Every millman engaged in the operations incident to the handling of crushing-rolls knows that in ordinary practice, when fine product is desired, the ore-materials delivered to the machine, divided into four sizes, may be estimated, approximately, as follows : This estimate refers more particularly to the requirements of medium-sized rolls and fine crushing. But, depending … Read more
Several interesting experiments were made in the sampling of the silver-lead bullion obtained from the water- jacket smelting-furnace. The smelting-plant is divided into two portions, known locally as the north furnaces and the south furnaces. The former group comprises nine and the latter six 80-ton water-jacket furnaces, besides which the south group has one small furnace used … Read more
The dry methods of assaying mercury-ores and other combinations of mercury all rest upon the volatility of this metal as a beginning. After the separation of the mercury in the form of vapor from the matrix upon which the assay is performed, the mercurial vapors are either condensed upon cold surfaces or received upon a … Read more
It is a tradition in the brass industry that bismuth is an injurious element in brass, even more deleterious than antimony; but such a belief has lacked verification. The occasional presence of bismuth in commercial copper (although less frequent than was formerly supposed) led the author to investigate this tradition. The following experiments were conducted … 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