How to Collect & Weigh a Sample
I have chosen this subject in view of the fact that, while there are many and ample opportunities of getting reliable assays made, there are but few who are in a position to obtain reliable data on the sampling of minerals and metals; my long experience, where, for five years, I had charge of the Refining […]
Water Wheel Design & Construction
Opinions differ as to whether the water-wheel almost universally known as the Pelton type belongs to the impulse, the tangential, the reactive, the jet or the percussion class, or to a cross between two or more of these classes. The fact is, that for an almost infinitesimal part of a second the axis of the […]
Mougin Rotating Turrets
In presenting the subject of “ Armored Turrets for Coast Defense ” to this Institute, I am indebted to the Gruson Iron-works, a company incorporated under the laws of the State of New York, for valuable information, model and plans, by which I hope to make clear the construction and peculiar merits of this class […]
Measure the Density of Rock: Prospector Tool
The determination of specific gravity dates from such antiquity, and the various published methods of determining it are so numerous, that one may well be skeptical as to the value of a new means of obtaining so well-known a quantity. I make no claim to any great novelty for the little device here described, the […]
Effective Hardness & Abrasive Efficiency of Corundum
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 […]
Cushioned Crushing Roll
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 […]
Mercury Assay Determination Method
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 […]
Shaker Table & Fine Particles Classification
The adaptation of European methods of concentrating ores to suit the conditions of this country has followed the lines that simplify machinery, diminish labor and increase capacity. Noteworthy instances are the substitution of hydraulic classifiers for the last one or two trommels in the series, and the substitution of a distributing-tank for the slimes in […]
Settling Tank Spitzkasten Classifier
In “ Sorting Before Sizing ” (a paper first announced at the Pittsburgh meeting, but delayed in preparation and now presented at the present meeting) it is shown that if slime-tables are to do their best work on slimes below 0.5 mm. or 0.02 inch in diameter, they must be carefully sorted or classified, and […]
Cementation of Gold by Zinc Shavings
Some months since, the attention of the author was directed to certain statements to the effect that the gold-contents of foul or extremely dilute cyanide-solutions could not be effectively precipitated in practice by the usual zinc cementation of gold called the “zinc-method”. Such statements caused all the greater surprise, because it is well known that […]