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
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.
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
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
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
The writer has devoted a number of years to practical operations and to the study of geology in the oil fields. In consequence, he has
The accompanying chart has been drawn for the convenience of engineers as a means of quickly determining the correct number of plies of conveyor belts
In view of the circumstance that very few important changes have been made within the last 15 or 20 years in the equipment of rod
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
The following conclusions on the work of the Hardinge mill are based on data furnished to the writer by the Hardinge Conical Mill Co. in