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FILE NAME: Trade Publications (TR) DATE: 1949 Nov DOC#: TR055 DOCUMENT DESCRIPTION: Trade Journal Article - A New Approach to Pneumoconiosis i r i NOVEMBER, 1949 Bror Nordberg editor R ock P roducts THE INDUSTRY'S RECOGNIZED AUTHORITY VOL. 52, No. n Nathan C. Rockwood editorial Consultant This Month We Hear 33 Editorial --Rock Products Industry Has Strong Case for Percentage Depletion 41 Rocky's Notes --Philosophy of the W elfare State 43 Labor Relations Trends 45 the Personal Side of the News 47 Industry News 51 Hints and Helps 54 New Machinery 56 High Temperature Laboratory Furnaces V arious types of furnaces and procedure discussed for use in research, free lime determ ination studies of bum ability Dr. Bberhard J. Spoha 58 Jet Piercing --Modern Technique for Drilling Rock Facturai data now available on jet piercing method of drilling rock as process enters advanced experi m ental stages a t Kingston T rap Rock Co. q u arry W aiter 0. Lenhart 60 A New Approach to Pneumoconiosis Research a t M arquette University indicates a direct relationship between form ation of fibrosis and elec tric al p ro p erties x>f du sts George ffwers 54 New Cement Plant For Mexico . C. s. Watson 65 Center Burner Vertical Lime Kilns Kelley Island's fo u r new gas-fired kilns a t W hite Rock, Ohio, are operated under forced d ra ft from single g as producer, w ith COr, recircu latio n Bror N ordberg 66 Processing Concrete and Masons Sand 70 Jet-Piercing Method of Drilling Quartzite Oxy-aeetylene flame used to drill extrem ely hard q u artz ite a t M athew s-C urtis Co. q u a iry W a lte r B. le n h a rt 72 Builds New Crushed Stone Plant Near Kansas City 75 Versatile Limestone Crushing Plant 76 First Rotary Drill O peration In Com m ercial Stone Q u a rry Two ro tary drills speed operations and give satisfac tory perform ance a t S uperior Stone Co. q u a rry 79 Sand and G ravel, Ready-Mixed Concrete Industries Prosper 81 Ohio Meeting of A.I.M.E. Howard A. M eyerhoff 86 Producing Aggregate From Expanded Ciay by Sintering Process M arietta Concrete Corp. producing 30-35 cu. yd. of lightw eight aggregate per hr. at new $250,000 plant using economical process suitable to clays of all com positions L. David M insk 105 Brick Company Enters Cinder Block and Concrete Specialties Field Three high pressure autoclaves being used for cur ing a t new cinder block plan t of Roanoke-W ebster Brick Co. 108 Prestressing Increases The Uses of Precast Structural Concrete l - Coff 110 Automatic Block Machine Steps Up Production Hanson, Wood & Hoel Industries, Inc., has installed new plain-pallet, vibrating stripper-type block m a chine for improved production W a l t e r B. L e n h a r t W o lte r B. le n h o rt. Associate Editor D avid Moeine, Associate Editor l . D avid M insk, Associate Editor M. K . Sm ith, Assistant Editor J. Sed lack, Assistant Editor Contributing Editors Victor J . Azbe Dr. F O . A n d ereg g M. W . Loving Jam es A. Barr, Jr. Home Office M o rgan K. Cottingham , Ad. Manager H. M. G ood enow , Dir. of Circulation M a ry A . W h a le n , Circulation Service I M. S. H en dricks, Dir. of Research C . M. H ancock, Production Manager ' C. P. Teats, Field Representative i District Offices Eastern Area---Richard Y. Fuller, M anager; John F. Lockitt, Assist an t, 622 F ifth Ave., New York 18, Tel. M urray Hill 2-7888. C en tral A rea--R. P. Keine, Manager, H anna Bldg., Cleveland 15, Tel. M ain 4362. M id w est A re a -- E. H. Hickey, Rep resen tativ e, 309 W. Jackson Blvd., Chicago 6, Tel. H arrison 7-7890. W e ste rn A re a ---L. C. Thaon, Man ag er, 309 W est Jackson Blvd., Chi cago 6, Tel. H arrison 7-7890. Pacific A re a --Duncan Scott & Co., Mills Bldg., San Francisco 4, TeL Garfield 1-7950. In Los Angeles 5, 2978 W ilshire Blvd., Tel. Dunkirk 8-4151. In Seattle, Wash., 827 Se curities Bldg., Tel. Seneca 6135. London, England-- Harold F. Charles, M anaging Director, Maclean-Hunter, Ltd., Sun Life of Canada Bldg., T ra falg a r Square, London, S.W.1. ROCK PRODUCTS is published monthty J g MACLEAN-HUNTER Publrshinu CoriwaUon. AW ____ r>..._s r s u : . n __ C I l l i n n t t * H O f a tC * d. L. rrnuier, oecrsuuj. uuhj**** ~ y l :. as second-class matter, Jan. 30, 1936. a* j J * capo, ML post office under the act Pf H * 1EE79. Additional entry at Milwaukee, Wrs. . ROCK PRODUCTS is indexed repularly W en neerinp Index, Inc. SUBSCRIPTION INFORMATION Subscription Price. United States Canada one year, 32.00; two years, W F a , ^ years, $4.00. Pan American, one year, 5^" ' . years, $7.00; three years, $10.00eien, one year, $6 00; two yearj, 512-F* efc years, $15.00. Twenty-nve cents for smeie ^ Indexed in the Industrial Arts Index. at Canadian subscriptions and r e m i t t a n c e * a q. in Canadian funds to ROCK PRO DUCT!. Box 100, Terminal *`A / ' Toronto, Canada. To Subscribers-- Date on wrapper, 'indicate? with which your subscription ,, ^ ne* to have address changed, give old A5 we S ilic o s is --------------------------------- --_ A New Approach to Pneumoconiosis Research at Marquette University indicates a direct relationship between formation of fibrosis and electrical properties of dusts U ESEARCH now being carried on a t the M arquette U niversity School of Medicine in Milwaukee, Wis., is giv ing new insight into the basic mech anism of pneumoconiosis, the strange, tuberculosis-like d i s e a s e affecting workers who breathe air laden with certain types of m ineral dusts. Results of vital interest to the rock products industry may develop from th is work. The disease has been known fo r years, but for a long tim e it was be lieved to be due only to dusts of m inerals containing silicon, and was called "silicosis." In recent years the list of m ineral dusts known to be ca pable of causing the disease has grown to include such m inerals as w ulfenite and berlinite, which do not contain silicon, so th a t th e m ore general nam e "pneumoconiosis" has been adopted. Pneumoconiosis is characterized by the growth of fibrous tissue in the lungs, and dusts which cause it are said to be "fibrogenic." D epending on its extent, the growth may im pair the functioning of the lungs to a su f ficient extent to cause death directly, or it m ay have a weakening effect which paves the w ay fo r tuberculosis, pneumonia, or other respiratory dis eases. There have been several theories about w hat makes dusts fibrogenic. An early belief was that the sharp edges of dust particles irritated the lung tis sues, but this has been discarded by most investigators because it has been impossible for them to show any defin ite relationship between the sharpness of particle edges and the ability of the particles to cause a fibrotic reac tion in the lungs. Silicon carbide, for example, has been tested, and is not fibrogenic. New Theories The theory accepted by m any in vestigators today holds th at fibrogenic dusts dissolve slowly in the lung tis sue fluids, form ing a toxic solution. This theory was lent stren g th in the days when only silicosis w as known, by th e fa c t th a t injections of colloidal silica into the bloodstream of labora tory animals was usually fatal. How ever, the slow solubility theory now known about pneumoconiosis, and cer tain experiments which have been per formed to test the theory directly seem to give lesults which indicate th at it is definitely not ti ue. D elicate analyses of the blood of anim als which have died of pneumoconiosis, fo r instance, do 'AJJis-Chalmers M fg. Co.. M ilw aukee, Wia. B4 By GEORGE ELWERS* not show in the blood any more than norma] am ounts of the chemical ele m ents of the dusts which caused the disease in the anim als. Searching for a common denom inator of all dusts which are fibro genic, Drs. Silas Evans, W alter Zeit, and their associates at M arquette have found evidence th a t there is a direct relationship between the abil ity of a dust to cause a fibrotic reac tion in tissue and certain electrical characteristics of the dust crystals. Specifically, it seems th at only dusts which exhibit the piezoelectric effect are fibrogenic. Piezoelectric Effect The piezoelectric effect m ay be de scribed as the ability of certain crys tals, under proper conditions, to effect an interchange between mechanical and electrical energy. A common ex ample of its use is in the electric phonograph, where the mechanical vi brations of a needle following the rec ord grooves are transform ed into elec trical impulses by a crystal. This property is found only in crystals which are poor conductors of elec tricity, and which are non-centro-symm etrical--th a t is, which have an un balanced, off-center arrangem ent of atoms in the crystal. If only crystals which exhibit the piezoelectric effect are capable of causing pneumoconiosis, then it would seem logical to conclude th a t the piezo electric effect itself is in some way the cause of the fibrous growth of pneu moconiosis. The experim ental evi dence obtained so fa r indicates th a t this is true. So far, the great m a jority of insoluble piezoelectric m in erals which have been tested have been found to be fibrogenic, and no m inerals which are non-crystalline or which have sym m etrical crystals have been proven to be fibrogenic. Q uartz, fo r example, is a well-known piezoelectric m ineral. It has also been long known as a m ineral which causes silicosis. B ut fused quartz, which is am orphous and so has no crystalline structure, has been shown to be nonfibrogemc. Chalcopyrite also has been tested, and does not produce pneumo coniosis. It does have an asym m etrical crystal, but it is a good enough con ductor of electricity so th a t it does not exhibit th e piezoelectric effect. R O C K P R O D U C T S M r , , , rr, h ,, . 10 40 Likewise, many other m inerals have been tested, and most give results which would be expected according to the theory. Certain m inerals have been found which do n ot have piezoelectric prop erties, yet cause a fibrotic reaction in laboratory animals. Aluminum phos phate and asbestos are examples. A possible explanation of these seeming discrepancies is th at these minerals undergo chemical changes while in the lungs which convert their physical structure into piezoelectric crystals. This hypothesis is being actively in vestigated in current experiments. Since involved questions of physical s tru c tu re and physical properties of m atter have arisen in these experi m ents, the M arquette scientists have called in outside experts to aid them in their work. The Allis-Chalmers M an u factu rin g Co. h as played an im portant role, rendering active assist ance through E. H. Brown, director, an d Jack T. Wilson, W illiam Allis, and Richard G raham , physicists, and other m em bers of its E ngineering De velopment Division. The company has also contributed funds and certain specially designed and constructed equipment. Dr. H arry Ihrig, physical chem ist of th e Globe Steel Tube Co., has contributed advice and assistance on X -ray diffraction and spectrographic analyses, and scientists of the Bell Telephone Laboratories and the U niversity of Minnesota also have contributed technical advice and serv ices. It is difficult to assess fully at this tim e th e possible value of these ex perim ents to the rock products indus try . C ertainly it seems possible to p red ict when a m ineral will he capa ble of causing pneumoconiosis, which will be valuable to the operator of a mine, q u arry , or processing plant in determ ining the extent of dust-con trol and other protective measures which he needs to take. In cases of pyro-processing of m inerals where crystalline stru ctu re m ay be altered, it can be determ ined a t w hat point in the process th e m ineral becomes or ceases to be dangerous, suggesting the possibility of alterin g th e process to prevent production of a dangerous dust or to convert a dangerous dust into a benign one. And finally, as science draw s closer to understanding the basic causes of pneumuconiosis, the discovery of better preventative and curative m easures is made more possible.