IN D U S T R IA L
1 - p
1 ^ / 1w l ^ r p p ~ n T " N y f 'f A N A LY TICA L E D IT IO N
Q jlli JQ ill W B 111 JG Bj JllJ.ll TI
20,800 Copies of This Issue PrintedC H E M I S T R Y
Is s u e d A p ril 15, 1939
V ol. 31, C o n s e c u tiv e N o . 15
H arrison E. H ow e, E ditor
Vol. 11, N o. 4
De t e r m i n a t i o n o f Un d i s s o l v e d Sl u d g e i n Us e d Oi l s...Harry Levin and Charles C. Towne 181
De t e r m i n a t i o n o f Di s s o l v e d Sl u d g e i n Us e d Oi l s .
Frank W. Hall, Harry Levin, and Wallace A. McMillan 183
Te t r a p h e n y l a h s o n i u m Ch l o r i d e a s An a l y t i c a l Re a g e n t . . Hobart H. Willard and George M. Smith 186
Du p l i c a t i n g Pi p e t s...Frederic E. Holmes 188
Sp e c t r o p h o t o m e t r i c De t e r m i n a t i o n o f Ni t r i t e a n d o f Ni t r i c Ox i d e i n Fu r n a c e At m o s p h e r e s . . . .
. . . . Herman A . Liebhafsky and Earl H. Winslow 189
Id e n t i f i c a t i o n o f Li n e s i n Qu a l i t a t i v e Sp e c t r o- g r a p h i c An a l y s i s...
W. C. Pierce, O. Ramirez Torres, and W. W. Marshall 191
De t e r m i n a t i o n o f Hy d r o g e n Pe r o x i d e a n d So m e Re l a t e d Pe r o x y g e n Co m p o u n d s...
. . J. S. Reichert, S. A. McNeight, and H. W. Rudel 194
St a n d a r d i z a t i o n o f So d i u m Th i o s u l f a t e b y Co p p e r, Us i n g Pe r c h l o r i c Ac i d ...Joseph J. Kolb 197
Qu a n t i t a t i v e De t e r m i n a t i o n o f Se l e n i u m i n Ti s s u e s a n d Fe c e s ...
... Ross A. Gortner, Jr., and Howard B. Lewis 198
Id e n t i f i c a t i o n o f Al d e h y d e s a n d Ke t o n e s b y Es t i m a t i o n o f Hy d r a z i n e Ni t r o g e n Ac c o r d i n g t o Ja m i e s o n Me t h o d...
... G. B. L. Smith and Thomas G. Wheat 200
C o l o r i m e t r i c D e t e r m i n a t i o n o f C h l o r i n e w i t h p - Am i n o d i m e t h y l a n i l i n e...
... D. H. Byers with M. G. Mellon 202
Se p a r a t i o n o f Wo o d Ex t r a c t i v e s i n t o Si m p l e r Co m p o n e n t s ...E . F. K u r t h 203
Fa c t o r s In f l u e n c i n g Qu a n t i t a t i v e De t e r m i n a t i o n o f Su l f a t e a s Ba r i u m Su l f a t e...
... Harold A. Fales and Will S. Thompson 206
De t e r m i n a t i o n o f Co p p e r i n Pa r i s Gr e e n a n d Or e s .
...J. P . Mehlig and T . P . Marsh 213
De t e r m i n a t i o n o f St r o n t i u m i n t h e Pr e s e n c e o f Ca l c i u m...
R. Norris Shreve, C. H. Watkins, and J. C. Browning 215
El e c t r o m e t r i c In d i c a t o r sw i t h De a d- St o p En d- Po i n t Sy s t e m. Ap p l i c a t i o n s t o Ne u t r a l i z a t i o n a n d Pr e c i p i t a t i o n Re a c t i o n s...
D. R. Clippinger with C. W. Foulk 216
Pr e p a r a t i o n o f Ca r b o n El e c t r o d e s f o r Sp e c t r o- g r a p h i c An a l y s i s...
... A. T. Myers and B. C. Brunstetter 218
Si n t e r e d- Gl a s s Fi l t e r s a n d Bu b b l e r s o f Py r e x . .
... Hosmer W. Stone and Louis C . Weisa 220
Th e r m o s t a t i c Ba t h f o r Lo w- Te m p e r a t u r e Vi s c o s i t y De t e r m i n a t i o n s...
...E. L. Baldeschwieler and L. Z. Wilcox 221
Hi g h- Pe r f o r m a n c e El e c t r o n i c Re l a y...
...Roland C. Hawes 222
Co r r e s p o n d e n c e: De t e r m i n i n g Go l d i n Cy a n i d e Pl a t i n g So l u t i o n s...
...Louis Weisberg; J. B. Kushner 223
M i c r o c h e m i s t r y :
De t e r m i n a t i o n o f An t i m o n y i n Wh i t e Me t a l s . . ... C . W , Anderson 224
An a l y t i c a l Ba l a n c e s i n Qu a n t i t a t i v e Mi c r o a n a l y s i s ...A . A . Benedetti-Pichler 226
Mo d i f i e d Pr e g l Sp i r a l Tu b e . . Charles W . Beazley 229
Ap p a r a t u sf o r Mi c r o a n a l y s i s o f Ga s ...
... C. H. Prescott, Jr., and James Morrison 230
Mo d e r n La b o r a t o r i e s:
Ch e m i c a l En g i n e e r i n g Bu i l d i n g a t Vi r g i n i a Po l y t e c h n i c In s t i t u t e . . . Frank C . Vilbrandt 234
T h e A m erica n C h e m ica l S o c ie ty assu m es n o re sp o n sib ility for th e s ta te m e n ts an d o p in io n s a d v a n o e d b y c o n trib u to r s t o it s p u b lic a tio n s.
P u b lic a t io n O ffice*
E d it o r ia l O ffic e : R o o m 7 0 6 , M ill« B u i l d i n g , W a s h i n g t o n , D . C . T e l e p h o n e : N a t io n a l 08-18. C a b le : J ie c h e m ( W a s h in g t o n )
P u b lish e d b y th e A m erica n C h e m ica l S o c ie ty , P u b lic a tio n Office, 2Qth <fc N o r th a m p to n S t s ., E a s to n , P a . E n te re d as seco n d -cla ss m a tte r a t th e P o st O ffice a t E a s to n , P a ., u n d er th e A c t of M a rch 3 , 1879, as 4 8 tim e s a year.
In d u str ia l E d itio n m o n th ly on th e 1 st; A n a ly tic a l E d itio n m o n th ly on th e 16th ; N e w s E d itio n o n th e 10th an d 2 0 th . A c c e p ta n c e for m a ilin g a t s p ecia l ra te of p o sta g e p ro v id ed for in S e c tio n 1 1 03, A c t o f O ctober 3, 1917, a u th o rize d J u ly 13, 1 9 18.
Ra t e s t o r Cu r r e n t Nu m b e r s: A n n u a l s u b scr ip tio n ra tes: In d u s t r i a l a n d En g i n e e r i n g Ch e m i s t r yco m p le te $ 6 .0 0 ; (a) In d u str ia l E d itio n $ 3 .0 0 ;
E a s t o n , P a .
A d v e r t is in g D e p a r t m e n t : 332 W e s t 4 2 n d S t r e e t , N e w Y o r k , N . Y . T e l e p h o n e : B r y a n t 9 -4 4 3 0
(6) A n a ly tic a l E d itio n $ 2 .5 0 ; (c) N e w s E d itio n $ 1 .5 0 ; (a ) a n d (6) to g e th e r ,
$ 5 .0 0 . F o reig n p o sta g e to co u n trie s n o t in th e P a n A m erica n U n io n , $ 2 .4 0 ; (a) $1 .2 0 ; ( b) $ 0 .6 0 ; (c) $ 0 .6 0 . C a n a d ia n p o sta g e o n e th ird th e s e ra tes.
S in g le c o p ies: (a) $ 0 .7 5 ; ( b) $ 0 .5 0 ; (c) $ 0 .1 0 . S p e cia l ra tes to m em b ers.
N o c la im s can b e a llo w ed for co p ie s of jo u rn a ls lo st in th e m a ils u n less such cla im s are r eceiv ed w ith in s ix t y d a y s o f th e d a te of issu e , a n d n o cla im s w ill b e a llo w e d for issu e s lo st as a re su lt of in su fficie n t n o tic e of ch a n g e of ad dress. (T e n d a y s ’ a d v a n c e n o tic e requ ired .) “ M iss in g from files”
ca n n o t b e a cc ep te d as th e rea so n for h o n o rin g a cla im . C harles L . P a r so n s.
B u sin ess M anager» M ills B u ild in g , W a sh in g to n , D . C ., U . S. A.
4 IND U STR IA L AND E N G IN E ER IN G CHEM ISTRY VOL. 11, NO. 4
M or e Ac c u r a t e - -A4 or e R a p i d — M o r e R e l i a b l e Than A
C o l o r i m e t e r
C E N C O - S H E A R D - S A N F O R D
P H O T E L O M E T E R
(Patent N o s. 2 ,0 5 1 ,3 1 7 and 2 ,0 5 1 ,3 2 0 )
P
H O T E L O M E T R IC m ethods of analysis replace m any of the usual colorimetric m ethods with slight modifications in procedure. No comparison standards are needed. A single calibration for any particular unknown holds indefinitely. Such simplification in laboratory practice greatly facilitates the work and saves much tim e in im portant analyses. For example, in the colorimetric determ ination of molyb
denum in steel, preparation of a new reference sample is required every few hours; with the “ Photelome- ter,” a single calibration holds indefinitely.
P R E S E N T A N A LY TIC A L A P P L IC A T IO N S F O R “ P H O T E L O M E T E R ”
Food A n alysis L e a d in m ic ro g ra m s C opper
Ir o n C a ro te n e F la v in
S le e l A n alysis M o ly b d e n u m M a n g a n e se C opper C h r o m iu m T it a n i u m V a n a d iu m
W ater A n alysis A m m o n ia M a g n e s iu m C a lc iu m S u lp h a te s N itr a te s N itr ite s A l u m i n u m
C h lo rin e
M iscellan eo u s C h r o m e P la tin g
S o lu tio n s S u lp h i te L iq u o rs
T a n n in L iq u o rs S o d i u m C h r o m a te S o d iu m D ic h r o m a te
C H I C A G O 17 00 Irving P k . Blvd .
Lak e vie w Station
For Full In fo rm a tio n , Ask For B u lletin No. 104F
sciî, a r a i i i R f j r n T ! E i c a
S C I E N T I F I C
I N S T R U M E N T S
dliii
New York • Boston • C H I C A G O • Toronto • Los Angeles L A B O R A T O R Y A P P A R A T U S
B O S T O N 79 A m herst St.
Cambridge A Station
APRIL 15, 1939 ANALYTICAL E D ITIO N 5
R E A D Y !
. . . for Analytical Work
M A L L I N C K R O D T E T H E R A N H Y D R O U S A . R .
This M allinckrodt reagent need n ot be treated w ith sodium to m ake it completely anhydrous. W ith its fixed maximum lim it of 0.01%
w ater—w ith an equally low lim it for alcohol—and w ith its almost perfect freedom from peroxide, aldehyde, and substances darkened by sulfuric acid—M allinckrodt E th er Anhydrous is ready for use in the Grignard Reaction and all analytical purposes.
The catalog of M allinckrodt A nalytical Reagents and other Laboratory Chemicals lists nearly 500 items of th e high quality necessary for control and research work. All M allinckrodt A nalyti
cal Reagents are m anufactured to pre
determined maximum limits of im purities ; fully complying w ith A.C.S. specifica
tions, where such specifications have been published. Ask your distribu
to r for a copy of the new cata
log showing these maximum limits of impurities.
C H IC A G O
ST. LO U IS NEW Y O R K
P H IL A D E L P H IA
C H E M I C A L W O R K S
6 INDUSTRIAL AND E N G IN E ER IN G CHEM ISTRY VOL. 11, NO. 4
Co R N 1 N G
Pyrex” is a registered trade-m ark and indicates manufacture by
CORNING GLASS WORKS • CORNING, N. Y.
-means- Research in Glass
1^ '
PYREX
‘ PYREX” LABORATORY WARE— MADE OF THE
BALANCED
GLASSV I S I T T HE G L A S S C E N T E R AT T HE 1 9 3 9 N E W Y O R K W O R L D ’ S F AI R W i t h Balanced Glass you can be certain. Cer
tain that your laboratory ware is mechanically strong, thermally safe, chem ically stable. And you can be equally sure that its strength and its stability have been scientifically balanced.
Each property o f Balanced Glass is adjusted to every other property. N o n e has been enhanced at the expense o f another. A ll are com bined for maximum value—for all-around use.
It is the “Balance” in Pyrex brand Glass that
makes it preferred by all laboratories. It is this
“Balance” that makes “ Pyrex” Laboratory Ware an econom ical necessity for many laboratories.
“Pyrex” Ware at today’s prices is a better “ buy”
than ever before. Every laboratory can profitably standardize on Balanced Glass—can specify
“ Pyrex” Laboratory Ware, confident o f its su
periority, certain o f its efficiency, sure of its savings. Insist on the Balanced Glass. D aily use gives daily p roof o f your g o o d judgment.
□
N O M Y A N D E F F I C I E N C Y B O T H P R O V E IT
P A Y S T O S P E C I F Y “ P V H ” I M A M I D E
A PR IL 15, 1939 ANALYTICAL E D IT IO N 7
IF AUTOMATIC RECORDING CONTROLS FOR YOUR PLANT WHY NOT RECORDING “ ROBOTS” FOR YOUR LABORATORY
P odbielniak A u tom atic, R obot-O perated, Recording, Self-C hecking, L ow -Tem perature F raction ation A nalysis Apparatus M odel “*L”
(Nos. 895 and 896)
For the precise fractionation analysis of natural and refinery gases and gaso
lines, liquefied petroleum gases, m otor fuels, and all types of gas and volatile liquid m ixtures, to determ ine individual com ponents ranging in boiling point from HELIUM ( - 268.9°C.) to OCTANE (125°C.) w ith accuracy as high as 0.03%.
100% S T A N D A R D IZ A T IO N O F L O W -T E M P E R A T U R E F R A C T IO N A T IO N A P P A R A T U S A N D IT S O P E R A T IO N , m a t ic o p e r a tio n a n d r e c o r d in g s u b s t a n t ia lly e l i m i n a t e v a r ia b le a n d u n c e r t a in h u m a n e le m e n t s . A u t o - R O B O T P A Y S O U T IN SA V IN G L A BO R C O S T S . T h e R o b o t e ith e r r e le a s e s m o s t o f t h e o p e r a to r ’s t im e fo r o t h e r a c t iv i
t ie s , or m a k e s i t p o s sib le fo r o n e o p e r a to r t o a t t e n d tw o R o b o ts s im u lt a n e o u s ly . D is t illa t io n c u r v e s a re m a c h in e - p lo t t e d , r e q u ir e l i t t l e a d d it io n a l c a lc u la t io n .
3. H IG H L Y A C C U R A T E A N D D E PE N D A B L E . T h e R o b o t is s c ie n tific a lly d e s ig n e d t o g e t m o s t a c c u r a t e r e s u lt s i n l e a s t t im e . I ts u n f a ilin g m e c h a n ic a l c o n tr o l e le m e n t s a re o n t h e Job every s e c o n d ; h o w ev er, if a n a d j u s t m e n t i s im p r o p e r ly m a d e e it h e r in t h e f r a c t io n a t in g a p p a r a t u s p ro p er or i n t h e R o b o t, t h i s is g la r in g ly r ev ea led i n t h e m a c h in e - p lo t t e d d i s t i l l a t i o n cu r v es.
4. R O B O T F U L L Y PR O V EN IN M A N Y Y E A R S SU C C E S S F U L U SE . T h e R o b o t h a s b e e n i n a c tiv e in d u s t r ia l u se fo r m o r e t h a n five y e a rs a n d h a s f u lly d e m o n s t r a t e d i t s s u c c e s s f u l o p e r a tio n as c la im e d .
5. A U TO M A T IC A L L Y P L O T T E D S T R IP C H A R T C U R V E, c o n t i n u o u s , c o m p le t e a n d e x a c t, fr o m w h ic h p e r c e n t a g e s a re c a lc u la t e d b y s im p ly p r o -r a tin g le n g t h s o f d is t in c t iv e c u r v e p o r tio n s . S p e c ia l le n g t h w is e m il lim e t e r a n d tr a n s v e r s e te m p e r a t u r e r u l in g s a n d m a r k in g s, w it h h y d r o c a r b o n v a p o r p r e ss u r e s e c t io n s . A n o r ig in a l, u n b ia s e d r e p o r t fo r t h e e x e c u t iv e s u p e r in t e n d e n t , or fo r u se a s c o u r t e v id e n c e .
6. A U T O M A T IC A L L Y P L O T T E D T E L L -T A L E D IS T IL L A T IO N T IM E R A TE C URVE, s e r v in g a s a s p e c ific c h e c k o n t h e c o r r e c tn e ss o f R o b o t a d j u s t m e n t s a n d o n t h e c o r r e c t f u n c t io n in g o f t h e e n tir e a p p a r a tu s.
7. A D JU ST A B L E FO R A C C U R A C Y A N D T O T A L T IM E O F D IS T IL L A T IO N D E S IR E D . T w o s im p le c a lib r a te d R o b o t a d j u s t m e n t s , p r e se t b e fo r e d is t il la t io n , serv e t o d e t e r m in e a p p r o x i
m a t e t o t a l t i m e o f d is t il la t io n a n d d e g r ee o f a c c u r a c y d e sire d . 8. S U IT A B L E FO R ALL T Y P E S O F SA M PL E S A N D A N A L T Y IC A L
R E Q U IR E M E N T S . W h e th e r r e se a r c h or i n t e n s iv e r o u t in e w o rk , w h e th e r g a s or liq u id , t h e R o b o t i s f u lly s a t is f a c t o r y . T h e a d a p t a t io n t o v a r y in g s a m p le s a n d a n a ly t ic a l r e q u ir e m e n t s is a c c o m p lish e d by u s e o f a p p r o p r ia te d i s t il lin g t u b e s a n d b u lb s a n d by v a r y in g th e tw o s im p le a d j u s t m e n t s o f t h e R o b o t.
9. E SPE C IA L L Y SU IT A B L E FO R C O M PL E TE C R A C K ED G A S A N A L Y S IS. T h e M o d el “ L M i s e s p e c ia lly d e s ig n e d a n d r e c o m m e n d e d fo r t h e c o m p le t e a n a ly s is o f refin e r y c ra c k e d g a s e s a n d s im ila r h ig h ly c o m p le x g a se s, by c o m b in e d lo w - t e m p e r a t u r e fr a c t io n a t io n a n d s u b s e q u e n t c h e m ic a l r e a g e n t t e s t s . T h e s e p a r a t e c o lle c t io n o f fr a c t io n s a n d t h e ir s a m p lin g fo r O rsa t t e s t s is a c c o m p lis h e d w it h o u t u s e o f d is p la c e m e n t m e d ia a n d w it h o u t i n te r fe r e n c e w it h a u t o m a t ic c o n t r o l a n d c u r v e p lo t t in g .
P O D B IE L N IA K M O D EL " L ” N o . 895 A P P A R A T U S
( D is t illa t e R e c e iv e r T a n k n o t sh o w n )
P A T E N T N O T I C E : T h e P o d b ie ln ia k M o d el “ L ” R o b o t-O p e ra ted R eco rd in g L o w -T e m p er a tu re F r a ctio n a l D is t illa t io n A n a ly sis A p p a ra tu s, as d escrib ed in th is a d v e r tise m e n t, a ls o a ll o th er P o d b ieln ia k L o w -T em p era tu re F r a c tio n a tio n A n a ly sis ^ A p p a ra tu s, in clu d in g v a r io u s lo w -te m p er a tu re fr a c tio n a tin g co lu m n an d d is tillin g tu b e d esig n s an d c o n stru ctio n s (such as th e " R e g u la r ,” " C .N .G .A .,” ‘‘P r eci
sio n " a n d “ S ta n d a r d P r ecisio n " ) an d m o d ific a tio n s th ereo f, an d o th er sp e c ia l c o m p o n en t p a rts of th e s e a p p a r a tu s, a re p r o te c te d b y n u m er o u s U . S . a n d fo r eig n p a te n ts a s liste d in P o d b ie ln ia k C ircular 17, lik e w ise b y p en d in g p a t e n t a p p lic a tio n s.
N o o n e o th er th a n th e P o d b ie ln ia k C e n tr ifu g a l S u p e r -C o n ta cto r C o m p a n y is a u th o r ize d t o manufacture^ fo r u se or s e ll or re co n str u ct th e a p p a r a tu s, fr a ctio n a tin g co lu m n s, d is tillin g tu b e s an d o th er p a rts co v e red b y th e se p a te n ts. C o o p e r a tio n is r e q u e s te d in in fo rm in g th is o o m p a n y of in s ta n c e s of in frin g e m en t. In fr in g ers w ill b e a c tiv e ly p ro secu ted .
W rite fo r C ircu la r 17 a n d P ric e L is t 17 fo r com plete in fo rm a tio n a n d p rices on the M odel " L ” Robot A p p a r a tu s .
PODBIELNIAK CENTRIFUGAL SUPER-CONTACTOR COMPANY
Code Podbielniak
8312-44 S ou th Chicago Ave., Chicago, Illin ois
Edward L. W ynne Export A gent, 80 Broad S t.,
New York, N. Y.
INDUSTRIAL AND E N G IN E ER IN G CHEM ISTRY VOL. 11, NO. 4
C H R O M E L - A L U M E L
L E A D S A N D C O U P L E S
F o r a c c u r a c y , y o u r C h r o m e l-A lu m e l C o u p le s s h o u ld b e c o n n e c t e d o n ly to C h r o m e l-A lu m e l L ea d s. T h e y b e lo n g to g e th e r . . . . I f s o -c a lle d “ c o m p e n s a t in g ” le a d s are u s e d , t h e ir j u n c t io n w it h t h e c o u p le (in t h e c o u p le h a n d le ) b e - a n o th e r t h e r m o -c o u p le . T h is j u n c t io n o f t e n b e c o m e s q u it e h o t , a n d in t h a t c a se m a y in t r o d u c e a n error u p t o a r o u n d ± 2 0 ° . In o th e r w o r d s, t h e s e “ c o m p e n s a t i n g ” le a d s d o n ’t c o m p e n s a te , e x c e p t a t a lo w e r t e m p e r a tu r e t h a n t h a t u s u a lly r e a c h e d b y t h e c o u p le - h a n d le . . . . W h en t h e le a d s h a v e t h e s a m e c o m p o s it io n a s t h e c o u p le , t h e a b o v e s o u r c e o f error o b v io u s ly d o e s n o t e x is t. S o, for a c c u r a c y , u s e C h r o m e l-A lu m e l C o u p le s w it h C h r o m e l- A lu m e l L ea d s. F o r a fu ll e x p o s itio n o f t h e s e fa c ts , a sk for fo ld e r G P . . . H o s k in s M a n u f a c t u r in g C o ., D e tr o it, M ic h .
T O G E T H E R
A PR IL 15, 1939 ANALYTICAL E D IT IO N 9
J lU te l *]b c d S o lv e d / I PnoJdem H
E R E are th e lin e s —in x-raydiffraction patterns — that led to correction of a faulty manufactur
ing process, solved a tricky problem.
These four patterns represent four forged bars of a permanent-magnet alloy steel. Coming originally from the same section of the parent ingot, and presumably receiving the same forging and heating treatment, the magnetic properties, nevertheless, were different. Bar A produced a magnet whose high coercivity and remanence were a maximum for the alloy. Bars C and D were of only average quality. In contrast, Bar B was practically worthless as a perma
nent magnet.
Chemical and spectrographic an
alysis showed all four to be identical in elementary com
position. All four showed identical micro-structures at all magnifications. X-ray diffraction, however, produced three distinctly different patterns, showing definite structural differences.
Pattern A shows the particularly good bar to have the structure of tetragonal martensite, in which all of the alloy
ing constituents are in solid solution. The high residual stresses resulting are indicated by the diffuseness of the diffraction lines. In pattern B are seen several lines in addition to the strong lines in A. Here tetragonal marten
site structure is replaced by alpha-iron, the extra lines being from a complex metallic carbide with a cementite structure. This structure indicates that practically all of the alloying constituents have been precipitated, leaving a nearly stress-free alpha-iron bar. The crystallites of the carbide held in the iron matrix are evidently submicro- scopic, since they could not be seen under the microscope, and it was for x-ray to reveal the structure indicating mag
netic properties in bar B approaching those of soft iron.
Patterns C and D show some lines in addition to those due to alpha-iron or cubic martensite, which wrere identified as coming from a trace of retained austenite and from a metallic carbide, the latter having a different structure and therefore a composition different from cementite. Thus it
is shown that some of the alloying constituents are not in solution in the martensitic lattice and that decomposition of austenite has not been complete. This accounts satisfac
torily for the difference in magnetic properties between bars C and D and bar A.
Bars B, C, and D, evidently, had not been heated to a sufficiently high temperature, or had not been held long enough at the proper temperature for complete solution of the carbides to take place before quenching. The difficulty was traced to unequal temperatures in the heat-treating furnace, and was soon eliminated by an adjustment of furnace operating conditions. R E S U L T S w ere: an improve
m ent in uniform ity of p ro d u c t; d ecreased losses from rejected material; and elimination of a perennial quarrel between the steel maker and the magnet manufacturer.
You, too, may have problems which can best be solved by x-ray diffraction. One good way to be sure is to consult with our diffraction laboratory staff. Their services are avail
able by writing to Dept. 194.
G E N E R A L % ELECTRIC
X -R A Y C O R P O R A T IO N
2 0 1 2 Jackson Boulevard * Chicago, Illinois
10 INDUSTRIAL AND E N G IN E E R IN G CHEM ISTRY VOL. 11, NO. 4
K R E B S P E N E T R O M E T E R S
A N EW D E S IG N W IT H A D JU S TA B LE P L A T F O R M , S T A T IO N A R Y H EA D , A N D S L O T T E D W E IG H T S M O U N T E D D IR E C T L Y A B O VE N EED LE
1 2 0 0 -F 1 2 0 2 -K 7 6 4 2 -F
P E N E T R O M E T E R S , K R EB S. F or m easuring the distance of vertical penetration of a stan d ard needle into a sam ple of bitum inous m aterial under known conditions of loading, time and tem perature, in accordance w ith specifications for A .S.T.M . stan d ard m ethod D-5-25, A.S.A. m ethod 1, A 37.1-1930 and A.A.S.H.O. m ethod T-49-38.
A new construction of Stainless steel and D uralum in, which offers the following advantages:
Adjustable platform for sample, permitting operation at convenient height so that the reflection of the image of the needle on the surface of the sample can be viewed without a mirror. Final setting is controlled by a micrometer screw.
Stationary head mounted at top of a solid Stainless steel column, which construction eliminates possible slippage of the needle from continual manipulation of a movable head assembly.
Weights mounted directly above the needle at lower end of needle bar, resulting in operation with minimum friction.
The weights are slotted for ready attachment and are provided with a spring ball locking device.
B oth models are furnished w ith dials of alum inum w ith clear black graduations from 0 to 380 m m in 0.1 m m divisions, enclosed under glass in case 5 inches diam eter, w ith a simple and efficient autom atic zero reset. Base of each model is provided with spirit level and leveling screws.
1 2 0 0 -F . P e n e tr o m e te r , K r e b s L ab oratory M o d e l, as a b o v e d escrib e d , w ith D u r a lu m in p la tfo rm 9 ^ x 6 H in ch es. A rack a n d C ode p in io n p r o v id es fo r ra isin g an d lo w er in g th e sa m p le for co a rse a d ju s tm e n t a n d fin al s e t t in g is m a d e b y fine m ic r o m eter W ord screw . N e e d le bar relea se c lu tc h is o p e ra te d b y a le v e r p ressed to w a rd a finger grip. O v e r-a ll h e ig h t 2 4 H in ch e s. C o m p le te w ith o n e ea ch 5 0 a n d 100 gram s lo t t e d w e ig h ts a n d tw o A .S .T .M . sta n d a r d n e e d le s ... $ 1 2 0 .0 0 A f e d f 1 2 0 2 -K . D itto , S im p lifie d M o d e l, fo r field or la b o r a to r y u se, w ith circu lar s ta g e 4 H in ch e s d ia m ete r. F in a l s e t t in g of th e n e ed le is
co n tro lle d b y fin e m icro m eter screw b u t th e rack a n d p in io n of th e larger m o d el is o m itte d a n d th e c lu tc h for n e e d le relea se is sim p lified . O v e r-a ll h e ig h t 21 in c h e s, w e ig h t w ith o u t c a se 8 lb s. W ith o n e ea c h 5 0 a n d 1 00 gra m s lo tte d w e ig h ts a n d o n e A .S .T .M . sta n d a rd n e e d le ... 5 0 .0 0 A ffa k 7 6 4 2 -D . C o n s is to m e te r , c o n sistin g of 1 2 0 0 -F P e n e tr o m e te r , L a b o ra to r y M o d e l, w ith n e ed le r ep la ced b y a s p e c ia l c o n e (a s sh o w n in
a b o v e illu str a tio n o f 7 6 4 2 -F ) for u se w ith lu b r ic a tin g g rea ses, e tc ., in a cco rd a n c e w ith s p e cifica tio n s for A .S .T .M . te s t D -2 1 7 -3 8 T an d A .S .A . m e th o d Z - l 1.3 ... 1 3 8 .0 0 L e rp u 7 6 4 2 -F . D itto , c o n s is tin g of 1 2 0 2 -K P e n e tr o m e te r , S im p lified M o d e l, an d s p e c ia l c o n e ... 6 9 .0 0 L e rp x
ARTHUR H. T H O M A S CO M PANY
R E T A IL —W H O LE SA LE— E X P O R T
LA B O R A TO R Y APPARATUS AND REAGENTS
W E S T W A S H I N G T O N SQUAR E, P H I L A D E L P H I A , U . S . A .
Cable Address, “ B alance,” Philadelphia
INDUSTRIAL «.< ENGINEERING CHEMISTRY
ANALYTICAL EDITION ♦ H a r riso n E. H o w e , E d ito r
D eterm in ation o f U ndissolved Sludge in Used Oils
HARRY LEVIN AN D CHARLES C. TOWNE T he Texas Company, Beacon, N . Y.
T
HE standard dictionaries—Webster’s New International Dictionary, Hackh’s Chemical Dictionary, and Van Nostrand’s Scientific Encyclopedia—give a variety of definitions for sludge, but the common thought running through most of them is that sludge is a muddy or slimy deposit that settles or is deposited on sedimentation. This fits very well the undissolved sludge encountered in used oils.
Ta b l e I . In s o l u b l e Ma t t e r i n Fi l t e r e d Us e d Di e s e l En g i n e Oi l s
S o lv e n t O il 1° O il 2 “ O il 3 a
M g . / 1 0 g. M g . / 10 g. M g . / 1 0 g.
I so p e n ta n e , c . p. 3 2 26 66
P e n ta n e , co m m ercia l 31 21 62
n -H e p ta n e 15 13 41
I so ô c ta n e , co m m ercia l 14 15 44
P r e c ip ita tio n n a p h th a 9 12 37
a M illig r a m s of p r e c ip ita te p er 10 g ram s o f o il, th e s o lv e n t to s a m p le ratio b ein g 10 t o 1.
The sludge is muddy or slimy, instead of dry or solid, be
cause it occludes oil. Since the amount of oil occluded con
tinually decreases as the period of settling increases, it is im
practical and of little significance to determine the mud or slime accurately. Therefore the proposed method for the determination of undissolved sludge measures only the non- oily component—that is, the characteristic constituent.
A knowledge of the amount of sludge which exists undis
solved in samples of used, oxidized, or other unclarified motor oil is of special interest to the research worker who is con
cerned with the effect of refining processes and modifiers on the performance of lubricating oil, as well as with the im
pression the customer gets when he sees his drained crank
case oil.
The methods which are commonly applied for the deter
mination of sludge are similar to those used to determine solubilities of bituminous materials. Among the solvents so employed are 86° (A. P. I. gravity) naphtha, A. S. T. M. pre
cipitation naphtha, special light petroleum naphthas, and various pure hydrocarbons. The general procedure involves the hot or cold digestion of a weighed amount of sample with a measured amount of the particular solvent, followed by a period of settling, filtration through paper, asbestos, porous glass, or Alundum, washing with the solvent, drying, and weighing.
Such direct solubility methods are unreliable for deter
mining undissolved sludge because the so-called solvent may
have a complex effect and not only dissolve the oil which is to be removed but also precipitate material which was actually in solution in the oil alone, the oil being commonly a better solvent than the analytical solvent employed in the analysis.
Such a procedure measures not merely the undissolved sludge, but at best the sumof the undissolved plus an indeterminate amount of "dissolved sludge.”
That ordinary paraffinic solvents may precipitate material which is in solution in the oil alone is illustrated by Table I.
These data were obtained by filtering the undiluted used lubricating oil through cotton and running solubility tests on the filtrate with each of the solvents shown. Frequently the precipitable “dissolved sludge” is greater than the truly un
dissolved sludge (Table II), so that a true measure of the undissolved sludge is not reliably obtained by a simple solu
bility test on the used oil.
T a b l e II. I n s o l u b l e M a t t e r i n U s e d O i l s c . p. Iso p e n ta n e C o m m ercia l P e n ta n e
S o lv e n t S o lv e n t
U n fil- F il- U n d is - U n fil- F i l- U n d is- tered tere d “ s o lv e d tered tered * s o lv e d O il U se d in s a m p le s a m p le slu d g e sa m p le sa m p le slu d g e
M g . p e r 1 0 gram a o f oil A u to m o b ile
A u to m o b ile truck
22 12 10 19 7 12
3 15 133 182 284 100 184
53 1 52 52 0 52
47 1 46 44 1 43
20 2 18 19 5 14
25 7 18 29 6 23
10 5 5 8 1 7
23 8 19 2 19 2 30 16 21 4
34 4 30 32 3 2 9
3 34 15 319 327 10 3 1 7
581 59 5 22 5 80 49 531
64 32 32 59 31 2 8
82 10 72 82 11 71
206 2 6 180 205 21 184
59 6 53 56 4 52
158 10 148 141 3 138
A u to m o b ile b us 1-C ylin d er D iesel C F R en gin e
6-C y lin d er D ie s e l truck D ie sel
o N o te th a t th e in so lu b le m a tte r in th e filtered sa m p le is o c c a sio n a lly g reater th a n th e u n d isso lv ed slu d g e, so th a t a sim p le s o lu b ility te s t on th e u nfiltered sa m p le is u n su ita b le as a m ea n s of d eterm in in g u n d isso lv e d slu d g e.
Furthermore, such solubility tests are influenced by the ra
tio of solvent to sample. There is an optimum solvent-to- sample ratio which yields the greatest amount of insoluble matter. I t is commonly found that a large ratio will show a greater amount of undissolved matter in a particular sample than will a lower ratio, and this anomaly is explained by the fact that the amount of "dissolved sludge” precipitated by the solvent varies with the solvent-to-sample ratio.
181
182 INDUSTRIAL AND E N G IN E E R IN G CHEM ISTRY VOL. 11, NO. 4
D e ta ils o f M eth od
The method which the authors use comprises the determina
tion of the pentane-insoluble matter in the sample and in the filtrate obtained by passing the undiluted sample through absorbent cotton. From the difference in the two values the undissolved sludge is calculated. This is the sludge un
dissolved by the oil itself; it does not include water, which may be separately determined. The method is theoretically sound and its laboratory manipulations are practical.
So l v e n t. Commercial pentane.
Ap p a r a t u s. The only special apparatus is a simple filter con
sisting of a glass tube, 508 mm. long X 17 mm. in inside diameter, containing a depth of 101 to 127 mm. of surgical absorbent cotton dry-packed at one end, a gauze cap supporting the cotton.
Pr o c e d u r e. A representative portion of the sample is gravity- filtered through the cotton filter. This filtration is, for con
venience, carried out overnight in a hot box at 65° to 75° C. On this clarified oil, as well as on a portion of the original sample, the matter insoluble in pentane is determined in the following man
ner:
Weigh 10 grams of sample into a suitable Erlenmeyer flask and to it add 100 ml. of pentane, agitating to maximum solution.
Allow to stand stoppered overnight, then filter through well- packed asbestos in a Gooch crucible, using suction. Wash thor
oughly with 100 ml. of pentane, suck dry, then heat in an oven at 110° C. for 1 hour and weigh.
Ca l c u l a t i o n'. From the diSerence in the weights of insoluble matter the undissolved sludge is calculated as follows:
1000
where A = sludge undissolved by pentane, original sample (grams per 10 grams)
B = sludge undissolved by pentane, clarified sample (grams per 10 grams)
C = undissolved sludge (mg. per 10 grams)
When A is low (0.1), for practical purposes C = 1000 (A —B).
The authors have found it convenient to report results in mg.
per 10 grams of sample.
This method gave results reproducible within 5 per cent on the sludge basis when the sludge content was high, but dup
licate tests within 4 mg. per 10 grams are considered its limit of reproducibility. Used oils from a variety of crankcase services varied in undissolved sludge content from a few to hundreds of milligrams per 10 grams of sample.
This method of analysis includes undissolved mineral mat
ter in the value for undissolved sludge. Determine the mineral m atter separately in the usual manner by solution in mineral acids or by ignition.
The sludge, which may become visible on settling, will of course include water that is present. Therefore, when de
sired, the water should be determined on another portion of the sample, and for this the A. S. T. M. method (1) is suit
able.
The proposed method is free of the faults of the other methods—namely, the error due to coprecipitation of matter which was dissolved in the oil sample itself, and the effect of solvent-to-sample ratio—because the solvent in identical ratio is applied to the filtered sample and the quantity of in
soluble matter so obtained is used to correct the test made on the unfiltered sample. The quantity of insoluble matter obtained in the filtered sample is in itself unimportant; it merely serves as a correction for the similar material copre
cipitated with the undissolved sludge in the original unfiltered sample. The ratio of solvent to sample is therefore unimpor
tant, except that the same ratio- must be used on the origi
nal unfiltered sample and on the cotton-filtered sample.
S electio n o f S olvent
Of the common hydrocarbon series the paraffins are the poorest solvents for asphaltic and tarry matter, and the lower-boiling members are the poorest solvents of this series.
Since the undissolved sludge of a used oil may contain ma
terial of an asphaltic or tarry nature, besides carbon and min
eral matter, the authors’ efforts were concentrated on the pentanes. These are the lowest boiling liquid paraffin hy
drocarbons that can be conveniently handled and experiments showed that they do not dissolve matter which exists undis
solved in the used oil itself.
Much of the authors’ original work had been done with c. p.
isopentane because the use of this solvent was established practice at this laboratory for certain solubility tests. Sub
sequent work showed that results with commercial mixed pentanes checked those by isopentane. Since c. p. isopentane costs about five dollars and mixed pentanes less than one dollar per gallon, commercial pentane was adopted. Each has good solvent power for lubricating oil and neither dis
solves sludge which is undissolved by the used oil itself. This latter point was shown by the fact that microscopical examina
tion (X 320) of the pentane-soluble matter from a large num
ber of used crankcase oils, taken at random, showed no black nor dark undissolved particles. The microscopical examina
tion was made at room temperature after the evaporation of the solvent. The absence of dark particles proves that the pentane did not dissolve anything which the oil itself could not hold in solution. Any other solvent can be used, provided it dissolves the oil of the sample but not the undissolved sludge.
C larifying U sed Oil
Various means were investigated for obtaining the clarified sample.
The filtering medium must be inert; hence active clays, etc., are to be avoided. A 15-cm. (6-ineh) layer of sand was inade
quate, permitting the passage of the line sludge of used crankcase oils. A 5-cm. (2-inch) layer of Filter-Cel was too dense, requiring weeks for the recovery of a few grams of filtrate. A 10-cm. (4- inch) layer of sand over a 5-cm. (2-inch) layer of Filter-Cel was unsuitable for the same reason as the Filter-Cel alone. Filtra
tion through filter paper (Whatman’s No. 44) was unsatisfactory;
a single paper allowed the sludge to pass through; three papers clarified the oil, but filtration required days and often weeks and creeping caused trouble. Absorbent cotton was the best filtering medium found, yielding a clear filtrate in a reasonable time. All these filtrations were of the gravity type.
Attempts at reduced-pressure filtration were unsuccessful, as the fine sludge of the samples soon came through the filter or clogged it completely. Centrifuging the undiluted sample at 75° C. for 4 hours at 6000 r. p. m. was also tried, but it did not en
sure complete sludge removal as judged by the appearance of the spot made on filter paper by a drop of the centrifuged oil.
Ta b l e I I I . Un d i s s o l v e d Sl u d g e i n Us e d Oi l s
C la rifica tio n P ro ced u re C en trifu g in g
F iltr a tio n th ro u g h c o tto n
For the authors’ purpose it is necessary that the filtering medium, used to obtain the clarified sample, be one which neither reacts with nor selectively adsorbs material com
ponents of the sample being filtered through it. That ab
sorbent cotton is such an inert filtering medium was shown by the fact th at results obtained with its use satisfactorily checked results obtained using clarified oil which was pre
pared by prolonged high-speed high-temperature (70° C.) centrifuging without the use of any filtration medium. A com
parison of typical results obtained with oils clarified by cotton and by centrifuging is given in Table III.
Some viscous oils which contain large amounts of undis
solved sludge do not yield as much as 10 grams of filtrate through cotton overnight. Such samples should first be centrifuged to remove the bulk of sludge and then filtered through cotton in the usual manner.
D ie se l M o to r A ir p la n e O il L u b rica tin g
O il 1 2 O il
M g . p er 1 0 o ram s
3 63 59 57
5 62 56 56
A PR IL 15, 1939 ANALYTICAL E D IT IO N 183
Microscopic examination ( X 320) at room temperature of the “filtrates through cotton at 65° to 75° C.” from numer
ous used crankcase oils, taken at random, showed no dark particles in most of them; a small percentage showed a few isolated particles estimated to be not more than 2 per cent of the amount visible in the samples before the filtration. The absence of the dark particles proves th at the oils while filter
ing at the elevated temperature did not dissolve sludge which they could not retain in solution at room temperature.
Since crankcase oils in use are commonly at these and even higher temperatures and hence have the opportunity to act on the sludge, the additional warm period during filtration should not materially influence the solution of the sludge in the oil.
Attempts at determining undissolved sludge by filtering the undiluted sample through a weighed filter, followed by wash
ing the residue on the filter with a suitable solvent, failed completely. The fine sludge of the sample soon came through the filter or clogged it completely.
A c k n o w led g m en t
The authors acknowledge their appreciation of the assist
ance of A. J. Millendorf, S. K. Williams, and F. P. Farrell, who did most of the analytical work. They also wish to acknowledge the unpublished contributions of C. G. Ludeman of this laboratory on this general subject.
L iterature C ited
(1) Am. Soc. T esting M aterials, “ S tan d ard s on Petroleum P roducts and L ubricants,” D95-30, 1936.
D eterm in ation o f D issolved Sludge in Used Oils
F R A N K W . H A L L , H A R R Y L E V IN , AND W A LLA C E A. M c M IL L A N T h e T ex as C o., B e a c o n , N . Y.
I
N THE present terminology of the petroleum industry the word “sludge,” when considered in connection with used oils, usually refers to material thrown out of oil by the chemical and physical changes resulting from use in an engine.
Some definitions include the mineral and metallic particles resulting from wear, abrasion, and contamination, while others particularly exclude these inorganic products and in
clude only insoluble materials of hydrocarbon origin. How
ever, most neglect those other degradation, polymerization, or oxidation products which may be dissolved in the used oil, but which may properly be considered dissolved sludge, since they are not present in the original oil but are formed during use. Such dissolved materials are probably an indication of what may come out of solution on further use or dilution and contribute to lacquer- or gumlike deposits on engine parts.
As separated in the proposed method, the dissolved sludge precipitates in forms varying from finely divided particles almost microscopic in size to large agglutinated particles, but in all cases on evaporation from benzene solution it is ob
tained as a lustrous, brittle, continuous, adherent lacquer
like film, varying from pale yellow to dark red-brown in color—
very similar to lacquerlike engine deposits.
Ta b l e I. Ef f e c t o f Pr o p a n e De s l u d g i n g Te m p e r a t u r e o n Sl u d g e Va l u e so f Us e d Oi l s
D e slu d g in g tem p era tu re , 0 C . 22 66
D is so lv e d slu d g e, m g . p er 10 3 0 31
gram s 148 167
148 185
157 177
640 750
Using the method for the determination of undissolved sludge previously presented (1 ) and the method for deter
mining dissolved sludge described here, the quantity and distribution of sludge present in used motor oils can be deter
mined.
To arrive at a measure of the dissolved sludge, the material insoluble in propane is determined on the clarified sample obtained by passing it undiluted through a filter tube packed with cotton (1). The determination is carried out at room temperature. Employing liquid propane a t higher tem
peratures commonly gives larger quantities of insoluble mat
ter (Table I), but since well-made lubricating oils may have
components which are insoluble in hot liquid propane, calling such matter sludge is unjustified. On the other hand, that which is thrown out by liquid propane at ordinary tempera
tures is asphaltic, generally absent from well-made motor oils, and considered undesirable.
The amount of insoluble matter found in an oil commonly increases as the boiling point of the paraffin hydrocarbon used as a solvent decreases. Though more insoluble matter may be found by using liquid ethane or methane than by using propane, their low critical temperatures would greatly complicate the apparatus and method and the same objec
tion would apply as to the use of hot propane.
Classifying as dissolved sludge only that portion (of a clari
fied used motor oil) which is insoluble in liquid propane is obviously empirical. However, it has been found useful in the study of motor oils to know not only the undissolved sludge which may be visually observed and is objectionable from the customer’s point of view, but also the dissolved sludge which may be just as objectionable from the engi
neer's standpoint, since it represents alteration products of the oil and may be considered as potential sludge.
On residual oils it is desirable to determine the dissolved sludge on the unused oil also, in order to evaluate better the change brought about by service or engine tests.
M eth o d
The following method has been in use in this laboratory for several years:
The sample is clarified by filtration, undiluted, through ab
sorbent cotton, using the apparatus previously described (1).
Ap p a r a t u s. The desludging apparatus is shown in Figures I
and 2. It consists of a 184 =*= 1 mm. section of Pyrex “high- pressure” gage glass tubing 32 mm. (+ 0 .5 to —1.5 mm.) in out
side diameter with a wall thickness of approximately 3 mm., having one end sealed, closed, and rounded to a radius of approxi
mately 16 mm., and the open end fire-polished flat at right angles to the axis of the cylinder. The tubes were made on order by the Corning Glass Works.
The pressure assembly for the test tube is shown in Figures 1 and 2. The outside tube is made of seamless brass tubing and should fit the glass tube snugly. The rubber cushion is made from a rubber stopper of good grade, hollowed to fit the bottom of the tube.
