Document QX9q9ZrJdzx8DB7wjJXwVn6Q8

FILE NAME: Trade Publications (TR) DATE: 1954 July DOC#: TR054 DOCUMENT DESCRIPTION: Trade Journal Article - More Efficient Mining and Modern Plant - Double Asbestos Production ( JULY, 1954 Bror Nordberg Editor ROCK PRODUCTS THE INDUSTRY'S RECOGNIZED AUTHORITY VOL. 57, No. .7 Nathon C. Rockwocd Sditorial Consultant What's Happening 33 Editorial--Research to D evelop Profits from W aste Products 37 Rocky's Notes--The Team sters' U nion and Its H oad M an 39 Labor Relations Trends 41 People in the News 43 Industry News 47 Hints and Helps 50 New Machinery 52 Increase Crushed Stone Capacity for Diversified Concrete Products 56 Maule Industries, Ine., grown to he one of the largest rock products companies, builds another crushed stone plant at Prospect, Pla. Pile-driver drilling and under water blasting and excavation are some of the unusual practices Walter B. lenhart Portland Cement from O il Shale 59 European experience points to substantial fuel econo mies in the manufacture of Portland eement. using oil shale and limestone Fred Kloiber Producing High-Grade "S u ga r" Stone 60 Weaver Construction Co., Alden, Iowa, is a large pro ducer of high-calcium limestone for the sugar beet industry, agricultural limestone and road materials R a y C. Grddings Recover Specification Sand and G ravel from a Clayey Deposit 62 Becker County Sand and Gravel C'o., solves problem of clay removal at Marlboro, S. C. plant by the use of sci uhber screen, blade mills and liquid cyclones Wattes B. ienhort More than Double Lime Capacity 66 M. J. Grove Lime Co., Stephens City, Va., installs ver tical kiln with an integrally located gas producer, having center and side burners, with recirculation of hot gases through gas producer Bror N o rd b e r g More Efficient M ining and Modern Plant Double Asbestos Production Morion 1. Briggs 74 Two Kilns in Series Produce Perlite Hubert c. Persons 81 Dedicate Million Dollar Stone Plant, New York Trap Rock Corp., Haverstraw , N. Y. 84 CONCRETE PRODUCTS- Block Plant with Push-Button Controls 113 U nited Cement P ro d u cts Co.. W ichita. Kan?., installs autom atic controls foi mixing and batching concrete Tip Brown Spinning and Rolling in the M anufacture of Concrete Pipe 116 Hubert C Persons Besser Celebrates Golden Anniversary 119 Radio Offers M any A d v a n ta g e s to the Ready-Mixed Concrete Industry 123 22. A p ro d u c e r view - th e 'e a d v - n m e d cum-rete in- dlistl V Jos A. Nicholson St. S. Torgrson, Managing E d ito r Woher B. Lenhart, Associate E d ito r M. K. Smith, Assistant Editor E. M. Amocher, Assistant Editor N. G. Lange, Assistant Editor Contributing Editors Victor J. A ibe F. O. Anderegg M. W. loving Jomes A. Barr, Jr. Home Office P. D. Allen, General Manager Mary A. Whalen, Subscription Dir. C. M. Hancock, Production Manager C. P. Teats, Field Representative District Offices Eastern Area--Reginald W, Davis, Manager; Chas. Daly, Assistant, 522 Fifth Ave., New York 36, Tel. Murray Hill 2-7888. Central Area--R. E. Keine, Manager, Hanna Bldg., Cleveland 15, Tel. Main 1-4362. Midwest Areo--E, H. Hickey, Man ager, 309 W. Jackson Blvd., Chi cago 6, Tel. Harrison 7-7890. Don ald C. White, representative. Western Area--L, C. Thaon, Man ager, 309 West Jackson Bivd., Chi cago 6, Tel. Harrison 7-7890. Pacific Area--Duncan Scott & Co., Mills Bldg., San Francisco 4, Tel. Garfield 1-7950. In Los Angeles 5, 2978 Wilshire Blvd., Tel. Dunkirk 8-4151. London, Englond--Harold F. Charles, Managing Director, Maclean-Hunter, Ltd., Wellington House, 126 Strand, London, W. C. 2. RO CK P R O D U C T S is published month!? by MAC* L E A N -H U N T E R Publishing Corporation, 308 Wwt Jackson Blvd., Chicago S, Illinois; Horae T. Hunter, President; P . D. Allen, V lca-P m ld ee l; Ralph K. Davis, Secretary. Copyright, 1954, 8? Maclean-Hunter Publishing Corporation. Entered u second-class matter, Jan. 3D, 1936, at the Chlca#*, 111., post office under the act oi Mar. 3, 1878Additional entry at Long Prairie, Minn. ROCK P R O D U C T S is indexed regularly by Engi neering Index, Ine. and the Industrial Arts lndXSU B SC R IP TIO N INFORM ATION Subscription Price. United States and Possession*. Canada one year, 52.00; two years, $3 00; tbrtf years, 54,00. Pan American, one year, $4.00; tw* years, 57.00; three years, 510.00. A ll other for!** one year, S6.00; two years, 511.00; three year*. 515.00. Twenty-five cents for single copies. Cn*' dian subscriptions and remittance may be sent 1 Canadian funds to RO CK P R O D U CTS, P. 0. Be* 100, Terminal " A ," Toronto, Canada. To Subscribers-- Date on wrapper Indie-stas U*u* + nh which your subscnptien expires. . , In orltin# ' p have address rhanged. give old as well a* new Modern mill ot asbestos plan* in Lowell, V*. Also may be seen dried ore storage building and conveyors between structures More Efficient Mining and Modern Plant Double ASBESTOS Production Ruberoid Co., Vermont Asbestos Division, with quarry near Lowell, Vt., constructs modern mill to process 10,000 tons of asbestos annually O NE i>K J'HE MOST fKJENT asbestos MUJL>ER,\ 4ND EKmining plants in existence. producing 125 t.p.h. of raw ole and about 50,000 tons of asbestos liber a vea< in i uund-the-eluch o p eia- tio.ic, six days a week, is th e R u b ero id Co. q u a n y in Lowell, n o rth cen tral Vermont. The erection of a new six- story mill and the in tro d u ctio n of a number of firsts to mining rncdbtds have greatly increased plant produc tion and flexilnlity Locate 1 on 33du-ft.-high B elvidere Mountain, the plant is operated by the Vermont Asbestos Mines division of the company an d produces ini p e r cent of the chrysolite, nonspinning;, shurt-fibe) asbestos in the United States. Its holdings extend over 2800 acres, equivalent to moie th an 50 times the size of Boston Common. Curient operations are confined to the noith slope of the m ountain at HjoO ft , 1J 5U ft. and 13U0 ft. levels When the K ubeioid I o. took over this open-face mine in lOoii ij urn th e Vermont Asbestos Corporation of Arnei h a , the quart y was yielding only about 50 t.p.h. of raw ore an d lU.IJUO tuns of asbestos a year. Operations iver e on the south slope of the m o u n tain in tire town of Eden, ,,.id were relatively simple. Within three '.ears By M A R IO N L. BRIG G S of ole, with longer asbestos fiber, on the north slope of the mountain. The new sourc e of ore was devel oped. and a 50Uh-ft. aerial cableway constructed over the mountain to take the rock to the original mill. When the second mine site gave evidence of extensive and suitable asbestos ore rieposits, the company closed down the old mine, discontinued the use of the aerial tram w ay, and m 1949 con structed its present modem six-story mill with industry-innovatmg-equip- ment and features. In construction, the mill is of struc t u r a l steel, h a s a t>5,000-=q ft. floor area, concrete main flooi, foundations and footings, and corrugated asbestoscement sidings and roofing, it con tains surplus capacity to allow for bypassing any machine temporarily -- J'" - Hh iTeastd by the company to ]qu t the installation ,,f n t\V nij tijuiplilent and the discovery, by curate prospecting, of a better g 74 Sample of the "silk" asbestos fiU ROCK P R O D U C T S IuJ , 1954 Left. O ne of the roto ry tore d rills fo r p ro vin g out of 0]io] <11ioil. Thi s bypa ss i ng, when neressai y, to no 'a .iv i h a n g e s eitbei the ipiality oj' the amount of the product Electi it motors in the mill sue in terconnected in cut h a way to perm it automatic stalling' and stopping. No bucket elevators aie used. The mill building is heated in cold w e ath er by means of hot air fed back from the ih y in g oi e. so t h a t even at /.eio de grees the tem peratuie is held between 60 and 7U deg. F. All processing from the third-stage crushing of the asbestos ore is done in the mill. From a wet stockpile, with a capacity of 75,000 tons, th e oi e is reclaimed by a 24-in. tunnel belt con vey oi, 250-ft. tenters, th a t carries the roc-k up 45 ft. to th e mill, w h e re it disch arges into two 7- x 60-ft. p a i a i lej-flow ro tary dryers. The innovation of outdoor stock piling of w et ore by the K uberoid Co. has the advantage of keeping about 25U men a t work the y e a r lo u n d , as operation of the plant can continue during low-temperature winter weath er. Full-time employment at the plant means a livelihood to many V erm ont ers in surrounding towns, who come to woik in company busses and get the highest average hourly wage in the area. High Faces -- Large Blasts New to the mining industry, and economical, is the use this company makes of high faces and large blasts. Blast holes are drilled with BueyrusErie 2ilT churn drills th a t averag e 2.40 f p.h. The holes a re 6 Jz-in. open ings, and a i e spaced 10 to 18 ft. along the face. Shots average about 80 holes ami pjuduce abo ut .50,000 to 100,000 tons of rock each. The unusually good breakage and a yield of close to 5 tons per lb. of explosive are partly a t t r i b utable to the seams of fiber in the asbestos ore. iTim aiord safety fuse is used with 75 an d 60 p e ice n t g e la tin dynamite. A t the KiOO-ft. level of th e (ju a iry , where current operations are in prngi ess, the oi e body is ab o u t 3000 ft . lo ng and from 400 to 800 ft. wide. Its sur- lepo slls In the asbesto s g u a rry . R igh t. M en at w ork paring blast holes laic slopes to the 1050-ft. level, and w o lfin g of the mine goes on in a p p ro x im a te ly 100-ft. benches IT mu the top level down, in order to get the desired blend of ore. A fter blasting, rock too large to handle is reduced in size by workers using hand-operated compressed air LB 57 ja c k h a m m e r s w ith d etachable bits, and Joy TM 40 d rifters. In w oiking on h a rd rock, c aib id e bits a r e used in the jackhamme-i s. Secondai y shots aie detonated by line current, and about 200 to 300 a r e m ade sim u lta n e ously. The recen t p u r c h a s e of tw o 3-< u vd. M arion p ow er shovels a n d one 7cu. yd. shovel, the largest in New England, have speeded plant produc tion. The big bucket lifts in one bite 7-cu. yd. of rock, w e ig h in g a b o u t 10 tons. All are powei ed by electricitv . B ear-d u m p 27 F D E uclid tr u c k s, of 15-ton capacity, load fiom the piles of blasted ore, and c a n y it on sboit hauls to the prim ary crushers kept close to the w ork in g face. A t th e 1050ft. level, the trucks discharge into a 40-ton steel hopper that feeds fiom a 15-ft. x 60-in. K ennedy-Van Satin pan feeder into a 48- x 60-in. Travloi p rim a ry jaw crusher. A t th e ]15l')-ft. level is a 36- :< 42-in. p r i m a r y ja w crusher. The minus 6-in. product fiom the prim ary crusher at the 1050-ft. level moves along a belt conveyor to a 5 Jjft. Symons cone crusher, amt fiom the p rim a ry cru sh er a t the 1150- ft. level, it is c a rrie d t.o a 4 1 1 -ft. Sym ons cone crusher. From both cone crush ers, th e cru shed ore is ta k e n by a conveyor to the wet. stockpile n e a i the plant. Collect W et Dust From Dryers An innovation in the ruining indus try, believed to be first employed at the Kuberoid plant, is the collection of wet dust from the dryers. In then circular air-jai keted, oil-fired combus tion chambers, the free m oisture in the asbesto s oi e is i u t down fr o m 5 to 6 peicent to less t h a n 0.5 percent, F ro m th e d is c h a ig e ends of th e di yen s, two 17,lH)0-r f.rn. falls sin k th e esiyp- w lth b o n d -operated com pressed air d rills pre- ing air, steam and gas a,id sweep it t h r o u g h two cyclone collectors 10 ft. in d ia m e te r into a 34,UOO-i .f.m. Orion cloth bag dust filter. The cloth re m ains efficient for more th an a year. H am pers with autom atic i controls keep the filter tem perature from exceeding 240 deg. F. by letting the fans exhaust to atmosphere above this point, and strip beaters prevent the gaseous ma terials in the filter fiom dropping be low the condensation point. The dried ore leaving the dryers is c a rr ie d on belt conveyors to a 5 1?ft. Symons short-head cone crusher, which reduces it to 1-in m inus size. They a re then carried on to a p air of 3-it. Symons short-head cone crushers f o r f u r t h e r red uctio n to 32 -in. minus size. In dry w eather, it is possible to have the ore bypass the dryers and go direct to the cone crushers. F ro m the 3-ft. short-h ead cone e r u s h e i , the '-in. m in u s product moves along a 24-in. conveyor into a s t o r a g e bu ild in g w ith a It),OltO-ton ca pacity. On a parallel belt conveyor, controlled by a Svntron vibrating feeder, the material moves to the processing mill, where it discharges onto a p a ir of identical flows. Note worthy is the remote control govern in g th e flow of oi e to th e feed convey or by means of a Merrick Weightometer with a rheostat regulator and recording meter. Removing the Fiber Some of the "silk of the mineral k in g d o m '' is a s p i r a te d by aii suction fiom sloping tables oscillating slowly and reached before the ore enters the fiberizing machines. Mole of the as bestos fiber is broken loose i j om the ore as it goes through the fiberizers, where the rock and hard fiber are hurled against bieaker plates. The loosened fiber in the machines is re moved by a ra p i d ilow n rn i i ent of a ir to Screens with L ami hs-in. openings, from w hith it is aspirated through piping into collectors. A fter leaving the fibeiiziiig m a chines. the asbestos ore goes over siieens with ` t - and 's-in. openings. The plus A -in. oil- moves on to tail- out of ojiotrttioii. This bypassing, when n ecess aiy , hi no 'a .iv ih a n g e s eitbei the ijuailty OJ' the am ou n t of th e p r o d uct E le c t n c m otors ijt the mill a t e mtereonnec t u l >n su< li a w ay to p erm it automatic starting' and stopping. No bucket elevators a ie used. The null building is heated in cold w e a th e r by means of hot air fed baek from the d iy in g oi e. s o t h a t even at /.eio de grees the tem peratui e is held between 60 and TU deg. F. All processing from the third-stage crushing of the asbestos ore is done in the mill. From a wet stockpile, with a capacity of 75,000 tons, th e oi e is reclaimed by a 24-in. tunnel belt con veyoi, 250-ft. tenters, th a t carries the rock up 45 ft. to th e mill, w h ere it disch arges into two 7- x 60-ft. p a i a l lej-flow ro tary dryers. The innovation of outdoor stock piling of w et ore by the R uberoid Co. has the advantage of keeping about 250 men a t work the year lound, as operation of the plant can continue during lovv-ternperature winter weath er. Full-time employment at the plant means a livelihood to many Vermont ers in surrounding towns, who come to woi k in company busses and g e t th e highest average hourly wage in the area. High Faces -- Large Blasts New to the mining industry, and economical, is the use this company makes of high faces and large blasts. Blast holes are drilled with BueyrusErie 2ilT churn drills th a t av erag e 2.40 f p.h. The holes a r e li'z-in. open ings, and a i e spaced 10 to 18 ft. along the fare. Shots av erag e about 80 holes and pi odute about 50,000 to 100,000 tons of rock each. The unusually good breakage and a yield of close to 5 tons per lb. of explosive are partly a tt r i b utable to the seams of fiber in the asbestos ore. Pnm aiord safety fuse is u s e d with 75 and 60 pen-ent gelatin dynamite. A t the 1800-ft. level of the ijuairy, where current operations are in progi ess, the ui e body is a b o u t 3000 ft . lo ng ami from 400 to 800 ft. wide. Its sur- iaic slopes to the 1050-ft. level, ami voil-ing of the mine goes on in a p proxim ately lOU-ft. benches fiom the top level down, in order to get the desired blend of ore. A fter blasting, rock too large to handle is reduced in size by workers using hand-operated compressed air I.B 57 ja c k h a m m e r s w ith d etachable bits, an d Joy TM -19 d r i f te r s . In vvoiking on h a rd rock, e a ib id e b its a r e used in the jack h a m m ei s. Secomlaiy shots aie detonated by line current, and about 200 to 800 a r e m ade s im u lta n e ously. The recen t p u r c h a s e of tw o 3-< u vd. M arion p ow er shovels a n d one 7cu. yd. shovel, the largest in New England, have speeded plant produc tion. The big bucket lifts in one bite 7-cu. yd. of rock, w e ig h in g a b o u t 10 tons. All are powei ed by electricitv . .Rear-dump 27 F D E uclid tr u c k s, of 15-ton capacity, load fiom the piles of blasted ore, and c a n y it on sboit hauls to the prim ary crushers kept close to the w ork in g face. A t th e 1050ft. level, the trucks discharge into a 40-ton steel hopper that feeds fiom a 15-ft. :< 60-in. K e n n e d y -V a n S aun pan feeder into a 48- x 60-in. T ra v h n p rim a ry jaw c ru s h er. A t th e 315l')-ft. level is a 36- x 42-in. p r i m a r y jawcrusher. The minus 6-in. product fio m the prim ary crusher at the 1050-ft. level moves along a belt conveyor to a 5 Jjft. .Symons cone crusher, an d fiom the prim ary crusher at the 1150-ft. level, it is ca rrie d t.o a -j1 1 -ft. Sym ons cone crusher. From both cone crush ers, the crushed ore is taken b\ a conveyor to the wet stockpile neai the plant. Collect W et Dust From Dryers An innovation in the mining indus try, believed to be first employed at the Ruberoid plant, is the collection of wet dust from the dryers. In then circular air-jai keted, oil-fired combus tion chambers, the free m oisture in the asbestos oi e is i u t down fr o m 5 to 6 pel rent to less t h a n 0.5 percent. F ro m th e d is c h a ig e ends of th e di yet s. two 17.O60-C f.rn. fa n s sin k th e escyp- ing- a ir, s team and g'as and sweep it t h r o u g h two cyclone collectors 10 ft. in d ia m e te r into a 34,UOO-i .f.m. Orion doth bag dust filter. The doth re m ains efficient for more than a year. H ampers with automatic i ontrols keep the filter tem perature from exceeding 240 deg. F. by letting the fans exhaust to atmosphere above this point, and atrip beaters prevent the gaseous ma terials in the filter fiom dropping be low the condensation point. The dried ore leaving the dryers is c a rr ie d on belt conveyors to a 5 1?ft. Symons short-head cone crusher, which reduces it to 1-in m inus size. They a re then carried on to a p air of 3-it. Symons short-head cone crushers f o r f u r t h e r reduction to 32-in. minus size. In dry weather, it is possible to have the ore bypass the dryers and go direct to the cone crushers. F ro m the 3-ft. short-h ead cone erushei, the li-in. minus product moves along a 24-in. conveyor into a s t o r a g e b u ild in g w ith a It),OttO-ton ca pacity. On a parallel belt conveyor, controlled by a Svntron vibrating feeder, the material moves to the processing mill, where it discharges onto a p a ir of identical flows. Note worthy is the remote control govern in g th e flow of oie to th e feed convey or by means of a Merrick Weightometcr with a rheostat regulator and recording meter. Removing the Fiber Some of the "silk of the mineral k in g d o m '' is a s p i r a te d by aii suction fiom sloping tables oscillating slowly and reached before the ore enters the fiberizing maebines. Mote of the as bestos fiber is broken loose fiom the ore as it goes through the fibeiizers, where the rock and hard fiber are hurled against bieal.er plates. The loosened fiber in the machines is re moved by a rapid do nrin i etit of air to Screens with L and bs-in. openings, from which it is aspirated through piping into collectors. A fter leaving the fibeiiznig ma chines. the asbestos ore goes over si i eens w ith L - and ' s-in. openings. The phis A -in. oi e moves on to taii- 1 'I a <J tin i Lo* i\ jt v* h ai j j u i i }jj