charcoal

Charcoal is produced in large quantities in southern Madagascar, where whole villages are dependent on its production for their income. Charcoal is the most important fuel for cooking purposes over many developing countries, leading to intensive exploitation of remaining native forests.

Black, porous form of carbon, produced by heating wood or other organic materials in the absence of air. It is used as a fuel in the smelting of metals such as copper and zinc, and by artists for making black line drawings. Activated charcoal has been powdered and dried so that it presents a much increased surface area for adsorption; it is used for filtering and purifying liquids and gases – for example, in drinking-water filters and gas masks.

Charcoal was traditionally produced by burning dried wood in a kiln, a process lasting several days. The kiln was either a simple hole in the ground, or an earth-covered mound. Today kilns are of brick or iron, both of which allow the waste gases to be collected and used. Charcoal had many uses in earlier centuries. Because of the high temperature at which it burns (1,100°C/2,012°F), it was used in furnaces and blast furnaces before the development of coke. It was also used in an industrial process for obtaining ethanoic acid (acetic acid), in producing wood tar and wood pitch, and (when produced from alder or willow trees) as a component of gunpowder.

charcoal

In art, soft, brittle material in stick or pencil form used for sketching and more free and expressive drawing, Charcoal is rich and crumbly, and smudges easily. Lines can be blended easily using fingers or a putty rubber to give great depth and body to a form. Effects vary according to the surface type of the paper, and water can be applied to create a charcoal wash. A spray fixative should be applied to preserve the finished work. Natural charcoal is black, although coloured charcoals are now manufactured.

Charcoal has been used for drawing since prehistoric times when pieces of charred wood would have been used. Today, charcoal sticks are made from kiln-fired willow twigs, and come in a variety of widths and hardnesses. Charcoal pencils are made of compressed charcoal, and lose some of the qualities of natural charcoal in the process.