To enable the use of burned ash as a soil conditioner without causing an obstacle to growth of agricultural products by treating the burned ash by a simple and inexpensive method as an alternative to a complicated and troublesome method of cementation or melting, and suppressing elution of boron.
The method for treating burned ash to reduce boron quantity to 1.0 mg/l or less according to an elution test method based on Notice No. 18 of Environment Agency in 2003 comprises burning coal in a combustion furnace A, treating the exhaust gas by an electrostatic precipitator, and re-burning the resulting electrostatic precipitator ash in a combustion furnace B with coal as main fuel while adding a calcium source. Preferably, the combustion furnace A is a coal stoker furnace, and the combustion furnace B is a fluidized bed combustion furnace.
NAGASE NORIAKI
TAKARAZAKI TAMOTSU
NAKAJIMA TADAO
KISHIBE MASAYUKI
