Cost of Producing Concentrates from Ore
From the viewpoint of mineral economics, the ultimate and significant production cost is that per unit of metal produced rather than the cost per ton of ore treated. This viewpoint is natural to processors of ores whose final product is refined or unrefined metal, whether they be companies engaged solely in smelting, or integrated companies […]
How & Where to Sell Ore, Concentrates, and Bullion
With the exception of gold, metal prices are subject to frequent fluctuation, resulting in corresponding variations in the value of their ores. Metal prices are quoted periodically in technical and trade journals and average yearly prices in the principal markets are discussed in the Minerals Yearbook, published annually by the Bureau of Mines. From time […]
Mining Property Engineering Valuation
Engineering valuations of raining properties are made for a number of purposes, principally the following: For purposes of purchase or sale on behalf of prospective buyers or vendors. For purposes of financing by bond issues or sales of stock. As a basis for taxation. In connection with trespass or damage suits. Theoretically the value of […]
Treatment Methods of Lead & Zinc Ore
Lead and Zinc Ores Minerals of lead and zinc commonly are rather closely associated in nature; zinc-free lead ores and lead-free zinc ores are exceptional rather than common, although there are such. Lead and zinc ores usually contain some silver, but those of the Mississippi Valley region are silver-free. Indeed, lead-zinc ores often are commercially […]
Power Electric Mining Shovel Operation
Power Electric Mining Shovel & Dragline Pits The determination of mining and stripping limits prior to undertaking exploitation by power-shovel methods requires careful engineering and often involves complicated computations. Engineering Estimates Stripping of overburden and capping in open-pit mining corresponds to development work in underground mining and, as previously pointed out, is a part of the ore-production cost. The […]
History of Mining Equipment & Practices
When most people think of shovels they think about the type of shovel used for metal detecting and general usage but since late in the last century, power shovels and draglines for digging and loading and locomotives and cars for hauling from the pit have been in general use at most large-scale open-pit operations. Starting […]
Miner’ Safety Lamps
While electric lamps both of the cap and hand type are being introduced into many mines requiring the use of safety lamps, the oil-burning safety lamp is still used in the great majority of cases, and even where the former are used the latter must continue to be employed when testing for gas. It is […]
Copper Ore Processing Methods
The four major steps in the production of marketable copper are mining, concentrating, smelting, and refining. In a few instances, however, leaching takes the place of concentrating, smelting, and refining. At present, although considerable leaching and direct-smelting ores are produced, the bulk of the copper ore mined is concentrated. The milling of copper ores as […]
Ore Dressing Methods
In this bulletin the subject of ore dressing is approached from the economic rather than from the technological standpoint, and the supporting data have been compiled with a view to their bearing upon the economic exploitation of ore deposits. Results obtained are stressed rather than the details of processes and the physics and chemistry involved. […]
Open-Pit Mining Methods
Open-pit mining methods are applicable to mining ore deposits that apex at or near the surface. If the deposit apexes below the surface, the overburden and barren capping overlying the ore must be removed in advance of open-pit mining. The removal of this material is known as stripping. The stripping-pit limits must be extended beyond […]