[2] The bones are heated in a sealed vessel at up to 700 °C (1,292 °F); the oxygen concentration must be kept low while doing this, as it affects the quality of the product, particularly its adsorption capacity.

The tricalcium phosphate in bone char can be used to remove fluoride[3] and metal ions from water, making it useful for the treatment of drinking supplies.

[5] Bone chars usually have lower surface areas than activated carbons, but present high adsorptive capacities for certain metals, particularly those from group 12 (copper, zinc, and cadmium).

Bone char possesses a low decoloration capacity and must be used in large quantities,[10] however, it is also able to remove various inorganic impurities, most importantly sulfates and the ions of magnesium and calcium.

However, a small number of companies remain completely or partially dependent on bone char for sugar refinement.