Determination of Effective Surface Area for the Chemical Reaction of Fine Particulate Materials

Abstract

A concept of effective surface area was defined as a geometrical controlling factor for a chemical reaction involving powdery materials. It is not uniquely determined for the specific material but depends on the sort of chemical reaction as well as the state of agglomeration. Case studies were given for dissolution or decomposition reaction for MgO, Mg(OH)2 and Pb(CO)3 with and without preliminary mechanical activation and granulation. The effective surface area for dissolution is mostly the external surface of the agglomerates, although the internal surface plays a role to some extent, depending on the compactness of the agglomerates.

Mechanical activation of natural acidic igneous rocks for use in cement

“…the amorphous components, remains active and subsequently contributes to the mortar strength development. This is in line with the remarks made by Senna (1989) that some structural changes or a part of them are not fully effective or accessible within the process.…”

Effects of mechanical activation on the reduction behavior of hematite concentrate

“…Probably, some structural changes and/or a part of some structural changes are not fully effective or available in the reduction process. This issue was noted by Senna (1989) and Tkáčová and Baláž (1988).…”

Mechanochemical Activation of (SeO2+Na2CO3) Mixture and Sodium Selenite Synthesis in Vibrational Mill

“…A material treated in this way transforms and stores a certain amount of received mechanical energy, thus becoming potentially capable of consuming this energy in different ways (4)(5)(6). A significiant number of research works have been devoted to the efforts to use such effects of mechanical activation in specific processes, with practical consequences of improved physicochemical characteristics of treated materials (7)(8)(9), mechanical alloying of metals (10)(11)(12), and mechanochemical preparation of mixed oxides, carbides, and borides (13,15).…”