Charcoal is a black, brittle substance that has a variety of uses. For example, it is used in pigments (coloring matter); in filters to remove unwanted colors, flavors, and odors; as a fuel; and as a drawing instrument.
Charcoal consists mainly of amorphous carbon and ash. Amorphous carbon is carbon made of tiny, irregularly arranged particles of graphite (a form of pure carbon). Charcoal also contains small amounts of impurities, such as sulfur and hydrogen compounds. Manufacturers produce charcoal by heating carbon-rich plant or animal materials, such as wood or bones, in ovens that contain little or no air. During the heating process, most of the hydrogen, nitrogen, and oxygen in the raw materials escape. The end product is a black, porous (full of tiny holes) material, which is charcoal.
Types of charcoal.
The two most common types of charcoal are wood charcoal, which is made from wood, and bone charcoal (also called animal charcoal or boneblack), which is made from animal remains, chiefly bones. Wood charcoal consists mainly of carbon. It has some ash and impurities. Bone charcoal consists mainly of ash. It has some carbon and impurities.
Activated charcoal is charcoal from which most of the impurities have been removed. Manufacturers make it by treating ordinary charcoal with steam and air heated to above 600 °F (316 °C).
Uses of charcoal.
Wood charcoal is the most widely used kind of charcoal. Small chunks of wood charcoal burn well and are an excellent fuel. Many people burn wood charcoal briquettes (small, molded pieces) in outdoor barbecues. Artists draw with small sticks of wood charcoal. In powdered form, wood charcoal is used in filters and as an ingredient in gunpowder.
Manufacturers use bone charcoal in powdered form to make pigments for dyeing leathers and coloring inks and paints. Powdered forms of wood, bone, and activated charcoal are used to adsorb (hold on their internal surfaces) unwanted colors, flavors, and odors from gases and liquids. This adsorption process is used in the manufacture of white sugar. Activated charcoal is the best adsorbent, because its spaces give it a large internal surface area.
