Feasibility analysis for granulation of silver using Granshot method

Abstract

Metal granshot is a process that is used to convert metal lumps or scraps into metal grains of uniform sizes and shapes. The concept of metal granulation is based on the heat difference between melting and pouring medium. The commercial uses of metal granules are jewelry making and spray coating of costly metals such as silver, gold, and platinum. The basic aim of the silver granshot process is to get uniform size, shape, and maximum yield of silver metal granules. During processing, the metal gets superheated within vacuum up to viscosity more than 2.2 cP flow out of the minimum diameter orifice and allow to drop in the coolant with high pressurized argon gas. The present study focuses on the granulation of silver and tries to achieve the maximum yield of metal. The shape and size of the granules produced were observed using scanning electron microscopy and the results show that the average diameters of granules are between 1.2 mm and 3.8 mm. Yield is also considered as an important factor for granulation of valuable metals like silver, and after experimentation successfully achieved the 99.9 percent yield. The granulation process of silver will help to ease the trading of metal in the jewelry industry.