11(1 



W. A. Turner— Separation of Vanadium. 



The separation of vanadium from uranium presents greater 

 difficulty and in fact as yet a good separation lias not been 

 accomplished. For this the same ammonium metavanadate 

 solution used in the previous experiments served. As a source 

 of uranium a solution of uranyl nitrate in distilled water was 

 made. This solution, when standardized by the ammonium 

 hydroxide method (in which ammonium uranate is precipitated 

 by ammonium hydroxide in the presence of ammonium 

 chloride, washed with a dilute ammonia solution containing 

 ammonium chloride, ignited first in the Bunsen burner and 

 then in the blast to U 3 O s ), gave : 



25 grms. uranyl nitrate sol.=C= 0'1991 grra. U 3 B . 



When these vanadium and uranium solutions are brought 

 together a yellow precipitate of uranyl vanadate is formed. If 

 sufficient hydrochloric or sulphuric acid is added the pre- 

 cipitate will dissolve. The precipitate appears to be insoluble 

 in ammonia. 



It is necessary therefore in order to effect a separation of 

 these elements to make the cupferron precipitation in a fairly 

 strongly acid solution. In the experiments recorded about 

 10 cm 3 of sulphuric acid per 100 cm 8 of solution were used. 

 The wash-liquid also was a sulphuric acid solution of about the 

 same strength containing 1*5 grms. cupferron per liter. 



Another expedient adopted to accomplish a more complete 

 separation was to place filter and precipitate after thorough 

 washing back in the original beaker, treat with ammonia 

 (which dissolves the. vanadium precipitate) then make nearly 

 acid and cool to 20° before bringing to acidity. After dilution, 

 acidification and the addition of a little more cupferron bring 

 down the vanadium which after filtration and washing is 

 obtained in fairly pure form. 



The uranium in the filtrate was determined by the ammonium 

 hydroxide method. 



In this way the following results were obtained : 



Grms. 



NH,V0 3 



sol. 



taken 



Grms. 



UO,(N0 3 ) 2 



sol. 



taken 



Grms. 

 V 3 O s 

 found 



Grms. 

 U 3 B 

 found 



Grms. V 2 6 

 per 25 grms. 

 NH.,V0 3 sol. 



Found Taken 



Grms. U 3 B 



per 25 grms. 



U0 2 (N0 3 ) a sol. 



Found Taken 



15-3903 



25-1603 



00683 



0-2013 



0-1109 



0-1082 



0-2000 



01991 



20-2137 



20-2317 



0-0905 



0-1610 



0-1119 



0-1082 



0-1990 



0-1991 



20-2757 



19-0602 

 June 14, 1916. 



0-0904 



0-1513 



0-1115 



0-1082 



0-1985 



0-1991 



