T H E JOL-R.!Z7ALOF IL‘\‘D17STRIAL 41.VD E S G I S E E R I S G C H E A I I I S T R Y
730
No. 2A.. . . . . . 2B.. . .. ..
.. .. 2c. . . . . . . . . 2 D . . . .. . . . . 2 E . . . .. . . . . 2F.. ... .. . . 2G. . .. . . . . . 2H. . . . . . . . . 21.. . . ,.. . . . 2J ... . . . .. . . 2 K . . . ... . . . 2L. . . . . . . . . 2M. . . . . ... . 2N. ..... . . . 2 0 . . .. . . . . . 2 P . . . .. . . . . 2Q. . , . . . . . . 2R. . .... . . . 2s......... 2 T . .. . . . . . . 2u. . . . . . . . . 2V. . . . . . . . . 2W. . . . . . . , . 2 . . . . . . .. . . hl. P.. . . . . .
.
Time exposed None 3l/2 hrs. 15’/z hrs. 1B1/2 hrs. 211/2 hrs. 24l/2 hrs. 27l/z hrs. 39I/z hrs. 4Z1/2 hrs. 45l/2 hrs. 48’/2 hrs. 511/z hrs. 63I/z hrs. 66l/2 hrs. 72l/2 hrs. 75I/z hrs. 8 7 I / ~hrs. 901/z hrs. 93’/z hrs. 96I/z hrs. 99l/2 hrs. 11 ll,’z hrs. 13j1/2 hrs. 11 1 I / a hrs.
KzO
Per cent sol. salt
15.82 13.43 14.96 13.05 11.00 11.59 13,68 10.31 16.39 11.77 16.69 15.77 16.74 16.75 14.67 12.61 15.54 17.62 17.03 15.61 20.28 15.72 15.60 15.27 30.00
40.88 34.82 37.66 34.34 30.22 30.52 38.94 27.84 38.78 32.44 39.72 40 80 42.58 38.64 35.58 34.74 40.84 41.42 42.44 3i.80 46.28 38.80 39.24 34.52 57.10
Per cent
TABLE 11-SAMPLE Per cent Per cent ash org. m a t t e r 11.80 47.32 8.64 56.54 9.58 52.76 5.54 60.12 7.26 62.52 9.56 59.92 10.50 50.56 9.78 62.38 7.92 53.30 7.02 60.54 5.96 54.22 13.32 45.88 12.06 45.36 6.08 55.28 6.30 58.12 9.80 55.46 10.24 48.92 49.48 9.10 13.06 44.50 7.i8 54.42 9.76 43.96 9.76 51.44 12.02 48.74 8.06 57.42 IO. 1 4 32.76
presence in harvested kelp is not detrimental t o t h e value of the kelp. U.
s.
BCREACO F SOILS DEPARTMENT O F AGRICULTURE WASHINGTON
A POSSIBLE COMMERCIAL UTILIZATION O F NELSONITE B y WILLIAMH. W A G G A M A N ~
Received June 23, 1913
I S T R 0 D UC T I 0 S
I n Nelson County, Va., there are large bodies of rock locally known as Nelsonite which consist essentially of the two minerals ilmenite a n d apatite. The material is not only of scientific interest b u t in the light of some recent experiments performed in this laboratory may be of considerable commercial importance. The rock occurs in the foothills of t h e Blue Ridge near Roseland, Va., a b o u t 7 miles northwest of Arrington, a station on t h e Southern R. R., a n d 24 miles northeast of Lynchburg. According t o WTatson2it is probably of pre-Cambrian age a n d occurs in dikes which are in places over 65 feet thick and 2,100 feet in length as exposed on t h e surface. T h e formation can be traced in a general northeast southwest direction Watson described i t as “a hard for a b o u t ’ 7 miles. rock composed of granular white apatite a n d black ilmenite.” After weathering, however, t h e rock can be readily disintegrated a n d a more or less clean separation made of the two minerals by either of the methods described further on in this paper. ILMENITE
Ilmenite or titanic iron is a black crystalline mineral having feebly magnetic properties. I t has a specific gravitywhen pure of 4. j to j . 0 a n d the following formula a n d composition: Titanium oxide (TiOz). . . . . . . . . . . . 5 2 . 7 per cent FeTiOa Iron protoxide (FeO) . . . . . . . . . . . . . 4 i . 3 per cent
{
According to Dana,3 however, the ratio of iron to Scientist in Fertilizer Investigations, Bureau of Soils, U. S. Dept. Agr. “Mineral Resources of Virginia,” 1907, p. 300; “Economic Geology,” U. S. Geol. Survey, 1909, pp. 206-7. “A System of Mineralogy.” 1892, pp. 217-219. 1
2
NEAR PT. L O M A Per cent Per cent N KC1 2.77 25 .oo 2.66 21.22 2.40 23.64 1.77 20.62 1.85 17.38 2.10 18.31 2.22 21.62 1.97 16.29 2.22 25.90 1.99 18.60 1.79 26.37 2.29 24.92 2.49 26.45 1.91 26.46 1.88 23.18 2.66 19.93 2.47 24.56 2.16 27.84 2.28 26.90 2.16 24.67 2.12 32.05 2.26 24.84 2.57 24.65 1.80 24.13 1.66 47.41
Vol.
j, No. 9
FROM
Per cent I 0.18 0.19 0.15 0.15 0.16 0.14 0.24 0.14 0.21 0.22 0.19 0.22 0.21 0.19 0.19 0.22 0.19 0.16 0.20 0.10 0.20 0.23 0.27 0.18 0.06
Remarks W e t , sent in j a r W e t , sent in jar Wet. sent in jar W e t , sent in j a r Wet, sent in j a r Wet, sent in j a r Wet, sent in j a r Wet, sent in jar Wet, sent in j a r Wet, sent in jar Wet, sent in j a r Wet, sent in j a r Wet, sent in j a r Wet. sent in jar Wet, sent in jar Wet, sent in j a r Wet, sent in jar Wet, sent in jar Wet, sent in jar Wet, sent in jar Wet, sent in jar Wet, sent in j a r W e t , sent in j a r Dried a n d sent b y mail Sea lettuce from Marrowstone Point
titanium varies widely corresponding to t h e general formula RIFeTi03.NFe203. Ilmenite is rather widely distributed in nature, occurring in beds in gneiss and other crystalline rocks; also in small particles in many crystalline rocks a n d frequently associated with magnetite. It is used in t h e manufacture of ferro-titanium for the steel industry. I n 1911 there were j 1 . 1 7 tons of ferrotitanium imported into this country valued a t $ 2 2 , 7 0 0 , which gives an average price of $443.61 per ton. APATITE
Apatite or phosphate rock is a brittle crystalline mineral which varies in color from almost white t o dark green-red a n d brown. There are two main varieties of this mineral; namely, chlor-apatite a n d fluorapatite, t h e latter being much more plentiful t h a n the former. The specific gravity of apatite varies from 3.17 to 3 . 2 3 a n d the formula a n d composition of t h e two varieties according t o D a n a , are as follows: f P205 = 41.0 per cent Chlor-apatite, CaC1.Ca4(P04)3= CaO = 53.8 per cent C1 = 6.8 per cent P205 = 42.3 per cent Fluor-apatite, C a F . C a 4 ( P 0 4 ) 3 ={ CaO = 55.5 per cent IF = 3.8 per cent
1
r
Apatite, however, is seldom found absolutely pure a n d though widely distributed in nature does not often occur in minable quantities. On treatment with sulfuric acid i t yields a very high-grade superphosphate, a n d if i t were not for the fact t h a t t h e better deposits are rather inaccessible a n d t h a t careful picking or “cobbing” is necessary before a product sufficiently high-grade for the market is obtained, this mineral mould be more extensively used in t h e fertilizer industry. S E P A R A T I O N O F APATITE AND I L M E N I T E
4 t first sight t h e association of apatite a n d ilmenite in a rock would seem t o seriously affect t h e commercial value of both of these minerals. I n the manufacture
S e p t a , 1913
T H E J O U R S A L OF I N D U S T R I A L A S D ESGI.\’EERI.VG
of steel, phosphorus is t h e most dreaded impurity which can occur in t h e iron or iron ore used, so t h a t ilmenite containing over I or z per cent of this element would be rejected as dangerous. On t h e other hand, t h e presence of comparatively small percentages of iron in phosphate rock nearly always causes trouble i n t h e acid phosphate produced therefrom, a n d when this element is present in large amounts i t often renders t h e acid phosphate unfit for use. According to Watson1 t h e ratio of apatite t o ilmenite in nelsonite varies widely from rock consisting largely of t h e former mineral t o t h a t in which ilmenite predominates. Before such a deposit can be economically worked, therefore, i t seems essential t h a t a method be devised for making a clean separation of t h e two minerals. There are t w o methods which suggest themselves for effecting such a separation. The first is based on t h e difference in t h e specific gravities of t h e minerals, a n d t h e second on t h e magnetic properties of t h e ilmenite. The ratio of t h e specific gravity of apatite a n d ilmenite is as 3.2 t o 4. j . This difference is sufficiently great t o warrant a fairly clean separation provided t h e rock is crushed t o uniform size. Unless i t is ground very fine, however, a preliminary screening is necessary before suspending the material in water. The various modifications of t h e methods of separating substances by t h e difference in their specific gravities are well known a n d need not be enumerated here. X separation of t h e two minerals b y means of a magnetic separator has also proved feasible b u t owing t o the rather feeble magnetic properties of t h e ilmenite i t is not entirely removed from t h e apatite, b y this method, and though a preliminary heating enhances somewhat this magnetism, such a procedure would probably prove too expensive in commercial practice. F r o m a number of experiments with nelsonite i t has been pretty well demonstrated t h a t while ilmenite can be fairly easily removed from apatite by either of t h e methods outlined above i t is practically impossible t o effect a clean separation b y mechanical means, since t h e nature of t h e rock is such t h a t there will always be particles of t h e tm-o minerals which adhere strongly t o each other. We must, therefore, resort t o chemical means t o bring about this desired end. I n t h e experiments described below i t is shown t h a t ilmenite m a y be almost completely freed from apatite b y means of sulfuric acid. with a minimum amount of waste a n d without inrolving a n y great expense. Moreover, all of t h e products obtained during t h e process can be utilized commercially. E X A M I N A T I O S .\SD
SEPARATIOK O F THE MINERALS I N ?;E LS ONITE
A typical sample of t h e rock was submitted t o a microscopic examination b y 11r. IT7. H. F r y of this Bureau a n d found t o consist essentially of crystallized ilmenite a n d partially decomposed apatite. T h e material was then crushed t o pass a mm. 1
“Mineral Resources of Virginia,” 1907.
CHEMISTRY
731
sieve a n d a separation made b y means of a strong magnet. Owing t o t h e rather feeble magnetic qualities of part of t h e ilmenite this separation was made at t h e expense of t h e apatite which was afterwards found t o contain a considerable amount of t h e former mineral in a finely divided state. T h e results of this separation are given below: Per cent Nelsonite as separated by magnet in the laboratory contained.. . . . . . . . . . . . .
Both t h e ilmenite and apatite t h u s separated were analyzed b y Mr. C. F. Miller of this Bureau, with t h e following results : Per cent Ilmenite as separated by magnet in the laboratory contained . .: . . . , . . . . . . . Apatite as separated by magnet in this laboratory contained.. . . . . . . . . . , . . .
Although t h e amount of phosphoric acid remaining in t h e separated ilmenite mas’less t h a n I per cent, such a clean separation could hardly be attained in actual works practice. Even this amount of phosphoric acid is objectionable a n d would probably seriously affect the sale of t h e material. Preliminary experiments showed t h a t ilmenite is almost entirely unattacked b y dilute sulfuric acid, while i t is well known t h a t apatite is acted upon quite energetically b y t h e same acid: so 3 samples of t h e separated ilmenite of I O grams each mere treated with sulfuric acid of different strengths. The mixtures were warmed slightly a n d stirred intermittently for 2 0 minutes. At t h e end of t h a t time t h e acid was diluted with water, filtered a n d washed. The filtrate was made u p t o 2 0 0 cc. and t h e percentages of iron a n d phosphoric acid t h u s dissolved determined in t h e two solutions. The residual ilmenite was again weighed a n d also analyzed for phosphoric acid. T h e results of these analyses are given i n Tables I a n d 11. TABLEI-ANALYSIS
OF SULFURIC ACIDEXTRACTS OF ILXEXITE
3 samples of 10 grams each treated with 5 0 cc. of sulfuric acid of various strengths. Amount of PzOs extracted Amount of FezOs by acid extracted Strength of Per cent Per cent HBOd used 0.22 0.46 0.41
5O’B. 32O B. 2.5‘ B .
TABLE11-ANALYSIS
OF
Strength of acid used in extraction 50° B . 32’ R . 25” B.
0.19 0.29 0.32
ILMENITE AFTER EXTRACTION WITH ACID
Loss in meight of ilmenite Per cent
Amount of Pz01 remaining in ilmenite Per cent
1.04
0.47
1. i S
0.31 0.36
1.58
SULFURIC
F r o m t h e d a t a given in Tables I a n d I1 i t will be seen t h a t t h e apatite remaining in ilmenite a f t e r t h e mechanical separation can nearly all be extracted b y means of dilute sulfuric acid ( 3 2 ’ B.) without appreciably affecting t h e ilmenite. The amount of iron
'
732
T H E J O U R N A L OF I l Y D U S T R I A L An'D ENGINEERIA-G C H E M I S T R Y
t h u s dissolved is too small t o lower t h e value of t h e acid extract which can be used in treating the separated apatite t o produce superphosphate. While this acid extract is considerably weaker t h a n t h a t employed in t h e manufacture of acid phosphate i t could be readily brought t o t h e desired concentration, either by evaporation, or by mixing i t with t h e sulfuric acid which is shipped in t a n k cars; this latter acid has a strength of 60' B. T h e apatite as separated in t h e laboratory contained a considerable amount of iron, b u t this impurity should cause no trouble in the making of superphosphate since only t h e compounds of this element which are soluble in sulfuric acid cause t h e objectionable reversion t o take place or render t h e acid phosphate too sticky for use. ECONOMIC COKSIDERATIOSS
If both the ilmenite a n d apatite can be disposed of a t a fair price t h e mining of nelsonite should prove quite profitable. Unfortunately the market for ilmenite is rather limited a t present, and i t is doubtful whether the steel industry would handle t h e large tonnage which extensive development could produce. If nelsonite could be depended upon t o yield a n average of jo per cent of apatite the exploitation of the rock for this mineral alone would be well worth while, b u t it is doubtful if t h e general mine r u n contains such a high percentage of apatite. T h e production of apatite from nelsonite would undoubtedly be more expensive t h a n the mining a n d preparation of Florida phosphate, since t h e rock is quite hard a n d would require rather fine grinding before a separation could be made. On the other hand, the average content of phosphate rock in nelsonite is considerably higher t h a n i t is in t h e Florida deposits. The amount of phosphate rock actually marketed from this latter state is probably not more t h a n 1 5 per cent of t h e total material t a k e n from t h e mines; in other words, every ton of phosphate produced involves t h e handling of over 6 tons of waste material. T h e following figures, while approximate, are conservative a n d give some idea of the cost of mining a n d separating t h e two minerals in nelsonite:
Val. 5 , No. g
be used in making acid phosphate by mixing i t with a n equal weight of the separated apatite. T h e cost ofTmanufacturing this product would be approximately as follows: TABLEv-COST OF MAKING ONE TONOF ACIDPHOSPHATE FROM ONE-HALF TONOF APATITESEPARATED FROM NELSONITE expense of mining and separating minerals.. . . . . . . . . . . . . . $0.88 P/s ton of sulfuric acid (60D B.) (cost included in expenses for cleaning ilmenite). 0.15 Cost of drying apatite (1/z ton). ........................... 0.50 Cost of mixing and handling.. 1/z
........................................ ............................. -
Total cost of 1 ton acid phosphate.........................
$1.53
The total cost of mining I ton of nelsonite (having t h e above composition) a n d producing therefrom 1 2 ton of ilmenite (practically free from phosphorus), and I ton of acid phosphate (16 per cent PeOs) would be (exclusive of interest on investment, insurance a n d taxes) about $6.86 per ton-an amount which would be more t h a n covered b y the value of t h e acid phosphate produced.
u.s.
BUREAUOF SOILS DEPARTMENT OF AGRICULTURE WASHINGTON
QUANTITATIVE DETERMINATION OF ROSIN IN PAPER By C. FRANKSAMMET Received July 7, 1913
As t h e necessity for securing record papers so free from chemicals a n d deleterious substances t h a t they may be preserved indefinitely becomes more apparent, the importance of t h e determination of the sizing materials in the papers, particularly rosin, increases. Obviously, the resistance of the cellulose fibers t o t h e action of light, heat, moisture a n d fumes is greatest in paper free from harmful materials. I n carefully prepared specifications for durable papers i t is customary t o limit the percentage of rosin which may be present, as this substance, especially when used i n large quantities, materially hastens discoloration a n d deterioration. Limits for rosin are now included in government paper specifications. ALCOHOL M E T H O D S
Of t h e numerous methods used for estimating t h e amount of rosin in paper, many are based on its extraction with alcohol, modifications being introduced TABLE111-COST OF MININGNELSONITE AND MAKINGA MECHANICAL in t h e subsequent treatment of the solution containOF THE Two MINERALS, APATITEAND ILMENITE PER TON SEPARATION ing t h e extracted rosin. Cost of mining.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . $1 . O O Cost of grinding.. ............................ 0.50 T u r b i d i t y Method.-The turbidity produced by t h e Cost of mechanical separation.. . . . . . . . . . . . . . . . . 0 . 2 5 precipitation of rosin from solution, on diluting t h e alcoholic extract with water, is compared with t h e Total cost .......................... $1.75 turbidity produced in a like manner in a n alcoholic Assuming t h a t I ton of nelsonite will yield '/2 solution, the rosin concentration of which is known. t o n each of ilmenite a n d apatite then t h e cost of pre- Although in many cases 0.0002 gram differences in paring this amount of ilmenite for the market will the same solution may thus be detected, it was found be as follows: t h a t in some papers the determinations varied 2 5 or even j o per cent from the actual amount of rosin TABLEIV-COST OF PREPARIXG ONE-HALFTONOF ILMENITE FOR THE MARKET present. Since more t h a n 0.006 gram of rosin pre'/z expense of mining and separatin'g minerals.. . . . . . . . . . . . . . . $ 0 . 8 8 cipitated in I O O cc. of water interferes with t h e delicacy l/z ton of sulfuric acid (60' B.) at $8.00 per t o n . . . . . . . . . . . . . . 4.00 of the comparison, t h e quantities used must be S O Cost of washing ilmenite (1/z ton) Cost of drying ilmenite (1/z ton), small t h a t t h e percentage error is greatly affected by t h e uniformity of precipitation, which depends Total cost of 1/z ton ilmenite.. ........................... $5.33 upon such factors as the sequence of operation, time The sulfuric acid extract after concentration can allowed for precipitation a n d subsequent comparison,
