There is a granular charcoal being sold for use with the new base
metal clays and for PMCPro. Would this type of charcoal be
suitable for refining fine silver or gold granules?
To answer it properly we have to understand what is involved in
formation of perfect granules.
Any natural process always conform itself to function with the least
amount of energy involved. For instance - water naturally flows
downward, but has to be pumped to flow upwards, and etc… Spherical
shape is the most energy efficient configuration in nature. That is
why whenever possible, substances try to form a sphere. That is the
reason behind such phenomena as surface tension.
To form a perfect granules, we must provide excess of energy (
temperature ), and after granules are formed, the environment must be
conducive to maintaining their shapes. That is why we surround them
with charcoal powder. The finer the power the more perfect the shape
will be. There must be no packing of powder, just sifting.
The idea is to allow granule to form into sphere. When this happens,
granule will sink into the powder, due to shifting of center of
gravity. Powder under the granule will be displaced. Newly formed
space, above the granule, will be filled. This process will create
and envelope around granules and allow them to solidify into perfect
shape. But this puts a number of requirements on charcoal powder. It
must be very, very finely crushed and sifted. The process is only
possible when particles are tiny and uniform, so they can flow past
each other like a liquid.