Automatic Ore Sampling Systems
The correct sampling of ores is a subject of far greater importance than is usually conceded to it. Of the little which has been published on this subject, the recent paper, is the latest and best, and well worthy the careful perusal of all interested in accurate sampling, whether by hand or by machine. It […]
Electro Magnetic Separator
The magnetic concentration of iron-ores has been so often and so widely studied and discussed among the members of the Institute that any remarks concerning its general importance, from an economic standpoint, would be superfluous; but it is thought that a description of the Ball and Norton ore-separator, designed for cobbing and separating magnetic iron-ores, […]
Tellurides Process Method
The occurrence of the tellurides of gold and silver, even in small quantities, is so rare that their metallurgical treatment has engaged little attention. A residence of several months at one of the few mines in North America the product of which consists entirely of such ore, has led me to arrange a method for […]
French Pocket Compass
The Transactions of the Institute contain nothing, as yet, on the subject of pocket-compasses; and in the belief that American miners, explorers, geologists, and engineers will gladly welcome any information about new forms of apparatus, simple in construction and adapted to rapid use, I offer a short description of an improved French combination pocket-compass, which, […]
Electrical Accumulators or Storage Batteries
The broad general distinction between primary and secondary batteries lies in the fact that in the former the current is produced by the consumption of one or both of the elements composing the cell, while in the latter the elements retain their form as such, and merely pass from one state of chemical combination to […]
Lethal Dose of Cyanide
The chemistry of cyanide solutions is complicated because the cyanide ion forms compounds and complexes with many elements. Some cyanide species are highly toxic whereas others are relatively inert and harmless. Molecular hydrogen cyanide (HCN) is the most toxic form of cyanide. Under most conditions, HCN exists as a gas which readily dissipates or reacts with […]
Roasting Furnace
Invented and first put into use, a “new and useful improvement in rotary ore roasting furnaces,” which was intended “to increase the capacity, effectiveness and working economies of such furnaces.” The following description and accompanying figures are taken from the patent papers: Fig. 1 is a side elevation of the feed-end of the Howell rotary […]
Arsenopyrite Flotation and Arsenopyrite Rejection
Flotation and depression control of arsenopyrite through pH and xanthate as the collector. Arsenopyrite Rejection
Testing Aluminum & Metal Alloys
Some explanation of methods of testing will be given before presenting the record of a series of physical tests of aluminum, other metals and alloys. The test-bars used, 12 inches long and ½ inch square, are cast in green sand, with chills bedded in such a way that the ends of the bar run against them. […]
How to Assay Gold Jewellery Scrap
This standard prescribes the cupellation or fire assay method for assaying of gold in gold bullion, gold alloys, and gold jewellery and artefacts covered in IS 1417 “How to Assay Gold” Procedure. The following standards contain provisions which, through reference in this text, constitute provisions of this standard. At the time of publication, the edition […]