786
T H E JOURNAL OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY M E T H O D IK D E T A I L
I-Weigh o u t a z gram sample of raw material (or clinker) or a 0 . j gram sample of treater dust a n d a d d t o t h e former 0 . j g. of ammonium chloride a n d t o t h e latter 0 . z j g. of ammonium chloride. Transfer t o a mortar, mix thoroughly a n d grind. Transfer t h e contents of t h e mortar t o a 20 cc. platinum crucible, t h e bottom of which has been covered with a generous layer of calcium c a r b o n a t e - - a b o u t z grams. Cover contents of crucible with about z grams of calcium carbonate a n d proceed with heating a n d sintering as in t h e J. Lawrence Smith method. After t h e mass has been slaked i n a small casserole, place on t h e hot plate a n d heat t o boiling. Filter into a flat-bottomed porcelain dish a n d wash t h e precipit a t e 3 or 4 times with very hot water. Add t o t h e filt r a t e an excess of acetic acid ( j t o I O cc.) a n d evaporate o n a steam b a t h until no odor of acetic acid remains. T a k e u p with a little hot water, using t h e precaution t o wash t h e sides of t h e dish t h o r o u g h l y . Now a d d from IO t o ~j cc. of cobalt reagent (see below) a n d evaporate o n steam b a t h t o pasty consistency. Remove from b a t h a n d when precipitate has cooled, t a k e u p with a b o u t 30 cc. of cold w a t e r , breaking u p precipitate thoroughly. Filter through a n asbestos padded Gooch crucible a n d wash precipitate once with cold watev.’ Wash contents of crucible into a 400 cc. beaker (containing a n excess of s t a n d a r d N,j potassium permanganate solution)2 with hot water a n d dilute t o 2 j O cc. Place on steam b a t h for about ~j minutes or until a decided black color appears. Acidulate with I O cc. I : I sulfuric acid. With a standard pipette ( I O cc.) neutralize t h e excess potassium permanganate with N / j oxalic acid solution, t h e potassium permanganate equivalent of which has been determined. When t h e final solution has cleared, t i t r a t e with s t a n d a r d potassium permanganate solution. COBALT-KITRITE SOLUTION-( I ) Dissolve 2 2 0 g. of sodium nitrite in 400 cc. of wa,ter. ( 2 ) Dissolve 113 g. of cobalt acetate in a mixture of 300 cc. of water a n d IOO cc. of glacial acetic acid. (3) Mix t h e above solutions a n d place under vacuum over night. Filter and dilute t o 1000 cc. Keep t h e solution in a dark bottle. Never use a solution over t w o weeks old. 11-When determining “water-soluble” potash by this method, weigh I O g. of t h e material into a 600 cc. beaker, cover with about z j o cc. of water a n d boil for 30 minutes. Pour i n t o a j o o cc. flask. Cool t o room temperature. Make solution t o mark. After shaking well, filter a portion of t h e solution through a d r y paper. Draw off 50 cc. ( I gram equivalent) a n d place i n a platinum or porcelain dish. Then proceed as i n t h e above method, beginning with “,4dd t o t h e filtrate a n excess of acetic acid ( j t o I O cc.) a n d evapo r a t e on steam b a t h until no odor of acetic acid remains.” 1 Water poured from a beaker causes less disturbance in the crucible and gives better results. 8 10 cc. for each 1 per cent KzO equivalent in the sample.
ILLUSTRATION-RESULTS
Vol. 9 , No. 8
ON SAMPLE OF RAW MATERIAL
cc. Permanganate originally used; IO cc. Oxalic acid used to neutralize excess Permanganate; I O cc. Oxalic acid found to equal 11 . z cc. Permanganate; 5 cc. Permanganate used to neutralize excess Oxalic acid. Now ( 2 0 cc. 5 cc.) - I I . 2 cc. (Oxalic acid equivalent) = h-0. of cc. of Permanganate used to complete titration. Therefore (KO. of cc. of Permanganate) X Factor = per cent KzO. CALCULATION OF KzO FACTORCaO Factor : 0.0056 = X : 0.00171, where X = KzO factor. DATA-~O
+
2
Regular .V/5 Permanganate is used where the calcium oxide factor is based on 0 . 5 gram. To calculate the KzO factor to I gram, one-half of the calcium oxide factor must be used in the above proportion. 82 LIMEC O M P A N Y HAGERSTOWN, MARYLAND
SECURITY CEMENT
DETERMINATION OF CARBONATES IN LIMESTONE AND OTHER MATERIALS B y J. F. BARKER Received M a y 18, 1 9 1 i
Results obtained in t h e determination of carbonates b y t h e apparatus herein described compare favorably with results from t h e use of a n y s t a n d a r d laboratory method. T h e advantage of this method over others is t h a t no mechanical balance or scale is required a n d there are no long calculations t o be made. Anyone x i t h some aptitude for accuracy can, with this instrument, make as reliable a determination i n home or office as a skilled chemist in a well-equipped laboratory using complicated apparatus. T h e invention depends upon t h e principle of t h e hydrometer, which take4 account of t h e law t h a t when a n object is immersed in a liquid i t is buoyed u p b y a force equal t o t h e weight of t h e liquid displaced b y t h e object. I n this a p p a r a t u s t h e carbon dioxide gas set free from t h e sample decreases t h e weight; a n d t h e rise of t h e graduation scale t u b e above t h e water records t h e percentage of carbonates from which t h e gas was released. PROCEDURE
T o analyze a sample of limestone for carbonates, measure out 40 cc. of HC1 (sp. gr. 1.1j ) , using a small graduate; pour this into t h e acid reservoir through t h e opening A . With graduated s t e m disconnected hang a Io-g. weight a t B . T h e hydrometer should t h e n float i n a cylinder of water a n d be immersed t o some point a t C. Remove t h e Io-g. weight a n d introduce pulverized limestone until instrument is immersed t o exactly t h e same point. Now connect u p graduated s t e m a n d a d d water a drop a t a time, through t h e funnel-shaped t o p , until immersed t o zero point. Raise hydrometer o u t of water a n d open stopcock D until acid drops slowly into reaction chamber, decomposing t h e limestone. As t h e reaction proceeds t h e instrument rises slowly a n d a t ‘the conclusion t h e point on s t e m a t t h e surface of t h e water gives t h e per cent of calcium carbonate equivalent t o t h e carbon dioxide in t h e sample. This figure is t h e c a l c i u m carbonate equivalent so often mentioned in connection with limestone analyses.
T H E J O U R N A L OF I N D U S T R I A L A N D ENGINEERING CHEMISTRY
Aug., 191 j
787
for floating t h e hydrometer, a small Fahrenheit thermometer, j o o cc. of hydrochloric acid (sp. gr. I . I j ) , a j o cc. graduate, a small dropping pipette a n d a scoop for convenience in transferring t h e sample. T h e manufacturer's price for a single outfit, i t seems now, will be less t h a n $10.00.
APPLICATION O F T H E METHOD
carbon apparatus. CALCILM CARBONATE EQUIIALEYTS Limestone Author's Standard
200 201 220 22 1 223 224 226 230 240 244 254 256 257 Calcite
U
80.0 81.5 i8.5
80.0 81.8 i8.6
71.0
71.1
,8.5 83.0 82.5 83.5 99.5 98.5 97.5 89.0 95.5 99.5
78.7 84.0 82.9 83.2 99.0 98.5 9i.i 88.9 95.8
..
For analyzing carbonates other t h a n limestone a n d similar materials, this instrument is fitted with a graduated stem which reads percentage of carbon dioxide, an arrangement which greatly extends its use. I t will be found especially suited t o determining t h e comparative strengths of baking powders and considering speed and accuracy is more suitable t h a n a n y other device novi employed for t h a t purpose. The method is adapted for use in all chemical laboratories, college, experiment station, or commercial laboratories. However, it is devised for use outside of chemical laboratories, also. Limestone companies can employ it t o check u p on every carload of their goods, or t o locate t h e stone in their quarry most suitable for grinding. County agricultural agents will use it t o keep posted on t h e quality of limestone being sold in their territory a n d t o determine t h e composition of local limestone deposits. Many a n individual farmer or some member of his household will no doubt wish t o own t h e apparatus. L*EWYORKAGRICULTURAL EXPERIMENT STATION GENEVA,NEW Y O R K
CARBONATION STUDIES: I-A MECHANICAL STIRRER FOR CARBONATION DIRECT IN THE BOTTLE By
SOME DETAILS
$ 1 Q
