What is Assaying?

Assaying is defined as the subjection of the metalThe most common and the traditional fire
to chemical analysis in order to determine theassaying method consist of six steps. The first
strength, and quality of its components. This isstep is the collection of the sample. The collected
one of the processes in metallurgy. It is a processsample is then subjected to the fusion process.
of extracting precious, or essential metals formThis includes the melting of the ore, and its mixing
their ores. An ore is a combination of manywith the other reagents. Thus, metal gains the
metals. Some of them are found in traces. Thisshape of droplet. This droplet, then easily
process analyses the specific metallic content ofdescends into the crucible. The left over material
the ore, alloy, or any other combination of metals.is called slag, which is ejected through an outlet.
It may be a complex, or a simple process. In theThe impurities are oxidised by using certain
complex process, the ore is subjected toreagents. These impurities mainly include lead, and
complete metals analysis whereas, in the simpleiron. At the high temperature, the left over
process, the quantity of only one or two specificprecious metals such as gold, and silver assume
metals is measured.the shape of droplet. The next very important
In the assaying technique, when the weight of thestep is the weighing of these beads. All the beads
metal is measured it is called gravimetric assay.are weighed to determine the quantity of the
Usually wet assay technique that employs theprecious metal in the ore.
liquid reagents is used in such analytical process.The next step is the individual measurement of
When the volume of the metal is underthe weight of gold, and silver. For this purpose the
consideration, it is called volumetric assay. The drysilver is dissolved by using nitric acid. Now the left
assay utilises the process of fusion of the ore toover gold beads are measured. This is the weight
get the metal in a pure state.of the gold. The weight of silver is measured by
There are many traditional and sophisticatedsubtracting gold weight form the total gold silver
methods used in the assaying process. Theweight.
ancient alchemists and the goldsmiths employedThere is a chance of molten impurities to get
the method of subjection of the base metals tomixed with the gold silver beads. For this purpose,
heat. This process is termed as fire assaying. Thisfurther specification are made by the use of arc
traditional method is still very popular among thespectrograph. This separates the gold, and other
commercial reefing processes. The otherimpurities based on their mass to charge ratio. A
sophisticated method is by means ofgraph is obtained that shows the percentage of
spectrometric analysis. It has its own importance,gold, silver, and other impurity metal present in
but it is not suitable when the precious metals arethe ore. Other metals including bismuth, tin,
randomly scattered. As in this case, large sampleantimony, and copper can also be analysed by this
is subjected to analysis.method.