To effectively utilize activated carbon and hydroxyapatite obtd. by acid-alkali treatment of bone black at a low cost.

Bone black is reduced to powder and activated carbon is utilized as a toner. A coating layer contg. hydroxyapatite is formed on base paper to obtain ink jet recording paper, apatite is stuck on base paper to obtain printing paper and a layer contg. apatite extracted from bone black is formed on a substrate to obtain a poultice. Apatite is utilized as a rust preventive or bone black is utilized as a far IR generating material and apatite is further utilized for a seasoning, soap, a building material, a filter medium and a material for judging the best time for exchange of activated carbon. Apatite is extracted from bone black or bone ash by acid-alkali treatment.