AbstractsLaw & Legal Studies

"Ball milling practice in the ore dressing industry is largely empirical. Although many investigators have worked on various of its phases, the present operating methods are mostly a matter of cut-and-try, with the result that the industry is not guided by its underlying principles. Consequently, practice varies extensively with regard to nearly all conditions of operations. Even in neighboring concentrators such factors as speed, ball charge, and ore load differ in similar ball mills. Since fine grinding is continually becoming of more importance, and often accounts for thirty per cent of the milling cost, it is very necessary that a study be made of ball milling, both in the laboratory and in the field. In view of this need the Mississippi Valley Experiment Station of the United States Bureau of Mines, in cooperation with the Missouri School of Mines and Metallurgy, Rolla, Missouri, is conducting an investigation of ball milling. This investigation is confined, to date, to the laboratory, but an attempt is being made to bridge the gap between theory and practice, so that the acquired knowledge may be utilized to improve ball mill operations. Some of the study has been completed and the work reported elsewhere. However, before going into the power studies, with which this paper deals, it will be well to review the associated results already reported" – Introduction, p. 2-3.