Document R26qe1mNbnVOy9MpaNLQ819bV

FILE NAME: Trade Publications (TR) DATE: 1942 June 10 DOC#: TR025 DOCUMENT DESCRIPTION: Trade Journal Article - Dust Diseases Y /l/xd -Z . 2 yC -il i~ ^ Z c c<. r v f f 3, Q ; ~fc> A ^ i L ^ -t/ ^ 1 >-/- Aft. c CS ! ! GARDNER WAERN & CO. PTY. LTD 481 Flinders Street, MELBOURNE Phones: M4451 (4 Unes), MU3441 45 W att Street, NEW CASTLE P h o n e : N ew castle 762 AGENTS: TASMANIA: wW,. & G. GENDERS lP'TJYl . lLTi Du ., HOobDaarrt anda Ll.auncresituon. Q-----U---E----E----Nn Sn L* nAnNnDn: ^BnRVITTnInSH1 T G*ESTNTE7R/IArnLfi1 ErLEACTR/AIC .. CO. (Queensland) PTY. 208 Clorence St., SYDNEY Phone: MA9134 (4 lines) Vt A .: ATKINS LTD., Brisbane. (W .A.) LTD., Perth. ' Registered at th General 'Post' 0(Bee. rjlelbdurnei, . 1H ' %; new :v K- h,i kv t- r et- Ti IP If. S {TP Pt P ... . N \ r '- Chemical Engineering and Mining Review, June 10, 1942 275 Dust Diseases Incidence and Symptoms of Dust Diseases . . Methods of Controlling Dust in Industry C AUSE and prevention of industrial diseases arising- from the inhalation of dust have received very close study in the past 25 2. Dust is definitely a menace in mines and quarries, chiefly because of its effect on the respiratory organs, but also in its action on other years, and mining and industrial organisations internal organs (stomach, liver, kidneys, etc.). have carried out much detailed research and The latter phase has not been studied sufficiently adopted very definite policies in regard to dust for a definite pronouncement to be made on the control measures. There is a wide range of diseases brought about. technical literature on this important subject to 3. The principal dust diseases of the lungs a re : which can be added an excellent, brief and con (1) Pneumoconiosis, a general term for all cise summary of "Dust Diseases," which appears dust diseases. in the Department of Mines of South Australia, (2) Silicosis, a condition of the lungs due to Mining Review No. 74, and which is reprinted the inhalation of free silica. below. (3) Silicatosis, a disease of the lungs thought In the last 20 to 30 years increased attention to be caused by silicates. has been paid to occupational diseases in various (4) Anthracosis, a dust disease of the lungs industries. One of these is pneumoconiosis, of coal miners. which is brought about by the inhaling of dust (5) Siderosis, a diseased condition of the lungs of various kinds into the lungs. The mining of metal workers, particularly in iron or and allied industries are particularly concerned ores of iron. with this disease. (6) Asbestosis, a lung disease caused by Drilling, both hand- and machine-drilling, breathing asbestos dust. shovelling broken rock, crushing operations, and The generic term "pneumoconiosis" or "dust to some extent the handling of crushed rock, all disease" appears to represent more accurately produce a certain amount of dust which is sus the common type of dust disease because numer pended in the air. When the air is inhaled a ous dusts are usually involved. proportion of the dust escapes the protective mechanism of the nose and throat, and lodges 4. Silicosis is characterised by fibrotic changes in the lungs, giving rise to pneumoconiosis. in the lungs which are said to be more clearly The disease takes years to develop but once noticeable and easier to diagnose than changes contracted cannot be cured, although in milder due to other dust diseases. The dust of free cases it may not incapacitate the workman. The silica is considered more dangerous than other amount and kind of dust taken into the lungs dusts, chiefly because its victims are thought to are the two chief factors, apart from the indi be more liable to contract tuberculosis than per vidual characteristics of the workman, that sons exposed to nonsiliceous dusts. influence the course and severity of the disease. 5. No cure is known at present for silicosis. Of the various dusts, silica dust is considered the It is not always beneficial to remove an affected most harmful. workman from a dusty job. The progress of the The fact that dust diseases are usually only disease is not altogether arrested though it may contracted after a number of years tends to pro be substantially slowed down. The rate of slow duce an attitude of indifference towards them, ing would depend mainly on the amount of dust especially in the smaller mines or plants. It is taken into the lungs. well to remember, however, th at the effect of Men suffering from tuberculosis in addition to dust on the lungs is cumulative, and th a t no silicosis should leave dusty work but men in the cure for these diseases is known. p rim a ry stage of silicosis could remain. T h ey The following points give a general outline of would probably be much better off in the same the information available on the subject:-- working places which have been freed from dust, 1. Dust has been defined as solid particles and from which men suffering from tuberculosis (usually dry, but they may be wet) ranging in were excluded, than in other occupations where size from less than 1 micron (about 1/25,000 in.) no health standards are maintained among the to about 150 microns. workmen. 276 Chemical Engineering and Mining Review, June 10, 1942 i 6. The symptoms of silicosis are:--Shortness of breath, pains in the chest, cough, spitting material, spitting blood, night sweats, loss of strength, and gastro-intestinal symptoms. Most of these symptoms also accompany diseases caused by other dusts. 7. The most dangerous dust is said to be that ranging in size from 5 microns to 0.5, micron or smaller; the smaller the particles the greater the danger. Particles of these sizes are too small to be seen by the naked eye. 8. Large quantities of larger sizes are harmful, because they tend to clog the mechanism of the respiratory tract and thus allow more of the smaller sizes to penetrate the lungs. 9. The quantity of dust taken into the lungs is all important. 10. The length of exposure to silica dust re quired to produce silicosis depends primarily on the individual, and the amount and size of the dust particles in the air breathed; but numerous other factors may exert a definite influence. In the granite industry in the United States of America some workers exposed to the heaviest dust develop silicosis after two years, whereas other do not develop the disease for 50 years. Data collected by the United States Bureau of Mines in one study show th at first-stage silicotics had Hvorked underground an average of 12.99 years for all men irrespective of occupation; second-stage, 15.8 years; third-stage, 18 years. In this particular study the shortest period worked underground for a first-stage silicotic was two years, and the longest for a third-stage, 40 years. 11. It is not logical to assume th a t the harm fulness of dust is in proportion to its free-silica content; no one knows whether a dust of 1 per cent, silica is or is not more harmful than a dust containing 2 per cent, or 3 per cent. Then again, men differ in susceptibility; men working on a con tract basis are more likely to become "dusted" than those on day-pay; and the temperature and humidity of the working place would also have a big effect on the harmfulness of the dust. To attribute harmfulness to dust on the basis of the silica content of the original rock, without due regard for the nature of the rock and the processes through which it goes, is even less logical. The physical properties of the rock and the crushing appliances have a big effect on the size and quantity of the dust produced, as well as on the proportionate breaking up of the par ticles of the constituents of the rock. The dust produced from a rock might contain a larger pro portion of one constituent than the analysis of the rock would show, if that constituent were more easily pulverised than the others. There is also the point that air-borne dust containi particles differing in specific gravity would vi. in composition as the heavier particles settled, 12. No definite, absolutely reliable stands of allowable dustiness are known. If some stai. ards have to be laid down, they should be tei tative and flexible. 13. Results have been obtained, however, thi show definitely the effectiveness of dust con measures. "South African Mining and Engineering Jouj| nal," vol. 46, p. 11, 1935--comment in t i "United States Bureau of Mines Bulletin" 400, ol statements in that issue--"The fact that no nei" miner who entered the industry since 1923 h| yet contracted silicosis is encouraging." "Mining and Metallurgy," July, 1935--referriii! to Broken Hill (New South Wales) mines and t t , system of medical examinations for miners whiel began in 1920--"So fa r no case of dust disea _ of the lungs has been detected in a man whl has passed the Bureau's initial examination and had done no mining prior to that examination,*?! 14. Measurements of dustiness are made bi gravimetric and particle-count methods. Grav metric methods (for example, using a suga tube or a water tube) take no account of tfc. size of the particles--a definite drawback, sin<| particle size is very important. It is appar also th at one very large particle may nullify t l || value of a sample. Particle-count methods (for example, usingfjj konimeter or a thermal precipitator) deal or ^ with dust within the dangerous limits, but tiff small amount of air taken in a sample makes tlf reliability of any one test questionable. Takeij in accordance with a standardised routinf samples should give good comparative results, % the number taken is large enough. 15. The South African standard of permissibf dustiness is 300 particles per c.c. (8.5 million c. ft). Dust is said to contain 85 per cent, fr silica as quartz. Wisconsin (United States of America) star ard is 15 million particles under 10 microns in c. ft.--silica content of dust 35 per cent. 16. Methods recommended for eliminating dd are as follows:-- Local exhaust ventilation at point of origil steam and water sprays, ventilation, plant clea ness, and housing of dusty operations. _ various methods and appliances are consider hereunder:-- (1) Fan-Exhaust System--For this system ;! be effective the crushing plant must be compag or else be capable of being sectionalised lfi compact units. The suction will only be efficie if the units are properly housed. It is obviott that, if there are gaps or leaks, the fan will Chemical Engineering and M ining Review , Ju n e 10, 19 4 2 277 mg be drawing its full capacity of dust-laden air after a thorough wetting. On windy days, in open iry owing to the admixture of fresh air from outside. plants, dust raised by the wind can be much Some points to remember are:-- worse than that being produced at the time by "ds a. Each section should be properly housed and general operations. A periodic spraying of the id- the housing kept in good order. walls and floor of a building will help in keeping m- the atmosphere clean by providing wet surfaces b. There should be a minimum number of on which dust will stick. i~aotl osyfsteexmh.aust pipes feeding into the main hou(5s)ingHoisusiensgse--ntWiali.th Ina thfeana-besxehnacuestof ssyuscthema c. The dust should be collected as near as system much good can be done by housing, par ir possible to the point of origin. ticularly if supplemented with other dust-allay ta d. Advantage should be taken where possible ing methods, such as water sprays. )n of any natural currents of air, or currents In any case elevators should be housed, as well w induced by the movement of the machinery. as screens, chutes and conveyor belts. It may iS e. The best positions for suction leads are:-- be possible to house one whole section of a plant with advantage. This might be done in a section g (a) Jaw crusher--on the top side of the that requires only an occasional inspection. le h chute under the crusher, so as to draw air down through the crusher. (6) Respirators--Though respirators do not e afford the wearer absolute protection at all (b) Elevator--on the upper side of the times, the use of them should be encouraged. The o d housing, a little above the loading discomfort caused by wearing them continuously point. is against their use for many jobs; but for short (c) Revolving screens--on the upthrow periodic inspections of dusty processes they are f side near enough to the feeding point very well suited. to control the movement of dust r released there. (d) Vibrating screens--on the top towards the upper (feed) end of the housing. (e) Conveyor belts--on the top side of the housing towards the feed end. (2) Steam and W ater Sprays--The value of sprays should not be overestimated. Although the effect is at times very noticeable to the eye, it is doubtful whether they remove all the finest fp particles ticles are of th dust from the air, e most dangerous. and these par : One advantage of sprays is that they can be Placed almost anywhere, but the disadvantages ;are that the effect is local, by no means perfect, sand not long-lasting. In summer time especially, dust may be caught up in the spray only to be released not far away owing to the evaporation .of the water. ' Sprays are useful in the feed bins, over a jaw crusher (there is often a certain amount of surging of the feed; a spray will control the Resultant dust which may be temporarily too touch for, say, an exhaust system ), around freens (steam sprays), in dead ends and corners flat are difficult to ventilate, and at the foot of elevator, especially if the elevator is housed. (3) Ventilation--Where a plant is situated in building, care should be taken to arrange the | entilation so that dust-laden air is carried away from the places where men have to stand while Working. (4) Cleansing of Plant--All accumulations of ust should be removed from the floor and framework) of the plant buildings, preferably Piezo Quartz Crystals Of all the many crystalline substances which have piezo-electric properties only rochelle salt, tourmaline and quartz are suitable for commer cial use. Tourmaline is little used because the crystals are scarce and expensive. Rochelle salt crystals can be prepared as required, but quartz is particularly useful as a source of large crystals from which slabs, rings, plates, bars or rods can be cut to meet specific requirements. Resonators and oscillators containing piezo-electric quartz are useful in depth sounders, submarine detectors, directional submarine signal devices, radio apparatus, range finders, direction-reading seismographs, periscopes, gunsights, and other instruments. Twinned quartz crystals are un suitable because they are not piezo-electric. It is also necessary to reject some crystals because of electric twinning which is about as common as optical twinning but cannot be detected until the crystal is tested for piezo-electric response. It destroys the asymmetry and hence the electrical response of the crystal. True piezo-electric quartz crystals are mostly imported from Brazil but they occur in many places. They also find applications in optical goods, scientific instru ments and fused silica ware. Hence there are other outlets for crystals which are not piezo electric.--Abstract from paper " Piezo Quartz" by Alfred W. G. Wilson, Canadian Mining and Progress Industries, 1942. 2 Chemical Engineering and Mining Review, June 10, I 9 4 2 REGISTERED TRADE MARK: TIMKEN BRITISH TIMKEN LTD., Birmingham, 7, England Associated Company: FISCHER BEARINGS CO. LTD., Wolverhampton, England. F a c to ry R ep resen tativ es fo r A u stra lia and New Z ealan d : K EM SL EY & CO. PT Y . LTD.. 109 Russell S tree t, M E L B O U R N E , f . l . AUSTRALIAN IN D U STRIA L D ISTR IB U TO RS:-- V IC T O R IA : B earing Service Co. of A ust. l*ty. L td., 70-76 Bouverie S tre e t. P.O . Box 2371. M elbourne, C .l. N E W S O L T H W A L L S : Bear in g Service Co. of A u stra lia P ty . L td ., 38 W en tw o rth A venue, Sydney. Q U E E N S L A N D : B earin g Service Co. of A u^t. P ty . L td ., 329-331 Adelaide Stieet. Bov 235D, G .P.O .. Brisbiin... ^OUTH A LK TRA LIA , & c>. ior-9 p in e A delaide, w k s t p r n a v S- TR A LIA * F lew ei. D av its A. Jo h n -o n L td ., 4 i,, -4 K M urray S u e tt. P e %;h. N E W ZE A LA N D : J:tv. J . N iven & Co. l t d . , 65-67 Taranaki S tre e t, P .O . Box ItibS, W ellington. hem ical Engineering and Mining Review, June 10, 1942 A \\\ i 'S . . % -xK**** ? ^ ' ? jmr-, - -- > i ! V^. W > *; is` V" ,: , ; :,: , i ^ ,' '^ ' \ S . / U / / i f ' .S ', ' fA%. _j j / _ , "S^^L ;, c i p M jsSfc ?%;ir "K s. -Mr,, w o rn / ^ % s a r quaBW ,,roitl0n rallas v* "The tougher the going, the more Goodyear quality counts." This fact, always accepted in peacetime, has been emphasised a hundredfold and proven to the hilt by the stress of Australia's great war munitions effort. Time and output being the vital factors in w ar production, Goodyear Mechanical Goods have earned heart-felt praise for their extra toughness and stamina in keeping the job going without hold-ups, breakdowns, time-losses and needless repair and maintenance costs. Little wonder that the factories, mines and mills of war-time Australia throw open their doors to the G.T.M. (Goodyear Technical Man). GOODYEAR MECHANICAL GOODS INCLUDE:-- Flat Transmission Belts Compass Cord Belts E-C Cord Multi-V Belts Conveyor Belts Elevator Belts Hog Scraper Belts Fruit G rader Belts Industrial Hose Air Hose Spray Hose Welding Hose W ater Hose Garden Hose Jointing r ~ *#--MG5 _/~ V Operated by compressed air -- simple, effective and reliable -- the GD-9 Mine Car Loader makes a hard job easy. Write for Bulletin GD-9. NOYES BROS (MELBOURNE) , (S Y D N E Y ) MELBOURNE, ADELAIDE, SYDNEY, NEWCASTLE, BRISBANE, BROKEN HILL, HOBART. LAUNCESTON. PERTH. KALGOORLIE (W. G. M anner* & Co.) C h a rio t P alm er & Co. Ltd., A u ck lan d . N.Z. RRDIIER-DEnVER 30 Chemical Engineering and Mining Review, June 10 I942 FUSEGEAR F * 1 JC O How many newspapers report--"The fire was caused by a short circuit in the electric wiring."? Short circuits and other faults not cause destructive fires if CAPACITY FUSES. r "ENGLISH ELECTRIC HRC" Fuses in addition to comply ing with B.S.S. 88/1939 are NON-DETERIORATING, and will interrupt without danger the heaviest short circuits likely to be met with on low voltage circuits in Australia. on electrical your circuits installations cannot be eliminated entirely, but are protected by ENGLISH ELECTRIC HIGH they should RUPTURING * Stocks available at all Branches, from 2 amp. to 800 amp. rating. ENGLISH ELECTRIC Fuses have been supplied in quantities to all important supply undertakings, industrial establishments, munition works, etc., throughout Australia. THE ENGLISH ELECTRIC Sole Agents in A ustralia CO. SIEMENS (AUSTRALIA) PTY. Sydney Melbourne Adelaide Brisbane FLOWER, DAVIES b JOHNSTON LTD., PERTH. LTD. Newcastle LTD.