| 摘要 |
<p>1444572 Hollow particles STANDARD OIL CO 13 July 1973 [13 July 1972] 7199/76 Divided out of 1444571 Heading C1A [Also in Division B5] An aggregate, Fig. 1, of solid particles having a rounded shape, a void centre and a single cavity in the external surface communicating with the void centre is produced by the process described in the parent Specification 1,444,571 modified by feeding the droplets of the slurry containing the solid particles on to a static particle bed so that the total droplet is not immersed in the bed and is allowed to dry in the bed without agitation. Specified materials include clay, ammonium nitrate and metal oxides.</p> |
