I S D U S T R I h L A N D E N G I N E E R I U G C €I E \I I S T H 1-
1061 TABLE
v1I.
SP.GR.
(25'/25OC.) 1.22255 1.22520 1.22790 1.23055 1.23320
O F GLYCEROL SOLUTIOSS (INTERPOLATED) i Continued)
ABSOLUTE \-ISCOsITIEs
GLICEROL
Q 85.00 86.00 87.00
I
20'c.
22.5'c.
VISCOSITY 25' c. 2 7 . 5 ' c .
88.00 89.00
112.9 129.6 150.4 174.5 201.4
95.5 109.1 125.6 145.7 169.1
81.5 92.6 106.1
7
1.23585 1.23718 1,23850 1.23983 1.24115
90.00 90.50 91.00 91.50 92.00
234.6 255.0 278.4 302.8 328.4
194.6 210.4 227.0 246.2 267.9
1.24248 1.24380 1.24513 1.24645 1.24778
92.50 93.00 93.50 94.00 94.50
356.2 387.7 421.3 457.7 498.5
1.24910 1.25038 1.25165 1.25295 1.25425
95.00 95.50 96.00 96.50 97.00
545 601 661 731 805
1,25555 1.25685 1.25815 1.25945 1.26073 1.26201
97.50 98.00 98.50 99.00 99.50 100.00
885 974 1080 1197 1337 1499
141.8
60.05 68.1 77.5 88.8 101.1
163.6 175.6 189.3 204.0 221.8
137.3 147.6 158.8 171.3 185.6
115.3 124.3 134.4 145.0 156.5
292.5 318.6 344.8 374.0 406.0
241.2 282.9 285.7 308.7 335.6
201.2 217.7 237.0 255.8 278.2
169.3 182.8 196.2 212.0 229.0
443.8 495.0 532.0 584.0 645
366.0 397.8 435.0 476.8 52'2.9
301.8 327.5 357.6 391.5 428.4
248.8 271.4 296.7 324.3 354.0
571 629 698 775 856 945
470.0 514.4 567 6'29 694 764
387.4 424.0 465.3 511.0 564 624
713 784 867 957 1065 1156
Table VI11 shows the comparison on a few lots of c. P. glycerol between percentage glycerol as determined by specific gravity and percentage as determined by viscosities at 20" and 25' C.
GLYCEROL DBTERMISATIOXS By viecoPity B y viscosity (250/250 C . ) (200 C.) (259 C.) 7 -
By sp. gr.
LOT 70,2 79.0 90.R 104.0 119.1
122.6
TABLEVIII. DETERMINATION OF PERCESTAGE GLYCEROL BY VARIOFS METHODS
30'c.
-C e n t i D l i a P s
Vol. 22, Yo. 9
72 94.86 94 94 94.96 94,87 94 94 94.97 94.94
%
%
94:93 95.01 94.98 94.98
94.86 94.88 94.90 94,75 94.95 94.94 94.92
LITERATURE CITED (1) Archbutt and Deeley, "Lubrication and Lubricants," 5 t h ed., p. 193, C. Griffin & Co., London, 1927. (2) Bingham, "Fluidity and Plasticity," 1st ed., pp. 295-318, RlcGraw-Hill, 1922. (3) Bingham and Jackson, Bur. Standards, Sci. Papers 298 (19171. (4) Bosart and Snoddy, IND.EKQ.CHEM.,19, 506 (1927). (5) Cocks, J . SOC.Chem. Ind., 48, 279 (1929). (6) Darke and Lewis, Ibid., 47, 1073 (1928). ( 7 ) Here and Wegner, 2. deut. 01- Fett-Znd., 45, 53 (1925). (8) Her2 and Wegner, Ibid.,45, 401 (1925). (9) Jones, Phil. -Wag., 37, 4 5 1 (1894). ( I O ) Kellner, 2. deut. 01- Fett-Znd., 40, 677 (1920). (11) Muller, Sitther. Akad. Wiss. W'ien, iTfath.-naturw. Klasse. 133, IIa, 133 (1924). (12) Schottner, Ibid., 77, 6 8 2 (1878); 79, 4 7 7 (1879). RECZIVED .ipril 4! 1932
Composition of Crude Phosphoric Acid Prepared by Sulfuric Acid Process kv. L. HILL,H. L. RIARSHALL, A S D K. D. JACOB Fertilizer and Fixed Nitrogen Investigations, Bureau of Chemistry and Soils, Washington, D. C. HOSPHORlC acid Six samples of crude phosphoric acid prepared concentrating to the d e s i r e d (H3P04) is now produced by sulfuricacid including one sample strength, is used directly, usuin the United States by ally without purification. Contwo processes-namely, the suleach Of and concentrated acid Obtained sequently, the fertilizer salts confuric acid process and the vola.from Floridapebble, Idaho, and Tennessee boWntain the greater portion of the impurities present in the phostilization process. Data on the rock phosphate, respectively, have been analyzed relative quantities of acid prof o r the following constituents: phosphoric acid, phoric acid. The amount and nature of the impurities will dee'd by these processes are not total silica, aluminum, iron, calcium, magpend upon the composition of available, but it is known that a large portion of the acid used in nesium, sodium, potassium, manganese, copper, the phosphate rock and of the sulthe manufacture of chemicals zinc, lead, chromium, t'anadium, molybdenum, furic acid used in its treatment. arsenic trioxide, sulfur trioxide, fluorine, chloCertain of the i m p u r i t i e s , for technical, i n d u s t r i a l , and rine, bromine, iodine, and organic carbon. if present in sufficient concenfood Purposes is Produced by tration, may affect, either adthe v o l a t i l i z a t i o n p r o c e s s , versely or favorably, the value whereas the greater portion of the acid used in the manufacture of fertilizer salts, such as of the fertilizers in promoting plant growth (11, 18). In an double or triple superphosphate and the ammonium phos- investigation of the action of crude and C. P. phosphoric acids phates, is produced by the sulfuric acid process. Although on metals, Kosting and Heins (9) have shown that impurities bone was formerly an important raw material for the manu- present in the crude acid accelerate the corrosion of certain facture of phosphoric acid, thp domestic production of acid metals and alloys, whereas they act as corrosion inhibitors in certain other cases. When phosphoric acid made by the is now derived almost entirely from phosphate rock. As s h o r n by Ross, Durgin, and Jones (179, the volatiliza- sulfuric acid process is used in the manufacture of technical tion process possesses an advantage over the sulfuric acid and food-grade chemicals, considerable trouble is sometimes process in that it produces directly an acid of comparatively encountered because of the difficulty in reducing the content high purity. This is one of the reasons why volatilized of impurities to the desired limits, and also because of the phosphoric acid has met with so much favor in the manu- effect of the impurities in producing undesirable colorations facture of technical and food-grade phosphates. The phos- in the finished products. Ross, Durgin, and Jones (17') report analyses of several phoric acid used in the manufacture of fertilizer salts is produced principally by the sulfuric acid process and, after samples of crude and commercially refined phosphoric acids
P
\ 1)
1: \
( I
I?? the mliiirir. ;wid and volnt,ilisation pro< Sianrfield (13) aud Iiosting and IIciiis (a: Tennemeeb \io"l*,en~
S%I,XlTN" I I
z
ACID. This acid was inasiu1'328 by a babcli process. 'The concentrated acid was o1,taiix:d 1i.y cvaporating the dilute acid in singlestage vac~iumevaporators oi the Sweiisoir type. The acids were shiplxd in woodw-i barrels arid were transferred to jmratlimd glass wntaiiicrs iimiiediiitely after being recrivod. ' l hairdyses were made oii samples of acid which had s t u d for a snlhcieiit length of time to permit praritically all suspentled matter to settle out. E 13non.+-H,oi:K
0I'ERATI"PS
S e u m I N r , OPsNAnol-s I N :
produced by the s u l f u r i c acid process ranges from approximately 20 to 28 per cent IJaPOr. For use in the manufacture of double or triple supcrphospliatc, the acid is concentrated to approximately 51) to 60 per cent I&I'04, whereas in the manufacture US the ammonium pliosplintes the dilute ticid is uscd directly. Analyses were made on both dilute and c o n cell t r a t e d arid8 prodiicrd froni each of the three types of rock. I'LollSn.4 I'EUULE ACID. Thisacid W M S manufactured iri 1028froro uiidriedFlorida p e b h l e phorphnte by the Dorr nrocess. The dilute arid was taken irom the first 1)orr T1,ickelier. T h e wucentritted acid was obtained by passfroiii tlu: wmbust.ion of fuel oil tlirough thedilute .pccially desigsml apparatus. The acids were shipped in citriiays aid were treiisferred to psrntliried glass rontaiiiers iinmediately after beiiig received. I n a m ACID. This acid TIW manufactured is, 1'330 by t,he irom Idnlio phospliatc whielr liad been calcined )O" C. The corrcerrtrated acid was obtained Ijy w q m a t i u g the dilute acid in single-stagg vacuum evaporators of the 8%-enson type. The a d s were sliipped in
7"
on
hnaiy'ar iuinislied by ,,rcd"?i,*z ""U,,'""i(.l. Origind iiiidlyai~ mhrie on 60- 116. arid ~mituiiiini:7 7 ~ 3 0 %H2SOa. Original ~ i i i i ! ~ imade i i ~ om 50' Be. m i d ~:oetiiiiiinp61.64% HtSOc.
Approximately 50 per ceiit oi tlie d f u r i c acid used iir the rrinriiifacture of duulilo or triple supcrpliosphatc is producotl as fl by-yroduct of cupper smelting operations, principally in hlootana and Tennessee. The Florida pebble and Tcnnt:ssee brown-rock phosphoric acids used in this invest,igatiim xcrc cuininercial products inade with by-product sulfuric acid froill it copper smelting operation in Tennessee. The Idaho phuspliaric acid was made with by-product sulfuric acid from a copper smelter in Montana. Aualyses of the sulfuric acids are given in Table I.
' H i e uictluds u a d in t.he aria1 oi the samples of ptiosplioric avid were briefly as follows: The prucedures iriitlint:d by Ilolis, Uurgin, arid Joiies ( I T ) w i w used in prqwing the samples for analysis, arid in the riott,rniinatii,r1 of pliosphoric acid, calcium, sodiuin, potassium, lead, and chlorine. TOTAL Hir.icn. h i 1 aliquot, pari oi the sample witj iieutralized witli 10 per cent sodium hydroxide solution, usiiig methyl nxl as an indicator, and the precipitate was filtered irfT and r i d with 2 prams of sodium carbonate. The melt was extracted with hot water aird the fildrate ~ d d c dto
10
R I 4 1.
4 h D tih G 1 R E ti t l 1 N G
hydroxide precipitation. Itrates and in the residue e carbonate fusion wits then mended by IIill and Jacob
c I1 E MI s 1'lI Y
Vol 24, No 9
by the procedure suggested by lloss, Durgin, and Jones (f7),and fluorine was determined in tho dried residue by the volatilization method as modified by Reynolds, Ross, and Jacob (16). This method accounts for about 93.5 per cent of the fluorine present. Consequently, the figures given in this paper have been corrected to 100 per cent recovery on this basis. IODINE. A 25ce. sample of the acid was distilled with sulfuric acid and hydrogen peroxide, and the iodine was a b s o r b e d in Dotassiuni carbonate soht i o n (4). T h e c a r bonate solution was e v a p o r a t e d to dryness, and the iodine was extracted with 93 to 94 per cent alcohol and determined colorimetrically b y McClendon's method
of the sample W ~ ouidi~ed S with pennanganate to destroy organic matter The iron was then reduced with stannous chloride soliitioii and titrated with ~ o t a s u u mdichromate solution. using dlphenylamiiie as an -internal indicator (6). ALUMINUM. From an aliquot. p a r t of the sample, iron and aluminum were prec i p i t a t e d together twice by t,he basic acetate method, acc o r d i n g to Lundell a n d Hoffman ( l e ) , and the alumiiiurii (W. BROMINE. T h e was c a l c u l a t e d by water solution from difference. the iodine extraction MAGNESIUM.Ai1 was tested for broexcess of aminonia niiiie microcolorimet was a d d e d t o t h e rically by extraction alcoholic filtrate from with c a r b o n tetrathe calcium sulfate chloride in the presprecipithon. The ence of free chlorine, precipitate, after according t o t h e filtering a n d washmethod of Swe e n c y ing with 5 per cent Ilvmnron VIEWOF P ~ o s ~ n o nACID i c PLANT and Withrow (1.9). ammonium hydroxide (Covered I h r r 'Tiiiokener in ioresround) ORGANIC CARBON. solution c o n t a i n i n g A sample of the acid a m m o n i u m citrate, was dissolved in dilute liydroclilorie acid, and the magnesium wits neutralized with calcium oxide to yield dicalcinm phosphate, evaporated to dryness, and dried at 105" C. Organic was precipitated as magnesium ammonium phosphate in carhon was determined in the residue by the usual dry comthe presence of ammonium citrate. MANGANESE.Manganese was det,erminedby the periodate bustion method, and the results were corrected for carbonatea present in the dried residue. using I) nitric , and phosphoric acids. method (% COPPER. Copper was precipitated as the sulfide and In all cases, blank determinations were made on the readetermined colorimetrically (81) with potasiurn ferro- gents, and the result9 were corrected accordingly. Whenever excessively high blanks were obtained, the reagents cyanide. ZINC. Ziiic was precipitated as the sulfide and determined were specially purified. iiephelometrically (88)with potassium ferrocyanide. CHROMIUM.Chromium was detrrmined colorimetrically COMPOSITION OF PHOSPHORIC Acin fts chromate on the ignited precipitate from the deterniiiiatiou Data on the composition of the acids as received are given of total iron and alumina. Molybdenum was precipitated from acid in Table 11. Table 111 gives the same data recalculated, MOLYBDENUM. solution .as the sulfide in a pressure bottle. The precipitate for purposes of comparison, to a uniform basis of acid conwas ignited gently, and the molybdenum determined colori- taining 50 per cent HJ'OI. Table IV gives summarized metrically with stannous chloride and potmium thiocyanate figures obtained in this laboratory on the so-called minor constituents present in a number of samples of the types of in ethereal solution (8j. VANADIUM.Hydrogeii sulfide was expclled from the phosphate rock from which these acids were made. The results given in Table 111 show that the dilute acids filtrate from the molybdenum sulfide precipitation, potassium permanganate solution was added to a faint pink contained considerably larger relative amounts of cerbin coloration, and the vanadium was determined colorimetri- impuritim than the corresponding concentrated acids, cally with hydrogen peroxide after adding hydrofluoric acid particularly fluorine and (in the case of the Florida pehhle and Idaho acids) silica. The figures for fluorine present as to bleach the color due to iron and titanium ( 7 ) . ARSENIC. After distillation from the acid as arsenous F- and Sip6-- were calculated on the assumption that all chloride, the arsenic was pecipitated as magnesium amino- the silica was present as fluosilicates and hydrofluosilicic nium arsenate, along with magnesium ammonium plios- acid. Although this assumption is probably not strictly justifiable, the results fall in line with the fact that the phate ( I ) , and determined by the Gntzeit method (8). SULFURTRIOXIDE. An aliquot part of the sample was dilute acids containing the largest quantities of silica lost neutralized with ammonia; concentrated hydrochloric the largest amounts of fluorine upon evaporation. The acid was added a t the rate of 2 to 3 cc. per 500 cc. of solution, decrease in the fluorine content of the acid upon concentraand the sulfur trioxide was precipitated and weighed ~ t s tion is due to its volatilization, principally as hydrofluoric barium sulfate. acid and silicon tetrafluoride, which result from the decompoFI.UORINE. A sample of the acid was prepared for aiialysis sition of .ligdrofluosilicic acid, and to deposit.ion 2s sodium
I N DUST R IA L A ND E N GI N EER I N G CHEM I STR Y
September, 1932
TABLE11. COMPOSITION
OF
CRUDE PHOSPHORIC
(Results on samples as received) FLORIDA T E N N E S S EBER O W N PEBBLE ROCK CONSTITUENT Dil. Concd. Dil. Concd.
Dil.
TABLE111. COMPOSITION OF CRUDE PHOSPHORIC ACID
ACID
ACID Concd.
%
% % % % % 20.26 37.80 44.14 16.04 41.38 27.96 52.19 60.93 22.12 57.11 0.50 0.06 0.04 0.21 0.02 0.36 0.70 0.75 1.59 0.77 0.20 0.38 0.84 1.41 0.73 0.10 0.00 0.14 0.01 0.03 .... . ,,, ... . .... 0.02 0.18 0,001 0.17 0.001 0.001 0.09 0.11 0.03 0.02 0.03 0.01 0.03 0.01 0.33 0.001 0.003 0.010 0.023 0.15 0.003 0.007 0.006 0.006 0.014 0.008 0.040 0.061 0,030 0.020 0.041 0,029 0.0004 0.0007 0.0006 0.0002 0.0006 0,0002 0.040 0 , 0 8 0 0.0014 0.0031 0.0005 0.0012 0.10 0.16 0,003 0.004 0.000 0.000 0.003 0.008 0.004 0.000 0.000 0,003 0.062 0.16 0,0031 0.0030 0,0046 0.0026 1.78 3.66 5.32 0.79 1.46 2.49 0.92 0.13 0.57 1.35 1.98 1.57 1.58 0.00 0.02 0.04 0.53 1.27 0.40 0.95 0.11 1.53 0.04 0.08 0.005 0.03 0.05 0.04 0.04 0.002 0.0000 0.0000 0.0000 . . . . 0.0000 0.0000 0,000033 0.00000 0.00000 0.000013 0,00010 , . . . 0.01 0.20 0.40 0.08 0.09 0.13
19.87 27.42 0.81 0.38 0.40 0.06
PI06
&Pod Si02
AI Fe C _ a_
Mg
P Mn
cu Zn Pb Cr V Mo
As903 SO8 F (total) F aa FF aa SiFa--
CI
Br
I
Orcanic C
Total impurities 5.97 Sp. gr. (22OC.) 1.237
8.14 1.581
4.21 1.190
7.15 1.560
4.29 1.225
1067
(Results calculated t o basis of acid containing 50 per cent &PO,, or 36.21 per cent PzOs) FLORID.% TENNESSEE BROWNIDlHO PEBBLE ROCK AcIn CONSTITUEXT Dil. Conod. Dil. Conod. Dil. Concd. Si02 A1 Fe Ca Mg
Za Mn Cu Zn Pb Cr
v
Mo
A9203
SOa F (total) F as F F a8 SiFs--
CI
nr I
Organic C
% 1.48 0.69 0.73 0.11
....
%
% 0.02 0.63 0.60 0.02
....
0.002 0.14 0.05 0.02 0.018 0,019 0.011 0.005 0.053 0.025 0.0004 0.0005 0.0025 0.0025 0.005 0.003 0.005 0.003 0.0047 0.0025 4.54 4.37 2.86 0.47 0.07 0.44 2.79 0.03 0.07 0.03 0.000 0.0000 0.000024 0.000082 0.24 0.33
Totalimpurities10.87
6.69
0.09 1.69 1.90 0.32
% 0.18 1.39 1.23 0.01
0.002 0.07 0.34 0.032 0.045 0.0005 0.0011
0.001 0.01 0.29 0.007 0.036 0.0005 0.0011
....
....
%
%
0.89 0.64 0.36 0.18 0.04 0.16 0.05
0.06 0.67 0.36
0.002
0.003 0.007 0.058 0.0007 0.077 0.15 0.008 0.15 3.51 0.12 0.02
0.00
0.17 0.11 0.01
0.005 0.071 0.0007 0.071 0.000 0.000 0.18 0.000 0.000 0.005 0.0068 0.0040 0.11 1.79 1.28 3.18 3.05 1.73 1.65 2.87 1.38 0.00 1.70 0.18 0.35 0.05 0.005 0.004 ,... 0.0000 0.000 . . . . 0.000029 0.0000 0.18 0.08 0.02 9,52
6.25
0.11
7.66
0.05 0.0000 0.00000 0.19 5.70
5.96 1.457
TABLEIV. MISOR COXSTITUENTS OF PHOSPHATE ROCK -FLORIDA Samples CONSTITUENTanalyzed
PEBBLERange
% AI Fe Na K Mn Cu Zn Cr
11 11 11 11 11 4 4
M O
3 3
V
ASIOI
'
11 11
0.38-0.59 0.49-1.81 0.05-0.46 0.07-0.37 0.0015-0.039 < O , 0004-0.0024 of the ropper R, arid K, lines. Sinre t,lie K , is inany times striinger than the lie, no filter was rleccssary. >Iulybdenum radiation was obtained from an ordinary General Elcrtric diffraction outfit. employing a Cooiid#! crystal-analysis x-ray tube operated a t about 30 kilovolts and 20 millianiperes. 4 . zirconia filter was used 80 that the heairi passing throiigli the specimen was essentially the molybifenum K mradiation. Most of the copper radiation registrations were obtained with an exliosnre time of 3 hours and a speeimeii-to-plate d i s t a i m of 4 mk.; honerer, e x c e l l m t pat,tenis fix the cuu-
rounding tlre central inmge prodii
