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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 … Read more

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 … Read more

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 … Read more

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 … Read more

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 … Read 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 … Read more