JOURNAL of THE SOCIETY OF CHEMICAL INDUSTRY

Val. XLIV.. No. 28.) TRANSACTIONS [July 10. 1925.

THE COMBUSTION OF SULPHUR-CON- TAININC MATERIALS IN HAND AND

MECHANICAL BURNERS.

(colz/;lIf~cd j1'0))l 1'. 320 T)

BY P. I'.iItlUSlI, A.I.C., JI.I.CI1JCJI.E.

'

Iluitcl u. nteckcctiicctl s p e d oxide 6tiriiem.

'J'lic nirtlior I)clic:ves 1 l i n t Iiniitl s p i t osidc biirncr~ Iinvc scvcrnl Iicciilinr Iiicrits, niiiong ~diicli tiit! following iirc tlic niost notublc : Low initial ciipitul cost; buriicr gusc.s COIL bc clivestccl of (lust within tlic I)urncm ; niicl yriitiiitoiw' concciitrntion of tlic Iiulk of tlic clin~nlicr acid ciin IJC cffcctctl. 'l'lic tlis- iidvniitngc of Iiniitl IJiiriicn is tliut tlic combi~stion dficlciicy is n u t SO goal ns with 11ie~l1111ii~ii1 biiriicrs.

Muiiy tccliiiiciiiris iirc iilcliiictl to sup1iosc tlint wit 11 Iinnd-Spent ositlc I)uriicrx, tlic coinliositioii of the gns1.u is iiot rcpiliir. It is triic t l i n t 11 iuiiforin fikqirc riiiiiiot bc inuiiitninctl tlirouglioot tlic twenty-four

ions nrc not Iicurly so pronoiiiicccl 11s iiiniiy bclicvc. ~ l O l l r j Of t l l C (111J', I J l l t 011 tllC Otl lCr Iltllltl, thC flllctllu-

'l'lic merits of niccliniiicnl biuncrs lic lnrgcly in a bcttcr coinbiistion clficicncy, nnd tlic fnct t l int 0110 is indcpcntlcnt of skillctl proccss workcis. It is not tlifficult to train UI\ ordinnry labourer, niid to producc nn cliicicnt biiriicriiinii witliiii n fcw \\-ccl;s.

Tlic disudnuitngcs of ~iiccliniiicnl-spc~it osidc buriicrs arc (a) tlic crcntion of dust, wliicli, witli iniiny typcs of fiirnncc, iiivolvcs sonicwhnt licnvy utltlitionnl mnnufncturing costs, in order to prodiicc tlic rcqiiirctl quality of acid, and (6) iiiccliuriicnl repairs n rc 1 1 0 t i nnpprcciablc.

h"tITES ASD h I < I T l < S ~ U J t S E I l S

Pyrites ~iiny bc broadly divitlctl into two cIasscs- vk. , iron pyritcs niid culirifcro\is iron pyritcs, 'I'licso two IJrontl clnsscs JU~I-J bc sub-divitlcd into urscnicnl iiiirl non-nrscnicnl, Sincc tlic wnr tlic quniitity of pyritcs iiscd i i i tlic Cnitctl Kingdom Iins clccrcnscd wry scnsilily. Siilplii~ric acid innnufncturcrs Iinvc foiiiid sulpliiir niitl slimt osidc iiiiicli morc ccoiioiiiicnl iiintcriuls.

Typicul niinlyscs of scrcrnl qiialitics of pjritcs nrc givcn iii tlic su1)joincrl tablc :-

Origin of S. Cll. I-:. Ib . rb . Zn. SiO :. 01 01 or or

m I0 * . 10 01 .O pyritw. Qiuilit y. Of

Sowoginn . . Foltlnl . . , . 4+:0 .. '1.0 .. 4i.0 .. 0.61 .. - . . 0.5-0-7.. u'% Spunisti . . Il i t~mr I k c y . . 4 W 2 . . 0.18 . . 4:i.O . . 0.13 . . - . . 0.; , . 2.00

X O ~ V W ~ I I I I , . J ~ I I ~ I J U I ~ I ~ C I I . . 4 U 4 S . . 1.0 . . 42.0 . . Frcc . . - . . - . - Sonvcuiiur . . I h s r n o . . . . 4 8 4 . . 0.5 . . 44.0 . , Trnces . . - .. - .. - .. .. .. - .. - Spaliisi; . 1'CWb . . . . .!8.0 . . 2-0 . . 42.0 . . - .. -

l'ortiip:c$o . . ;\ljnstrol . . .. 47.5 .. 0.4 .. 4 1 4 5 .. 0.33 .. 1.05 .. I. .1 .. 4.0 . . 42.44 .. 3.0 .. 42.0 .. - .. - ,. - . . 5.0 Spunid: . . l%I)cninu . . 4ti.O . . 1.7 . . .ll.0 . , 0 .6 :~ . . -- . . - .. - Gpnnis l i . . Itio 'Jhto . . 48.0 . . 3.2-3.5.. . 40.71 . . 0.25 . . - .. - .. -

Spnniuli . . Swill0 . . 0.64

Fig. 11 is n typicnl continuom tciulicrntm-c record tukcn on tlic I i is t chnmbcr of n sct wlicro spciit ositlc is bunictl in Iinntl fiiriiuccs, mid wlicre tlic

,

I

h-10. 11.

potting operation io carried out cncli Iiour. Equnblo tcml~criiturcs may be talccn as a mcnsiiro of tho iliiiforinity of t,lic composition of tho burner giiscs. It will bo sccii tlint tho tc~iipcr~iturcs do not fluctunto 11101'0 tlinii 10" C., nnd i t is IL fact t l int tlio operation of ncid innnufncturo procccds witli markcd rcgulnrity.

Coitiiticrcid p r i ~ l i c e of I l~e Ityrifes otoicrs.--'l'lic lnrgc siilliliur untt coppcr coiii~~u~iics, siicli ns ltio Tinto, 'l'linrsis, uiid Scvillc, Iinvo iiivnrialAy sold oiily tlic siilpliiir content of the ore. A strict coiiditioii of the coiitrnct provitlcs t l i n t tlie pyritcs cindcrs, rcmuining nftcr coiulnstion, Iinvc to be storctl iiiidci* cover, i d urc to rcinuin tlic csclusivc propcrty of tlic scllcrs. Usually, tlic pyritcs ciiidcrs Itnvc to

port of sliipmcnt. Soinc of tlic Imgc acid iunkcrs, howcvcr, ILSC pyritcs to sucli nn cstciit us to wnrraiit tlicir iicgotintiiig witli compnnics otlicr tlinn tliosc nnincd, whicli nro disposcd to sell tlicir pyrilcs out- right, and iiot iiicrcly tlic sulphur contcnt of tlic orc.

It is importniit to consider tho form in ivliicll tlic jiyritcs is sold-wlictlicr ns luiups or as lilies. If sold in lump form, it is iicccssiiry t o nsccrtiiin wlictlicr tlic orc is frinblc or liurd, ni id to dctcriiiiiic itu pccculinritics under co~nbustioii.

Soiiic of tlic pyrites from ccrtuiii of tlio Scvillc inid 13spcrn1izc~ veiiis tire csylosivc. Sliortly nltcr clinrgiiig tlicsc ores to tho buriicr~ tlicy detonate niid tlic fino po\vdcr foriiictl is u prolific ctLiisc of thc blocltagc of the intcrsticcs of tho oro bctl, tlius Icntliiig to tlic foniintioii of scnrs or cliultcr.

of dotoiintioii uriscs from tho prcscnco of kiydrntcd

bC dCli\VrCd f.O.r., bllpcr's YtUtiOJl, Or f.0.b. IlcUrcst

It l1ns bccn suggestcd that tho ndvorso propcrty

D

silicntcs in tlic orc. Attempts Iinvc bccn iiiaclc t o OVC~COIIIC this trouble by snbjccting tlic pyrites to n ~~rcliniiiinry trentincnt a t n snitnblc part of t l ~ c biinieru Idore clinrging, niitl sonic nicnsurc of siicccss lins bccn securcil. Tlic nutlior would iiot couiitcnniico tlic ilsc of csplosi~-c ore in coiincsioii with lump pyritcs l~iriicis, ns iiicficicnt coinbust ion of tlic siilpliur is riliiiost inc\-itnblc. Orc of tlic lntter clinractcr slioiiltl bc cri~slictl and groun~l, so as t o bc siiitablo for coinbustion i n pyrites fiiics (Iiantl or mechanical

Liiiiip cord Ji~ros.-l'lic biilk of tlic lump orc ns ~isunllg tlclivcrctl is too Inrgc in sizc to IJC siiitalJlr for Im-~iiiig in Iuiiip orc I)unicrs. C'nisliing is tlicrc- forc ncccssnry niid t8lic sim wliicli lins IJccii foiititl IJCSt s u i t d t o Iniiip pyritcs biinicrs is 25 iii. to 3 in. roiiiitl. Tlic disatlvniitngc altcnding tlic brcnkiiig of n frinblc orc is tlic lnrgc amount of fiiics wliicli rcsiilts, cspccicdly if tlic pliiiit for cflcetiiig tlic brcnk- ing is n mccliniiicnl onc. Xot infrcqacntly wit11 siicli 1111 orc Iiriiid-brcakiiig is ntloptcd in onlcr to rcdticc tlic qiimtitirs of fincs to n iiiiiiiiiiiiiii.

type) 1JurIlcra.

combnstion in mechnnicnl burmrs is rcsortctl to. I ) q ) i t c this, n Inrge numbcr of ncicl mnnufncturcrs still use lump pyritcs.

Fig. 12 nffortls dctnils of tlic tjlic of burncr iLsct1 for the conibwtion of lump orc. Cast-iron fronts arc ilsunlly atloptcd, to wliich tlic rcfractory brickwork is built. Usunlly, tlic 1,uriicix arc plncctl bnck to bnck. Sn.ngct1 bnrs nrc uscd, niitl a scrics of tlicsc coiistitutc tlic gmtc. Air for conibi~stion is tlrnwi tlirougli thc nsli-pit doors, aiicl tlic port for tlic tlis- clinrgc of tlic bumcrs gnscs into tlic inuin ftiic is 11 cciitrnl 0110, provitlcd i n t l iu cniubcr nrcli itunicdintcly nhovc tlic bars. Tlic or(: is clinrgccl tliroiigli n door, 13 or 16 in. ~ J O V C tlic gratc.

Slarlitig (I botfery of lu i i ip ore biirricrs.--Iii COIU. iiicncing n bnttcry of hiinp orc biinicru for tlic first tiaic, i t is isiinl to dry tlicsc with (L siiinll firc iiindc of \vood. Aftcrwnrcls, nljout ci in. of rouiitl pyrites citidcm nro plnccd on tlic bnrs, niid n firc is startctl l y tlic ignition of wood or colic. 'l'h tlrnuglit iqnartiirc of cncli biuiicr is closctl wit11 n tilc clniu )cr, nntl tlic working door is left opcii. Xftcr 24 to 30 1m.

Fio. 1. Hond lurnerr-lunip p~riles-mrd clovolioti.

lInrtt p y ~ tcs, ~ I i c n Iinnd-brokcn, will not produce

cliniiicnl plniit, possibly 12 to 14yo of fiiies will result. By " fiiics " is iinplicd ti11 tho siiinlls pnssiiig IL i - i i i . nicsli scrccti. 'l%o brcnking of n friablo ore by Iiniid will rcsult iii about 10% of f i l m . If brcnkiiig is cffcctcd by mncliincry such oru will yicltl iilJout 15%, of fines. Witli some ciitnlitic~ of pyritcs i t is possiblo to burn about 8 to loo/, of tlic siiinlls nloiig with tlic liunps. hi otlicr cnscs so/, is tlic limit. \\'licro iuccliniiicnl brcalting rcsiilts iii tho prodnetion of 16% of sii~iills, t l i u lnttcr Iin\w to bc sold or otlicr\viso pyrites Biics burricrs Iinvo to bo urcctcd, to work in coiijuiictioii with tlio Iuiiiy ore l~~lrl lcrs.

Lnbour conditions hnvo nltorcd w r y inntcrinlly ditriiig the In& decndc, n i i d wlicrover possible,

morc t11nn (i to 8% of fincs. If broken by i l 1110- ilssuiiiiiig tlic brickwork is dry, tlic cniiibcr nrclirs a tlic burners will Y ~ O W n dull rctl Iicnt, ns iilso the pyrites cinders.

TIic nlternatc bars of tlic grntc nru sliakcii with tho key, dILst is rciiiovcd, und tlic rouglicr 1)ni.t of the fuel 011 tlio top of tlic cindcrs witlidrn\v~i. Tlic tilc

~nccliaiiicnl clrnuglit, niid clinrgcd. 'l'lic iiir which is ndiiiitictt tlirougli tlic nsli-pit doors, us hiis nlrcndy bccn iiidicotcd, ctiii bc ndjustcd n t this stngo.

J lie ~rsud griitc iliiiiciisions of cncli bunicr are, npprosinintrtly, 4 it. by 4 f t . 6 in. long. Such n buriicr is cnpnble of dcnliiig with cibou~ 'i cwt. of pyritcs every 24 hours, nccortling to tlio burning properties of t h o o w . A t sonic \vorl;s it is tlic prnc. tic0 to olinrgo nbout 34 cwt. ovcry 12 liouru. Other

(1x1 ll11JM' Cnll be I.CIlIO\'Cd, nlld bllrliCrS pltt UlldcI'

I 1

\\.orlis 1)rCfcr to n t l I l e~~ to SQ-Ilot~r clitti~gcs. Fro111

h m i o l nf rhe Society of Cfienaical Indurlry.

.TlIIY 10, 1025.1 ~ ~ ~ l l I l I S I l . - C O J I ~ L ' S T l O S OF SUI,I 'III;IL-COSTAISIS~~ J[ATEIlI.\I-~ IS H . \ S D .\SD ~IkXlr . \SIC. \L I ~ t l l S E l l S . 32.7 T

the point. of vie\\- of rcgii1nrit.y nntl iiniforniity of ovcr thc sistli bed. This mode of proccdrirc is coii- gas coiiipositioii tlic aiitlior's csl)cricncc iiicliiics tinucd uiitil tlic top, or first, bcrl is clcarctl of pylitcs to tlic vicw tlint l2-lioi1r clinrgcs arc to bc fiiics, niitl is rcndy for niiotlicr clinrgc, wliicli is tlieii prcfcriwl, as this iiictliotl tciitls to cnsiirc bcttcr nttciitioii, niitl t.lic 1)ossibility of clhilter forniing (wliicli tlislocntcs C O l l l ~ J U S t i O l l iu id tlic proccss gciicrnlly) is iiiorc rciiiotc.

H ~ s n PYRITICS SJr;\w.s Uuin ixs .

introdiicctl cia the Iioppcr.

1Irrird pyrifes siirrclls Iriiriier.-Fig. 13 rcprcsciits n scctioii of n pyritcs siiinlls biiriicr. Tlicsc nrc iiot iiow inricli iwctl bccnusc tlic Iiibour ciitnilctl iii tlicir opcrntioii lins 1)ccn fouiid to bc too cspciisivc. TIic Clovcr ncitl, lio\vcvcr, ~)rotliicctL with tliis type of brinier is not iicnrlg so tliscolorircd uiitl tiirl)itl ns t l int producctl 1 9 - iiiost ~nccli~aiicnl pyritcs siiinlls bnrncrs. Tlic I)iinicrs ciiibotly scvcii slicl\-cs. In stiii-tiiig ii bnttcry, 11 cokc fire is ligiitcd i i i the ciiitlcr pit., tlic plug of tlic fcctl Iioppcr b iwiiovctl, niitl tlic iiilct, to tlic mniii fliic cnrryiiig tlic biiriicr giiscs to tlic potting ovcii is clo~ctl.

Seelioiuil del'cttioir of tlrc '' Il'cdgc " ppi tee Ircrncr.

A skillcd innii cnii ciirry oiit tlic iiitter opcriitio~i in 30-5 iiiiii . Wlicii 12-1ir. shifts lire workctl, tlicsc cliarycs of 6:. civt. coiistitutc i i iiinii's work. This, sis buriicrs irrc nllocntctl to Iiini. It is iniportunt tlint tlic pyrites fiiics nrc slicccl cvcry two 1 1 0 1 1 ~ . tywciiilly tlie top tlircc IJCCLS. Otlicrwisc, tlic fornintion of scnrs " will bc dillicult to n\-oiti. Tlie tlr~\\l)ilcl< of this mcthod of working is thnt i t is cspciisive in point of labour ; the fcctl is discoiitinuous niid tluriiig cliurging, n good dcnl of nir is introduced, \vliicli Iiiis 11 disturbing iidiiciicc. Tl~csc factors Iinvc ccrtniiily lctl to tho incrcnsing poptilarity of iiiccliniiicirl buriicrs.

5. :' 8 . ,a, S.I.r..\-n.

FIG. 13. Snictll pyrifea hand birrturd (pitali a i i c l p idl fypc).

Occnsionnlly n tcruporary cliiiiiiicy-a boiler fluc tubc-is crcctcd on tlic top of ilic sctting, t o nssist i n tlic crcntion of nil nticquntc tlrniiglit.. 011 the thy follo\viiiy tlic lnttcr proccdiirc, it. is i w n l t o start fircs 011 tlic sccoiid, fourtli, niitl sistli I d s . Thrcc days slioirltl suliicc t o sccurc tlic reqiiisitc initial tciiiperiiturc to ndmit of t.lic pyrites liiics bcing clinrgcd. 'UF;ually, tlircc clinrgcs pcr ticr ~irc ~iintlc tlririiig t,lic first dny, nnd two on tlic succcctliiig t h y . About se\-cii clinrgcs iirc iiccdctt bcforc tlic ciiidcrs rcncli tlic pit, so tlint t.lic nctitnl tiiiic coiitnct of the pyritcs fincs in tlic biiriicis is soiiictliiiig of tlic ortlcr of 50-56 Iirs. Ihch sliclf is 5 ft. witlc niid 11 f t . long. C:cncrnlly, 6.;- cn+. of pyritcs iiiics 11rc clinigctl c\-cry 12 lira. 'J'liiis, nilout Ib. of pyrites lirics iirc tlciilt. wit.11 pcr sq. f t . of sliclf iircn pcr tliiy.

Tllc i~ sua l iiictliotl of worltiiiy, wlicii noriiinl F I G . 16. operiitioii l ins bccii cstnblislictl, is iis follows : 'Xlio

pyrites 1-ciniiiiiiiig on tlic sc\~ciit,li sliclf, now l ) i ~ ~ c - t,icnlly t~cl,utlctl of t,llcir sull,ll,tr COlltCllt, nro ,)ilsllctl Il'ccbc t m h t l i c d i w i t w ho7icr wilh Ij ioWcJ 1lowurJ dual

into tliu pit ; tliosc on tlic sistli sliclf nro ( l r i ~ w i i froiii tliis bcd, n~itl droppcd to t,Iic, sc\~ontli Ijetl, niid ilIcclmir.ica2 pyrilcs burasrs.-It is not proposed siibscqtmntly ovcnly distributed. Tlic pyrites oii to ciitcr into niiy tlotiiilctl dcscriptioii of tlic various t.110 fifth I)cd arc plislicd to tho sisth bcd, niitl tire 'iucolimicnl pyritcs bunicrs, but ~iioroly to den.1 with nftcr\\wds tlistributcil by oporntiiig n spccinl slio\d outstniidiiig points of prncticnl iiitorcst.

cliu~ti6cr i / i coiirso OJ erccfioii.

D 2

Fig. 14 sliows n scctioiial cle\.ntion of tlic \\‘cdgc incclinnic~il burner, nnd Fig. 16 rcprcsciits this biinicr in courso of coristriiction.

%'lit iiiitlior, \din Iiiis lint1 espcriciicc of tlic crcct.ion niitl \ \ .~rl<i~ig of this IiirIiiiCc, cnii 0 1 1 1 ~ S ~ I I C i i i tcriiis of coi~irncntl~itior~ i i h i i t its u ~ c f i i l i i c ~ ~ . TIic siicccss of iiny iiiccliiiiiicnl 1)iiriicr tlcpciitls Inrpcly on 1110 tlcsigii, niicl t Iic ciirc escrcisctl in thc construction. Ylic choicc of tlic iiiiitcriiils, p:irticirliirly rcfrnctory iiintcrinls, is iilso very iiiiportiiint.

‘l’lic \\‘ctlgc furnace can be h i l t i n vnrious cliiiiiictcrs 111) to 25 ft., iiiitl provitlctl wit11 tlircc, fivc, niid scvcii or iiioro Iierirtlis 11s tlcsirctl. ‘1lic cciitrnl s l inf t is 5 ft. i i i tliiiriictcr, nntl is insiiliitctl with slwcinl lire tiles iintl iiisiiliitiiig mntcritil wliicli iirc i i t tdict l to, iiiitl revolve with, tho sllnft,. Xo cooliiig iiirtliuiii, ritlicr w t c r or nir, is rcqiiirctl for tlic criitrril sliiift, IIS i t is opeii top i i n d hottoin, i i i i t l tlic civrciit of iiir crc!i\tccl is weli 11s to Itccp i t

‘Ylic IJiiriicr slio\\ii i n Fig. 15 coiitciii~~l~itcs tlic provisioii of sc\*tw sliclvc*s, 21 f t . 4 in. in tlinnictcr.

Soiirc coirslriiclioircil tloltiils.-Aftcr Iinring 1)rcl)iirctl 11 siitishctory coiicrctc f ~ i i ~ i d i i t i ~ ~ i , it is iicccssnry to set out iiiitl crcct tlie 1~ricl;worlc bnscs for tilo \voriii gciir iintl tlriviiig sliafts. ‘l’lic iiutlior 1111s fount1 tiiiit i i very siitisfiictory rctliictioii gciir for tlic \\’ctlgo fiiriiitcc consists of IL Covcntry cliniii gcnr, 9 to 1 rcdiictioii , i i i two stngcs. ‘l’lio coil- iicsioii I)ct\\.c.cii t l io cli:iiii rrdiictioii gciir niid tlio woriii gciir is ciu ii flcsil~le coiipliiig.

Hiiv i~ ig coiii1)lctctl this prt*Iiiiiiiiiiry work, tlic cciitriil slinft sliould be crcctctl, a i d siilJsccliiciitly tlio cluiniicl stiiiicliions, ciglit of wliicli nro provitlctl. ‘YIic {-in. stccl casing is in eight picccs, :ind is riveted closc to tlio rcr t icd cliaiiiicls 1)s two r o w of rivcts. ‘Ilicro arc circiimfcreiitinl iiiiglcs, top tint1 bottoin, to which tlic ciising is tittnclicd.

l’iio ivooticn t:ipcr lntlis arc usunlly pl;icctl over 11 scrics of concciitric f l t i t iron rings, so tliat t l iu IjcrlS of tho bwiicr ciiii bc erected. ’l‘liis is 1)robilbly t iio liiost iiiiportnnt worli in\~olvcd in tlic \vliolu constiwtion.

Arclics Iinving it spnn of 31 f t . 4 in., with a riso of nboiit Sin., wliicli arc likely to bo subjcctcd to flrictuntioiis of tcnil)cri~ture, obriously need to bo very cnrcfully built. ~Vlicn i t is rccnllcd tlint tliu force cscrtcd on t,lic pcriplicry of L L cniubcr nrcli, 16 in. s1)uii, inclincd orit of Iiorizontnl to tlic cstcnt of 6”, is npprosiinntcly 25 tons, niid wlicii to t.liis must bc i it lt lctl thc fiirtlicr forcu diic to cspnnsioii, oiic rcntlily iipprcciiitcs how \vclconio would bo i L sirnplificiitioii of this part of inccliiinical biuncrs. Coiistructioiial engineers Iinvo givcn D good dcnl of thought to this iispect, iind attempts hnvo Lccn inndo to coiistruct tlic nrchcs with 1111 npl)rccinbly grciitor riso tlinn Iiiis becn past prncticc, but so far tlicir ondci\vours in this tlircctioii ccuiiiot bc

Tlic Iiiglicst tcin1)crnturo iii tho Wcdgc furiincc is %jO”. ‘h2 tciii])ernturc at \vliicli tlic rcfrnctory tiles iiiid b1ocl;s coiistituting the Iicnrtlis sliould bc buriictl sllould not bo bolow 1400”. TI10 tilcs forming t l iu tinso should not bo iuiwioldy in sieo ; profcrnbly

Illotlcriltt!ly cool.

rcgnrded ns otl1cr tllilll tcntiiti\w.

tongiictl nnt t groovcd, niid tlic tliinncst possiblc joints slioiiltl bc cnsurctl.

Dryiitq tlsc burncr.-Tt is iisiial to stnrt wit11 R ~vootl lire nii tlic bottom, or scvciitli Iicnrtli, niitl to opcn out tlic doors two or tlircc stnges nhovc. ‘J’iiis is done to iivoitl coiidcnsntioii of tlic n p o u r in tlic iqq)cr licnrtlis. ‘l’lit- wood lire in l l ic bottom sliclf iicctls to bc coiitiniicd for t l i~cc or four tliiys ; tlicir II fiutlicr \vootl firc citii 11c stiirtccl 011 tlic fourth Iicnrtli. This slio.iilt1 IJC I i1 i i i i i t i i i i i c t l for n fiirthcr tlircc or foiir tliiys, by wliicli time the iiioistlirc of

niatlcrntc Iiciit iittiiinrtl. J t is now 1111 o]~portiiiio timc to coiii~iic~icc :t colic lire oil t l r t b t\\.o Iicnrtlis i n qiiestioii. ‘l’licse slioiiltl 1)t- stiirtctl gclitly iit first, hit grntliinlly iiiciciisctl iintil tlic tt*iiiI)criitiiro of tlic I~ctls is siicli tli:it tlic pyrites siiiiills igiiitu rcnclily \ ~ I i t * i i 1 Iirowi 011 tlic 1)ctls.

I’rcl)iiriitory to clirirgiiig, t Iic w t c r ~ i ~ ~ i t l i i t i o ~ ~ iirrniigcinciit r;lioultL be tcstctl, to ciisiirc tliiit no wiitcr joints or coniicsioiis iirc h i k i n g in tlic iiiiicr shift . ’l’lie clcvntor bpcctl iiiitl riitc o f fivxliiig

pyrites fcctliiig tlcvicca, wliicli t ~ l i c ~ tlic form of two iitljustiihlc iipcrtrircs fisctl iiroiiiitl tho celitrc of tho shaft itt givcn poiiits oii the tlcsiccntiiig liciirtli, niitl ~vli ic l i nrc in tlic forin of siiiitl Iiitcs.

O ~ E ~ I I I i t ; q t M c i ~ L Y . - ~ I s s pcrici i cc 11 :IS s~iowii t Iin t i t is iiiiwise to iiiniirt:~iii the cooliiig \vntcr in circuln- t ion for iiiorc t liiili 24 Iioiirs. ‘l‘lic tcinpcrnturo to ivIiicIi tlic witer is riiisctl Iciitls to tlic rcniovnl of tlic tciiilmrnry linrdncss, with coiiscqiiciit ttcpositioii of calciiiiii i i i it l rnrigiicsii!in snlts, \vliicli, if nllo~vctl to ncciiiniilatc, tiiinlly cniisc 11 bloc lag^ which will jcopardisc tlic life of tlic nrnis. Flusliing tlic uriiis witli \viitcr cvcry otlicr thy rciiiovcs iiiiy possi1)lo clcposit ion, iiiitl iiitls tlio cliiiiiiiiitioii of iiir locks, wliicli occiisioiinlly nrc 11 source of troublo.

Froiii i i si i l~~l i~ir ic w i t 1 ~iiiiii~ifiictiiriiifi point of view, tlic driiiiglit rc~giil~ition on the fuiniicc is of vitiil iiiiportiinec. \Vlicrc the fiiii is pliiccd nftcr

csccssiw s~iction, ~vliieli lciitls to tlic iiitrodiiction of air, with IL coiiscquciit high sodium nitriitu or nitric iicicl consiiiiiption. 011 tlic otlicr Iiiiiid, to rcguliitu Clic tlruiiglit SO tliiit no iiisorgiiiiisiitio1i of tlic cliiinibcr p1:iiit occurs, itiitl elliciciit coiiibilstioii of the pyrites ~ i i i i i l l ~ is ol,tiiiiietl, \vitli pr01)cr tctli-

lieat in tlic l o \ ~ c r Iiciirtlis, rcquircs not only t l iu coiitrol which cliciiiicnl tcsts nfTord, but iuucli sltill iind loiowletlgc of t h o irliosyiicrnsics of tlic pliint.

tlcvicc i i i t h o forin of ii slicnr pin, wIiicIi is calcu- liitcd to I)rcnl< wlicii un obstncle is met wit11 in tlie bctls. TI10 niitlior’s ospricnco is t h t this typo of siifcty device riiidy, i f cvcr, fiuictioiis nt 1110 psy~l10- logicnl nioiiicnt. It is fiir better to dcpciid up011 i L 3-iiinp. lead fuso wirc, pliiccd bctivccn t i l o torminiils of tilo motor switch, th11 to rcly on IL slicnr pin. A fuso wire is iiiiicli iiioro susceptiblo to t h o s l i g l i t ~ ~ t rjlioclc to tho nrins, r~nd I i i is dufinituly provcd olrcctiro in reducing brcnkagc:cs to ib niiiiiiiiuiii.

t l l C I,ricl;\vorlc sl1oultl Ilnvc I ~ r c l l cspcllctl, ant1 a

slioi1l(l Ills0 be c i i ~ f ~ i l l ~ ~ l i ~ c l i ~ t l , IIS iiitlcctl tl10

tile Clover to\\cr, tllc telltlcllcy is to secure 1111

1)criitui’cs i l l tile rcs]>ccti\.c beds, iiiitt iiot too 1ii11Cli

It is us~i i l for tlic ~iiitlicr~ to provitlo i~ d c t y

Journal o/ the Society oj Chemical Inditrtry.

.111iy 10, iny,.] 13llO\\ .S ATD I’.\IITIS(ITOS.-LE.\D nC#llATFS.

C‘ordmfion cJicicnc!/.-‘i‘licrc is no doubt thnt iiicchniiicnl pyrites Iiuiiicrs givc II liiglicr coiiilws- tion cfricicncy tlrnii 1iniitl-ol)crntctl l)iiniers, citticr of tlic I i i i i i p or siiinlls vnrict,y. II]lic cstciit of tlicir siiptariority tlcpciitls i n 11 lnrgc tlcgrcc mi tlic clinr- iIctt.rist ics o f tlic pyritw, but, brontlly spcnkiiig, tlicre is n snviiig of nboiit 16yn of siilpliiw, I)iisct\ oil t lit. wiglit of tlic ciiitlcrs, which reprtsciit nboitt 1.1 of tlir siilpliiir coiitciit of tlic origiiinl orc.

(7’0 6c roiilintied.)

LEAD BORATES. IIY E. C. lSltO\VS I S D J. R . I’,\RTISGTOS.

\:cry little work iipI‘c’nis to Iinvc I)ccii tloiie in rccciit Yciim 011 t l i ir sirbjcct, with t lit. esccpt ioii of tlint of €1. I-. Tlioiiil)~~ii (Tmiis. G‘tmiiii. Soc., l91!), 18, 51 I ) . I;iiriitl~~y (I’liil. ‘Jhiis., lS30, 120, I ) obtniiicrl nti iiirpiilu Itwl horatc by fiisiiig togctlicr lcntl iiitrntc, lcncl silicntc, niitl h i e ncitl. He also ol)tniiied n soft, yt~llo\v g1Iis.s hy fiisiiig togctlicr I12 parts of Iriitl osidc niitl 24 piirts of boric iicitl. N‘itli treblc tlic tlliiiiitity of boric ricitl Iic ol) t i i i i i r t l II

coloorlt*.~s, I innl filiiss w1iic.h WIS Iiiglily rc-friictivc. ‘ I ‘ l i ~ ~ work tliroiw no light oil tlic coiupositioii of t l l C sul~st;lllccs.

Solil)c+iiii (J. l’liiiriii. Chciii., 1R%, 11, 31) tic- scrilwtl tlic Iirqarntioii of n polyboriitc 3Pb0, 311,0,, .IH,O, I)y prccipitatiiig n hoiliiig soliilinii of horns with lcntl iiitriitc, tlic forincr hciiig in CWXSS.

C:. Rosc (l’ogg. A i i i i . , 1833, 29, 4-45) stntctl tliiit in tlic prcstwcc of ntincous niiiiiioiiia n lcnd incta- Ijorntc, P I i ( BO,),,H,O, wns foriiictl d i c n solutioiis of borns n i i t l iicutrnl lciicl nitrate wciv iiii%ctl iii tlic cold.

IItrnpatli (llliil. Mng., IS-N, (iii.), 34, X>) dcscribctl n t grccit length tlic ~ ~ ~ p i r n t i o i i of vnrioiis lend born teas : I’hO, U,O,, 21’1 10,:) l3,0;,, 1%0,’7 1320:l. H is iiiinlyws wcw, Iio\vcvcr, fiir froin ngiuciiig with tlic tlicorctical valucs iuqiiilrtl Ly t1ic.x coiiipoiiiids nilti tlic work cniiiiot. bc rcgiirtlctl ns vcry importnnt.

11. l!osc (l’ugg. A i i i i . , 1852, 87, 4iO) sliowctl 11it. csistciicc of various borntcs coiitniiiiiig I’bO : l&03 : H,O in fairly silnplo proportions (c.y., 2 : 1 : 2,

‘l’liesc w x c probably hydrolysis products obtniiictl by vnrying d c g i ~ s of wnslihig (scc I\lcllor, “ Trentbc,” vol. V., 19%).

Tlioiiipson ciitlenvooid to prcpnic I’b(SO,),,H,O (Icntl iiictiiborntc) by iiiisiiig cold sntiirntetl solutioiis of Icnd iiitiatc niicl borns i i i cqiiiiiiolcciilnr propor- tions, i i i tlic 1)rcseiicc of nqiicous niiiiiioiiin. Tlic prccipitutc, which scttlctl slowly, wns w\.nshctl I)y tlccniitntioii sc\~cral tiiiics, liiinlly liltcrcd witli siictioii niitl tlrictl n t 1OO”-IOs”. Tlionipsoii 011- tnhied ligurcs for PbO vnryiiig from (i531% to (is. 1 S yo.

In nil nltcriintivc iiicthod of prcpnrntion ‘I’lioin~isoo” nddctl nil L‘SCCSS of lend iiitrcita solutioii to tlic snt~irntctl horns solution, thus 01)tniiiiiig n ~iiorc IyipitlIy scttliiig 11rcc!j)itntc, which Iic trcatcd ns nbovc niitl tlrictl nt 00”--05”. 111 this Iic foiiiicl

: :I : 5).

PbO wrying froin 75.30% to 7G40%. Tlio pcr- cciitngc of I’bO rcquircd €or tlic inctnboratc i.; 71.72,

iuctliorls gnvc prccipitntcs of hitlcfiiiitc composition. 1 lioiiipoii ciitlcnvourctl to obtniii Soubcirnii‘s

polyborntc, 31’I~OJ:~13,O,,.~H,0, by ndtling 45 g. of sntiimtctl solutioii of IcntI iiitriitc coiitniiiiiig 16 g. of snlt to OOO C.C. of n solutioii of IS g. horns in the cold. Tlic prccipitntc, which wns grniiiilnr, settlctl irntlily niitl tluriiig 10-12 tlnys wns wnslietl \vcll by tlccniitntioii, Iiiinlly liltcrctl niitl tlrictl n t 110’. ‘l‘lioiiipsoii tliiis obtniiictl J’bO ( I ) 51.;?Syb, (2) i I*;?OO/,. Anotlicr prccipitntc diicli lie tlrictl a t S5” gnvc l%O = i 1 .S ix , J3,03=2P.51i%, 1120 =5.G7yo. 1;roiii thew rcsulls Tlioiiipsoii coiicliidctl tlint tho prc- cipitnte foriiictl \vns tlic iiictnborntc Pl~(130,)2,H,0 (l’b0 i I - i2%) niitl not tlic polyhorntc stntctl.

Htwq)ntli’s poIyl)orntc, l’b0,213,0,,4M20, was stntctl to hc foriiictl by boiliiig tlic piuvioris poly- I)orntc with nii csccss of soliitioii of boric ncitl. ‘l‘liis wns trictl 1)y ‘J‘lioiiipsoii, who ivnsliccl the Imc‘ipitntc wAI wit11 hot wntcr, wid tlrictl it ntq SS”, iiid obtniiictl tlic I’bO vnlurs ( I ) fji-I2?&, (2) G0.i77!0, bu t RS tlic foriiiula irqiiirctl 111AJ=(il.’7S~o, lie coiicluclcrl tliiit tlic prccipitntc wiis of iiitlcliiiitc coiiipo4 ioii.

11. Ic Clintclicr (lhill. SOC. cliiiii., 1S!)9, (iii.), 21, 35) fouiitl a i d cwiiiiiiitd n wries of niiliytlroiis crystnlliiit. lroriitcs of tlic gcncrnl foriiiula 31~,0,,310, e.g., 3l3,0~,,IAiO. I-Ic coricludcd that tlic lead compound uoiiltl I)c of the saiiic type BJz,O,,l’b0, aiitl siippos“t1 tlint this is foriiictl I J ~ fusioii of lcncl cnrboiintc with boric ncitl.

rlllioiiil)soii fiisctl p i i r c IAI cnrlJoiintc wit11 four to five tiiiirs tlic cdculntctl quniitity of ivcrystnllkctl . boric acid riiitil ii liiiipid iiiclt wis obtniiictl. Tlic coolccl iiinss wns fiiicly powtlcrcd in nil ngntc niortnr niicl waslid with cold wntcr I)y dccniitatioii diiriiig fourtccii tluys. Tlic irsiduc, nftcr filtcriiig niitl tlryiiig u t IO;,”-l lo”, was ngniii fiiicly ground and wnslictl wit11 cold water. Tlik wns filtcrctl and clrictl a t 103”--I 10”. ‘J’lionipsoii obtniilcrl 1’)Jo= .71.210,{, ant1 coiisitlcrcd tlint this was in ngrcciiieiit with tlic xeqiiirctl 61 .5% PbO of tlic Iicsnbornt~.

n11tl “llolu]~”on tllCrcf0rc concludctl that tl1csc r i

E ~ ~ l c r i l t l c ~ l I d . Tlic four sets of cqcrimcnts iiindc by Tlioinpsoil

wcrc rcpcntccl. 1’11 tlicse cspcriiiicnts tlic pcrccntagc of PbO wns obtained by dctcrluiiiiiig tlia lcnd gravi- iiictricnlly ns clvoiiintc. ‘I‘hc pcrcciitngc of B,03 wns obtniiiccl t)y n volumetric tlctcriiiiiintioil of tlic frcc boric ncitl ohtniiicd ns follows. Tlic lcatl borntc \WS suspciidctl in wntci,, n i ~ l Iiydrogcii srilpliitlc pnssccl with coiitiiiunl slinking, tliirs prccipitnting tlic lend ns siilpliitlc. ‘J’his wns filtcrcd off niitl tlirougli tlic lilti-ntc niid wnsliiiigs wns l~ubblctl nir frcc froiii carbon tliositlc i i i ortlcr to rciiiovc tlic OSCCSY of liyclrogcn sulpliitlc. !l!Iic frcc boric acid wns tlicil titrntctl ngaiiist ~ / 1 0 nlkali (frcc froni cnrboii diositlc) in the prcsciicc of glyccrol nntl iising pliciiol- plitlinlciii ns iiitlicntor (scc H. A. Cougtlon a i ~ l

Trentlwc!ll, “ Qiiniititntivc Aiinljrsis,” 1). 568). Tlio iigiircs yivcii nrc tlic iiicnii of iiiniiy rlctcriiiinntioiis.

5. 31. LOSSO, Chclll. NCW, Oct. 10, 1924, nlso

All expcriiiiciits w*crc done in solutioiw n t rooiu tcnipcrnturc iiiilcss otlicnvisc stntcd.

A sntiirntcd solution coiitn.uiiiig 10 g. of lent1 iiit.rntc wns ntltlcd to n sntiirntcd solution coiitnining 6.1 g. of piirc horns, to ~vliich lint1 lwcii ndtlctl 1 C.C. of coiicciitrotcd niiiiiioiiin solution, wit11 coiistniit stirring. 'l'liis wns trcntcd csnctly ns by Tlionipson in his first nttciiipt to prcpnre tlic nictnborntc nnd drictl n t 110'. Rcsults : PbO=S?-ISo(, ; U20,= -13*i(iyo. .

AR no iiiciitioii is iiintlc iii Tlioiiipsoii's pnlm of thc csnct qiiniitity of niiiiiioiiin ~iscd, tlic cslwriiiiciit wns rcpcntcd iisiiig tloiil)lc tlic qiiniitity of niiiiiioiiin. Results : PbO=S'7.SG% ; 1320,=11*31u/,.

'l'lic esperiiiiciit \\as tlicii rcpcnted using iio nmuionin. 1Lsulta : (i.) PbO=Ti.l50/ t3,0,= 15.250/, ; (ii.) ~bo='i7-3su/ , ; (iii.1 1'bO=oj'i.s%. B20,=16.6:JYo. 'l'lic boralc tlius prcpnwd ww scnrccly soliiblc in witc.*r, rentlily soliiblc iii (1:1) acetic, nitric, niitl liytlrocliloric ncids. On fiisioii i t gnvc n wry pnlc ~"llo\v glutrs.

'l'lic nltcriinti\v iiictliotl of 'J'lioiiipsoii wns n1.w rclwntctl. 11 sntiiriitctl soliitioii coiitniiiiiig 10 g. of lcntl iiitrntc wnn ntltletl with coiixtiiiit stirriiig to i i mtiirntctl soliitioii, coiitniiiiiig 5 g. o f horns, thc lcntl iiitnitc tl i i is beiiig iii c.~sccw of aiolcciilnr pro. portioiis. 'l'lic Iirecipitntc wttlctl Ripidly niitl wns trcntccl ns by 'l'lioiiipsoii, niitl clrictl a t 95". l~csiilts : (i.) l'bO=5G*;?(i~/,, 1&0,-15.25% : ( i i . ) l'bO= 78.1-t70, B,O,= 15.ci2yo ; (ui.) l'b0=78-I070, B,O,= 16.91%. 'l'lic prccipitntc wns IIION* soliiblc iii ncctic ncid tlinii tlic 1)revioiis prcpnrntioii niitl siiicc it scttlctl morc rupitlly i t wns iiiiicli cnsicr to wndi.

Wlicii csactly tlic sniuc riuniititics us iisctl I,y Thoiiipsoii in tlic prcpnrntioii of Soubcirnii's silt wcrc takcii, n prvcil)itute wis o1)tuiiictl \vliicli, wlicii trcntctl in n siiiiilor wny niitl tlrictl n t I lo", gnve t l i c followiiig set, of figures. Results : ( i . ) l'bO='i;?.q!)~~, B,O3=18.3r?0;, : (ii.) l'l)O=i6*I(io/o, U,O,=I.i-.Sq: ; (iii.) l 'bO=5i .35~o, J1,0,=19.1%. Tlic bornte t h i i s prcpnml wns n liiic white powder less solublc i i i acetic ncitl tliaii I., but ot.liciivisc siiiiilnr iii propcrtics.

111. 'l'hc l~orntc of Il. wis ntltlc~l to n boiliiig solution of boric ncitl (coiitniiiiiig five tiiiics iis iiiucli boric ncitl by wig l i t ns lend borntc talcen). Tlic prccipitate, trcntcd (is by 'l'lioiiipsoii, wns tlricd n t S5". Ilcsults : (i.) 1'1,0=76.58%, l%20n=18.JS~o ; (ii. ) l'bO = 7 7 -67 yo, 13203 = 18.1 7 Yo. TI1 is born t c irsciiiblcd borntc I. hi its propwtics.

Pun, lcnrl cnrbonntc (10 g.) \Yn8 fusctl wit.Ii 50 g. of rccrystnllisccl boric acid i i i R iiiclccl crucible uiitil n limpid iiiclt was obtniiicd. Tlic iiiclt sct

tliflicult to extract. To facilitntc t.lic cstrnct,ioii of tlic iiielt, it wns wntcr-coolcd froiii n wliitc licnt by dippiiig t,lic criiciblc in wntcr. Tlic cst.rnctct1 mass was trcntctl ns by Tlioiiipsoii, nnd tlricd a t 110'. 'I'lircc ])rcpiirntioiis iwrc iimlc, differing remnrlinbly fro111 ciicli otlicr. In tlic first two the

I.

11.

ISr.

a t n dull rctl 1icat to n glass nlld wns tl1us rcry

wliolc iiiclt u-ns groiiiitl, ~vliilst in tlic tliirtl oiily tlic corc wns csniniiictl. Iii 1111 tliwc, tlic effcct of ntltlit ioiinl \vnshiiig was vciy iiitwkcd. Rcsdtu : l'rcpiirntioii ( I ) , nivhitcglossy powlcr: I'I~O=f(i*G30/o ; ivivnslicd l'bO=.X.G?%, R20,=:il*l(i%. 'J'h 1JOrntc lifter wnsliiiig wns t i dusty wliitc po~vtlcr. l'mpnrn- tioii (?), n givyi~li po\vdcr: l.%Jo=(i!t*:H~o ; rc-wnshctl, 1'1)0= i 1 .!bt%, 1%203=22*44y$. Tlic borntc nf tcr wisliiiig wiis n givy, fliiity powtlcr niicl ICK! SOIIIIJIC iii ncctic ncitl tlinii prcprntioii (1 ) . I'rcpnrntioii (3), siiiiilnr to 1)rcpnriitioii (2) : P l ~ O = ( j o - 2 4 ~ ~ ; m-ivnhxl,

sitlernldy oii unsliiiig. Iii nll tlirec cnws tlic boratcs wcrc ritn.iiicly linnl niitl ilifficiilt to griiitl. Qiinli- tiitivc tt-sts gnvc no iiitlicntioii of tlic pirsciicc of iiickc.1 in tlicse tlircc borntcs.

1 ' 1 ) ( ) = ~ ~ ~ { * ~ ~ > ' ~ ~ . 'r]Ih !JOl.ntC nlS0 I l l I r ~ x l l C t l CO11-

S r r n r wiry . 'J'lic CIIJOVC figiircn give littlr, if nay, positivc

cvitlciice for tlic csistciicc of n siniple borntc of Icntl. 'J'lic oiily pnprntioiis which g n ~ c coiisistcnt coiiipodioiis \vcm tliosc of Jlct l id T. 'l'1ic.w ligtims, Iio\vcvcr, corrcspoiid to iio simplc foriiiiiln, tlic ratios I~ciiig l'bO : : JI,O=3.7 : l.ci(5) : 3.3 for tlic pwpnriitioiis iir prcsciicc of nniiiioiiin niitl 1.7 : 1-2 : 1.S for tlic prclinrntioiiri in nbsciicc of iiiiiiiioiiiii. 'hvo fnctors grently nircct tlic prtynrn- tioii o f the 1)onitcs:-

I . [I%c rrittly occlrrxiori o j Icml iiilrcttc by tlrc imcip i - ttt/c.-Iii tlie cciw o f tlic I)riyiirntioiis by JIctliocl T. this wns iiiost iiinrkccl. Tlionipsoii iiinkcs no rcfcr- imc to tlib cwxpt tlint proloiigcd ~vnsliiiig of tlic prccipitntcs is iicccenry.

'l'lic dicct of nildiiig thc borns soliitioii t o tlic lead solutior. was tried, but no iilnrkctl diffcrciicc irsiiltctl. The rc~inovnl of occliidcd lend iiitmte was n tliflicult iiinttcr. Even nftcr foiir or fivu wnslibigs by tlcciiiitntioii (a do\\* niitl iiincciiriitc process owiiig to tlic doir rntc of rjcttliiig of tlic prccipitatc) aid furtlier wisliiiig on tlic 1)1iiiip, the tlriccl product still guve sigiis of tlie ~~rcsciicc of iiitrntc wlicii fused, n pnle yellow glass rcrjultiiig niitl brown fuiiics being c\~olred. With rcpntcd wnaliing the prceipitutc ~110\vcd n iiiarltctl tciitlciicy to pnss t IiroiigIi tlic filtcr-pnpcr. 3. Y'ke rjjcct of trashi,cg cmrtot (Ic rtqlcc(u1 (c j .

Prqxtratirc 7rretlrod 1 l'.).-'J'lic motlicr liquor of tlic first two or thrcc dccciiitntioiis ivns gciicrnlly clcnr, but furtlicr wasliiiig protluccd iiiilky liquors ~vhicli gnvc 110 iiitlicatioii of scttliiig oil loiig stnntlhig. In tlic casc of tho fusioii prcprntioiis t h r c ivn8 i~ w r y ninrkctl clinngc aftcr wasliiiig.

k'roin tlicsc cx-pcrhnciitu it nppcnrs that sucli borntcs of lcad ns Iinrc been tlcscribctl nrc lmic substances, tlic composition of wliicli tlcpciids 011 tlic coiiceiitrntioii niid tcinpcr~turc of tlic rcnctiiig solutions, mitt tlic tlcgrcc of wnsliiiig to wliich the prccipitntcs nrc subjcctctl.

University of Lontloii. Enst Lolitloll c'ollcyc,