Magnetite Processing & Extraction Jig

This Conkling Jig (ore-concentrating machine or jig), as it is called, is not entirely unknown, having been used at several places with more or less success; but as yet, I believe, no drawings of it or records of its work have found a place in print. Although the jig will be found to be merely … Read more

Silver Chlorination Leaching by Trough Method

In tank-lixiviation of silver by chlorination, the extraction of the silver from chloridized ore by solutions of hyposulphite salts is performed by filtration. The ore-particles are kept stationary, while the solvent moves down through the mass of ore. The quickness of extraction, other conditions alike, is in direct proportion to the rapidity of the movement … Read more

Silver Ingot Melting

The method of making silver ingots in use at this Mint being radically different from that employed at any other Mint of the United States or, so far as known to me, any Mint in the world, there may be some interest in a description of the apparatus used and a brief history of its … Read more

Gold Prospecting Methods

  The modern gold prospector has advantages that to some extent make up for the increased difficulty of finding ore deposits. One advantage is greatly increased knowledge about the geologic factors that localize ore deposition. The search for new deposits has become a complex undertaking, and the prospector should be as well-informed as possible. The … Read more

Prospecting for Minerals

Prospectors have made a tremendous contribution to the development of this Nation’s mineral resources. Since the time of the earliest settlement, the need for iron for tools and guns, lead for bullets, and copper for utensils has prompted a search for sources of these metals. The lure of gold and silver provided the impetus for … Read more

A Underground Method of Mining Iron Ore

Some ore deposits found in jasper-slates and in the horizon between these and their associated clay-slates; in the latter they are true contact-deposits. They are found in this jasper- and clay-slate formation under varied conditions, yet, in all, certain characteristic laws are preserved. The angle of dip varies from 15° to 20°, and up to … Read more

Fine Rock Crushing with Jaw Crushers

The introduction of a new machine for fine crushing, or The Blake multiple-jaw crusher, which, in combination with the ordinary Blake breaker, could be used in the reduction of ores or any hard and brittle substance to almost any degree of fineness.  How can you use a jaw crusher to crush fine enough to feed … Read more