Bone char

Bone char (also known as bone black, ivory black, or animal charcoal) is a granular material produced by charring animal bones. The substance is primarily composed of tricalcium phosphate, carbon, and activated carbon. It is used in various applications, including sugar refining, water filtration, and as a black pigment in art.

History

The use of bone char dates back to prehistoric times, with evidence of its use found in paleolithic cave paintings. In the 18th and 19th centuries, bone char was commonly used in the production of sugar, where it served as a decolorizing and deashing agent. Today, it continues to be used in some sugar refining processes, although its use has declined due to the development of more efficient and cost-effective alternatives.

Production

Bone char is produced by heating animal bones in the absence of oxygen, a process known as pyrolysis. This process results in a material that is primarily composed of tricalcium phosphate (approximately 80%) and carbon (approximately 10%), with the remainder consisting of other minerals.

Applications

Sugar refining

In the sugar industry, bone char is used as a decolorizing agent. The bone char is used in a process known as adsorption, where it binds to and removes color-causing impurities from the sugar.

Water filtration

Bone char is also used in water filtration systems. The activated carbon in the bone char adsorbs various impurities, including fluoride, chlorine, and certain heavy metals, improving the taste and safety of the water.

Art

In art, bone char is used as a black pigment. Known as ivory black or bone black, this pigment has been used in oil painting and other art forms for centuries.

Health and ethical considerations

The use of bone char in sugar refining has raised health and ethical concerns. Some individuals, particularly vegans and certain religious groups, object to the use of bone char due to its animal origins. Additionally, there are potential health risks associated with the consumption of sugar refined with bone char, although these risks are generally considered to be low.

See also

• Activated carbon
• Sugar refining
• Water filtration