| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a treating method of a waste gypsum board which can be recycled not only as construction materials such as a reclaimed gypsum board but also for manufacturing recycled products such as a planter or as a soil solidification agent, moisture adjusting material, etc. <P>SOLUTION: A method for manufacturing reclaimed gypsum from the waste gypsum board comprises a step wherein the waste gypsum board is pulverized and a step wherein refined gypsum is obtained by heating the pulverized waste gypsum board powder in a rotary kiln to fire and separate impurities (ignition loss) contained in the gypsum board and drying a gypsum component. Here the firing temperature and the rotation frequency of the rotary kiln are adjusted to change the ratio of anhydrous gypsum (CaSO<SB>4</SB>), gypsum hemihydrate (CaSO<SB>4</SB>-1/2H<SB>2</SB>O) and CaSO<SB>4</SB>-2/3H<SB>2</SB>O contained in the refined gypsum. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
