ey o r w as p u t into use in 40-in. coal a t the M ayflow er m ine of the B lue D iam o n d C oal Co., B onny Blue, V a. P re s e n t equipm ent consists of one c h ain -ty p e room co n v ey o r an d one c h ain -ty p e face conveyor. R oom s a re being d riv e n 75 ft. w ide. A s y e t th e w o rk is only e x p e rim e n ta l; th e re fo re no idea has been form ed as to th e p ra c tic a b ility of ta k in g p illars. Speed of developm ent an d lo w er m in in g costs a re th e p rin cip al o b jects in g o in g to co n v ey o r w o rk . If the w ork is successful it is th e in tention to in stall e ig h t room u n its an d one m o th er belt conveyor.

S ince 1929 a sh ak er co n v ey o r on a 300-ft. face h as been o p erated by the P ru d e n C oal & C oke Co., P ru d e n , T enn.

It is novv in serv ice in Jellico coal, 30 to 42 in. in th ick n ess a n d topped by 6 to 8 in. of d ra w sla te , 4 to 5 ft. of w eak slate an d , above th a t, a 6- to 10-in. seam of coal. S teel ja c k s a re used, an d the roof b reak s a fte r each cut. N o shoot­

ing is done on th e w all an d th e loaders a re paid p er foot of face w id th loaded.

P e n d in g com pletion of a new cleaning p lan t now u n d e r w ay, th e m ine h as been on s h o rt tim e fo r sev eral m onths.

A rtic le s d e sc rib in g th is co n v ey o r w o rk ap p eared in Coal A g e , M ay, 1931, p.

234, an d M ay, 1932, p. 185.

In A u g u st, th e U n ite d S ta te s Coal &

Coke Co. received a t L ynch, K y., th re e ch ain -ty p e room con v ey o rs fo r use in m in in g a 40-in. top sp lit in a section w h ere a p a rtin g ap p eared an d th ick ­ ened to 18 in. C o v er ru n s as h ig h as 2,000 ft. a t th is o p e ra tio n a n d bum ps o ccu r r a th e r freq u en tly . I t is expected th a t th e co n v ey o r w o rk w ill be confined to ra th e r n a rro w room s.

A n o th e r A u g u s t in sta lla tio n w as th a t of the A ja x Coal Co., B u lan , K y., w hich put in serv ice one 300-ft. ch ain -ty p e room co n v ey o r an d one 60-ft. chain- type face conveyor. T h is equipm ent w as installed in th e 32-in. H a z a rd N o. 4 coal, in th e w o rk in g of w h ich top w as tak en in the ro o m s to g a in h e ig h t fo r

loading d irectly into m ine cars. O b ­ jectiv es in g o in g to conveyors w ere co n cen tratio n of w o rk in g s to reduce cost and to obtain m ore block coal.

S h a k e r conveyors have been used in the H a z a rd N o. 7 seam since 1927 by the H a rd y -B u rlin g h a m M in in g Co., H a rd b u rly , K y. A s m any as six sh ak ers on 275-ft. faces h ave been in o p eratio n a t one tim e, b u t a t p resen t only one is in re g u la r use. T h e re g u la r system of w o rk in g , both w ith an d w ith o u t co n ­ veyors, is to develop a panel by d riv ­ ing room s 15 to 18 ft. w ide an d 275 ft.

deep on 80-ft. centers, each room being cut th ro u g h in to th e n e x t panel h e a d ­ ing. T h e room is th en w idened by suc­

cessive slabbing cuts, w o rk in g b ack in the d irectio n of the room la st w idened.

W h e n a cu t b reak s into a n y of a series of pockets m ade alo n g one side of each room as it is d riv en in th e n a rro w , w o rk in the room is stopped an d the pocketed p illa r a d ja c e n t to th e m in ed -o u t a re a is abandoned. S oon a fte r a room is com ­ pleted the top falls an d the p illa r stum ps betw een th a t room an d the p reviously fallen a re a a re crushed.

T h e coal is 52 in. thick, free of p a r t­

ing an d is topped w ith 12 to 24 in. of d raw slate. O rd in a ry ro o m -an d -p illar w ork w as not successful because w e ig h t caused c ru m b lin g of th e d ra w sla te an d resulted in d irty coal. W ith the lo n g - face plan th e re is n o t sufficient w eig h t on the face to crum ble the d raw slate.

O rd in a rily a tra c k is m ain tain ed parallel to th e face to accom m odate m ine c a rs fo r a load in g crew . O nly w h ere th e roof is to o w eak to allow sufficient open space fo r a tra c k is a conveyor su b sti­

tuted. T h e co n v ey o r a t th is m ine is looked upon p u rely as a tra n s p o rta tio n m edium re q u irin g less w id th th a n tra c k and cars. M ain ten an ce of the old-type sh ak er equipm ent h as been so h ig h as to lim it its continued ex ten siv e use in the m ine.

T h e one conveyor now in o p eratio n a t H a rd b u rly is w o rk in g u n d er about 400 ft. of cover. A t presen t the e ig h t lo ad ers w o rk in g on th e face a re being paid a g a n g ra te because th is p a rtic u la r g ro u p w orks well to g e th e r an d p refers th a t m ethod. A s a w hole the com pany has found th a t p a y in g p er foot of face is th e m ost sa tisfa c to ry m ethod.

In F e b ru a r y of th is y ear the W ells E lk h o rn Coal Co. installed one ch ain u n it co n sistin g of a 300-ft. room con­

veyor an d a 42-ft. face conveyor, the p rin c ip a l o b je c t being to load clean er coal fro m the E lk h o rn N o. 1 seam , 3 3 i in. thick. W ith c a r m ining, c u ttin g is done in th e bottom , w hich is a ra th e r soft m a te ria l, an d 6 to 12 in. of th is b o t­

tom is tak en up in room s. W ith con­

v ey o r m in in g th e c u ttin g is done in th e coal. O n e of the p rin cip al difficulties is a to ¿->n. v ein of slate n e a r th e cen te r of the bed to w hich th e coal sticks.

R oom s a re d riv e n 54 ft. w ide a n d the p illa rs (2 0 ft. w id e ) a r e abandoned. T h e u n d e rc u t is 6 ft. an d tim b ers a re set on 6-ft. ce n te rs each w ay. T w o 7 -h o u r sh ifts a re w orked, an d th re e sh ifts a re not co n sid ered p racticab le. B ecause th is m ine is equipped w ith c a rs only 20 in. h ig h (1 2 in. a t th e back e n d ) , w ith a cap acity of 2£ tons level full, an d because of ad v e rse p a rtin g conditions, the conveyor h as as yet n o t show n econom y. E x p e rie n c e h as been lim ited, how ever, because of slack ru n fo r th e la st tw o o r th re e m o n th s. U n d e r the local co n d itio n s en co u n te red it is calc u ­ lated th a t to show an econom y th e con­

v ey o r u n it w ould h ave to han d le 60 tons on each of tw o sh ifts p e r day, an d th a t th is could be accom plished w ith m ore fav o rab le conditions.

L eckie C o llieries Co., A flex, K y., on th e o th e r h an d , finds conveyor w o rk an o u ts ta n d in g ly successful d e p a rtu re fro m old m ethods in w o rk in g th e 32-in. P o n d C reek seam . T h e p rim a ry o b jectiv e in s ta rtin g conveyor w o rk la s t O cto b er w as to o ffer th e m ark et a h ig h er-q iiality coal. L o w er m in in g cost w as th e sec­

o n d a ry o bject, also being a tta in e d . S e p ­ a ra te d by 8 in. of bone a t th e top of the 32 in. o f h ig h -g ra d e coal is 4 to 5 in.

of lo w -g rad e coal. W ith conveyor m in­

ing th is top coal is not taken.

R oom s a re d riv e n 95 ft. w ide w ith o u t n a rr o w necks, a n d p illa rs ab o u t 5 ft.

w id e a re left betw een room s. U p to A u g . 15, one ch ain u n it, co n sistin g of a 190-ft. room co n v ey o r an d a n 85-ft. face conveyor, w as in use. S in ce th a t d a te a n o th e r u n it h a s been added. T w o 7- h o u r sh ifts h a v e been th e p ractice, b u t it is th e in ten tio n to tr y th re e sh ifts soon.

A face crew co n sists o f e ig h t m en, in­

c lu d in g fo rem an an d locom otive ru n n e r, all paid d ay ra te s. T im b e rs a re set on 3-ft. cen ters, tw o ro w s p er 6-ft. u n d e r­

cut. Close beh in d th e face co n v ey o r th e re is k ep t in place lig h tly w edged a ro w of 1 4 x l4 -in . sq u a re tim b ers. T h ese a re ad v an ced w ith each co n v ey o r m ove.

A lth o u g h panel e n trie s h av e a lre a d y been developed in a co n sid erab le t e r r i ­ to ry w hich w ill be co n v ey o r m ined, and alth o u g h th ese e n trie s a r e h ig h enough fo r tra c k and cars, th e com pany in ten d s to install a 1,300-ft. m o th e r conveyor b efore long. A p p a re n tly the w hole p ro ­ d u ctio n of th e m ine w ill be co n v ey o r coal.

September, 1934

— C O A L A G E 341

AIR-SAND PROCESS

+ ci eans Railroad and Industrial Coal A t Chickasaw M ine

C

cretely the stre ss now being placed by in d u s tria l p lan ts an d ra ilro a d s on w ell-cleaned an d w ell-sized coal. A t first, cleaned coal w as so u g h t on ly by m e ta llu rg ic a l an d g a s-m a k in g plants.

T h e n th e public u tilitie s b egan to a p ­ p re c ia te its value, but ra ilro a d s, in d u s­

tr ia l p la n ts a n d b ig h e a tin g in sta lla tio n s fo r a lo n g tim e w ere relativ ely in ­ d iffe re n t to its appeal. N o w ad ay s, few indeed a re th e in sta lla tio n s th a t a re not lo o k in g fo r fuel of h ig h h e a t value and low ash, an d th e dem and is becom ing so in siste n t th a t it can no lo n g e r be ig n o red by co al-m in in g com panies in te r­

ested in p re s e rv in g m ark ets.

S itu a te d in A rm s tro n g C ounty, P e n n ­ sy lv an ia, C h ick asaw m in e a n d village lie n o rth of M a h o n in g C reek and in th e elbow betw een R ed B ank C reek an d the A lleg h en y R iv er. T h is plant, o p erated by th e A lleg h en y R iv e r M in in g Co., em bodies a m ethod of clea n in g k now n as th e a ir-s a n d process, devised by T h o m as F r a s e r an d th e H y d ro ta to r Co. In this, coal is floated in san d w h ich , by p assing a ir th ro u g h it, is' kept in a g ita tio n an d m ade fluid.

T h is C h ick asaw p lan t w as installed by th e coal com pany a fte r lo n g e x ­ p erien ce w ith th e a ir-s a n d pro cess a t C adogan, P a ., w h e re u n ifo rm ly good r e ­ sults w ere o b tain ed o v e r a p erio d of y e a rs. T h e new c le a n in g p la n t had been ru n n in g a b o u t a m o n th w hen th e su m m er d e p ressio n m ade it n ecessary to close som e m ines, and, a s C hickasaw w as lack in g in developm ent u n d e r­

g ro u n d , it w a s decided a fte r a m onth of o p e ra tio n to close th e m ine dow n so as to p u t it in go o d sh ap e fo r th e w in te r dem and, C ad o g an su p p ly in g w h a t m e­

ch an ic ally cleaned coal th e m a rk e t r e ­ q u ired .

A ll th e coal in th e C h ick asaw m ine conies fro m th e L o w e r K itta n n in g , o r M iller, bed, w h ich is 3 ft. 6 in. to 5 ft.

thick. I t is loaded en tirelv by hand in to c a rs w ith a cap acity of 2 tons w hen topped. L ig h t w e ig h t of th e c a rs is 2,200 lb., an d all a re of such h eig h t

th a t they can be used in th e th in n e st of the coal th a t h a s to be m ined.

C a rs com e in tr ip s to th e tipple preceded by an elec tric locom otive, w h ic h a p p ro ach es th e dum p a t low speed. T h e locom otive clea rs th e c a r feeder an d tak es a cro sso v er to the em pty tra c k , leav in g th e fr o n t end o f' th e fr o n t c a r o v e r the c a r feeder, w hich is sh ifted m ech an ically so th a t its p ro n g s in te rc e p t the ax le of the c a r a n d b rin g the tr ip fo rw a rd a c a r len g th . T h e c a r feeder au to m atically re v e rse s an d goes back as soon as it h as fed th e trip the req u ire d d istan ce. T h e w hole trip is th u s m oved fo rw a rd a c a r le n g th a t a tim e to w a rd an d on to a R o b e rts &

S ch aefer ro ta ry dum p. H e re th e c a rs a re d isc h a rg e d one by one, th a t o p e ra ­

tion b ein g ren d ered possible by sw ivel couplings.

H o w ev er, the c a rs m ig h t ru n aw ay u n d er the influence of g ra v ity if it w ere n ot fo r a c a r stop a n d release a b o u t 20 ft. ah ead of the c a r feeder, w h ich holds the tr ip in place as each c a r is dum ped.

A H o w e dial scale w eig h s th e c a rs as th ey a p p ro a c h th e r o ta ry dum p. A t no tim e a re th e c a rs u ncoupled a t the tipple.

Som e of th e c a rs, of co u rse, co n tain coal an d som e rock. T h e coal on le av in g the ro ta ry dum p d is c h a rg e s on to a ch u te w h ich slopes tra n sv e rs e ly acro ss th e tra c k to th e left, an d a fiy- g a te is p ro v id ed w hich, w hen opened fo r the p assag e of a c arlo ad of rock, c a rr ie s th e ro ck to th e r ig h t an d de­

liv ers it into a recep tacle fo r disposal.

T h is, w h en th e m ine is e n tire ly read y fo r o p eratio n , w ill be e ith e r a la r r y or the bucket of an a e ria l tra m w a y . F low D iag ram , C hickasaw A ir-Sand S eparator

S a n d c ircu la tin g elevator

,.■■■ S an d hopper

_ Three-co m p artm en t ' a ir -s a n d s e p a r a to r

.■S lo w e r

LEGEND Raw coal Clean coal •

Sand ...

P rim a ry refuse —

F in a l refuse -o—o-o-o

342 C O A L A G E —

C hickasaw P rep aratio n P lan t In th e w eig h -h o u se is a pipe panel on

w hich a re g ro u p e d th e v a rio u s con­

tro ls w h ich re g u la te th e c a r feeder, car stop an d release, ro ta ry dum p an d fly- gate. T h e w eig h m an can co n tro l these by p re s sin g a p p ro p ria te b u tto n s. C ars leave th e ro ta ry dum p in a solid trip , tra v e lin g a c a r le n g th a t a tim e, till a full tr ip is obtained, w h en th ey a re ru n to th e end o f the tra c k all coupled and read y fo r a tta c h m e n t to w h a t w as the fro n t end of th e locom otive 011 its a rriv a l fro m th e c ro sso v er. A ll e n te rin g rail at the tip p le an d fo r a m ile inside the m ine w eig h s 80 lb. p e r y a rd .

C oal fro m th e ro ta ry dum p, w hich has a cap a c ity of 250 to n s p e r ho u r, is d isch arg ed b y th e c h u te m entioned onto a ru b b e r belt, 3 ft. w id e a n d 200 ft.

lo n g betw een pulley cen te rs, w h ich ru n s in a g a lle ry fro m dum p to p re p a ra tio n plant. A r r iv in g a t th e la tte r, th e coal passes o v er a M a rc u s screen w hich sep arates it into plus 4-, 4x 2 -, and 2x0- in. sizes. T h e plus 4 -in. coal passes ov er a p ic k in g tab le an d tra v e ls to the end o f th e screen table, an d thence by one of tw o lo a d in g boom s to th e ra il­

ro ad tra c k . T h e 4x 2 -in . coal is picked by h an d on tw o o u tr id e r screens and tables, one on e ith e r side of th e low er end of th e sc re e n in g table. A ll the rest of th e coal— 2 in. a n d u n d er— is carried by bu ck et co n v ey o r to th e top of the clean er to w er, w h e re it is deposited in a 15-ton s u rg e bin.

T h is coal is d eliv ered to the cleaner by a fine w ire screen 10 ft. w ide and 8 ft. long, o v e r w h ich all b u t th e -JxO-in.

coal passes. B y a n ec c e n tric d riv e of sm all th ro w , a ra p id re c ip ro c a tio n w hich is ta n ta m o u n t to v ib ra tio n causes the coal to sp re a d evenly ov er th e cloth—

a m a tte r of g r e a t im p o rtan ce fo r good sc re e n in g resu lts. F in e coal th a t falls th ro u g h th e re c ip ro c a tin g screen m en­

tioned is c a rrie d to th e M a rc u s screen by a ch u te an d jo in s th e re s t of the slack a t th a t point, finally g o in g to a slack bin. T h u s th e coal cleaned is 2 x f-in . m a te ria l only. I t passes o v er th e de­

liv e ry end o f th e f- in . slack screen and d ro p s in to th e second co m p artm en t of the a ir-s a n d se p a ra to r box.

E ach of the th ree co m p artm en ts of the a ir-sa n d clean er consists of a box 32.6 in. long an d 10 ft. w ide in h o riz o n ­ tal dim ensions, len g th m ean in g in th e d irection of th e flow of m a te ria l, w ith a 16-in. p erv io u s C a rb o ru n d u m plate bottom , th ro u g h w hich filtered a ir, but not sand o r coal, w ill pass freely.

U n d er th is floor is a n a ir-b o x th e a ir flow to w hich is re g u lated by th re e valves in each com partm ent. I f an y one of these valves is w idely opened, it w ill d iv e rt a ir to the p o in t on th e a ir - sand table n e a r th a t valve an d m ake an y needed ch an g e in a ir delivery. H o w ­ ever, ov er all is a m a s te r valve w hich regulates th e to tal q u a n tity of a ir de­

livered to th e clea n in g plant, le av in g to the sm all valves m erely th e jo b of re g u la tin g d istrib u tio n .

Coal and sand e n te rin g an y c o m p a rt­

m ent is lifted in to suspension by the upflow of a ir, an d th e coal im m ediately begins to stra tify , th e coal flo atin g on top and the d ir t on th e bottom . T h e sand, because of its sm all size, m ay be found in all p o rtio n s of th e bed. T h e coal and sand a re delivered n o t to the first but to th e second, o r m iddle, c o m ­ partm en t. T h e u p p er la y e r of coal and sand passes ov er a w e ir a t the f a r end of th a t co m p artm en t an d goes w ith the sand in w h ich it is suspended to the th ird , o r last, com partm ent, w h ere the floating actio n is repeated. M eanw hile, the im purities, w ith m uch m arketable, but relativ ely heavy, coal, a re tak en out by a v e rtic a l chute tinder the w e ir in each c o m p a rtm e n t; the C arb o ru n d u m floor, w hich slopes 1 in. in 12, is hot continuous in a n y of th e th re e c o m p a rt­

m ents b u t h as a drop of a b o u t 4-j- in. a t the lo w er end, th u s p ro v id in g am ple space fo r th is chute opening.

T h e im p u rities from co m p artm en ts 2 an d 3, w ith the sand in w h ich th ey are floating, a re tak en by an e lev a to r to the top of the tipple, w h ere th ey fall into th e sand bin, a lread y m entioned, fo r reuse. T h e im purities, c o n stitu tin g the p rim a ry refuse, a re h ere freed from m ost of th e accom panying san d by a sm all sta tio n a ry screen an d a re fed to the first co m p artm en t of th e cleaner,

w hich is a d u p licate of th e second and th ird . T h e clean coal reco v ered from the p rim a ry refuse an d its com m ingled sand overflow to th e second c o m p a rt­

m ent an d th u s jo in th e ra w feed. T h e final refu se delivered by th is re c le a n ­ ing co m p artm en t is desanded ov er th e lo w er deck of the d esan d in g screen and d isc h a rg e d to th e ro ck bin. T h e cleaned coal is desanded o v er th e top deck of th e d e sa n d in g screen, an d all th e sand th ro u g h both screens, w ith th e p r i­

m ary refuse d escribed above, is re tu rn e d to th e sand h o p p er in the top of the p lan t by a 30-in. b elt-an d -b u ck et sand elevator. S an d is fed only to N o . 1 c o m p artm en t of th e s e p a ra to r an d flows thence in a c o n tin u o u s stre a m th ro u g h the th re e -c o m p a rtm e n t b ox a n d o v e r­

flows a t th e end on to th e coal d esan d ­ in g screen. T h e th ird co m p artm en t of the clea n in g p la n t is a n a d d itio n al r e ­ finem ent. T h e C adogan p la n t o rig in a lly h ad only tw o c o m p artm en ts, th e raw coal an d sand b ein g d eliv ered to the second of th e tw o. I t w as la te r changed to th e th re e -c o m p a rtm e n t design.

T o a v o id d isin te g ra tio n , th e cleaned an d desanded coal, w h ich is a m ix tu re of p ea an d n u t, is carefu lly low ered by sp ira l ch u tes to th e M a rc u s screen. I t tra v e ls w ith th e 4 x |- i n . coal on th a t screen to th e o u trid e r p ic k in g table, w hich, h a v in g a screen section, p ro ­ v ides fo r th e se p a ra tio n of th e coal into 4x2-in. ( e g g ) , 2 x l- in . ( n u t ) an d I x J - in. ( p e a ) , th e tw o sm aller sizes p assin g by ch u tes to th e ra ilro a d c a rs a n d th e 4x2-in. to a lo ad in g boom. S om etim es the 2 x l- in . coal is loaded o v er th e 4x2-in. lo ad in g boom .

C apacity o f th e c le a n in g p a r t of the p la n t is a p p ro x im a te ly 100 to n s per h our. A b o u t 2^ to n s of san d is c ir ­ culated p e r to n of coal cleaned by the process, but, as the sand is reu sed an im m ense n u m b er of tim es, a b o u t 3 lb.

of m ake-up sand suffices fo r each ton cleaned. T h e coal on le a v in g th e de- sa n d in g screen is e n tire ly d ivested of its sand. M ake-up sand, all o f w hich is m inus 12-m esh, is b ro u g h t to th e tipple by ra ilro a d c a rs a n d is ch u ted into a steel tan k , an d w ith a ir a t a p re s su re of 80 lb. p er sq u a re inch fro m an a ir re c e iv e r is elevated to th e sand b in th ro u g h a 2-in. pipe. A by p ass pro v id es fo r th e sw itc h in g o f th e sand, w hen desired, to a n o th e r 2-in. pipe, w hich c a rrie s it to a bin su p p ly in g th e locom otives.

I f th e coal is m oist, th e san d m ay be d ried an d h eate d w ith steam coils on the s h a k e r by w h ich it is d eliv ered to the clea n in g p lan t, b u t if th e coal is v e ry w et, so th a t it can n o t be screened of its |x 0 - i n . coal, it is d eliv ered to th e M a rc u s screen w ith o u t cleaning. L ittle, h ow ever, is of such w etness.

A ir fo r o p e ra tin g the c lea n in g b ox is p rovided by a C o n n ersv ille b lo w er of the R o o ts type, w h ic h d eliv ers 6 cu.ft.

of a ir p er rev o lu tio n . R ev o lv in g a t 450 (T u rn to page 352)

September, 1934

— C O A L A G E 343