Aspects of Powder Technology in Ancient and Medieval India

Abstract

The production, characterisation, and application of metal powder in ancient and medieval India have been investigated on the basis of literary evidence. It has been shown that metal powder was produced by a variety of methods, including mechanical comminution, amalgamation, atomisation, filing, and cementation. Aspects of powder characterisation are also described. Perhaps the first application of powders of metals such as gold, silver, copper, and tin was in coloured paints. An important application of very fine metal powders was in making bhasmas – compounds of the respective metals in powder form that are used medicinally. Evidence shows that metal in granular form was recognised as a means of enhancing the reaction rate in processes such as gold refining. An experimental study on the production of silver powder by an ancient Indian method based on mechanical communition of very thin silver leaves has been carried out, and it has been shown that fine, flake like powder is produced. The famous Delhi iron pillar was manufactured by successive hot forging of porous sponge iron pieces obtained by the reduction of selected iron ore, a process very close to powder forging. PM/0504