Document BRmk718EGagbekwd4LdnpjY9w

FILE NAME: CERAMICS (CER) DATE: 1944 Aug 19 DOC#: CER032 DOCUMENT DESCRIPTION: Journal Article - Industrial Dusts: The Prevention of Pneumoconiosis <11 THE CHEMICAL AGE Aucusr 11), lt)44 Plant for the Chemical Industry J tafa rv Pmp j i f a r t i w . miik Pitrk r m T m ift, l^ a il C *** a a i irrmpi* Kntfe. te r AGIO N E U TR A LIZA TIO N . CLA R IFIC A T IO N O P LIQ U ID S, DKWATCRINU O F SLU D G ES, EFFLU EN T PU RIFICA TIO N . FILTRATION AND FLOCCULATION, PICKLING LIOUOR TREATM ENT. PURIFICA TIO N OF TRADE WASTE, SED I M ENTATION AND TH ICK EN IN G , SEPARATION OF SOLIDS FROM LIO U ID S, SODA R ECOVERT. W ET M ATERIAL HANDLING tlKM Ifll AGITATORS C A U S T lC ttERS, CLARIFIERS. CLASS IFIERS. C O N V E Y O R S . DEW ATERING M ACH IN ES ROTARY VACUUM FIL TERS* SAND W ASHERS. SLUDGE FUMES. TH ICK EN ERS. Wc. Jtafarf Votttum P tiler, mttk la W - a / fimtler mnd Ihpwiper. UNIFLOC REAGENTS LTD., --,,ss- 5,64 - SWANSEA -- O fna i UnSftoc, Sw taw i BRITISH TAR PRODUCTS * -------------- L I MI T E D ---------- -------- Makers of P Y R I D I N E o o ANTHRACENE OIL CARBOLIC CRYSTALS CRESYLIC ACID o o NAPHTHALENE ORTHO-CRESOL TOLUOL XYLOL SH EFFIELD , 10 418* G LO SSO P RO A D , TsU^liaat! MOTM T *lp(fim r CAESOl  The ChemicalAge A Weekly Jo u rn a l Devoted to Industrial and E ngineering C hem istry BOUVKRIK H O tlS S , IM FL E E T S T R E E T . LO N D O N . B .C .4 T W ttm : ALLANGAS FLEET LONDON GLASGOW : 11 H o t Stroot ( C n t n l }*7o) TiW pbeee: CENTRAL j tt (io iw BIRMINGHAM i D sla ta r H a m , Pw o IIm S l m t (Mfcflood o?8 j l TH B CHEM ICAL AGS offlor* oro m a d S i u N l n la aeoorSaaoo M S IM aSopllaa a Ik a Bh Bw U wi L M l t d , ** 4 V O L LI No. i j i i . August 19, 1944 Annual Snltacrlpllnn at. O v en tfit Export Research M A N Y th in g * a rc im p o rtan t in operating a business successfully. In telm i<a| art* , such a* th a t of likew ise h as m ad e tn a tk e t reseat h difficult an d um ertaiM . Ilritish trade has thereby lost heavily. h e m ir a t ntnnufac tu rc , th e te c h n ic a l m en A m ove is announced w hich w ill bring a r c p r o n e to c o n s id e r t h a t th e ir* * th e about a ch an g e if it operate.s as its most essential p art of the undertaking. sponsors intend. A fter several m onths It is tru e, of course, th at unless produc "f n egotiation a project is tak in g shape tio n i* e ffic ie n t, th e u n d e r t a k i n g c a n n o t tor setting up a self-supporting, non- prosper. T ech n ical sk ill is the first pro fit-m ak in g E x p o rt R esearch A ssocia essential, w ithout w hich no undertaking tion. T h e p ro ject is still in the em bryo r a n e v e n h o p e to s t a r t it* th e c h e m ic a l stage, b u t it has been developed far field and in m an y o th e r fields--it is en o u g h fo r th e sponsors to feel able to alm ost act u rate to state th at as a ask business firm s w hether or not they u n iv ersal tru th in to-day's conditions. are p rep ared to act as g o dparents to such Hut th ere is an o th er p a rtn e r w hose w ork an asso ciatio n . T h e p ro ject in question is co m p le m e n ta ry en d e q u a lly im p o rtan t h as been fa th e re d by th e A d v eitisin g --that of the salesm an. T he m odern A sso ciatio n ; an d it is lin k ed w ith a plan scientific salesm an m ust not be confused for the creation at the sam e tim e of a w ith the old-tim e carpet-bagger. Sales N ational O verseas A dvertising Service. tech n iq u e is sp e cialised an d em p lo y s T h is is th e first re a l in tim atio n th at m any weapons. One of these is a d v e rtis in g ; another is m ar ket research ; a third is th a t som ew hat in On O ther Pages .Vote a n d C o m m in fi ... ... 171 KtcWrotytie Hydrogen ' Produc- tinti, I ............................ ... 173 S y n t h e t i c Oil in S p a in ................ 178 th ere is beginning to be an appreciation of the vital connection betw een m ark et research and com tnet- definable asset of per sonal co n tact Itelsvoen buyer and seller on u h ifh is built tip an edifice of m utual tesp rrt and reliance. These tools, as we may term then, arc S a f f i # trith (late* in Cylindera 170 /ttWti*frttf tinaia ' ............... ... 180 iterov*ry of Tin ... ... 181 S a f e Production o f 5 f y r tc ... 182 Detecting M ercury in A i r ... 183 /frette#* ... ... ... ... 182 /lenti Itrnthera* Annunt Meeting IM H tying Point b y T o r n ( l e t ... 184 tirann ie Chetnicet Mnrkrta ... 185 cial efficiency. In 1941 th e G overnim m t set u p F.xport Croup* in m ost in d u stries, w hich w ere intended to be the spearhead of a great drive to obtain m ore ex p o rts in oidei nl importance in the home trade and arc essential in the export market. Unfortunate ly, distance has too often prevented suffi ciently intimate per sonal contact ami f / .*N. ifeitu m Production ... 18fi / 'ritm iti/ Sntca ... ... ... 187 Sitimaia in FowndriVg ... ... 187 Prtt nttd Weed Control ... 188 T l f o h r o m i n c in S p a in ... ... 188 n ifw iV iil /mfw!ry in K rancc ... 188 (corral Nnc * from Week to W e e k 180 Sitici* and Sbarra ... ... 101 lln tith Chemical Price* ... 102 to provide ru rirtt'v for the purchase of m u n i t i o n . 1 `h r t.ease-T .end arrange, m ent rem oved the ne cessity for thi< d iiv e an d p erm itted in to put nur w hole indus. I Ck) I ) I fio THE CHEMICAL AGE A ug u st 19, 1944 , before m aking any connection end sulphur dioxide. Anmsthotic effects v,ith ei|Mpmcn( w here th e gee is to 1>e need. ere produced on b re a th in g acetylene, M..rrc\rr. develop the h ab it of opening end butene, ethylene, ethyl chloride, methyl , |<mng Ah 'a lv c a slowly. ^ chloride, nitrous oxide, end propane; irri Hear in tniinl the p a rtic u la r projicrlies of ta n t gases includo am m onia, ch lorine, end ili* gnes which e re in. use. Among inflam- su lp h u r dioxide. T h e inflam m able range, nintOe gsaes e re am m onia, acetylene, in ad m ix tu re w ith a ir , v aries co n sid erab ly ; Imtane, ethylene, ethyl chloride, hydrogen, it lies between 2.5 and 80 por cen t, in the Militivi chlo rid e, end p ro p e n e ; those which case of acetylene, is frnm #4.1 to 75 per cent. n rr iim.inflammable include carimi dioxide, In th e case of hydrogen, an d from Ifl to 20 <hlniinr( nitrogen, nitrous oxide, oxygen. per cent, with ammonia. Industrial D usts The Prevention of Pneumoconiosis A IIK O E N T i-.ur of the llullelin of the Nnlinnul A w c ia lm n for Ilia l'reven1itili nf Tiiborcnloaia ( I)i-cemlirr, I W 3) wea lurjii-U (IcvotrU In arlicloa on Ilia v n rim ii nlrrl. of piiaimioconinaia, o r lu n g diaanao 1.ni.nl h r d ii.I |iarllol.ia. T l i" iireenion >>f |iiriunoniiio.ia m m d n . ll w ith b t U r . Tlicm n. Ilnlfnrd, of Ilio InHiialrlnl Health Itcrnr.-li Hoard, M edical llcaenrcli Com icll. I'nciiiiincnninaia " ia gro u p nam e cover,11" .iteli (li-flatc. aa ailicoais and beatosi. S ilir n .it i< cauard lif Ilia inh alation of tilirn.ui (Inala aneli aa ilioae o f aandaloiie nml ipinrlr. I I iwcnra, write* Itr. Ilnlford , in t.i r k r r . follow ing a arieljr of occupa1i.nt. principal am ong aliteli arc aatulblaalini{. lurlal grinding, aenilflone qu arryin g mol norbing, alata quarrying, pottery roanuIm-lura. Hie inaiiufacture of abraaiva aoap imuilrra, Iiialallifaroua m in in g,' and the Iriliug of hard heading in coal tninea. I I he hraatlting of aaliealoa du st, uaually I ni er a long period, cauaea the diaaaaa known I at a.lia.to .ia. Many coalminer engaged in heuiiig coal co n tract a diaeaae romewliat iotilar. rtesrlv, sny measure* designed to reduce nr nt>olish t h e incidence of pneumoconiosis mini rdm s i nreventing the worker from hrenlhiup sir laden with hsrmful dust. The mrthtKls hy which protection from noxious itir contaminants, including pneumoconiosis* producing dusts, msy he schieved sre, in order of preference : () substitution of Ihe notions suhstsore hy n hsrmless one; iii) j.1.`trillion of th e escape of dangerous dust toll* the gener sl atm o sp h e re; (iti) copious ^mirrsl xeiifilstiou ; sod (it) |ersona| pro. lednni of the worker. \n exemple of substitution esn hr taken (ioni th e |Httery industry. Pow dered flint Im, locg h e rn used for th e firing of ch in s nrr. sud the worker who removed the tvnrr a fter Tiring were exposed to flint dust lo th is s potent reuse of silicosis. Matin fn d n rc r ex p erim ented to And s efe su b t i t u l e smi it aim eared th s l slu m in s cmild he used satisfactorily in place of (lint. In s n investigation c a rrie d o u t In* th e M edical Hesearch Council among men who had been ex|>osed to alu m in a d u st fo r m any years 110 evidence of pneumoconiosis was found. Tims hy using alum ina in place of flint in this pottery process the risk of pneumoconiosis can a t any ra te be g re a tly red u ced . An* other instance of substitution is the extensive change-over from grindstones made of sandstone to artificial abrasive wheels in the grinding of m etals. W here the harmful suhstanco must neces sarily Ih> usod th e eseape of d u st in to the general atm osphere should he prevented if at alt possible. As n ts r as possible to the point of origin of the d u st a suitably de signed lihod is p laced, and from th e ho*d a m etal duct leads to a p ressure fan which is made to pull air into the hood. The shape an d locatio n of th e ImmhI , th e s ite of the d u c t, and th e pow er of th e fan are so arranged th a t Uie air-flow over th e point at which the d u st is g en erated is such as will ensure th at the dust is draw n straight into the duct and transported to a suitable col lecting device. Tca! oxhaust hoods are commonly used with m any types of rotary machinery, such as grindstones; they are also used in a variety of other processes such as, for exam ple, stone dressing, rock crushbig, and some operations in the pottery industry. Som etim es it a p ra c tic a b le for Ihc pro. res* In he completely rm ln so d . O flen, a* tn rock-drilling and some m etal grinding pro cea*es, Ihe form ation o r dispersion of dust ran lie much reduced hy the use of w ater. In spite of precautions such as those deserilted. it often happens th at enough dust to constitute a haxard to health escapes into the air. In such cases generous voulilation must lie provided, an th a t (tie suspended dust is dispersed in a larg e enough volume of air to ensure that its concentration does not reach a harm ful level. T h ere are other prtH'esses iii which none of th e m ethods will I > A u g u s t 19. 1944 THE CHEMICAL AGE Millie* 1.1 m n i n t n i n n ^nfo A tm o s p h e r e , nnl Ihen rcKpirntom ir o th er b reath in g a p n aralit iiiiihI he w orn 1v (h e o p e ra to rs , and (he process m ust he segregated in special com partm ents. S an d b lastin g in Much a process. S tatu to ry R equirem ents There sre statutory requirem ent* concent' mg dust roM rnl in industry. T he Factories Act. 111.17, req u ires th a t provision shall he made for ren d erin g harm less no Tar as (true Health all d u st, etc., th a t may he in ju rio u s to lu a ltli; another serlinn require* t h a t moans shall be taken for preventing the inhalation of dust, and a further section requires th e exclusion of persons from work rooms in which siliceous dust is produced during the interests allowed for meals nr rest. In addition, various regulations have liecii m ade Tor th e co n tro l of special industrics or processes. T hus, briefly, sandblast* ing m ay only be done in an onclnaed ch am ber in which no other work is ordinarily pcifoimt'd, and in which efficient means are provided to prevent the escape of du st o u t side the cham ber : the sandblaster working in th e ch am b er m ust w ear o v eralls an d a suitable protective helm et and gauntlets; the helmet m ust be provided with a supply of pure air and a way of escape for exhaust air, and m ust (tear the m ark of the person using it. A nother set of regulations applies Ut pritccsaes c a rrie d o u t in q u a rrie s in w hich the strum contains a t least 80 per cent, of silica. M achines used for the crushing and grinding of stone m ust be entirely enclosed, or he provided with efficient arrangem ents to prevent the escape of dust. The* exam ples of official regulations are enough to indicate the care th at is required to protect industrial workers. D ust S am pling s ire d in trthulion for s In rg r g ro u p of Mani ples taken in one anthracite m ine showed th a t 94 per cent, of the dual particles were Itelow 5 microns in sirs, 75 p er cent, were less than 2 microns and roughly 55 per cent, were sm aller than 1 micron. V arious instrum ents have Iteeti devised for sampling air-hom e dusts. G enerally, th o se used fo r **m illing pneum oconiosisproducing dusts are designed to en trap the lust particles from a known volum e of a ir on a glass surface or in a tiniiid T h e par. tid e s are then counted under the microscope, and in some cases the particle d ia m eter* a r c almi m easured and th e p a rtic le lia!riluttim i th u s ascerta in e d . Sampling Instrum ent* D r. Medford considers it unfortm m le th at the various available dust sam pling in stru m ents differ considerably in their sam pling efficiencies, so th a t for th e sam e d u st cloud different instrum ents may give *uhlniUi*llv differen t results. (A discussion of th e rcla. tire m erits of such instrum ents w as presented by l>r. S . C. IDacktin in T im C memicai. Aur.. 1943, 48, p. MS.) Therefore, in consider ing a stated dust concentration ono should have regard to the methods of sam pling em ployed. One of the sampling instrum ents designed hi G reat Jlrttain, the therm al p re cip itato r, is highly efficient. T he dust is deposited on two microscope cover slips which are subsequently moulded on slide*. C ounting and m easurem ent of tin* du*t paitirles a re done later under a higl-|iowor microecn)ie. W hite, as has been indicated, some of the dust-sam pling instrum ents now in use do not give extrem ely accu rst* in form ation concerning dust concentrations, th e y have iirv e rlliH n i been ofl in estim ab le value in controlling the dust hazard in many industries. If one is to asses* the risk of pneum o coniosis, o r lo decide on the efficacy of d u st control m easures, one m ust know something about the nature and quantity of the dust present in the air. In ord er lo define an air-tm m e du*t completely it is necessary to know the chemical and tnitteralogtcal nature of the dii*l. its concentration. ami o th er p h y sical characteristics. T hese physical ch arac teristics include : the mans concentration i.e.. the w eight of dust in unit volume of the dunt clo u d ; the num ber of particles per umt volume - ami the size distribution of the panicles. Inform ation about the size of the hist parlieies is very necessary because it is unlikely llis t many p articles la rg e r,th a n about Id micron* (l m icron equals onethousandth of * m illim etre, or about I/25,000th of ftn inch) reach th e d eep er parts of the lungs. The sm aller dust p a r ticles are regarded as the more dangerous. G enerally, in ndiistrial dust clouds p ra c ti cally all the particles are much sm aller than 10 m icrons. T h u s, fo r exam ple, th e average RECOVERY OF T IN As a result of special research w ork on tin recovery, induced by the loss of M alayan tin supplies, the A ustralisn Council for Scientific and Industrial Research has de veloped a new process for extracting tin from lode ores. I t is reported th a t the new process promises to make possible the se p a ra tio n , from ** ta ilin g s," of a la*ge pro portion of the tin not previously recoverable. Flotation replaces the gravitation 'm ethod now customarily employed. la b o r a tory tests have achieved the recovery of s high proportion of metallic tin ftom on* w hich were difficult to tre a t. I t is now planned to establish an experim ental plant, and Mr. \V. II. W illiam s, d irecto r of the T asm anian Mines D epartm ent, lias offered h is d e p a n m e n t's aid in th e com m erc)*) d e velopment of the process. (Inttnitrutf A m - irnltn* end Mining Standard.) C