A Simple Retort
Practical Action
Assembling the retort (Figure 2)
- Connect the 1/2-inch-to-1/4-inch reducing bush to the1/4-inch diameter pipe
(2b to 2a) by screwing tightly. Note: The reducing bush is not obviously
required if a 1/2-inch diameter pipe is used.
- Connect the 1&1/2-inch-to-1/2-inch reducer to the ½-inch-to-1/4-inch reducing bush (2c
to 2b) by screwing tightly.
- Connect the 1&1/2-inch plug to the 1&1/2-inch-to-1/2-inch reducer (2d to 2c).
- The retort is now ready for use.
Using the Retort
Purpose
The purpose of the retort is to separate the gold from the mercury components of the gold
amalgam. By applying heat to the amalgam (Figure 1), the mercury is burnt off as a gas, which
passes along the pipe to re-condense as a liquid. The gold remains in the distilling chamber of
the retort, while the mercury is collected at the discharge end in liquid form.
Process
Wrap the amalgam into small balls
with a piece of paper (the foil from a
cigarette packet is ideal). This will
help prevent the gold from sticking to
the distilling chamber under heat.
Note: Wear rubber gloves whenever
you are handling mercury to avoid
contact with the skin.
Cloth rolled into
tube connected
at the end of the
pipe
Place the wrapped amalgam in the
plug (2d) and screw tightly.
Seal all the joints with wet clay or
mud. This will prevent mercury gases
escaping into the atmosphere during
the heating process.
Prepare the source of heat, normally
charcoal (an oxy-acetylene torch can
also be used).
Figure 6: Tap the pipe to remove the
mercury
Secure the retort on a stand that places the distilling chamber directly over the source of heat. At
the discharge end, place a glass of water, with the cloth “tube” connected at the end of the pipe
submerged (Figure 1).
Use bellows to increase heat. Continue applying the bellows until the distilling chamber is red
hot or bubbles stop coming out of the discharge end. This part of the process normally takes
about 5 to ten minutes.
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