| 摘要 |
<p>PURPOSE:To enable the addition and deposition of pulverized inorg. powder onto the entire surface of stock particles without spoiling the inorg. porous surface condition by depositing the pulverized inorg. powder onto the granular surface of completely hydrolyzed PVA, adjusting the grain size thereof to a specific grain size and specifying the granular density in the moistened stage. CONSTITUTION:While 100pts.wt. completely hydrolyzed PVA is kept agitated at 20-80 deg.C, 5-10pts.wt. cold water is added thereto and the mixture is pelletized. 2-25pts.wt. Pulverized powder activated carbon is added to the mixture during or right after the pelletization thereof and the pellets having 1-15mm grain size and the granular density in the moistened stage larger than 1 are produced. Since adhesive agents or bonding agents are not used at all at the time of said addition and deposition, the inorg. powder can be added and deposited to the entire surface of the stock particles without spoiling the inorg. porous surface condition. The secure bonding force enough for practicability is obtd. by coating, adding and depositing the inorg. porous material to the stock particles under heating. This filter medium has the large surface area of the filter medium itself and in addition, the pores of the porous material added and deposited to the front surface thereof are not closed and therefore, excellent effect as filter medium is exhibited.</p> |
