Preparation of aluminum amalgam
100 grams of thin aluminum foil in strips about 15 cm long and 2.5 cm wide, loosely folded, are placed in a 3-litre flask and covered with a 10% solution of sodium hydroxide. The flask is warmed on a water bath until a vigorous evolution of hydrogen has taken place for the several minutes. The foil is then thoroughly washed with water and with ethanol. A 2% solution of mercury(II) chloride is added to cover the aluminum completely and is allowed to act upon aluminum for about 2 minutes. The excess solution of mercury(II) chloride is then poured off, and the aluminum amalgam is washed with water, ethanol, and finally with moist ether. The aluminum amalgam is covered with about 1.5 litres of moist ether and is ready for immediate use. If another solvent, e.g., methyl or ethyl acetate, is to be employed in the reduction with moist aluminum amalgam, the ether is replaced by such solvent.
A text book of practical organic chemistry, by A. I. Vogel, 189-190, 1974