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What is charcoal? -- In general, wood charcoal is a substance obtained by partial burning or destructive
distillation of wood. It is largely pure carbon. Wood charcoal is prepared by heating wood in the absence of oxygen. In this
process volatile compounds in the wood (e.g., water, hydrogen, methane and tars) pass off as vapors into the air, and the
carbon is converted into charcoal. (Tar is a generic name for big, smoky, sticky molecules that form liquids when they're
cool. The tars, in particular, can contain carcinogenic compounds, like benzo-A-pyrene.) With the volatile component driven
off, you are left with wood charcoal that is about 20 to 25-percent of the original volume of the wood. It's chiefly carbon,
with traces of volatile chemicals and ash. When it burns, it won't produce as much smoke as burning wood, and it will burn
long, hot and steady. Charcoal, being almost pure carbon, yields a larger amount of heat in proportion to its volume than
is obtained from a corresponding quantity of wood.
What Is Extruded
Charcoal? -- Extruded charcoal is charcoal that is made by compressing sawdust into some
shape via the process of extruding the sawdust through a die. The heat and pressure of the extrusion process serves to bind
the sawdust into a log that can then be carbonized, i.e., made into charcoal.
Two forms of raw material are known to us to be used in this process, sawdust
collected from sawmills, and ground coconut shells. The raw material is dried and then compressed by a screw extruder or forming
machine. The material is then extruded under a pressure of approximately 40 tons through a hot (300 to 350 degrees C) mold.
The heat and pressure cause the lignin in the raw material to bind the material together into a solid log which is denser
than the original material.
Once the logs are formed, they can be carbonized in a kiln. The carbonized
logs are then either cooled in the kiln or in a cooling chamber or box before being graded and packed. Once source on the
web indicates the following grading system is used.
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