April, 1934
INDUSTRIAL AND ENGINEERING CHEMISTRY
battery of valves for controlling the ethylene production is shown in Figure 19. A consignment of finished product on the shipping platform of the ethylene dibromide plant is shown in Figure 20. The power house employs hand-fired boilers and makes steam only for heating and evaporating purposes. Its capacity is about 15,000 pounds of steam per hour a t a pressure of 150 pounds per square inch. Operating electric power is purchased from the Tidewater Power Company. It is delivered to the plant a t 33,000 volts where it is stepped down to 2300 volts in two transformer banks. The entire plant is functioning as anticipated and is removing about 15,000 pounds of bromine per day from sea water. This is being converted into ethylene dibromide a t an efficiency somewhat over 90 per cent. The direct recovery of minerals for industrial use from sea water has long held the attention of chemists, and it is believed that the plant which has been described is the first to accomplish this achievement on a commercial scale of opera-
369
tion. The extraction of gold from sea water in which it is present to the extent of but a few parts per billion has always been the investigator’s most fascinat.ing goal, but no success along this line has been reported thus far. Now that the recovery of bromine, which is present to the extent of less than 70 p. p. m., has been successfully executed, it does not seem beyond reason to expect the chemist of the next decade to extract gold from sea water commercially. LITERATURE CITED (1, Grebe, J. J . , U. S. Patent 1,891,888 ( D e c . SO, 1932,. (2) Grebe, J. J., and Boundy. R. H., I b l d . , 1,885,255 (Nov. 1, 1 9 3 ~ ) (3) Grebe, J. J., Boundy, R. H., and Chamberlain, L. C . , Ibid., 1,917,762 (July 11, 1933); Grebe and Boundy, I b i d . , 1,944,735 (Jan. 23, 1934). (4) Stine, C . M. -4., IND.ENG.CHEM..21, 434-42 (1929).
RECEIVBD February 26, 1934. Presented before the General Meetlng at the 87th Meeting of the American Chemical Society, St Petersburg, F l a , Meroh 25 to 30, 1934
Aluminum Priming Paint Effect on the Ilurability of House Paints on Wood F. L, BROWNE, Forest Products Laboratory, Madison, Wis. the coating and in XIO case did it A S EARLIER publicaRepealed comparisons of the durabilily of white shorten it. Similar results have tion (3) the writer reported paints on wood when applied over aluminum been reported by other workers e x p o s u r e tests of special priming paint and when applied in the customary (9, 10, 11). priming paints on seven species manner, using the white paint itself for the primer, The present paper deals solely of wood. In those tests the subw i t h t h e effect of aluminum consistently demonstrated a distinct superiority stitution of aluminum paint for priming paint on the durability the customary white paint primer in service for paint applied ouer aluminum of house paints on wood ab clei n c r e a s e d the d u r a b i l i t y of primer. Thp improvement in durability was termined by test fence exposures succeeding coats of white lead manifested by a retardation in the rate at which following in general testing methpaint from 44 to 48 months, and paint coatings, embrittled with age, jlaked from ods that are described elsewhere of lead and zinc paint from 42 to the bands of dense, horny summerwood present (6). I n all cases the test panels 49 months on the average, alwere rated for appearance and though the aluminum priming in softwood lumber. The benejt gained by integrity of the coating and for paint used was seriously faulty in priming with aluminum paint was greatest for m a i n t e n a n c e of p r o t e c t i o n certain respects that will be diswoods that have much summerwood, such as against wood weathering, in acrussed later. The increase in southern yellou! pine and Douglas fir. When cordance with the generalmethod durability of paints applied over for e v a l u a t i n g paint s e r v i c e repainting was neglected f o r some time, coatings the aluminum primer was greatadopted by the Forest Products est on those woods that usually applied over aluminum primer suffered less Laboratory ( 7 ) . For the present hold paint least satisfactorily damage, and the surfaces were then more easily purpose, however, only the integand was e f f e c t e d b y marked and durably repainted. rity and durability of the coatr e t a r d a t i o n in the flaking of ings the coatings from the bands of - n e e d be reuorted. Ordisummerwood after age had made the coatings brittle (2, 4). narily the appearance of coatings (largely a matter of color The beneficial effect of the aluminum primer became all the and cleanness) is not affected by the uBe of aluminum priming more marked after the coatings passed the point a t which good paint, and the contribution made by aluminum priming to practice calls for repainting and entered the (‘period of paint the maintenance of protection against wood weathering is reneglect,” because the coatings over aluminum primer after vealed most clearly by special tests of moisture movement such neglect offered much more satisfactory surfaces for re- that have recently beeii the subject of a publication by the writer ( 5 ) . painting than the coatings over the white primers. Many paint technologists have been reluctant to admit GENEHAL h U C E D U K E the merits of aluminum priming paint. For that reason it I n tests in which comparison of alumiuurii priming paint has been deemed necessary to repeat the earlier experiments several times and to build up unusually extensive data on the with the customary white priming paint was the principal subject. The later tests thoroughly confirm the earlier find- objective, the two painting procedures were followed on ings. Nearly two hundred test areas have been primed pC-ith neighboring areas of the same test panel so that the comparialuminum paint as a base for coatings of white paint in tests son could be made on identical boards. As a further preby the Forest Products Laboratory; almost without excep caution each test panel was made of three, four. or five tion the aluminum primer materially prolonged the life of boards. In certain other experiments for which pertinent
I
S
I N D U S T K I A L ,4N D E N G I
370
TABLEI.
pi
E E R I N C;
C H E 11 I S T R Y
COhfPOSITION OF SPECIAL P R I M E R S
(Composition in per cent of primer by weight) PIQMENTS
Aluminum powdern 21.4 21 .o 17.0 20.7 4.8 F, 9 2 .R
RYblBOL
Ai
Zinc dust I
.
Red lead
Raw linseed oilc
White leadb
..
.
Vol. 26, N o . 4
..
Boiled linseed oil
..
Bodied linseed oild
...
...
-___.-Synthetic drying oilf
Varnish' 78.6
..
Turpentine
Liquid paint drier
...
... ... , . .. ... . . 79.0 A2 ... .. .. .. ... 83.0 Aa . . . ... 79.3 A4 9.6 52:s 22:7 1 0 4.7 4.3 SP1 0.7 , . . 68.9 15.2 9.3 SPZ SP, ... 27., ... 4.6 0.7 1oo:o SPa SPi ... 100 :o Standard varnish grade. b Basic carbonate. C Examination of a typical shipment revealed an acid number of 5 , 5 mg. potassium hydroxide per graiu and an iodine number (Wijs) of 178.0. Made by heating varnish makers' linseed oil a t 300' C. for 2.5 hours, adding lead and manganese paint drier, continuing the heating f o r 0.5 hour loriger rooling, and thinning with mineral spirits until the nonvolatile content of the mixture was 60 per cent by weight. e A commercial aluniinum vehicle of 80-gallon (302-liter) length in oil and presumably made chiefly of ester gum, tung oil, and thinners. I t contained .il per cent nonvolatile by weight. f A commercial aluminum vehicle of the glycerol-phthalic acid type, "for iiae under U. d . Patents 1,108,3?4-30 and 1,119,592.''
.
TABLE11.
_ ~ ~ _ _ _ _ _PIQMENTS _ White lead"
SYUROL
LI L? LZ1 LZZ LZa LZi Lz6 LZS TZi TZz TZa
Zinc nwde h
92.0
..
38.4
2215 24.8 19.2 19.8 23.1
85.0 45.0 49.5
39.6 36.2 29.t
26.4
23.4 23.6 23.1
Titanoy R
Magnesiuni silicate
e
TABLE111.
Linseed oil
..
.. .. .. ..
8.0 15.0 25.0
i:5 8.3
17.4
6.4 6.6
32.4 30.6
30.6 30.6 21.9 21.4 30.6
6.6 9.9 11.7 7.9 6.6
43.0 47.1 36 3
Basic carbonate. b Lead-free. Prepared paints for wbiah the unit weight for mixing
6
COMPOSITION OF WHITE P A I S T S
(Composition in per cent of paint by weight) -1nac1~ti ----------
Is
MIXES OF WHITE PAINTS FOR r l P P L I C h T I O X
S?MBOL
Bodied linseed oil
Varnish
Turpentine
Mineral spirit8
Liquid paint drier
2.0
0.125 0.25 0.125 0.125 0.125
UIXER FOR PRIUIXQ COAT ' 'M
, 51 '
'I?
aa
ar
56 55
ai 0x
3.5
... ...
. .
...
. . ...
0.125
,
...
,
4.0
3.0 2.78 2.0 1.5
...
... 1.5 ... 2.75 0.125 1.6 1.25 0.125
... . .
.
. .
2.0
2.0 2.0 1.85
2 :o 0.26
. .
0.5
.
0.25
4.0
1.5
2:o 2.0 2.0 2.0 1.85
...
3.5
..
...
0.125
...
... 0.31
0.5 0.16
. ,
16.0 2.0
1.86
0.25
o:ik 0.25 0.126 0.125 0.125
..
2.0 2.0
..
0.125 o:ik 0.125 0.25
M I X E S FOR I N T E R > l E D I A T E COAT
C" CI C: c3 C4
Ci
3 .J 3.0 2.62 2.5 2.25
...
MIXEii F O R F I N A L COAT
...
...
...
,..
... .. ...
...
..
... ...
0.125
o:i2 0.125 0.125
o:izs ..
..
Mineral spirits
Liquid paint drier
...
...
... ...
I
.
.
...
...
1.8 1.7
..
1.7
... ... ,..
...
... 1.7 . I . , I .
...
1.;
...
...
1.8
.I 1.t 1
1.7 .,.
...
1.7
UNIT WEIGET PAINTFOR MAKINO 111 Povndr Ko
OF
>lIXES IN T.4BLE
100 100 100 86 16.6C 17.2C 16.SC 16.9' 68.4 70.0 16.1'
45.4
45.4
45.4
39.0 7.53
7.80 7.62
7.65
31.0 31.7 7,3
the weight of 1 gallon (3 78 liters)
(The liquids are those hearing similar designations in Tables I and 11.) VOLUME OF LIQUIDS I N GALLONS" ADDEDTO UNIT WEIQAT OF PAINT RIKORDEDIN LARTCOLEMN OF TABLEI1 Raw linseed oil
Turpentine
0.125 0.125 0.22
0.125 0,125
...
One gallon = 3.i8 liters.
data are shown, the principle of 'hatched specimens" doeb not apply, but the number of boards painted was large enough to accomplish fair comparison through the principle of averages. Some technologists have attributed the beneficial effect of aluminum priming paint to the varnish or bodied oil vehicle
with which aluminuiii paint is made rather than to the aluminum pigment (16, 16). For that reason some of the experi ments included tests in which these vehicles were used with the white paints as primers or in which the clear vehicles without any pigment were applied as primers. Some tests also included special priming paints in which aluniinuni powder was used in admixture with other pigments. All test panels were exposed fscing south. Some were placed on the test fences in the vertical position, as on the qide of a house, others were placed a t a slope of 45". Paint fails iiiore rapidly on inclined than on vertical panels (1'7); the degree to which failure is accelerated by the inclined position can he gaged from tests involving concurrent exposure in both positions. Most of the tests were made a t Madison, Wis., but some were repeated at stations representing distinctly different climatic conditions.
COMPO~ITION OF PAINTS The paints and their various mixes are listed in Tables I, 11, and I11 R-ith a system of symbols that will represent them in the whqequent discussion. TESTSON WESTERNLARCH A serieb of tests was begun in 1927 a t Madison, Wib., to study the painting characteristics of western larch, a heavy softwood Fvhich contains much summerwood and is therefore difficult to paint durably ( 2 ) . For that reason some of the painting procedures tested were based on aluminurii priming paint, Each panel contained five boards of commercial 4-inch (actual width, 9 cm.) strip flooring. Teston panels of flat-grain boards and on panels of edge-grain boards mere made in duplicate with panels in the vertical and inclined positions. After 26 months and again after 52 months of exposure most of the inclined panel. were repainted with white paints.
thinner, and to tlie moderate addition of liquid in the priming-coat mixture. Paints that contain no white lead, however, are subject to serious disadvantages that make it unwise to recommend tiiem for general use by painters, Paints containing titanium pigment, white lead, and zinc oxide in suitable proportions prove
primer continued after tlie panels liad been repainted witli
vhitc paints. When first painbed, one final coat of the white paints failed to hide the color of the ahnninuni completely: RS time passed, however, the coatings began to chalk, and their opacity increased enough to hide the aluininum color satisfactorily. The repainted coatings showed no s i p of tlir alinuinoni color a t any time. TABLE
V. P A l r T I N G PHOCEDUaEs A N D ~ U n r f % r M " Y Or Coa~rvosTESTEDON Somcm~~v Y E L u w PINE
lF;,;z:r
ConTINo INIT,I*L
I N l ' r i n . P*INTINI:
P*OCEDDaE
g " i F : p
s:sd
!'$
Ratiny. for io. tegritg
.wontha
IS 16
30 23 19 28
..
is 41
Bad Bad Good Good Bed Bad FSii F*i, F*ii FSii Fnir Faii
Fair
'TWL;
neeAINTINr.
PnocsounB P$z;C Sz;;d
$ ;:;
Retiw for integritx
& ::;
Monthr
vertical exposure and seven for inclined exposure were made from hoards of each of the ten classes. Each panel cont,ained three hoards. Vertical panels were divided irtbo two test areas, inclined panel? provided only one test mea each. The painting procedures and the results appear in Table VI. By far the most durable coatings were obtained when t,he priming coat was aluminum paint, whether A, or A 2 . After 47 months the coatings over aluminum primer on most of the vertical panels were still serviceable and rated "fair" in inteaitv. The imurovement in durability must be attributed chiefly to the action of the aluminum pigment in the prinie~. The white primers containing bodied linseed oil and the clear bodied oil primer, although superior to the ordinary white paint prinlers, proved muclj l e s ~satisfa.ct,orythan the almniniini primers.
I9 29 27 0 + folluwinz h rating for durability iridiratea that the cwnsidered seivioeable when laat insnerted
aoirlinys
were siill
TESTS ON PONDEROSA P1XE AT ' h C X I N AND FE-HESNO Aluminuni priniing paint was included in some tests of Addition of varnish to the priming coat of the white paint6 painting ponderosa pine started a t Fresno, Calif., and at proved slightly deleterious on the whole (13, lo), just as was Tucson, Ariz,, in 1929. The test panels consisted of three boards of commercial 6-inch (actual width, 14 om.)bevel t,he case in the tests on western larch. Titanox and zinc paint TZa proved outstandingly durable. siding forming a panel area of 16 by 72 inches (41 by 180 cm.), which was marked off into three test areas of 16 by 24 inches 60 much so that it made little difference whether i t was applied over aluminum or over white priming paint. Paint (41 hy 60 em.). Only those test areas that were primed with TZ2applied in repainting did not last quite as long as in first aluminum paint and the neighboring areas on which a white painting but proved more durable than either repainted white paint primer was applied are considered here. The painting procedures and results appear in Table VII. lead or lead and zinc. The outstandingly good results with '& are attributed to the high volume of pigment, 31 In every case the use of aluminum priming paint materially paint Z per cent, in the coat,ing after evaporat,ion of the volat~ile inrrexsed the durability of the coating,
. + following B ietiri
Eoi dursbility iridiontes tibat the coating was still considered seiviosslrlc w f m the panel was removed tiom the fenre. a
TBTS BEGUNIN 1930 AT FIVESTATIONS In 1930 a series of tests of special priming paints was begun a t Madison, Wis., Sayville, N. Y., Washington, D. C., Fargo, X. D., and Fresiio, Calif. Present concern is only with those primers that contained aluminum or the varnish vehicle used with aluminum. Tiie test panels were made of four boards of commercial &inch (actual width, 14 em.) bevel siding, comprising one hoard each of redwood, northern white pine, Douglas fn,and southern yellow pine. The panels were 18 by 72 inches (46 by 180 em.) in size and were marked off into three test areas FlGUEE 3. EE'FECT OF ALUHINUH PE ~ nriahhnviea t,ha on wood e v e n t u a l l v deC ilE I
IWS i t m l instead i i i A,, Eight inure areas were piiited in tlic ~aiiieway a i tlie first ciglit, except that leuil arid zinc paint I,%, repiaced white lead paint L,, ani1 a further g r w p of eight iireas were similarly painted witli paint TZI. l h i l l y , t i m e areas were painted, resiiectively, with each of tlrc tliree ivliite
paint,.iuver white pririiers L,a,, L%,n,, and TX2na. In tlie coatings of white lead paint, finely ret,iculiite cliecking was first obsen-erl a t 10 minitiis of exposure :iird was tlicn we11 developed 011 all aretis, whether primed witti wliit,c or with alurninuni p i n t atid regardless of the t,iiiie :dlmwl for tlie aluniinuni primer to lr:ir&n. The sulrscyiient devclo1,inent of t.lie checking \vas ttie sanii! oil :~llwl>itelettd areas. In ttie coatings of lead and siitr: paint, parallel c1it:cking was observed a t 10 irionttis over the wliit,e primer ill :in early stage of i l e v c l o ~ i t n e i i t . At 17 inontlts parallel cliecking was well derclopcd in LZ coatings over both white and aluniiriiitii primers, but it was inconspicuous and siniilar on all areas, and it did nut seriuiisly affect tlie appearance of t.lte coatiiigs. At still lat,er stages the checking gradually became coarsely reticulate in patt,ern, until at 29 months it was as conspicuous as it Irad been in the 1925 tests, and tlie white paint appeared gray over tlie alutninum primers, The checking riia& ,with becanie cmispicuous aliglitly faster over prinier .Iz bodied oil, t h over A,, made with varnish, but tlie t,irne nllowed for the jiriiners to harden had no effect on the conspicuousness of tlic checking. Since the coat,ing over tlie white prinier wits judged unserviceable becaitw of flaking from sitminer\v~~od after 18 months, diereas tire coatings were still rated as serviceable over the alinniiiutii primers after 31 niontlis, despite tlre checking, the alurninrini primers had already contributed notably to the duralility of tile coatings belure the cticcking became conspicuous. In tlic 1925 tests such was not tho case, the checking over :iltit~iiitttiii primer liaviiig become conspicoous at, much earlier st,ages. In tiie coating8 of Titanox and zinc paint, checking never appeared, hut critcking was observed at 17 nitintiis. At that time it was well ileveloped over aluininum primer :12 (inado with bodied nil), partially developed over tlte white primer, and barely started over prioier A,, niacio with varnish. It. becarno well developed over tire white primer at 22 inontiis and over primer A , at 29 inonths. Even wlicn well &\dtiped, lioivever, the cracking did not cause the white paint to appear gray. 'fliere was no relntion between cracking atid the tiinc allowed for the primers to harden. The ilurability of the white paints over white primers in these tests was 22 months for white lead paint, 18 months for lead and zinc paint, and 20 months for Titanox and zinc paint. Over aluminum pritners the coatings of all three paints were stit1 serviceable after 31 montlis, although disintegration over tlie hands of tlie summerwood had begun. These experiments make it necessary to find some otlier explanation for the early appearance of conspicuous checking w e r aluniininn primer in the 1925 tests. &consideration suggest,s that it may have resulted from t.lie use of an excessive amount uf alurniniini porvder in tho aliirriinuin priincr in 1925, when the amount was 2.43 pounds per gallon (0.29 kg. per liter). Tlie current recoinmendation of 2 pounds of alurninuin Imwder per gallon of vehicle (0.24 kg. per liter) may be regarileil as tiie maximum permissilile. .iL\J\liNU\l
Pir:\rER .ANY P A I N T
RCiLl~G
Coiifusion has ariseii about tlie bearing of nluiniiiuiii priiiiirig upon the moisture-blistering and subsequent scaling ( fA, 1.6)of house paints (8). The fact that aluniiniiin prinirrs iiicreasc the resistance of coatings to moisture imwetnent 1ms led painters and lioiise owners to assume that it sliouhl prow helpful in minimizing the defects in question. On tlie otlier Itand. inanv " naint . teclinoloeists assume tliat coatincs arr inore susceptible to moisture-blistering the greater their re~
I
rice to moisture movement, iiiastnucl~ as the liarrriiul moist,ure nearly always operates froin tlie Iiack of the painted Immls. The inecltanisin of rooistiire-blistering, liowever, is by no ineatis completely underst,oorl, nor do ttie facts thus far nvailalrle permit acceptance of either of the ahovc assinnptions. Tests 11y a riietlioil recently ilescribed by the writer (a indicate that white lead paint applied witli a priming. coat also of white lead is more resistant to peelii result of inoist,ure-~listerinl: tlran other kin If the white leait paint is applied over alii stead of white lead primor, the danger of serious dainage by moisture acting behind tlrc boards is undoubtedly increased. Lead arid zinc paints applied in the customary manner are inore scnsitive t,linri white lead paint to scaling following Iilisterirrg, and siil,stit,utLin of ordinary alnnrin:nn primer for wliitr primer ilues not iriat,erially improve tlieir heliasior under the conditions in question. On t,lie iitlier hand, tlie writer finds that aluininnni primer nt:rile with illuininuni powder of standard lining grade instead of standard varnisli grade irrakes lead and zinc pain% sonierrklat niore resistant to f u n k y moisture conditions. \VI& p i n t s of t.tie clas&xttiixi contaiuing no wliite lead sitive to scaling follinving moisture nce of s i i c l i paints is found to be pplyitig tliein over ordim.ry alnntinum primcr. The writer's cxperiinents also inrlicat,e that 1iai:k-priniiiig of exterior woodwork with aluniininn paint does not reduce tlic chances of blistering and scaling wlien moisture penetrates behind tlic boards. Rack-priming may, liowever, protect woods that contain water-soluhlc colored tilaterials ~~
INDUSTRIAL AND ENGINEERING CHEMISTRY
376
against discoloration by water that temporarily finds its way behind bevel siding and then seeps out between the overlapping boards to run down over the paint. ACKNOWLEDGMENT Acknowledgment is made of assistance of C. E. Hrubesky in supervision of the tests on western larch, of Don Brouse in supervision of the tests on Douglas fir and in the making of inspections, and of the following organizations in providing test fences for some of the experiments: Bureau of Standards, North Dakota Agricultural College, National Lead Company, W. P. Fuller Company, and Southern Pacific Railroad. LITERATURE CITED (1) Am. SOC.Testing Materials, Proceedings, 191, 384 (1919). (1A) Browne, F. L., Am. Paint Varnish Mfrs.’ Assoc., Sei. See., Circ. 317, 480 (1927). (2) Browne, F. L., Federation Paint Varnish Production Clubs, OfiCial Dkest 95, 106 (1930).
Vol. 26, No. 4
Browne, F. L., IND.ENQ.CHEM.,22, 847 (1930). Ihid., 23, 290 (1931). Ihid., 25, 836 (1933). Browne, F. L., J. Chem. Education, 10, 529 (1933). Browne, F. L., PTOC. Am. SOC.Testing Materials, 30, Pt. 11, 852 (1930). Edwards, J. D., Paint, Oil Chem. Rev., 88, No. 13, 10 (1929). Edwards, J. D. and Wray, R. I., Federation Paint Varnish Production Clubs, Oficial Digest,122, 15 (1933). Edwards, J. D., and Wray, R. I., IND.ENQ.CHEM.,17, 639 (1925); 19, 975 (1927). Gardner, H. A., Am. Paint Varnish Mfrs.’ Assoc., Proc. Sci. Sec.. Circ. 412, 181 (1932). Gardner, H. A., Ibid., 428, 107 (1933). Gardner, H. A., and Hart, L. P., Ihid., 374 (1931). 406 (1932), 422 (1932). Hartwig, 0. R., Ibid., 355, 742 (1930). Am. Paint J.,15, N o . 28, 20 (1931). (15) Nelson, H. -4.. (16) Schmuta, F. C., Palmer, F. C., and Kittleberger, W. W., IND. ENQ.CHEM.,22, 855 (1930). (17) Walker, P. H., Ihid., 16, 528 (1924). RECEIVED October 2 4 , 1933.
New American Iodine Industry G. Ross ROBERTSON, University of California at Los Angeles
A
Oil-well brines in southern California are now marine vegetation yielded first able to furnish the entire iodine requirementsof petroleum as an organic residue young petroleum chemist of S i g n a l H i l l , L o n g and iodide as an aqueous exthe United States at present business levels, with Beach, Calif., was s t r u g g l i n g tract. Districts lying outside some possibility for expansion when needed. with the problem of separating the supposed seaweed zone, such emulsified brine from the native The iodine present in very dilute solution as as a t Santa Fe Springs, of great crude oil of the local field. The iodide is separated either as the free element, adoil fame, do not show such high great resistance of this mixture to sorbed in or in the form of silver iodide, iodine content; the large oil c o n v e n t ion a1 demulsification fields to t h e north are not from which the desired element may readily be obtechnic led him to look for disDromisine. both from lack of water and” distance from the turbing substances among the marine location. The bromide ionic components of the aqueous phase, It was soon noted that the addition of an acidic oxi- content is not high, so that no special concentration of a predizing agent, such as nitrous acid, turned the brine slightly historic sea water is indicated. The iodine industry, always something of an uncertain yellow, and considerable quantities of iodine were revealed. Although iodine has been observed in oil-well brines of commercial quantity, is no more of a bonanza here than in other districts, such as Louisiana, the high content in the Chile, Japan, or other foreign production center. Production California wells was particularly encouraging. Later sur- costs are always substantial. Since Los Angeles County’s veys have shown, however, that only a few petroleum zones three iodine producers are now meeting the equivalent of the of the Far West have enough iodine content to warrant de- entire United States’ demand for iodine, a future potential revelopment. These lie in and near Long Beach, Calif., and source is recognized. At the present writing approximately include not only Signal Hill, of the 1922 boom-time oil fame, one-half ton per day of so-called “crude” iodine, of purity but the near-by Dominguez and Seal Beach fields which are above 99 per cent, is being manufactured. Even the high figure of 70 parts per million, while favorable, not far from the city limits of Los Angeles. I n these districts the day of flush oil production is long past, and the current naturally requires plant processes suited to huge flows of flow from wells shows a high percentage of saline water. brine. If the raw material were clean, one might hope to pa,y the expenses of concentration by running an adjunct salt These facts are to the advantage of the iodine producer. The brines in question, aside from iodine content, approxi- business. The contaniinstion of oil and mud, however, inmate sea water in general composition. The usual high per- troduces serious difficulties. Fortunately there are several characteristic properties of centage of sodium chloride, and substantial calcium and magnesium content, are found. Iodide ion, in amounts ranging iodine which offer aid in reclamation from extremely dilute solution. Chief among these are the ease of oxidation of iofrom 30 to 70 parts per million, is the unique feature. A reasonable explanation pictures a vast forest of seaweed in dide to volatile iodine, and the readiness and completeness of some past geological epoch in the southern part of what is precipitation as silver iodide. These two fundamental renow Los Angeles County. It is known that the whole actions are the basis of the present California processes and southern coast, running for many miles on either side of Long are discussed in detail below. Beach, has had comparatively recent elevation from subMINORPROCESSES marine levels. The entire lowland section adjacent to Los The classical experiment of extracting iodine from solution Angeles was under water during the Tertiary geological period. Not only ordinary kelpweed, but possibly deposits with the aid of chloroform or similar oil solvent led to considof diatoms and similar small plants may have accumulated. erable investigation of the application of the cheaper kerosene Presumably the decomposition of huge quantities of the to a large-scale method. Emulsion difficulties and fire hazBOUT seven years ago a
