Apr
~
19i3
T H E JOL-RIVAL OF I,\-DL-STRIAL
A N D E-YGISEERI-YG CHE-IIISTRE-
’97
The following table shows the amounts of oxygen found in t h e various brands of tungsten powders made both in t h e U. S.and abroad. Each numeral represents a different make.
THE DETERMINATION OF PHOSPHORUS I N FERROTUNGSTEN, METALLIC TUNGSTEN POWDER, TUNGSTEN OXIDE AND TUNGSTIC ACID BY DIRECT SOLUTION
The reduction was particularly poor in the second ‘lot received from the German manufacturer designated as I1 ( N o . z in his second shipment). When so much oxide is present i t can be easily detected b y t h e eye, being equivalent t o 10.92 per cent. of tungstic oxide. Such so-called metal has a distinct brown color.
The author found in the course of an investigation t h a t the practice of decomposing tungsten-bearing materials by fusing them with a mixture of sodium carbonate and potassium nitrate, leaching out t h e fusion, acidulating with hydrochloric acid, removingthe tungstic acid by several evaporations t o dryness, and then using the filtrate and washings from t h e tungstic acid for the determination of the phosphorus, gave f a r less of t h e latter element t h a n was actually present. He then devised the following method which he has found t o give near enough t o the true phosphorus for technical purposes.
TABLE111 Imported or domestic
Oxygen found Per cent. Consignment
German German German German German American hmerican American American american .-2merican American
THE .4
DECARBOSIZATIOK
OF
1 02
..
1.10 2.26 0 18 0 53 0.37 0.47 1 24 0 80 0 45 0.08 0 07
so. 1 No 2
STEEL
..
.
....
A d d 30 cc. of concentrated nitric acid t o one gram
?io. 2 NO. 3
,.. . , . . . .. .
..... IGSITED
IK
STREAM O F HYDROGEK FOR T H E O X Y G E N TEST
I n 1909 the writer called attention t o the fact t h a t hydrogen will produce a bark, or decarbonized surface, on steels when the latter are heated in a current of this gas. Supplementing this statement’ t h e following tests were made on three steels t h a t were analyzed for oxygen: TABLEIV Percentage carbon Grams of content m drillings taken No. of hours 7 for the ignited in, Before After oxygen test hydrogen ignition ignition I.,.. . 9 6 3’i2 1.04 0.90
?ample Sample I1 . . . . . Sample111 . . . . .
16.0 19.5
3’/2
3’/2
1.08 0.83
0 83 0
io
I n the foregoing method, no preheating furnace or tube is used such as was recommended b y Ledebur in his ‘
