Arsenic-containing solid and method for producing it

Abstract

Provided is an arsenic-containing solid comprising 100 parts by mass of a scorodite-type iron-arsenic compound and at least 1 part by mass of an iron oxide compound added thereto, in which the scorodite-type iron-arsenic compound is produced by adding an oxidizing agent to an aqueous acidic solution that contains a 5-valent arsenic (V) ion and a 2-valent iron (II) ion, then promoting the precipitation of an iron-arsenic compound with stirring the liquid, and finishing the precipitation thereof within a range where the pH of the liquid is at most 1.2. The iron oxide compound includes goethite, hematite and their mixture, preferably having a BET specific surface area of at least 3 m2/g, more preferably at least 20 m2/g.

Dependencies are inferred from the claim text.