Thornton and Hay den — Separation of Zirconium. 139 



and aluminum were taken by weighing off portions of the 

 standardized zirconium solution and dry recrystallized ammo- 

 nium aluminum sulphate respectively. The solution was made 

 neutral to methyl orange with ammonium hydroxide, which 

 had been redistilled and kept in bottles of Jena glass. Meas- 

 ured volumes of sulphuric acid (1 : 1) were then added and the 

 solution made up to 400 cra3 . About 20 cm3 of a 6 percent " cup- 

 ferron" solution was added gradually with constant stirring. 

 Thereupon the zirconium came down as a very bulky and 

 flocculent white precipitate. Without much delay the precip- 

 itate was filtered on paper with the aid of gentle suction and 

 washed thoroughly with hydrochloric acid (made by diluting 

 100 cm3 of acid of sp. g. = 1*20 to one liter). The precipitate 

 was placed in a tared platinum crucible, dried at 110° C, and 

 carefully ignited to zirconium oxide. Table I contains the 

 results of four experiments. 



Table I. 

 The Separation of Zirconium from Aluminum. 





Zr0 2 



A1 2 3 



Zr0 2 





H 2 S0 4 



Volume 



No. 



taken 



taken 



found 



Error 



(1:1) 



of soln. 





grm. 



grm. 



grm. 



grm. 



cm 3 



cm 3 



1. 



0*1091 



01127 



0*1090 



—o-oooi 



40 



400 



2. 



0-1088 



0-1127 



0-1090 



+ 0-0002 



40 



400 



3. 



0-1086 



0-1127 



0-1090 



+ 0-0004 



60 



400 



4. 



0-1091 



0-1127 



0-1094 



+ 0-0003 



60 



400 



In the second series of experiments zirconium was separated 

 from iron. Known quantities of iron were introduced by 

 weighing off portions of Kahlbaum's ferrous ammonium sul- 

 phate. Since the technique is the same for the separation of 

 zirconium from iron only as for the separation of zirconium 

 from both iron and aluminum, the procedure will be described 

 below for the more general case. Table II embodies the 

 results of two experiments. 



Table II. 



The Separation of Zirconium from Iron. 



Zr0 2 Fe 2 3 Zr0 2 Tartaric H 2 S0 4 



No. taken taken found Error acid (1 : 1) 



grm. grm. grm. grm. grm. cm 3 



5. 0-1088 0-1018 0-1091 +0'0003 2 40 



6. 0-1090 0-1018 0-1093 +0*0003 2 40 



In the third series of experiments known mixtures of iron, 

 aluminum, and zirconium were analyzed. The iron and alumi- 

 num were introduced into the solution by weighing dry por- 

 tions of ferrous ammonium sulphate and ammonium aluminum 



