Parameters affecting wet ultra-fine grinding of talc ore [ ]


Fine and ultra-fine grinding have several applications in many industrial fields such as advanced ceramics, porcelain, cement, paper coating, plastic and pigments. The stirred mills are much more efficient for fine grinding and regrinding than conventional tumbling mills. Conventional mills require long retention time and tremendous energy input for micron size production. This work aims at studying the parameters affecting wet ultra-fine grinding of Egyptian talc from Shalatin locality of the Eastern Desert to produce ultra-fine product less than 10 microns. Attritor mill (Union process type 1S) is used to achieve the desired size that is utilized as a filler material for different industrial applications such as paints, plastics, paper coating, and other advanced applications. Crushed talc less than 6630 microns used as a feed. The studied parameters were media size, stirrer speed, solid content in slurry percentage by volume, and media to talc percentage by volume. The results showed that in wet grinding, about 96 % by weight with maximum size reduction d90 and d50 were 12 µm and 3.8 µm at 180 min overall grinding time. Particle size enlargement occurred after the time aforementioned. The scanning electron microscope of ultra-fine grinding showed that distortion of platy structure occurred after 180 min. Therefore, in order to keep the platy structure and crystallinity of talc in order to be used as filler material in different industrial applications, it is recommended not to grind talc for more than this time. The submicron ultra-fine grinding products of Egyptian talc could be used in different industrial filler applications such as paints, ceramic and paper coating.