Nearly every mining and metallurgical engineer will recall his early experience and method of producing step- or stage- reduction in preparing ore-samples for assay, in which he employed idea, step- or stage-reduction simply because it was a self-evident fact that it would be easier to break coarse ore with a hammer than it would be … Read more
When making comparisons of the efficiencies of different grinding and crushing machines it is desirable to be able to estimate the work actually done in crushing the ore from a given size of feed to a given size of product, the screen analysis of both feed and product being determined. Messrs. Klug and Taylor, in … Read more
Many power-based grinding models exist, and most operators are familiar with Fred Bond’s “third theory”. Bond’s model is most commonly used to describe primary and secondary grinding to product sizes above, for example, 100 µm. Operators sometimes use Bond’s equation to describe grinding in situations where it is not appropriate, such as fine grinding … Read more
The Relation Between the “ Effective Hardness ” of Corundum and its Content of Water: A specimen of corundum from Acworth, Ga., which was reputed to be of markedly inferior quality for the manufacture of corundum-wheels, was received by the Geological Survey of Georgia, with the request that it be analyzed, in order to ascertain whether this inferiority was associated … Read more
The object of the present paper is to call attention briefly to a novel method of analyzing the action of the ordinary gravity stamp, which has not only thrown much light upon the exact motion of the stamp-head, but promises also to be of value in determining the efficiency of a new mill before setting … Read more