'
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 containSEPARATION OF THE Two MINERALS, APATITEAND ILMENITE PER TON 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,
Sept.,
I913
T H E J O U R N A L OF I N D U S T R I A L A N D ENGILVEERING C H E M I S T R Y
the a m o u n t of alcohol present, t h e foreign materials extracted by alcohol, a n d the undetermined factors influencing t h e size of t h e precipitated rosin particles, It is probable, however, t h a t if t h e alcoholic extract were freed from foreign materials b y evaporation, extraction with ether, a n d washing with water, as described below, t h e turbidity method would give more accurate results. Acidified Alcohol Method.-The rosin is precipitated from t h e alcoholic extract b y dilution with acidulated water, filtered off, washed, dried, a n d weighed. T h e sources of error here are incomplete precipitation in the presence of colloidal materials, the escape of minute suspended particles through t h e filter, a n d the contamination of t h e rosin b y t h e co-precipitation of foreign materials. Direct Evaporation Method.-The acidulated alcoholic solution with which t h e rosin is extracted is evaporated directly a n d t h e residue weighed. This method gives results which, in some instances, may be too high by 60 per cent, because of the contamination b y such foreign substances as glue, invert starch, cellulose, soda, aluminum salts, fats a n d greases, which are also removed from t h e paper by the acidified alcohol. Schztmann’s IMethod.l-The rosin, having been extracted by a dilute solution of alkali, is precipitated from the extract, filtered off,washed, dried, a n d weighed. T h e difficulty of removing the alkali resinate, especially from soft papers which are easily pulped by the action of the alkali, a n d the contamination of t h e precipit a t e d rosin by foreign substances extracted by t h e alkali renders this method unsatisfactory. Were this precipitate of rosin t a k e n u p in ether a n d t h e ether extract washedwith water, thenevaporated a n d weighed, more accurate results could be obtained, although t h e loss from incomplete extraction a n d washing would still occur. ACIDIFIED E T H E R METHOD
Acidified ether is t h e solvent in this method, t h e ether extract of t h e paper being directly evaporated, dried, cooled a n d weighed. I t is open t o t h e objection t h a t t h e resinates are not readily extracted b y ether. ALCOHOL-ETHER
METHOD
Because of t h e objections to the current methods, a procedure reasonably accurate a n d a t t h e same time simple in execution was sought. The modifications of t h e method as first devised,2 which have been developed b y experience, are incorporated in t h e following procedure : C u t j grams of paper into strips approximately one-half inch wide a n d fold t h e m in numerous small crosswise folds. Place t h e folded strips in a Soxhlet extractor a n d fill with acidulated alcohol diluted t o approximately 83 per cent, made b y adding t o I O O C C . of 9 j per cent alcohol ~j cc. of acidulated water containing j cc. of glacial acetic acid t o I O O cc. of distilled water. Place t h e Soxhlet flask directly in t h e boiling water of a steam b a t h a n d extract by siphoning f r o m six t o twelve times, according t o t h e nature of 1
Sindall, “Elementary Manual Paper Technology.” 1910. U. S. Dept. A=., Office of the Secretary, Report 89, 1909
733
t h e paper. Wash t h e alcoholic extract of rosin, which may contain foreign materials, into a beaker a n d evaporate t o a few cubic centimeters on a steam bath. Cool, take up in about 2 j cc. of ether, transfer t o a 300 cc. separatory funnel containing about I 50 cc. of distilled water t o which has been added a small quantity of sodium chloride t o prevent emulsion, shake thoroughly, a n d allow t o separate. Draw off t h e water into a second separatory funnel a n d repeat t h e treatment with a fresh 2 5 cc. portion of ether. Combine t h e ether extracts which contain the rosin a n d a n y other ether-soluble materials a n d wash twice, or until t h e ether layer is perfectly clear a n d the line between the ether a n d water is sharp a n d distinct, with I O O cc. portions of distilled water t o remove salts a n d foreign matter. (Should glue, which is extracted from t h e paper by alcohol, interfere b y emulsifying with t h e ether, it may be readily removed b y adding a strong solution of sodium chloride t o the combined ether extracts, shaking thoroughly a n d drawing i t off, repeating if necessary, before washing with distilled water.) Transfer the washed ether extract t o a weighed platinum dish, evaporate t o dryness and dry in a water oven a t from 98’ t o 100’ C. for exactly one hour, cool, a n d weigh. This length of time is sufficient t o insure complete drying; prolonged heating causes a continual loss of rosin. I t may be noted t h a t a n y alcohol- a n d ether-soluble fats, waxes or other foreign materials present in t h e paper will be extracted with the rosin. These substances, however. if present at all, occur in such small amounts in high-grade papers t h a t their influence on t h e result is negligible. I t has been found t h a t the quantity of rosin obtained from 5 grams of paper is sufficient for accurate work, a n d t h a t a greater amount of paper materially interferes with complete extraction within a reasonable time. T h e folding of t h e strips is important, as it prevents t h e sticking together of t h e pieces when wet a n d consequent incomplete extraction which results when t h e paper is merely torn or cut into small pieces. It is well, although not essential, t o saturate the folded strips with acidulated alcohol when they are placed in the Soxhlet flask, as this hastens t h e breaking up of t h e resinates. If the alcohol is t o o dilute, t h e extraction of rosin from the paper is incomplete, and large quantities of glue interfere with t h e subsequent separation with ether. If acidulated alcohol of 9 j per cent concentration is used, t h e acid does not break up the resinates which, therefore, will not be extracted. By placing t h e Soxhlet flask directly in the boiling water of a steam bath, distillation is hastened a n d t h e solvent in the extraction chamber is kept hot by t h e surrounding steam, which completes the extraction in a minimum length of time. I t was found t h a t neutral 9 j per cent alcohol does not completely remove t h e rosin within a reasonable time, probably because resinates are not readily soluble. A representative instance occurred when I O grams of paper were extracted in a Soxhlet flask with 1 2 5 cc. portions of g j per cent neutral alcohol by t h e alcoholether method, t h e following results being obtained:
’
T H E JOL-RlYAL OF I L Y D U S T R I A L An'D EA'GIA-EERISG C H E M I S T R Y
734 TABLE I-ROSIN
OBTAINEDFROM NEUTRALALCOHOLSOLUTION Time of extraction
No. of extraction 1 2 3 4 5
Hours
Rosin obtained Per cent
4 3 3 3 4
1.786 0.138 0.094 0.066 0,040
I t was also found t h a t t h e percentage removed in successive extractions with neutral 95 per cent alcohol varies with t h e a m o u n t of rosin originally present a n d with t h e nature of t h e paper extracted. T h e alcohol-ether method has been subjected t o tests, which may best be illustrated b y t h e following typical examples t a k e n from numerous determinations : Ten grams of rosin were dissolved in a solution of sodium carbonate a n d made up t o 1000 cc. Twentyfive cubic centimeters, representing 0 . 2 5 gram of rosin, were withdrawn from this solution, the rosin precipit a t e d b y the addition of aluminum sulfate a n d acetic acid, a n d t h e whole then extracted with t w o 2 j cc. portions of ether. T h e ether extract was washed with distilled water, as directed in the method, evaporated, dried a t 100' C. for one hour, cooled, a n d weighed. T h e dried material weighed 0 . 2 509 gram, agreeing closely with t h e a m o u n t of rosin taken. T h e method was further tested b y extracting m a n y different kinds of paper a n d determining t h e a m o u n t of rosin present. A second extraction was made on t h e same sample of paper a n d t h e rosin then taken u p in ether a n d determined, with the results shown in Table 11. Third a n d fourth extractions with 8 3 per cent alcohol have not given, in a n y case, more t h a n 0.04 per cent of rosin.
Val. 5, No. 9
8 3 per cent is preferable t o one of 79 or 7 3 per cent, which gives slightly lower results. E v e n a t these latter concentrations, however, t h e results are within t h e experimental error of 0 . 2 0 per cent, except in t h e case of t h e 7 3 per cent concentration in t h e first extraction of the writing paper where t h e percentage error is 0 . z I . T h e variations in results due t o sampling are shown b y the following figures, obtained b y extracting different sheets of t h e same sample of ledger paper as t h a t reported in Table 111. TABLEIV Amount of rosin extracted 7
Extraction No. Sample I: 1
......................
2 . ..................... 3 ......................
7
86 per cent 83 per cent 79 per cent 73 per cent alcohol alcohol alcohol alcohol 1.67 1.56 1.65 1.66 0.02 0.07 0.04 0.09 0.01 0.04 0.08 0.01
Total.. . . . . . . . . . . . . . . Sample 11: 1...................... 2 ...................... 3 ......................
__
__
-
-
1.76
1.70
1.67
1.77
1.79 0.04 0.02
. 1.79
1.70 0.02 0.03
1.75 0.02 0.03
0.04 0.04
~
Total. . . . . . . . . . . . . . . . 1.85
_ .
__
__
1.87
1.75
1.80
These results are entirely within t h e experimental error of 0 . 2 0 per cent, as far as the 8 6 a n d 8 3 per cent concentrations are concerned. A comparison of the results obtained by t h e alcoholether method with t h e results obtained b y t h e alcohol evaporation a n d acidified ether methods, in which the total extract is dried, weighed a n d calculated as rosin in each case, gave the following results: TABLE V Amount of rosin extracted
TABLE11-DETERMINATION OF ROSIN Amount of rosin extracted
Kind of paper Ledger.. ................................. Bond .................................... Writing Sized and supercalendered printing.. Manila Double coated..
..................................
First extraction Per cent 1.72 1.90 1.20 0.81 1.48 1.57
Second extraction Per cent
........ ................................... ..........................
0.02 0.01 0.06 0.04 0.03 0.05
T h e effect of t h e concentration of acidified alcohol on t h e extraction of rosin is shown in t h e following table. Ninety-five per cent alcohol diluted t o the approximate percentage given was used in the determination : TABLE I11 Amount of rosin extracted C . - ~ _ _ _ _ h - _ - _ _ _ 7
86 per cent 83 per cent 79 per cent 73 per cent Extraction No. Ledger paper: alcohol alcohol alcohol alcohol 1. . . . . . . . . . . . . . . . . . . . . . 1.67 1. i O 1.63 1.53 2 . ..................... 0.02 0.02 0.03 0.09 3 . . .................... 0.01 0.01 0.02 0.01
__
Total.. . . . . . . . . . . . . . . Writing paper: 1 ...................... 2 ...................... 3 .......................
_ .
-
~
1.70
1.73
1.68
1.63
2.17 0.07 0.01
2.03
1.96 0.06 0.03
2.00 0.12 0.09
..
0.03
__
__
-
__
T o t a l . . . . . . . . . . . . . . . . 2.25
2.06
2.05
2.21
These results show t h a t a concentration of 8 6 or
evaporation . . . . . . . . . . . 2.87 Acidified ether direct evaporation . . . . . . . . . . . 2.65 Acidified alcohol-ether .... 2.47
1.39
1.85
30.6 2.61
2.82
1.79
1.22 1. I 8
0.94 1. 7 0
2.86 1.66 0 . 9 2 1.25
1.90 2.00
1.20 1.22
This table shows t h a t t h e acidified alcohol extract followed b y direct evaporation gives results which are too high, due t o the presence in the extract of both soluble a n d insoluble foreign material. I n t h e alcohol-ether method these materials are eliminated through precipitation a n d washing. Acidified ether does not extract as much rosin in the same number of siphonings as acidified alcohol. T h e method has a tendency t o yield low results. I n some instances, however, insoluble material is separated from t h e paper, thereby giving results which are too high. T h e amount of material which may be extracted from coated paper by acidified alcohol is indicated when t h e extract is evaporated directly. T o report such material as rosin is obviously erroneous. T h e acidified alcoholic extract was very opalescent a n d gave positive tests for glue a n d casein. Ordinarily,
of course. one would not report such results as rosin. I n those cases, however, where t h e error is less obvious t h e analyst may frequently fail t o detect i t . c0 s c L C S I O sS The alcohol-ether method has consistently given t h e most accurate a n d concordant results i n this laboratory i n all comparatixre work. Contrary t o our first experience with i t , when a n insufficient amount of acid was used, estraction with one portion of acidified alcohol, making from six t o twelve siphonings, has been found t o be sufficient for all practical purposes. The results, when 83 per cent alcohol is used, are within t h e experimental error of 0 . 2 0 per cent, as are t h e variations due t o sampling. S o other procedure tried has proved equally satisfactory. L E ~ T H E RASD P A P E R LABORATORY
B U R E A UOF
CHEMISTRY
~ASHISGIOP;
COLORIMETRIC METHOD F O R TITANIUM I N IRON AND
STEEL By C. R . MCCABE
Received March 6, 1913
I n the colorimetric method for titanium, t h e color is usually produced i n a sulfuric acid solution of t h e iron or steel. T h e color of the ferric sulfate is i n most cases much more intense t h a n t h a t of t h e titanium. The color employed for comparison is therefore a blend of two colors in which the color on which we base our method is t h e subordinate one. If t h e quantities of iron present in standard a n d test are t h c same, i t follows t h a t so far as iron is concerned the two solutions have the same color a t equal volumes. If comparison be attempted a t unequal volumes, even though t h e divergence be slight, t h e more concentrated solution contains a more intense iron color t h a n t h e other. Hence, vie must have a standard which contains t h e same percentage of titanium as the test sample, within very narrow limits. This consideration led t h e writer t o seek some plan whereby a standard would be always available precisely like t h e test sample. T h e plan adopted is t o produce t h e color in a sulfuric acid solution of t h e iron or steel and then imitate i t in a solution of a nontitanium steel b y adding a standard solution of titanium from a burette. P R E P A R A T I O S O F T I T A S I U M STASDARD SOLUTION
Place about I O O grams of ferro-titanium in a dish a n d pour over i t about 50 cc. of strong HC1. Heat, a n d when t h e solvent action has progressed for a few moments add j cc. of nitric acid (sp. gr. 1 . 2 ) . Continue heating until t h e acid is about half evaporated, dilute with I j or 20 cc. water a n d filter through a large filter paper. Treat t h e ferro-titanium again with hydrochloric a n d nitric acids, dilute, a n d filter in this manner a dozen times or more until t h e desired quantity of ferro-titanium has been dissolved. Simultaneously with t h e solution of t h e ferro-titanium the combined filtrates are evaporated in a large beaker on a hot plate. Evaporate until separation of titanic acid is observed. Pour into several separatory funnels, a n d a d d t o each 50 cc. ether. Make repeated
ether extractions of the iron until t h e titanic acid is free of iron as shown b y t h e potassium sulfocyanide test. Combine t h e several acid solutions a n d place in a 400 cc. beaker. T o t h e titanic acid emulsion a d d I j o cc. sulfuric acid ( I : 3 ) . Heat a n d filter from t h e insoluble portion, which is usually slight. Dilute t h e filtrate t o about j o o cc., in a liter beaker, a d d ammonia i n excess, boil a n d allow t h e precipitate t o settle. Decant or siphon away t h e supernatant solution a n d wash t h e hydrated titanic acid free of chlorides b y decantation. Dissolve t h e titanic acid in jo cc. of sulfuric acid ( I : I ) a n d dilute t o a liter. Determine t h e strength of this stock solution b y precipitation of I O O cc. with ammonia. Calculate t h e dilution required t o yield a standard solution containing 0.0002 gram of titanium per cc. Remove t h e requisite quantity of t h e stock solution a n d dilute according t o t h e calculation. Finally check t h e strength of t h e standard solution b y precipitation of I O O cc. with ammonia. TITAhIL,M IIi
I R O S AND S T E E L
When titanium exists in iron or steel above 0 . 0 2 per cent i t may be readily determined in less t h a n hour b y t h e color method t o 'ne described. K h e n present in smaller amount i t may be determined with great precision b y the writer's more refined color method requiring a n ether separation of iron. PROCEDURE
FOR
TITAIiIUM ABOVE 0 . 0 2 P E R C E S T
P u t two grams each of t h e titanium steel and a nontitanium steel into 300 cc. Erlenmeyer flasks. Pour into each flask So cc. of sulfuric acid ( I : 3 ) and heat on a hot plate t o complete solution. To each a d d 4 cc. of nitric acid (sp. gr. 1 . 2 ) and continue boiling until t h e solutions are free of fumes; cool. Transfer t h e solution of non-titanium steel t o a comparing tube, using as little wash mater as possible. Pour t h e test sample into t h e companion tube and dilute N o w obseri-e if t o t h e same volume as t h e other. t h e two solutions have colors of the same character a n d depth, as they should. If t h e test sample be cast iron, filter t h e solution into t h e tube. preferably using a small wad of absorbent cotton because of gelatinous silica. Match t h e color with t h a t of t h e non-titanium steel solution. Owing t o t h e fact t h a t cast iron contains a much larger percentage of metalloids t h a n steel, i t is usually found t h a t t h e volume of t h e iron solution is a trifle less t h a n t h a t of the nontitanium steel when t h e colors match. I n this case discard sufficient of t h e non-titanium steel solution t o make t h e volumes equal. Having obtained solutions showing t h e same color i n equal volumes, introduce into each 2 cc. of 3 per cent hydrogen peroxide. Mix, and observe closely if t h e test solution shows a n y deepening of color. If titanium be present in as small a n amount as 0 . 0 2 per cent, this deepening will be in evidence. It may even be detected with 0.01 per cent present, b u t in t h a t case i t is better t o rely on t h e more refined method t o be described. Titanium if shown t o be present in notable quantity is determined b y adding from a burette a sufficient
