Plans How to Make a Hanging Compass
In working brown iron-ore mines on the system employed at Longdale, namely, stoping from the top down, the usual procedure is to drive a succession of upraises from the lowest adit to the highest, or to the top of the deposit, as the case may be. These upraises are usually driven 120 feet apart, along […]
Variable Speed Pulley
Every constructing engineer and designer knows how often it is desirable to provide a speed-adjustment between parts of a machine performing different functions, or between a prime mover and the devices to which it furnishes power, and how bulky and unsatisfactory are most of the methods by which the result is usually accomplished. Of course […]
Phosphorus Determination Method
To have a complete text for a Method for the Determination of Phosphorus we must first discuss the interaction with other elements: The Effect of Arsenic.—A question involving the temperature of precipitation of ammonium phospho-molybdate, which was brought to my attention some time ago, led to the following experiment: A known quantity of arsenic was […]
Magnetic Ore Separator
After considerable experience in connection with the magnetic iron-ores at the South, especially in the Cranberry district of western North Carolina and eastern Tennessee, the writer was led into a thorough investigation of the magnetic separation of iron-ores, and, from this investigation, has gradually been developed a separating machine which it is the purpose of […]
Ore Roasting & Oxidizing Furnace
This furnace is designed especially for the oxidation of sulphur or arsenic in pyritic ores, but may be used for all oxidizing or desulphurizing operations, and for calcining, roasting and chloridizing ores, or for drying ores in large quantities preparatory to treatment by magnetic separators or otherwise. It is of the tabular, revolving type, with […]
List Minerals Containing Phosphoric Acid
The occurrence and distribution of phosphorus is one of the most important questions with which the steel-maker has to do. Large sums are invested in processes for the removal of this element from ores before they come to the blast-furnace, and much greater sums in freeing the pig-iron from it. Mechanical engineers are becoming more […]
Extraction Method of Silver Lead by Smelting
Although the subject has no practical bearing on the metallurgy of the present day, it may not be entirely uninteresting to note how the art of silver-lead smelting has been, and in a few remote districts of Peru is still practiced by an old method, and under conditions widely different from our own. The subject […]
Precipitation of Metals from Hyposulphite Solutions
Metallurgical processes cannot be conducted successfully without the aid of analytical chemistry. The great perfection of lead-smelting in the West, for instance, has only been accomplished by the analysis of ores, fluxes, slags and all products of the furnace. Ores are mixed and fluxed to obtain a slag of desired composition. Account is even taken […]
How to Remove Fluorine from Copper Concentrates
Some copper deposits presents a small amount of fluorine associated with copper sulfide ores. Depending on the initial fluorine content and the mineralogical characteristics of the ore, the fluorine may report to the copper concentrate as an impurity. Fluorine levels of more than 200 ppm are subject to penalties in their commercialization. The presence of […]