| abstract |
The invention provides an iron arsenate powder prepared from an arsenic-containing solution and exhibiting an extremely low elution concentration. The iron arsenate powder is a powder of iron arsenate dihydrate which has a mean particle size of 8µm or above, preferably 10µm or above, a content of particles of 5µm or below in size of 10% or below, preferably 5% or below, and a BET specific surface area of 2m2/g or below, preferably 0.5m2/g or below. The amounts of calcium and magnesium contained as impurities are each 2% by mass or below. |