344 Method of separating Iron from Manganese. [Nov. 



acid. I am therefore induced to communicate to you a very 

 simple and easy method of perfectly separating manganese from 

 iron, &c which 1 have for many years employed in various 

 experiments and analyses, although I have not hitherto had 

 occasion to state it in any publication. 



Sect. I. 



A solution of any ore of manganese having been made as 

 usual in muriatic acid, and filtrated, must be diluted with three 

 or four pints of cold distilled water. To this diluted solution add 

 gradually pure ammonia, occasionally stirring the liquor until 

 the acid has become perfectly neutralized ; a few drops of 

 ammonia may then be added j so that the liquor shall very 

 slightly restore the blue colour to litmus paper which has been 

 reddened by acetous acid. 



The ferruginous precipitate must then be separated by filtra- 

 tion, and the liquor which passes will be found devoid of colour, 

 and contains the pure manganese in permanent solution. It 

 affords a white precipitate with prussiate of potash, and the oxide 

 of manganese may be obtained by evaporating the solution to 

 dryness, and by expelling the muriate of ammonia by heat ; 

 after which, if any of the muriate should be suspected to remain, 

 it may be separated by washing the oxide upon a filter. 



Sect. II. 



Pure oxide of manganese may be also obtained by adding 

 ammonia in considerable excess to the cold diluted muriatic 

 solution, which then, without loss of time, must be poured 

 upon a filtre of one fold. The liquor which passes becomes in 

 a few minutes turbid and brownish, a pellicle is formed, and in 

 about 24 hours the greater part of the manganese separates 

 spontaneously in the state of brown oxide ; and if the remaining 

 liquor be evaporated to dryness and heated, the whole of the 

 oxide will be obtained. But the objection to this method is, 

 that the manganese is so rapidly separated from the ammoniacal 

 solution, that it is scarcely possible, even by the quickest filtra- 

 tion, to prevent some part from being deposited on the filter, so 

 that it becomes again mixed with the precipitate of iron, alu- 

 nn'ne, &c. 



4 he effects of ammonia on the green oxide of iron are well 

 known ; but I do not recollect any instance of this oxide being 

 found conjoined with manganese: and therefore it is not likely 

 to inter. ere with the process above described. 



When ammonia in great excess is added to the neutralized 

 solution (Sect. I.), the same effect is produced as in Section II., 

 and the manganese is spontaneously deposited. 



