I N D V S T R I A L A N D ENGINEERING CHEMISTRP
January, 1924
ANALYSISOF FERROMANGANESE The weight of sample used is governed by the manganese content; for 80 per cent ferromanganese from 0.25 to 0.30 gram niay be used. As there is no difficulty in obtaining a uniforni sample, it is preferable to weigh out individual portions of the 100-mesh sample for the determination, instead of using an aliquot part of a large sample. The following procedure as regards the quantity of acid and final volume presupposes the presence of about 0.2 gram of manganese. When working with high-carbon ferromanganese, dissolve the sample in 60 cc. of nitric acid (specific gravity 1.42) and boil in a flask or covered beaker until nitrous fumes cease to be evolved. If the sample contains over 1 per cent of chromium, it is necessary to dilute the solution with an equal volume of water, filter, ignite the residue, and fuse it with a little sodium carbonate, dissolving the melt in the least possible quantity of nitric acid and adding it to the main solution. Oxidize the carbon present by adding ammonium persulfate, a little a t a time, until a total of from 2 to 2.5 grams has bern introduced. Boil the solution about 10 minutes, and then add small amounts of bismuthate to the boiling liquid, until a precipitate of manganese dioxide has formed. Dissolve the precipitate by the addition of sulfurous acid, drop by drop, adding an excess of 1 cc. after the precipitate has dissolved to reduce any chromium to the trivalent form. After having boiled the solution for 5 minutes, bring it to a volume of 200 cc., and cool with ice. This cooling is essential in order that any chromium may not interfere, as it would be oxidized by the bismuthate if the solution were at elevated temperatures. The manganese is then oxidized with bisniuthate and determined as described under “Analysis of Manganese Ore.” The following data are from typical determinations on a sample of standard high-carbon ferromanganese: TABLE IX-MANGANESEIN FERROMANGANESE KMn04 Equiv0.1 N
Weight of Ferrous Sample Salt G. G.
0.2500 0.2500 0.3000
7.5 7.5 9.0
alent of Ferrous Salt cc
Back Titration cc.
KMnO4 Consumed Cc.
Per cent Manganese
191.3 191.3 229.2
13.4 13.4 15.7
177.9 177.9 213.5
78115 78.15 78.19
.
Low-carbon ferromanganese is dissolved directly in nitric acid of 1.135 specific gravity (about 1 cc. for every milligram of manganese present). After preliminary oxidation and reduction of the solution, it is made up to the original volume with nitric acid (specific gravity 1.135) and cooled as a preliminary to the oxidation and determination of the manganese.
AKALYSISOF MANGANESE METAL Dissolve 0.2500 gram in 250 cc. of nitric acid (specific gravity 1.135) in a 750-cc. Erlenmeyer flask provided with a cut-off funnel or some similar device to prevent loss by spraying, and make a preliminary oxidation with bismuthate, subsequently reducing with sulfurous acid. If the carbon is high (4 per cent) oxidation with ammonium persulfate should precede the bismuthate oxidation. Dilute the solution to a volume of 250 cc. by adding nitric acid (specific gravity 1.135), cool with ice, and finish the determination as pre~iouslyoutlined. About 6.5 grams of sodium bismuthate are necessary for the oxidation and 9 grams of ferrous salt will reduce the permanganic acid resulting from a 0.2500 gram sample of 95 per cent manganese metal. TABLE X-MANGANESEIN MANGANESE METAL KMnOa Equiv0.1 N
Weight of Ferrous Sample Salt G. G.
No.
1 0.2000 2 0.2500 3 0.2500
8.000 9.000 9.000
alent of FerBack rous Salt Titration cc. cc.
203.8 229.2 229.2
28.5 10.0
10.2
KMnOa Consumed Cc.
Per cent Manaanese
175.3 219.2 219.0
96T29 96.32 96.24
63
BIBLIOGRAPHY Schneider, “Methode zur Bestimmung des Mangans,” Dingtms poly-
fech. J . , 869;224
(1899).
Reddrop and Ramage, “The Volumetric Estimation of Manganese,” J . Chem. SOC.(London), 67, 268 (1895). Compredon, “Sur le dosage rapide des principaux elements des produits siderurgiques,” Res. Chim. Ind., 9,306 (1989). Mignot, “Dosage volumetrique d u manganese dans les Fers, fontes and aciers,” Ann. chim. anal., 6, 172 (1900). Ibbotson and Brearly, “Analysis of Ferro-Silicon and Siliconspiegel,” Chem. News, 82, 269 (1900). Ramage, “Volumetric Estimation of Manganese,” Ibid., 84, 209, 269
(1901). Ibbotson and Brearly, “Volumetric Estimation of Manganese,” Ibid., 84, 247, 302 (1901). Dufty, “Volumetric Estimation of Manganese,” Ibid., 84, 348 (1901). Ibbotson and Brearly, “Volumetric Estimation of Manganese,” Ibid., 86, 59 (1902). Jaboulay, “Dosage du manganese dans les Aciers,” Rev. gen. chim., 6 ,
119 (1903). Blair, “The Bismuthate Method for the Determination of Maneanwe,”
J . A m . Chem. Soc., 26, 793 (1904). Metzger and McCracken, “A New Volumetric Method for the Determination of Manganese,” Ibid., 82, 1250 (1910). Brinton, “The Determination of Manganese by the Sodium Bismuthate Method,” J. Ind. Eng. Chem., 3,237,378(1911). Hillebrand and Blum, “The Determination of Manganese by the Sodium Bismuthate Method,” Ibid., 8, 374 (1911). Cain, “The Determination of Manganese in Vanadium and ChromeVanadium Steels,” Ibid., 8, 630 (1911). Cahn and Little, “Waldemar Fischer’s Modification of Volhard’s Method for the Volumetric Estimation of Manganese, and Its Comparison with Other Well-Known Methods,” Analyst, 86, 52 (1911). Little, “The Estimation of Manganese by the Bismuthate Method,”
Analyst, 37, 564 (1912). Blum, “Determination of Manganese as Sulfate and by the Sodium Bismuthate Method,” J. A m . Chem. Soc., 84, 1379 (1912). Demorest, “The Bismuthate Method for Manganese,” J. I n d . Eng.
Chem., 4, 19 (1912). Gortner and Rost, “The Determination of Total Manganese in Soils;’
Ibid., 4, 522 (1912). Kinder, “Manganbestimmung in Eisen und Stahl nach dem Wismutatverfahren,” Stahl u. Eisen, Si’, 197 (1917).
Eminent Chemists From time to time there have come to us requests for sources of portraits of eminent American chemists prepared for framing and suitable for decorating laboratories, lecture rooms, and the halls of educational institutions. Diligent search having shown that very few Americans had been included in such collections of portraits as had been made by publishers, we persuaded our associate editor to undertake the preparation of such a collection, calling upon a number of men to assist in compiling a list of those to be included in the first series. This work has been completed and, if advance subscriptions warrant, a set of thirty-three portraits, beautifully done on the best grade of paper, will be available in a loose-leaf binder, these portraits being interleaved with short sketches of the work of each of the subjects. The portraits themselves are 4l/2 x B1/2 inches on sheets a1/2 x 10 inches. Announcements will be made soon as to prices and other details. We give below the list of the men included in this set and believe that if a larger number of people become interested in the personalities which have so greatly contributed to the advancement of chemistry, a historical and cultural background will be estabished which cannot fail to make our science still more attractive. Baekeland, L. H. Bancroft, W. D. Boltwood, B. B. Booth, J. C. Chandler, .C. F. Chittenden, Russell H. Clarke, F.W. Cottrell, F. G. Cooke, Josiah P. Franklin, E. C. Gibbs, J. Willard Gibbs, Wolcott Gomberg, Moses Hare, Robert Hillebrand, W. F. Hunt, T. Sterry Langmuir, Irving
Lewis, G. N. Mallett, J. W. Morley, E. W. Noyes, A. A. h-oyes, W. A. Priestley, Joseph Remsen, Ira Richards, T.W. Rumford, Count Silliman, Benjamin, the Elder Smith, Edgar Fahs Smith, J. Lawrence Stieglitz, Julius Van Slyke, Donald D. Whitney, W. R. Wiley, H. W.
