B. B. Biggs — Separation of Iron, Manganese, etc. 135 



Aet. XYIT. — The Separation of Iron, Manganese and Cal- 

 cium by the Acetate and Bromine Methods / by R. B. 

 Riggs. 



Having in hand the analysis of a series of samples contain- 

 ing iron, manganese and calcium in large amounts, it seemed 

 advisable to test the two analytical methods involved, namely, 

 the separation of iron from manganese by precipitating it as a 

 basic acetate, and the separation of manganese from calcium by 

 means of bromine. The object was not so much to test the 

 accuracy of the acetate process as to determine the conditions 

 favorable or otherwise to its successful use. In the case of the 

 manganese-calcium separation on the contrary, the value of the 

 method was in question, for where either or both constituents 

 are present in quantities its accuracy has been doubted. 



For convenience and accuracy standardized solutions of the 

 three substances were used. Piano wire was the basis of the 

 ferric chloride solution. This was dissolved in hydrochloric 

 and oxidized by means of nitric acid. The nitric acid was in 

 turn expelled by repeated evaporations with hydrochloric acid. 

 Last traces of ferrous iron were oxidized by bromine. The 

 value of this solution was found by means of a standard* per- 

 mangate solution. 



Mean. 

 0-7382 



For the manganese chloride solution, manganese dioxide was 

 the starting point. This was digested with nitric acid, dis- 

 solved in hydrochloric and nitric acid — twice evaporated to 

 dryness and filtered — treated three times by the basic acetate 

 process (each time allowing a considerable precipitation of 

 manganese), and recovered from solution each time by a brom- 

 ine precipitation. The last precipitate was dissolved in hydro- 

 chloric acid and the excess of acid expelled by evaporation. 

 This solution was standardized by determining the manganese 

 as pyrophosphate. 



Weight of MnCl 2 Weight of Mn 2 P 2 7 Weight of MnO in 



solution taken found. 1 00 grams of solution. 



grm. grm. grm. Mean. 



(4.) 9-98 0-1346 0"6743 ) n . fi7 „ Q 



(5.) 10-095 0-1360 6735 j uo,oy 



* The permanganate solution was standardized with the same wire so that the 

 results are relatively correct. 



Weight of FeCl 3 



Weight of Fe 



Weight of Fe in 



solution taken. 



found. 



100 grams of solution. 



grm. 



grm. 



grm. 



(1.) 20-32 



0-14957 



0-7378 ) 



(2.) 20335 



0-15017 



0-7385 V 



(3.) 20-30 



0-14957 



0-7383 ) 



