Minnig — Separation and Estimation of Aluminium. 19' 



Art. XII. — The Separation and Estimation of Aluminium 

 Associated with Iron, by the Action of Acetyl Chloride in 

 Acetone ; by H. D. Minnig . 



[Contributions from the Kent Chemical Laboratory of Yale Univ. — cclxiv.] 



Water becomes so modified as a solvent for barium chlor- 

 ide when hydrogen chloride is dissolved in it to saturation 

 that this salt, which is easily soluble in pure water, dissolves in 

 the saturated aqueous hydrochloric acid only in the proportion 

 of 1 to about 20,000 parts. The addition of ethyl ether to the 

 concentrated aqueous hydrochloric acid thus produced so 

 diminishes the solvent action of the mixture upon barium 

 chloride that the salt will then dissolve in the proportion of 1 

 to about 120,000 parts. Barium chloride may, therefore, be 

 separated with accuracy from the ether-hydrochloric acid solu- 

 tion of the chlorides of calcium and magnesium which remain 

 soluble in high degree, as was shown in a former paper from 

 this laboratory." 



Aluminium chloride, as was subsequently shown, f may be 

 similarly precipitated by thorough saturation of the cooled 

 aqueous solution after addition of an equal volume of ether, 

 and effectively separated from iron ; and by the same procedure 

 aluminium may be separated from beryllium, zinc, copper, 

 mercury and bismuth 4 



Instead of charging the water solution with gaseous hydro- 

 gen chloride that reagent may be produced by the action of 

 acetyl chloride upon the water, and this reaction has been 

 tested more recently § in its application to the precipitation of 

 barium chloride — inconvenient violence of reaction being mod- 

 erated by acetone, which mixes in all proportions with both 

 acetyl chloride and water and by itself exerts no appreciable 

 solvent action upon hydrous barium chloride. 



The present paper is the account of results obtained in 

 applying the acetone-acetyl chloride mixture to the precipita- 

 tion of aluminium as chloride and the separation of that ele- 

 ment from iron. In preliminary experiments it was found 

 that the hydrous aluminium chloride, A1C1 3 .6H 2 0, may be pre- 

 cipitated completely by the [4 : 1] acetone-acetyl chloride mix- 

 ture and, after careful drying, may be converted directly to 

 the oxide by ignition. In the quantitative experiments recorded 

 below the aluminium chloride, prepared by saturating a strong 

 solution of the commercial salt with gaseous hydrogen chloride 

 and washing with concentrated hydrochloric acid until free 



*Mar., this Journal (3). xliii, 521, 1892. 

 f Gooch and Havens, this Journal (4), ii, 416, 1896. 

 \ Havens, this Journal (4), iv, 111, 1897: vi. 45, 1898. 

 § Gooch and Boynton, this Journal (4), xxji, 212, 1911. 



