Abstract: A method of producing fluoroapatite powder by using a calcium compound, a phosphate compound, and a fluorine compound as a raw material is provided. The method comprises: preparing a slurry containing fluoroapatite produced from the raw material by using a wet process; applying an ultrasonic wave to the slurry; and drying the slurry to obtain the fluoroapatite powder mainly constituted of the fluoroapatite. The method provides fluoroapatite powder having improved particle strength. Further, an adsorption apparatus including the fluoroapatite powder is also provided.

Abstract: Coated particles according to the present invention are comprised of particles each having a surface. At least the vicinity of the surface of the particle is constituted of a calcium phosphate-based compound. The particles are coated with a polyamine-based compound, and an average particle size of the particles is 1 ?m or more. Furthermore, such coated particles are produced by preparing a preparation liquid containing a liquid containing at least one of water and an alcohol, the coated particles and the polyamine-based compound and then heating the preparation liquid to coat the particles with the polyamine-based compound. Furthermore, it is preferred that the liquid used in preparing the preparation liquid contains methanol as a main component thereto.

Abstract: The present invention is powder constituted from particles of a compound represented by the following general formula (1), (Ca1-aMa)10(PO4)6((OH)1-bFb)2 (1), where in the formula M is a divalent metal element, and the following relations are satisfied: 0<a?1 and 0?b?1. Each of the particles has a surface, a central part, a specific distance part in which a distance from the surface toward the central part is 15 nm, and an area part from the specific distance part to the central part. An amount of the divalent metal element is 3.2 wt % or more in the area part.

Abstract: Coated particles according to the present invention are comprised of particles each having a surface. At least the vicinity of the surface of the particle is constituted of a calcium phosphate-based compound. The particles are coated with a polyamine-based compound, and an average particle size of the particles is 1 ?m or more. Furthermore, such coated particles are produced by preparing a preparation liquid containing a liquid containing at least one of water and an alcohol, the coated particles and the polyamine-based compound and then heating the preparation liquid to coat the particles with the polyamine-based compound. Furthermore, it is preferred that the liquid used in preparing the preparation liquid contains methanol as a main component thereto.

Abstract: A method of producing fluoroapatite powder by using a calcium compound, a phosphate compound, and a fluorine compound as a raw material is provided. The method comprises: preparing a slurry containing fluoroapatite produced from the raw material by using a wet process; applying an ultrasonic wave to the slurry; and drying the slurry to obtain the fluoroapatite powder mainly constituted of the fluoroapatite. The method provides fluoroapatite powder having improved particle strength. Further, an adsorption apparatus including the fluoroapatite powder is also provided.

Abstract: A method of producing a fluoroapatite is provided. The method comprises preparing a slurry containing a hydroxyapatite which has at least one hydroxyl group, preparing a hydrogen fluoride-containing solution containing a hydrogen fluoride, mixing the hydrogen fluoride-containing solution with the slurry to obtain a mixture to thereby adjust a pH of the mixture in the range of 2.5 to 5, and reacting the hydroxyapatite with the hydrogen fluoride in the mixture in a state that the pH of the mixture is adjusted within the above range to thereby obtain the fluoroapatite by substituting the at least one hydroxyl group of the hydroxyapatite with fluorine atom of the hydrogen fluoride. The method can produce the fluoroapatite having improved acid resistance by reducing an impurity, such as ammonia, derived from a raw material to a low or very low level. Further, a fluoroapatite having high acid resistance is also provided. Furthermore, an adsorption apparatus using such a fluoroapatite is provided.

Abstract: A method of producing a fluoroapatite is provided. The method comprises preparing a slurry containing a hydroxyapatite which has at least one hydroxyl group, preparing a hydrogen fluoride-containing solution containing a hydrogen fluoride, mixing the hydrogen fluoride-containing solution with the slurry to obtain a mixture to thereby adjust a pH of the mixture in the range of 2.5 to 5, and reacting the hydroxyapatite with the hydrogen fluoride in the mixture in a state that the pH of the mixture is adjusted within the above range to thereby obtain the fluoroapatite by substituting the at least one hydroxyl group of the hydroxyapatite with fluorine atom of the hydrogen fluoride. The method can produce the fluoroapatite having improved acid resistance by reducing an impurity, such as ammonia, derived from a raw material to a low or very low level. Further, a fluoroapatite having high acid resistance is also provided. Furthermore, an adsorption apparatus using such a fluoroapatite is provided.

Abstract: A method of producing a fluoroapatite is provided. The method comprises preparing a slurry containing a hydroxyapatite which has at least one hydroxyl group, preparing a hydrogen fluoride-containing solution containing a hydrogen fluoride, mixing the hydrogen fluoride-containing solution with the slurry to obtain a mixture to thereby adjust a pH of the mixture in the range of 2.5 to 5, and reacting the hydroxyapatite with the hydrogen fluoride in the mixture in a state that the pH of the mixture is adjusted within the above range to thereby obtain the fluoroapatite by substituting the at least one hydroxyl group of the hydroxyapatite with fluorine atom of the hydrogen fluoride. The method can produce the fluoroapatite having improved acid resistance by reducing an impurity, such as ammonia, derived from a raw material to a low or very low level. Further, a fluoroapatite having high acid resistance is also provided. Furthermore, an adsorption apparatus using such a fluoroapatite is provided.

Abstract: Fluoroapatite dried particles are obtained by reacting hydroxyapatite primary particles having hydroxyl groups and hydrogen fluoride molecules having fluorine atoms so that at least one of hydroxyl groups of hydroxyapatite primary particles are substituted by the fluorine atoms of the hydrogen fluoride molecules. The fluoroapatite dried particles can exhibit superior acid resistance. Further, an adsorption apparatus using such fluoroapatite dried particles is provided.

Abstract: A method of producing fluoroapatite by using a calcium-based compound containing calcium, hydrogen fluoride and phosphoric acid is provided. The method can be produced fluoroapatite having improved acid resistance by reducing an amount of an impurity derived from a raw material to a low or very low level, and ability capable of separating a large amount of a protein due to a large specific surface area thereof. Further, fluoroapatite having high acid resistance and a large specific surface area is also provided. Furthermore, an adsorption apparatus using such fluoroapatite is also provided.