METHOD FOR PRODUCING COAL ASH GRANULE

To provide a method for producing coal ash granules in which a granulation step and a granulation device are simple, and the grain size distribution of the obtained granules is narrow.SOLUTION: A method for producing coal ash granules using a granulation machine with a rotary drum having openable/closable cover comprises (A) a preliminary mixing step of charging powder at least including coal ash and a binder into the rotary drum oriented at a tilt angle of 0 to 45° with respect to a vertical axis, with a face having the cover of the rotary drum facing upward, thereafter, closing the cover, and rotating the rotary drum for preliminary mixing; (B) a granulation nuclei production step of rotating the rotary drum oriented at a tilt angle of 5 to 45° with respect to the vertical axis, with the cover of the rotary drum open, and with the face having the cover of the rotary drum facing upward, at 15 to 20 rpm for 25 to 30 min, while intermittently adding water into the rotary drum to produce granulation nuclei; and (C) a grain size adjustment step of adjusting grain sizes of granules while rotating the rotary drum at 1 to 5 rpm for 5 to 10 min, with the cover of the drum open or closed.SELECTED DRAWING: Figure 3 【課題】造粒工程や造粒装置が簡素で、得られた造粒物の粒度分布が狭い石炭灰造粒物を製造する方法を提供する。【解決手段】開閉自在な蓋を有する回転ドラムを有する造粒機を用いて石炭灰造粒物を製造する方法。（Ａ）回転ドラムの蓋のある面を上面にして、垂直から０〜４５°の傾斜角を有する回転ドラム内に、少なくとも石炭灰および結合材を含む粉体を投入した後、蓋を閉めて回転させて予め混合する、予備的混合工程、（Ｂ）回転ドラムの蓋を開けた状態で、回転ドラムの蓋のある面を上面にして、垂直から５〜４５°の傾斜角を有する回転ドラムを１５〜２０ｒｐｍで２５〜３０分間回転させながら、回転ドラム内に断続的に加水して造粒核を作製する、造粒核作製工程、（Ｃ）回転ドラムの蓋を開けた状態、または閉めた状態で、回転ドラムを１〜５ｒｐｍで５〜１０分間回転させながら、造粒物の粒径を調整する、粒径調整工程を含む。【選択図】図３