AbstractsPsychology

"In the dry grinding of most materials in a ball mill or similar apparatus, a degree of fineness is eventually reached when a noticeable decrease in the efficiency of grinding occurs. The degree of fineness where this phenomenon occurs, as measured by the specific surface of the material being ground, varies greatly with different materials. The accompanying effect in all cases, however, is the formation of a coating upon the balls; this coating in the case of cement adheres tightly to the balls and increases in thickness as grinding progresses after the initial "coating' fineness has been reached. Usually an agglomeration or flocculation of the fine particles which have previously been produced also occurs. The first effect tends to cushion the blows of the balls, and both effects tend to defeat the object of continued grinding. It was the purpose of this work to study these effects" – Introduction, p. 1.