| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a technology, by which a scorodite compound excellent in crystallinity in the form of a compact compound barely swollen by moisture or the like, i.e., an iron-arsenic compound excellent in filterability can be synthesized by treating an arsenic-containing solution even when some amount of impurity elements is present in the arsenic-containing solution. <P>SOLUTION: A method of producing the iron-arsenic compound comprises adding an oxidizing agent to an aqueous solution containing arsenic ions and bivalent iron ions, wherein the arsenic concentration is 15 g/L or greater, and allowing an iron-arsenic compound precipitation reaction to proceed under stirring of the solution, wherein the precipitation reaction is terminated at a solution pH in the range of 0 to 1. When the arsenic concentration of a pre-reaction solution is 25 g/L or greater, the reaction can be terminated at a solution pH in the range of -0.45 to 1.2. The pH of the pre-reaction solution is preferably greater than 0 and not greater than 2.0. A ferrous sulfate can be used as the source of the bivalent iron ions. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
