IRON ARSENATE POWDER

摘要

Provided is a ferric arsenate powder which is produced from an arsenic-containing solution, and from which arsenic is eluted at an extremely low concentration. The ferric arsenate powder is a powder of ferric arsenate dehydrate, has an orthorhombic crystal structure, and has the following lattice constants at ambient temperature and ambient pressure: a = 0.8950 to 0.8956 nm, b = 1.0321 to 1.0326 nm, and c= 1.0042 to 1.0050 nm. The ferric arsenate powder is produced by adding a bivalent iron ion to an arsenic-containing solution so that the molar ratio of arsenic to iron (Fe/As) in the solution becomes 1 or greater, adding an oxidizing agent to the mixed solution, heating the mixed solution to a temperature of 70°C or higher while agitating to cause the reaction, separating the reaction solution into a solid material and a liquid, and washing the solid material.