The Melting of Platinum and the New Metallurgy of … · The Melting of Platinum and the New Metallurgy of Deville and Dehrav ... for platinum. ” HENRI SAINTE-CE AIR E DEMI.IE AND

15

The Melting of Platinum and the New Metallurgy of Deville and Dehrav

“ / t is therefore necessary to have a m ethod o f treatment more expeditious and more practical than that now adopted. It is fo r this reason that we are proposing an entirely new metallurgy for platinum. ”

H E N R I S A I N T E - C E A I R E D E M I . I E A N D J U L E S H E N R I D E B R A Y

All the p la t inum so far described as having been worked into useful articles had been p rep a red from the p ow der form by hot forging, an d all a t tem p ts at its melting h ad succeeded only on a m ost m inu te scale. T h e t im e was approach ing , however, w hen m elted p la t in u m was to becom e available to industry . T h e first effective p rocedure w as devised by R o b er t H are , the young son of a b rew er of the same nam e in P h iladelphia w ho h ad em ig ra ted from E n g lan d in 1773 an d who later becam e Speaker of the S ta te S enate of Pennsylvania. W hile a t ten d in g the lectures on chem istry given by J a m e s W oodhouse at the Univers ity of Pennsylvania and also helping his fa ther in the b rew ery business the younger R obert H a re undertook research in his spare t im e in th e cellar of th e house in which he lodged on the corner of Dock S treet an d W a ln u t S treet (1). H e was deeply interested in the possibility of ob ta in ing very high tem p era tu res by m eans of an oxy-hydrogen blow-pipe an d he was also aw are of Lavois ier’s m elting of a very small am o u n t of p la t in u m by the use of oxygen alone, described in C h a p te r 4. H e felt th a t Lavoisier’s a p p a ra tu s was bo th too unwieldy an d too expensive, while he reasoned th a t a n even h igher tem p era tu re w ould be o b ta in ed by the com bustion of hydrogen an d oxygen together. H e therefore designed an d built the ap p a ra tu s i l lustrated on the following page, based up o n a b a rre l from the brewery an d not noticeably less unwieldy or less com plicated th an Lavoisier’s e q u ip m e n t ! By supply ing a lam p or a cand le with a con tinuous s tream of oxygen an d hydrogen kept in s torage vessels an d expelled by hydros ta t ic p ressure th rough a com m on orifice, H a re was able to melt a n u m b e r of substances, among them platinum , th a t h ad h i ther to been regarded as extrem ely refractory. H e had in fact achieved the highest tem p e ra tu re as yet a tta ined.

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“A History of Platinum and its Allied Metals”, by Donald McDonald and Leslie B. Hunt

© 1982 Johnson Matthey

T h e a p p a r a tu s des igned and built by R obert H a r e in 1801 for the m el t ing of p la t in um a n d o th e r re f ra c to r ) s u b stances. Based u po n a b arre l from his fa th e r 's b rew e ry , it c o m p r i s e d two s e p a r a t e sto rage vessels for hydrogen an d oxygen , the gases being d r iv en th rough a com m on orifice in to the flame of a lam p, shown at th e top left, m o un te d on an ad ju s tab le table

Hare had become a member of the Chemical Society of Philadelphia, founded in 1792, of which James Woodhouse was President, and in December 1801 he demonstrated his apparatus before the society. His long and detailed account of the equipment and his experiments was immediately published in pamphlet form by the society and was reproduced in England in The Philosophical M agazine and in France in the Annales de Chim ie (2).

Among his fellow boarders in the house was Benjamin Silliman (1779-1864) who had been invited to accept the chair of chemistry at Yale but having no knowledge of the subject had been sent to study at the University of Pennsylvania. He and Hare co-operated in improving the apparatus and in obtaining a higher purity oxygen by heating potassium chlorate in stone retorts. Silliman later recorded in his autobiography:

“The retorts were purchased by me at a dollar each and as they were usually broken in the experiment the research was rather costly, but my friend furnished experience and as 1 was daily acquiring it 1 was rewarded both for labour and expense by the brilliant results of our experiments. ” (3)

During the winter of 1802-1803 Hare had an opportunity of demonstrating272



his blow-pipe to the discoverer of oxygen, Jo sep h Priestley, now ap p ro ach in g seventy, who it will be rem em b ered had been inform ed by B enjam in Franklin tw enty years earlier of Lavoisier’s experim ent. Priestley acknow ledged th a t H a re ’s experim ents were “ qu ite o r ig in a l” . (4)

For a n u m b er of years H a re w as occupied in the brew ery business, and then in 1818 he becam e for a short t im e Professor of N a tu ra l Philosophy at the College of W illiam an d M ary in W ill iam sburg b u t was soon ap p o in ted to the post he had long earnestly desired, Professor of C hem is try in the M ed ica l School of the University of Pennsylvania. H ere he took up the s tudy of electricity, collaborating w ith J o se p h H e n ry an d corresponding with M ichae l Faraday . Silliman, on the o ther hand , annua lly d em o n s tra ted the fusion of p la t in u m and of o ther substances by m eans of H a r e ’s b low -pipe to his s tuden ts at Yale.

The C ontroversy w ith Professor ClarkeA lthough H a re did not p u rsu e his b low -pipe researches any fu r the r for a nu m b er of years he was aroused to great ind ignation in 1819 by w h a t ap peared to him an ap p ro p r ia t io n of his invention. A letter from a M r. H. I. Brooke of Keppel S treet in L on d o n to T h o m s o n ’s Annals of Philosophy in 1816 described the design of a new form of blow -pipe w hich the writer h ad asked the in s tru m en t m aker J o h n N e w m an to construc t (5). T h is cam e to the notice of E d w a rd Daniel

E d w a r d D a n i e l C l a r k e I 769 - I 8 2 2

P ro fe s so r of M ine ra logy al C a m b r id g e a n d a f r ie n d of W ol la s to n . S m ith so n T e n n a n t a n d H u m p h r y D avy , C la rk e e x p e r im e n te d with a n im p ro v e d fo rm of blow p ipe f rom 1816 un t i l his d e a th , successfu lly m e l t in g sm all q u a n t i t i e s of p la t in u m . A f te r d e s c r ib in g his resu lts in severa l p a p e r s , in 1819 he p u b l i sh e d a sm all book th a t p ro v o k e d R o b e r t H a r e to an in d ig n a n t re sp o n se

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Clarke, Professor of M in e ra lo g y at C am b rid g e , w ho h ad been in the habit of subm itt ing his mineral spec im ens to the o rd inary blow-pipe. C la rk e p ersuaded N ew m an to modify his a p p a ra tu s to som e ex tent a n d then p roceeded to carry out a nu m b er of experim ents w i th it, using hydrogen a n d oxygen in the carefully controlled proportions of two to one. H e m elted a range of substances , including p la t inum an d pallad ium , and b eg a n to pub lish a series of papers , first in the Royal In s t i tu tio n ’s Quarterly Journal of Science an d then in the Annals of Philosophy (6). In the first of these papers h e wrote:

“ Platinum was not only fused the instant it was brought into contact with the flame of the ignited gas, but the melted metal ran down into drops. ”

W ollaston then wrote to h im suggesting th a t he tr ied to m elt “ ore of i r id iu m ” an d this he claim ed to have d o n e successfully as well as m elting a small q u an t i ty of irid ium -osm ium residue th a t h a d belonged to S m ithson T e n n a n t . After m any further experiments, and after suffering a dangerous explosion of his ap p a ra tu s , C larke devised a w ooden screen to p ro tec t him self or his m an-servan t, an d again he melted p la t in u m b u t only in small quantit ies . T h e n in 1819 he pub lished a small book (7) describing the w h o le ran g e of his work, the in troduc tion inc luding the sentence:

“ The American Chemists lay claim to it as their invention in consequence of

In s tead o f using two s e p a ra te c o n ta in e r s for his oxygen a n d h y d ro g e n C la r k e em p lo y e d only one . w ith th e c o n s e q u e n t d a n g e r o f exp los ion . A f te r o n e such e x p e r ie n c e he dev ised a w o o d en sc ree n to p ro tec t h im se l f or his m an s e r v a n t w h i l e m e l t i n g p la t in u m a n d o th e r s u b s ta n ces with his blow pipe.

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experiments made in 1802 by Mr. Robert Hare, junior, Professor of Natural Philosophy in Philadelphia.”

O n receiving a copy of the book H a re im m edia te ly reacted angrily, ad d ress ing a long letter to his friend S illim an who h ad ju s t recently founded th e American Journal of Science and Arts, quo ting some lines of Virgil w ri t ten o n hearing th a t the R o m an d ram a tis t Bathyllus had cla im ed some of his own verses (8). T h e opening page of this d ia tr ibe is rep roduced here. O n e of his more interesting com m ents was:

“ He (Clarke) would evidently wish the reader to adopt the false impression that the facility with which platinum may be fused is owing to ‘the great improvements’ made fourteen or fifteen years after I had devised and used them. Will Britons tolerate such conduct in their professors?”

H art's Blowpipe* 281

C H E M IST R Y , PHYSICS AND T H E A R TS.

T h e o p e n in g page o f H a r e ' s le t ter to the American Journal o f Science in w hich he a t t a c k e d C la rk e fo r w ha t he co n s id e red to be th e a p p r o p r i a t i o n of his inven t ion . T h e L a t in l ines f rom Virgil r e a d in t r an s la t io n :

“ I indeed have m ade these verses but a n o th e r has received the honour.So your b ird s m ake nests, not for yourselves.So your sheep b e a r fleeces, not for yourselves.So your bees m ake honey, not for yourselves.So your oxen do not b ea r the p lough for yourselves. ”

A jit. X I I I .— Strictures on a publication, entitled Clark's Gas Blowpipe ; by R o b e r t H a r k , J\l. D . Professor of Chemistry in the mcdical department o f the University of Pennsylvania, and the real inventor o f the compound or hydro-oxygen fdourpipe, in that safe and cjficicnt fo rm by which the fusion o f tkr most refractory earthst and the uo/a- tUization and combustion o f P latinum teas firs t accomplished.

(los ego vrrsiculos fed, tulit alter honores,S ir vos non vobis niWtiiciiiis ;»ves,Sic vos non vubis V«*ll«‘ra frrti * ©ves,Sic vos non votws «nHili<-ati«c apes,Sic vos non vobis fen is aratra Coves.

VI ROIL.

D r . C i .a r k has published a book on the G as B low pipe, in w hich he professes a “ sincere desire to ren d er every one his due.** T h a t it would be ditiicult for the conduct o f any au thor to be m ore d iscordant w ith these professions, I pledge m yself to prove in the following pages, to any reader w hose love o f ju s tic e m ay gain for them an attentive perusal.

In the y ea r 1802, in a m em oir republished in the 14th Vol. o f T illo c h ’s P h ilosoph ical M agazine, L ondon , and in d ie 45 th V ol. o f the A nualc* de C liim ie , 1 had given the rationale o f the heat p roduced by th e com bustion o f the aerifonn e lem ents o f w ater, and hud devised a inode o f igniting them free from the danger o f explosion . I had also stated in the sam e m em oir that the light and h ea t o f the flame thus p roduced w ere so intense, that the eyes could scarcely sustain the one , no r the m ost refractory substances resist the o th e r, and had likewise m entioned ih e fusion o f the pure earth s and volatilization o f th e perfect m etals as am ong the resu lts o f the invention. *

S ubsequen tly in the first part o f the 0 th V ol. o f A m erican P hilosophical T ran sac tio n s, an account o f the fusion of s tron tite s , and the volatilization o f P la tiuu iu , w as published by me.

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T h e letter also conta ined a series of d raw ings of th e various forms of the co m p o u n d blow-pipe as devised by H a re over the years. C larke died in 1822 and there is no evidence that he ever re sp o n d ed to or acknow ledged this ra th e r harsh piece of criticism, or th a t he p u rs u e d his work on the m elting of p la t in u m any further.

O n his part, H a re again took up the subject after a long interval. In 1836 he m ad e a visit to E ng land an d a t te n d e d the m eeting of the British Associa tion for the A dvancem ent of Science, h e ld th a t year in Bristol, m eeting the leading scientists of the time including th e seventy yea r old J o h n D alton , then a Vice- President of the C hem istry Section, a n d con tr ibu ting several short p ap e rs on im provem ents in chemical a p p a ra tu s . In A ugust 1837 he w ro te to D a lto n to report his melting of a m ore su b s tan t ia l q u an t i ty of p la t inum :

“ I beg leave through you to communicate to the British Association for the Advancement of Sciences that by an improvement in the method of constructing and supplying the hydro-oxygen blow-pipe, originally invented by me in the year 1801, I have succeeded in fusing into a malleable mass more than three fourths of a pound of platina. In all I fused more than two pounds fourteen ounces into four masses, averaging of course nearly the weight above mentioned. I see no difficulty in succeeding with much larger weights.”

T h is letter was duly read to the British A ssocia tion by D a l to n during its m eeting in Liverpool a m o n th la te r (9), b u t H a re was still not satisfied. In S ep tem ber 1838 he exhibited to the C hem ica l Society of P h ilade lph ia an even larger specimen of p la tinum , w ri t in g to S illiman:

“ I have by improvements in my process for fusing platina succeeded in reducing twenty-five ounces of that metal to a state so liquid that, the containing cavity not being sufficiently capacious, about two ounces overflowed it, leaving a mass of twenty- three ounces. I repeat that I see no difficulty in extending the power of my apparatus to the fusion of much larger masses. ” (10)

After a fur ther interval of so m e eight years H are , tow ards the end of his occupation of the cha ir of chem is try , an n o u n ced the m elting of b o th irid ium an d rhodium , specimens of which he h ad ob ta ined from Jo h n so n an d Cock. (11)

H are took no com m ercial ad v a n ta g e of his long series of investigations, b u t his work did lead to two fu rther deve lopm ents in qu ite different directions. First, his oxy-hydrogen blow-pipe w a s a d a p te d to good effect by the Sco tsm an T h o m a s D ru m m o n d (1797-1840) who served in his earlier years in the British O rd n a n c e Survey where he devised a source of intense w hite light by directing the flame on to a block of lime. T h is was designed as a n im provem ent to navigational safety, and his invention b eg a n to be installed in lighthouses in 1829, later being adop ted for th e th ea tre from w here th e expression “ in the lim eligh t” originated.

W orking with this m eans o f i l lum ination in Paris, M arc A n to ine G a u d in (1804—1880), a former studen t o f bo th D u m a s and A m p ère w ho w as em ployed by th e Bureau of Longitude, p re sen ted a p a p e r to the A cad ém ie des Sciences in 1838 in which he described his m e th o d of p rep a r in g a crysta lline form of lime

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from which he m ad e crucibles (12). In these he w as ab le to m elt a n alloy of 10 per cent iridium an d 90 per cent p la t inum , a lm ost certain ly the first occasion on which a synthetic alloy of p la t in u m h a d been produced . H e co m m en ted on the lustre, the malleability an d the ex trem e resis tance to corrosion of his alloy.

T h e second an d m ore significant ou tcom e of H a r e ’s work was d u e to his assistant in the U niversity of Pennsylvania. T h is was J o a q u im Bishop (1806-1886) w ho after working in the jew elle ry t rad e a n d then in a b ra ss foundry becam e H a r e ’s in s trum en t m aker in 1832 a n d took p a r t in th e experim ents on pla tinum . Leaving H a re in 1839, he set up in business for h im self and so founded the p la t in u m works th a t bo re his n am e for very m an y years and tha t will be dealt w ith m ore fully in a la te r chapter .

The Work of D ev il le and D ebrayH are noticed th a t if he m a in ta ined his m olten p la t in u m in an oxidising a tm osphere it g radually freed itself from any base m etals p resen t by oxidation, and it was this observation th a t led to the next m ajo r step forw ard in the history of p la tinum , this taking place in Paris in the eighteen-fifties at the han d s of Deville an d D ebray an d consti tu ting a revolution in the p la t in u m industry.

H enri Sain te-C laire Deville was b o rn in St. T h o m as , one of the V irgin Islands, the son of a prosperous ship ow ner w ho h ad em ig ra ted from F rance. H e was sent to Paris to be educated , s tudy ing m edicine b u t also a t ten d in g the lectures of T h e n a rd a t the Sorbonne. In 1839 he set up a small p rivate labora to ry in which he began to m ake original investigations on organ ic substances inc luding essential oils. O n the reco m m en d a tio n of T h e n a rd he was appo in ted Professor of C hem is try at Besançon in 1845 a t the age of only twenty-six. W h e n B alard was appo in ted Professor of C hem is try in the College de F ran c e in 1851 Deville succeeded h im at the École N o rm a le w here he rem a in ed for the rest of his life, converting a m ost in adequa te labora to ry for the tra in ing of teachers into one of the ou ts tand ing centres of research in Europe. H e re he found J u le s H en r i Debray, a native of A m iens w ho h ad been a s tuden t th e re since 1847 and w hom he appo in ted as his assistant in 1855, the association developing into a great friendship an d a m ost fruitful co llabora tion w ith D eb ray eventually succeeding him as professor.

T h e ten years following Deville’s ap p o in tm en t were cha rac te r ised by quite exceptional activity and achievem ent in the field of h igh tem p era tu re reactions. F irst he succeeded in producing a lu m in iu m by the reduc tion of its ch loride with potassium , later w ith sodium, an d his results being b ro u g h t to the a t ten t io n of N apoleon III by D um as, he was given a governm ent g ran t to establish a pilot p lan t at Javel. T h is was followed by the erection of a larger works a t N an te rre , Deville an d his colleagues D eb ray a n d Paul M o r in subscrib ing capita l to form the Société de P A lum inium de N ante rre .

W ith p roduc tion established, Deville re tu rn ed to his labo ra to ry and again gave his m ind to the need for be t te r m ethods of p ro duc ing h igh tem pera tu res . In

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H en r i S a in te -C la ire I)ev il le

1818-1881P ro f e s s o r of C h e m is t ry a l the Ecole N o r m a le in P a r i s . Devi l le fo l low ed u p his r e se a rc h e s on ih e p ro d u c t io n o f a l u m i n i u m by s tu d y in g the m e ta l lu rg y o f th e p l a t in u m m e ta ls . In 1857 he a n d J u l e s D e b ra y d ev ised t h e lime- block fu rn a c e f ired by a m ix tu re of oxygen a n d coal gas w h ich for th e first t im e m a d e it poss ib le to re f in e an d m el t p l a t i n u m a n d al loys on a large sca le . T h e i r m e th o d r e m a i n e d in use un t i l the d e v e lo p m e n t of th e in d u c t io n f u rn a c e in th e 1920s

1856 he h ad published a long s tu d y of the use of coal gas a n d oxygen in blowpipes and their applica tion to b o th m elting a n d w elding in w hich he referred to the earlier work of G au d in (13). At first Deville an d D ebray used the eq u ip m ent to produce m anganese , ch ro m iu m , nickel an d cobalt in a s tate of purity , using crucibles m ad e of lime or m agnesia .

T h ey then tu rn ed to the p la t in u m m etals an d for four years p u rsu e d their researches with great activity. A lread y in the 1856 p a p e r Deville had m ad e the poin t tha t his m elted p la t inum h a d properties qu ite different from those of the po w d er m etallurgy product. H e h a d enjoyed th e co-opera tion of a P ar is ian goldsm ith and m an u fac tu re r of “ d o u b lé ” or rolled gold, A ugus te F ranço is Savard, an d he com m ented:

“Cast and refined platinum is a metal as soft as copper, as confirmed by the Paris Mint; it is whiter than ordinary platinum and does not have the porosity that has so far proved to be an obstacle in the manufacture of an impermeable doublé of platinum. ”

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Savard, whose firm, founded in 1829, still exists in the R u e S ain t Gilles, had pu t his furnaces an d rolling mills at Deville’s d isposal an d h ad m ad e a very th in piece of p la t inum -c lad copper th a t com pletely resisted the ac tion of n itr ic acid.

Deville a n d D e b ra y ’s final design of a fu rnace for the m elting of p la tinum , illustrated here, com prised two cylindrical blocks of lime b o u n d to ge ther with steel strip. A hollow was formed in the lower block to co n ta in th e m etal, a pouring channel being provided to th e edge. T h e u p p e r block w as also hollowed out to form a roof which was p ierced to receive the coal gas a n d oxygen. T h e whole unit could be tilted for pouring the m olten p la t inum . By this m eans p la t inum was not only m elted in q u an t i ty for the first t im e b u t could also be refined to som e extent by exposure to an oxidising a tm osphere , while the lime served to absorb any slag formed by the ox ida tion of base m eta l impurities.

Following this, Deville and D eb ray w en t on to devise a process for refining native p la tinum . T h e i r p re lim inary results w ere described to the A cad ém ie des Sciences in 1857 (14) a n d in the sam e year b o th F ren c h a n d British p a ten ts were filed, not in Deville’s n am e b u t in th a t of D ebray , a n d assigned for som e reason to the Société de l ’A lu m in u m de N a n te r re (15). T h e British rights w ere a t once

J u l e s H e n r i D e b r a y 1 8 2 7 - 1 8 8 8

A n a t iv e o f A m iens . D e b ra y s tu d ie d at the Eco le N o r m a le a n d th e n b e c a m e first a n a s s i s ta n t a n d la te r a c o l l a b o r a to r o f D ev i l le ’s, e v e n tu a l ly s u c c e e d in g h im as P ro f e s s o r t h e r e in 1881. T h e i r a s so c ia t io n w as e x t r e m e ly close, a n d t h e i r jo in t w o rk o n the m e l t in g of p l a t i n u m a n d its a lloys e x t e n d e d ov e r m a n v y ea r s

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François A uguste Savard1803-1875

T h e f o u n d e r o f a f i rm p ro d u c in g ro lled gold in P a r i s in 1 8 29 , S a v a r d t u r n e d to th e p r o d u c t io n of p la t i n u m -c l a d c o p p e r , b ra ss a n d s i lv e r in 1854. D u r in g th e r e s e a rc h e s o f D evi l le a n d D e b ra y he p u t a t t h e i r d isp o sa l bo th his f u rn a c e s a n d his ro l l in g m il ls so tha t they c o u ld in v e s t ig a te th e physica l p r o p e r t i e s of t h e i r a l loys. H e also p r o d u c e d e x t r e m e ly th in co a t in g s of p l a t i n u m o n c o p p e r f ro m th e i r m el ted m e ta l th a t d i sp la y e d c o m p le t e f r e e d o m f ro m p oros i ty . H is c o m p a n y c o n t in u e s in o p e r a t i o n to th is day

P h o to g r a p h by c o u rte s y of

VI. J e a n P ie r r e S a v a rd

acquired by George M atthey whose long career in the p latinum industry will be described in the next chapter, while the French patent was shortly afterwards acquired by Desmoutis and Chapuis.

T he response from Russia was even more positive. Ju s t at this time the government in St. Petersburg was considering restarting the minting of a platinum coinage, and in Ju n e 1859 their representative, Academician Boris Semenovich Yacobi (Known in W estern Europe as M oritz H erm an n Jacobi), Industrial Adviser to the M inistry of Finance, visited Paris to study the techniques of Deville and Debray. His visit coincided with the publication of a long paper by them, O n Platinum and the M etals that Accompany It (16), in which they detailed not only the properties of each of the six p latinum metals but gave a complete scheme for their analysis and finally proposed a simple and economical process for yielding a ductile and industrially useful iridium-rhodium-platinum alloy directly from the Russian mineral. T he process included the preliminary alloying of the native platinum w ith lead to separate osmiridium and earthy matter, the lead alloy then being cupelled to leave the p latinum rich material ready for melting.

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T h e o p e n in g p a g e of o n e of D e v i l i e a n d D e b r a y ' s n u m e r o u s p a p e r s on the m e ta l lu rg y of the p l a t in u m m eta ls . T h is o n e . f ro m the Annates de Chimie et de Physique in 1861. d e s c r ib e s t h e i r work on th e re f in ing of na t ive p l a t in u m on b e h a l f of th e R u ss ian g o v e rn m e n t

DE LA

MÉTALLURGIE DU PLATINEHT M U

MÉTAUX QUI L’ACCOMPAGNENT,

P a b MM. H. SAINTE-CLAIRE DEVILLE e t H . DEBHAY.

Nous avons exposé, dans le L VIe volume de ces Annotes, un projet de métallurgie nouvelle du platine fondée sur l’emploi des moyens de la voie sèche : notre travail était liai et publié, lorsque le Gouvernement russe, par l’intermédiaire de M. Jacobi, conseiller d’État et membre de l’Académie des Sciences de Saint-Pétersbourg, nous proposa d’étudier, sur une échelle relativement assez grande, touie la partie pratique de la question que le manque de matériaux nous avait obligés de négliger momentanément. Nous avons accepté cette mission avec empressement, en nous imposant à nous-mêmes la condition de diriger nos travaux de telle manière qu’ils pussent être adaptés le plus complètement possible aux besoins du Gouvernement russe. La Monnaie de Russie reçoit en effet chaque année des quantités de minerai de platine de l'Oural assez variables, qu’elle traite elle-même par un procédé qui sera bientôt

Deville and Debray demonstrated their process to Jacobi, who was so impressed that he asked his Minister of Finance to sponsor further research on melting and on the working up of the residues that had accum ulated in great quantity in the refinery in St. Petersburg. An agreement was quickly concluded by which the Russian government financed the setting up of furnaces and of an oxygen plant in the École Normale and Deville and Debray were enabled to carry out their experiments on much larger quantities of material. O n February 23rd they received from St. Petersburg some 56 kilograms of mineral from the Demidov workings at Nizhny Tagil, demonetised coinage and refinery residues. O n June 15th “ after three and a half months of incessant work day and n igh t”, they delivered to Jacobi 42 kilograms of ingots, rolled sheet and cast objects, together with an ingot of iridium weighing ju s t over a kilogram. Their loss of platinum amounted to only 120 grams. This remarkable piece of work was described in detail in a further long paper (17), of which the opening page is reproduced here, with full particulars of the amounts of lead, oxygen and reagents consumed.

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A n o r ig in a l d r a w in g of ihe l im e-b lo ck f u r n a c e dev ised bv Devil le a n d D e b ra y for ib e m e l t in g of p l a t i n u m . T h e Iwo c y l in d e r s A a n d B w ere ho l lo w ed o u t a n d p ie r c e d at K to a d m i t th e o x y gen-coa l gas b u r n e r s . T h e m o l ten p l a t i n u m w as p o u r e d th ro u g h th e c h a n n e l on th e r ight by t i l t ing the f u r n a c e bv m e a n s o f th e le v e r C. T h i s ty p e of f u r n a c e r e m a in e d in use in t h e in d u s t ry fo r m an v years u n t i l th e d e v e lo p m e n t of the in d u c t io n f u r n a c e

Jacobi also enjoyed the use of the melting furnaces and rolling mills of Savard as well as of the facilities of the Paris M in t through the co-operation of its Director, Professor Pelouze, and in the December of 1859 he was able to send to the Minister of Finance thirty-eight medals struck in several alloys of platinum containing 5, 10 and 20 per cen t of iridium. These were first shown to the Académie des Sciences by Pelouze, together with an ingot of iridium weighing 267 grams which Jacobi presented to the Académie (18). Unfortunately, despite Ja co b i’s recommendation in a pam phle t published in 1860 (19), the Russian government abandoned all thoughts of a new p latinum coinage.

Despite this disappointment, Deville and Debray continued their intense work, elaborating their methods of preparing platinum and the other metals of the group in commercial quantities and in a high state of purity. In 1860 they laid before the Académie two ingots of p latinum weighing together 25 kilograms (20) while two years later they reported to them on the industrial progress so far m ade with their melting process (21). In this they referred to the casting of an ingot of platinum weighing 100 kilograms by George M atthey, “ the mass becoming so liquid that it filled exactly with metal every part of the mould and reproduced all its imperfections w ith unexpected precision” . In a footnote to one of their earlier papers (16) they had already recorded in referring to their two licensees that

“Today these procedures are functioning and are being perfected every day in the hands of the clever craftsmen to whom they have been confided. ”

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B o ris S em en o v ich J a c o b i 1801-1874

B o rn in P o t s d a m in G e r m a n y a n d k n o w n in his e a r ly y ea r s a s M ori tz H e r m a n n v o n J a c o b i , he left to m a k e his c a r e e r in R u ss ia a n d was a p p o in t e d P ro fe s so r a t th e U n iv e rs i ty of D o rp a t in 1834. l a te r m ov ing to St. P e t e r s b u r g to t a k e c h a rg e of th e P hys ic s la b o ra to ry of the A c a d e m y o f Sciences . In 1859, by then se rv in g also as In d u s t r i a l A dv ise r to th e R u s s ia n M inis try of F in a n c e , h e v isi ted P a r i s a n d s p o n so red f u r t h e r in ves tiga t ions by D evil le a n d D ebray b u t f a i led to p e r s u a d e his g o v e rn m e n t to r e - in t r o d u c e a p l a t i n u m coinage

T he N ew Standard MetresJacobi was again destined to play a part in the work of Deville and Debray. In 1867 a Great International Exhibition was held in Paris, he was among the visiting scientists and he took the opportunity to jo in in discussions on standard weights and measures in which the French were deeply interested because of their long sustained efforts to spread the use of the metric system. W ith Ja c o b i ’s support a committee of delegates from a large num ber of countries was formed and strongly recommended the universal adoption of metric weights and measures, this resulting in the setting up of the International Metric Com m ission in 1869

“for the construction and verification with the best appliances of modern science of new international standards of the metre and the kilogram”.

The Franco-Prussian W ar delayed things, but in 1872 the first full meeting took place with twenty-nine countries represented, leading to the Convention du M etre signed in Paris in 1875. This finally achieved the support of all the

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In 1873 th e P re s id e n t o f F r a n c e , L o u is A d o lp h e T h ie r s , to g e th e r w ith a n u m b e r o f his m in is te rs , pa id a visi t to D evil le 's l a b o r a t o r y in th e E co le N o r m a le to w i tn ess th e m e l t in g of ten k i lo g ra m s of i r id iu m —p l a t i n u m fo r t h e p r o d u c t io n o f th e new s t a n d a r d m e tre . Deville is s ta n d in g in f ro n t o f th e d o o r looking th o u g h t fu l : D e b ra y is a t th e o p p o s i t e en d of the f u rn a c e , w hile th e i r a s s i s t a n t C le m e n t is t i l t ing th e l im e-b lo ck to p o u r th e a lloy.T h e P re s id e n t is h o ld in g a p r o t e c t iv e glass in f ro n t of his eyes

important countries and the establishment of the still existing International Bureau of Weights and M easures with its headquarters in Paris (22).

An examination of the original s tandard metre, the M ètre des Archives, m ade by Janety in 1796 and described earlier in C hap ter 10, showed that the ends were no longer plane, but th e Convention decided that they would not go back to the original definition of the metre as one ten-millionth of a quarter of the world’s meridian, as there was no agreement as to its exact value. They preferred to use the M ètre des Archives “ in the state in which it is found” but to convert its length from an “ end” s tandard to a m arked “ line” standard.

T he next question to be decided was the most suitable material from which the new standard and its copies should be made, and in 1862 Deville and Debray put forward a suggestion that a n alloy of p latinum with 10 per cent of iridium offered the best possibilities. It has to recommend it high density, high melting point, great resistance to hum idity and air, a fine grain, perfect polish, great hardness and full malleability. Deville and Debray claimed to have put in ten years of study, assisted by m any other people, before they arrived at the possibility of preparing this m ateria l in a satisfactory form and were satisfied

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that it was better than anything else available. O ne of their greatest troubles had been encountered in the preparation of large ingots of this alloy, completely free from blisters and cavities. The only method available in those days of detecting their presence was the undertaking of very careful density determinations. Deville himself carried out large numbers of these, working long hours into the night and exhausting his strength in the service of the posterity that he dreamed of but could not hope to see (23). In one way and another the a ttem pts to produce a sufficiency of homogeneous metal occupied several years at the hands of Deville himself and his assistants, the Norwegian O. J . Broch, the Belgian J . S. Stas, and George M atthey (24). T im e after time the metal failed and, even after attaining the necessary qualities at its original preparation, was found to have taken up iron during the subsequent mechanical fabrication.

A detailed account of these matters and of the m ajor role played by George M atthey will be given in the next chapter.

During this work an immense num ber of analyses of the p latinum metals and mixtures thereof had to be undertaken, and the conscientiousness of Deville and his collaborators was such that continual advances were m ade in the accuracy of the determinations. T he final methods were set out by Deville and Stas in 1877-1878 and these remained the last word on the subject for a generation or more afterwards (25). All these labours connected with the metre filled up the last years of Deville’s life, but he had the satisfaction of seeing them completed before he died in 1881.

C onclusionThe important invention of the lime furnace by Deville and Debray enabled platinum to be melted commercially on a large scale for the first time and remained the sole means of effecting this until the coming of the induction furnace a great many years later. But it must not be thought that this a t once solved all the problems of the fabricator of platinum. It provided him with a means of preparing alloys b u t it was not the answer to all the questions raised in handling pure platinum. Here problems of purity gradually grew to be of paramount importance and it became evident tha t not only were the gases of the blowpipe capable of introducing impurities (and not only gaseous ones) into the melt, but that at the high tem perature involved the refractory was capable of yielding them too. The former could introduce oxygen, iron dust, and carbon and sulphur products from the coal-gas; the latter calcium and silicon from the reduction of the oxides of these elements in the lime. So the forging of sponge continued for a long time, and was still used by refiners for many years.

In addition to the introduction of melting, Deville’s work covered the commercial analysis, the refining, the alloying and the fabrication of all the six members of the p latinum group metals. Over twenty-five years of careful experimental work in these fields by such an experienced scientist pu t a t the disposal of the platinum industry a rationalised technique that formed the basis for the

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F o r sixty y e a r s , un t i l the d e v e lo p m e n t of th e Ajax* N o r t h r u p h ig h - f r e q u e n c y in d u c t io n f u r n a c e in 1918. the m e l t in g o f p l a t i n u m a n d its a l loys was c a r r i e d o u t on an in d u s t r i a l sc a le in th e l ime block f u r n a c e in t ro d u c e d by D evil le a n d D e b r a y , w ith an o x y -h y d ro g e n f lam e a n d the t i l t ing of th e f u rn a c e to p o u r th e m o l te n m eta l in to an ingot m o u ld

operations of all the firms working in it for at least the next thirty or forty years. In the hands of Deville, science and practice were brought together and an important industry m ade possible.

In July 1981 to commemorate the centenary of Deville’s death, an appreciation of his life and work was compiled by Dr. J . C. Chaston (26) who concluded his contribution with these w ords :

“The platinum industry has, since then, expanded to an extent far beyond anything he could have foreseen, but among those who laid its foundations there are few who deserve commemoration more than the modest, hard-working research worker and teacher, platinum chemist and technologist, Henri Sainte-Claire Deville.”

T he successful adoption of Deville and D ebray’s method of melting p latinum by leading refiners in England, F rance and Germ any will be described in the following two chapters.

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1 E. F. Smith. The Life of Robert Hare, Philadelphia, 19172 R. Hare, Memoir on the Supply and Application of the Blow-Pipe, Chemical

Society of Philadelphia, 1802; Phil. Mag., 1802, 14, 238-245; 298-308; Ann. C.him., 1803, 45, 1 13-138

3 N. Reingold, Science in Nineteenth Century America, London, 1966, 7—94 E. F. Smith, loc. cit., 85 H I. Brooke, Ann. Phil., 1816, 7, 3676 E. D. Clarke, Quart. J . Sci., 1817, 2, 104—125; Ann. Phil., 1817, 9, 89-967 E. D. Clarke, The Gas Blow-pipe, or Art of Fusion by Burning the Gaseous

Constituents of Water, London, 18198 R. Hare, A m .J . Sci., 1820, 2, 281-3029 R. Hare, A m .J . Sci., 1838, 33, 195-196

10 R. Hare, A m .J . Sci., 1839, 35, 328-329; Phil. M ag, 1839, 15, 487-48811 R. Hare, Am. J . Sci., 1846, 2, 365—36912 M. A. Gaudin, Comptes rendus, 1838, 6, 861-86313 H. Sainte-Claire Deville, Ann. Chim., 1856, 46, 182-20314 H. Sainte-Claire Deville and H. J. Debray, Comptes rendus, 1857, 44, 1101-110415 French patent 18532, British patent 1947, of 185716 H. Sainte-Claire Deville and H. J. Debray, Ann. C.him., 1859, 56, 385-496. This was

also published as a pamphlet17 H. Sainte-Claire Deville and H. J. Debray, Ann. Chim., 1861, 61, 5-14618 T.J. Pelouze, Comptes rendus, 1859, 49, 896—89719 B. S. Jacobi, About Platinum and its Use in Coinage, Imperial Academy of

Science, St. Petersburg, 1860 (in Russian)20 H. Sainte-Claire Deville and H. J. Debray, Comptes rendus, 1860, 50, 1038-103921 H. Sainte-Claire Deville and H. J. Debray, Comptes rendus, 1862, 54, 1139—1144;

Chem. News, 1862, 6, 150-15122 A. Perard and C. Volet, Les Mètres prototype du Bureau International, Paris,

1945; B. Swindells, Platinum Metals Rev., 1975, 19, 110—11323 H. Sainte-Claire Deville and H. J. Debray, Comptes rendus, 1875, 8 1, 83924 O. J. Broch, H. Sainte-Claire Deville and J. S. Stas, Ann. Chim., 1881, 22, 120-14425 H. Sainte-Claire Deville and J. S. Stas, De l’Analyse du Platine iridié, Paris,

Gauthier-Villars, 1878; Procès-Verbaux de Comité International des Poids et Mesures, 1877

26 J. C. Chaston, Platinum Metals Rev., 1981,25, 121-128

References for Chapter 15

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G eorge M atthey 1825-1913

J o in ing P. N. Jo h n so n as a n ap p re n t i c e a t the age of th i r tee n , he re t i red as C h a i rm a n of Jo h n so n M a t th e y a n d Co. L im ited w hen h e was eighty- four. D ur ing th is e x t r a o rd in a r i ly long c a re e r he d eve loped th e refin ing a n d fab r ica t ion of p l a t i n u m from a la bo ra to ry scale to a successful in dus tr ia l o p e ra t io n u pon w h ic h his successors h av e been ab le to build . H e was elected a Fellow of t h e Royal Socie ty in 1879

F rom a p o r tra i t in th e possess ion o f J o h n so n M atthey



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The Melting of Platinum and the New Metallurgy of … · The Melting of Platinum and the New Metallurgy of Deville and Dehrav ... for platinum. ” HENRI SAINTE-CE AIR E DEMI.IE AND